1
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Toivanen J, Paldanius A, Dekdouk B, Candiani V, Hänninen A, Savolainen T, Strbian D, Forss N, Hyvönen N, Hyttinen J, Kolehmainen V. Simulation-based feasibility study of monitoring of intracerebral hemorrhages and detection of secondary hemorrhages using electrical impedance tomography. J Med Imaging (Bellingham) 2024; 11:014502. [PMID: 38299159 PMCID: PMC10826852 DOI: 10.1117/1.jmi.11.1.014502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 12/22/2023] [Accepted: 01/08/2024] [Indexed: 02/02/2024] Open
Abstract
Purpose We present a simulation-based feasibility study of electrical impedance tomography (EIT) for continuous bedside monitoring of intracerebral hemorrhages (ICH) and detection of secondary hemorrhages. Approach We simulated EIT measurements for six different hemorrhage sizes at two different hemorrhage locations using an anatomically detailed computational head model. Using this dataset, we test the ICH monitoring and detection performance of our tailor-made, patient-specific stroke-monitoring algorithm that utilizes a novel combination of nonlinear region-of-interest difference imaging, parallel level sets regularization and a prior-conditioned least squares algorithm. We compare the results of our algorithm to the results of two reference algorithms, a total variation regularized absolute imaging algorithm and a linear difference imaging algorithm. Results The tailor-made stroke-monitoring algorithm is capable of indicating smaller changes in the simulated hemorrhages than either of the reference algorithms, indicating better monitoring and detection performance. Conclusions Our simulation results from the anatomically detailed head model indicate that EIT equipped with a patient-specific stroke-monitoring algorithm is a promising technology for the unmet clinical need of having a technology for continuous bedside monitoring of brain status of acute stroke patients.
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Affiliation(s)
- Jussi Toivanen
- University of Eastern Finland, Department of Technical Physics, Kuopio, Finland
| | - Antti Paldanius
- Tampere University, Faculty of Medicine and Health Technology, Tampere, Finland
| | - Bachir Dekdouk
- Tampere University, Faculty of Medicine and Health Technology, Tampere, Finland
| | | | - Asko Hänninen
- University of Eastern Finland, Department of Technical Physics, Kuopio, Finland
| | - Tuomo Savolainen
- University of Eastern Finland, Department of Technical Physics, Kuopio, Finland
| | - Daniel Strbian
- Helsinki University Hospital, HUS Neurocenter, Helsinki, Finland
| | - Nina Forss
- Helsinki University Hospital, HUS Neurocenter, Helsinki, Finland
- Aalto University, Department of Neuroscience and Biomedical Engineering, Helsinki, Finland
| | - Nuutti Hyvönen
- Aalto University, Department of Mathematics and Systems Analysis, Helsinki, Finland
| | - Jari Hyttinen
- Tampere University, Faculty of Medicine and Health Technology, Tampere, Finland
| | - Ville Kolehmainen
- University of Eastern Finland, Department of Technical Physics, Kuopio, Finland
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2
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Hotta J, Saari J, Harno H, Kalso E, Forss N, Hari R. Somatotopic disruption of the functional connectivity of the primary sensorimotor cortex in complex regional pain syndrome type 1. Hum Brain Mapp 2023; 44:6258-6274. [PMID: 37837646 PMCID: PMC10619416 DOI: 10.1002/hbm.26513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 06/16/2023] [Accepted: 09/17/2023] [Indexed: 10/16/2023] Open
Abstract
In complex regional pain syndrome (CRPS), the representation area of the affected limb in the primary sensorimotor cortex (SM1) reacts abnormally during sensory stimulation and motor actions. We recorded 3T functional magnetic resonance imaging resting-state data from 17 upper-limb CRPS type 1 patients and 19 healthy control subjects to identify alterations of patients' SM1 function during spontaneous pain and to find out how the spatial distribution of these alterations were related to peripheral symptoms. Seed-based correlations and independent component analyses indicated that patients' upper-limb SM1 representation areas display (i) reduced interhemispheric connectivity, associated with the combined effect of intensity and spatial extent of limb pain, (ii) increased connectivity with the right anterior insula that positively correlated with the duration of CRPS, (iii) increased connectivity with periaqueductal gray matter, and (iv) disengagement from the other parts of the SM1 network. These findings, now reported for the first time in CRPS, parallel the alterations found in patients suffering from other chronic pain conditions or from limb denervation; they also agree with findings in healthy persons who are exposed to experimental pain or have used their limbs asymmetrically. Our results suggest that CRPS is associated with a sustained and somatotopically specific alteration of SM1 function, that has correspondence to the spatial distribution of the peripheral manifestations and to the duration of the syndrome.
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Affiliation(s)
- Jaakko Hotta
- Department of Neuroscience and Biomedical EngineeringAalto University School of ScienceEspooFinland
- Aalto NeuroImagingAalto UniversityEspooFinland
- Department of NeurologyHelsinki University Hospital and Clinical Neurosciences, Neurology, University of HelsinkiHelsinkiFinland
| | - Jukka Saari
- Department of Neuroscience and Biomedical EngineeringAalto University School of ScienceEspooFinland
- Aalto NeuroImagingAalto UniversityEspooFinland
- Department of Applied PhysicsUniversity of Eastern FinlandKuopioFinland
| | - Hanna Harno
- Department of NeurologyHelsinki University Hospital and Clinical Neurosciences, Neurology, University of HelsinkiHelsinkiFinland
- Department of Anaesthesiology, Intensive Care and Pain MedicineUniversity of Helsinki and Helsinki University HospitalHelsinkiFinland
| | - Eija Kalso
- Department of Anaesthesiology, Intensive Care and Pain MedicineUniversity of Helsinki and Helsinki University HospitalHelsinkiFinland
| | - Nina Forss
- Department of Neuroscience and Biomedical EngineeringAalto University School of ScienceEspooFinland
- Department of NeurologyHelsinki University Hospital and Clinical Neurosciences, Neurology, University of HelsinkiHelsinkiFinland
| | - Riitta Hari
- Department of Neuroscience and Biomedical EngineeringAalto University School of ScienceEspooFinland
- Department of Art and MediaAalto University School of Arts, Design and ArchitectureHelsinkiFinland
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3
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Itälinna V, Kaltiainen H, Forss N, Liljeström M, Parkkonen L. Using normative modeling and machine learning for detecting mild traumatic brain injury from magnetoencephalography data. PLoS Comput Biol 2023; 19:e1011613. [PMID: 37943963 PMCID: PMC10662745 DOI: 10.1371/journal.pcbi.1011613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 11/21/2023] [Accepted: 10/18/2023] [Indexed: 11/12/2023] Open
Abstract
New biomarkers are urgently needed for many brain disorders; for example, the diagnosis of mild traumatic brain injury (mTBI) is challenging as the clinical symptoms are diverse and nonspecific. EEG and MEG studies have demonstrated several population-level indicators of mTBI that could serve as objective markers of brain injury. However, deriving clinically useful biomarkers for mTBI and other brain disorders from EEG/MEG signals is hampered by the large inter-individual variability even across healthy people. Here, we used a multivariate machine-learning approach to detect mTBI from resting-state MEG measurements. To address the heterogeneity of the condition, we employed a normative modeling approach and modeled MEG signal features of individual mTBI patients as deviations with respect to the normal variation. To this end, a normative dataset comprising 621 healthy participants was used to determine the variation in power spectra across the cortex. In addition, we constructed normative datasets based on age-matched subsets of the full normative data. To discriminate patients from healthy control subjects, we trained support-vector-machine classifiers on the quantitative deviation maps for 25 mTBI patients and 20 controls not included in the normative dataset. The best performing classifier made use of the full normative data across the entire age and frequency ranges. This classifier was able to distinguish patients from controls with an accuracy of 79%. Inspection of the trained model revealed that low-frequency activity in the theta frequency band (4-8 Hz) is a significant indicator of mTBI, consistent with earlier studies. The results demonstrate the feasibility of using normative modeling of MEG data combined with machine learning to advance diagnosis of mTBI and identify patients that would benefit from treatment and rehabilitation. The current approach could be applied to a wide range of brain disorders, thus providing a basis for deriving MEG/EEG-based biomarkers.
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Affiliation(s)
- Veera Itälinna
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Aalto, Finland
| | - Hanna Kaltiainen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Aalto, Finland
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, Neurology, University of Helsinki, Helsinki, Finland
| | - Nina Forss
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Aalto, Finland
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, Neurology, University of Helsinki, Helsinki, Finland
| | - Mia Liljeström
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Aalto, Finland
- BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland
| | - Lauri Parkkonen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Aalto, Finland
- Aalto NeuroImaging, Aalto University School of Science, Aalto, Finland
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4
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Mannismäki L, Martinez-Majander N, Sibolt G, Suomalainen OP, Bäcklund K, Abou Elseoud A, Järveläinen J, Forss N, Curtze S. Association of admission plasma glucose level and cerebral computed tomographic perfusion deficit volumes. J Neurol Sci 2023; 451:120722. [PMID: 37393736 DOI: 10.1016/j.jns.2023.120722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/19/2023] [Accepted: 06/24/2023] [Indexed: 07/04/2023]
Abstract
INTRODUCTION Hyperglycemia in acute ischemic stroke (AIS) is frequent and associated with worse outcome. Yet, strict glycemic control in AIS patients has failed to yield beneficial outcome. So far, the underlying pathophysiological mechanisms of admission hyperglycemia in AIS have remained not fully understood. We aimed to evaluate the yet equivocal association of hyperglycemia with computed tomographic perfusion (CTP) deficit volumes. PATIENTS AND METHODS We included 832 consecutive AIS and transient ischemic attack (TIA) patients who underwent CTP as a part of screening for recanalization treatment (stroke code) between 3/2018 and 10/2020, from the prospective cohort of Helsinki Stroke Quality Registry. Associations of admission glucose level (AGL) and CTP deficit volumes, namely ischemic core, defined as relative cerebral blood flow <30%, and hypoperfusion lesions Time-to-maximum (Tmax) >6 s and Tmax >10s, as determined with RAPID® software, were analyzed with a linear regression model adjusted for age, sex, C-reactive protein, and time from symptom onset to imaging. RESULTS AGL median was 6.8 mmol/L (interquartile range 5.9-8.0 mmol/L), and 222 (27%) patients were hyperglycemic (glucose >7.8 mmol/L) on admission. In non-diabetic patients (643 [77%]), AGL was significantly associated with volume of Tmax. >6 s (regression coefficient [RC] 4.8, 95% confidence interval [CI] 0.49-9.1), of Tmax >10s (RC 4.6, 95% CI 1.2-8.1), and of ischemic core (RC 2.6, 95% CI 0.64-4.6). No significant associations were shown in diabetic patients. CONCLUSION Admission hyperglycemia appears to be associated with both larger volume of hypoperfusion lesions and of ischemic core in non-diabetic stroke code patients with AIS and TIA.
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Affiliation(s)
- Laura Mannismäki
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Helsinki, Finland.
| | - Nicolas Martinez-Majander
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Helsinki, Finland
| | - Gerli Sibolt
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Helsinki, Finland
| | - Olli P Suomalainen
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Helsinki, Finland
| | - Katariina Bäcklund
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Helsinki, Finland
| | - Ahmed Abou Elseoud
- Helsinki Medical Imaging Centre, Helsinki University Hospital, Helsinki, Finland
| | - Juha Järveläinen
- Helsinki Medical Imaging Centre, Helsinki University Hospital, Helsinki, Finland
| | - Nina Forss
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Helsinki, Finland; Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland
| | - Sami Curtze
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Helsinki, Finland
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5
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Forss N, Strbian D. Effect of epileptic activity on outcome for critically ill patients. Lancet Digit Health 2023:S2589-7500(23)00097-3. [PMID: 37295972 DOI: 10.1016/s2589-7500(23)00097-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023]
Affiliation(s)
- Nina Forss
- Department of Neurology, HUS Neurocenter, Helsinki University Hospital and University of Helsinki, Helsinki, Finland; Department of Neuroscience and Biomedical Engineering, Aalto University, Aalto, Finland.
| | - Daniel Strbian
- Department of Neurology, HUS Neurocenter, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
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6
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Haanpää A, Laakso SM, Kinnunen A, Kämppi L, Forss N. Early clinical features of new-onset refractory status epilepticus (NORSE) in adults. BMC Neurol 2022; 22:495. [PMID: 36539824 PMCID: PMC9764533 DOI: 10.1186/s12883-022-03028-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND The aim of this study was to identify early clinical features of patients with new-onset refractory status epilepticus (NORSE) that could direct the treatment in the first days of hospitalisation. METHODS A retrospective cohort study of adult NORSE patients treated in the intensive care units of Helsinki University Hospital 2007-2018. RESULTS We found 19 adult NORSE patients who divided into three subgroups on the basis of their clinical features: viral encephalitis (n = 5, 26%), febrile infection-related epilepsy syndrome (FIRES) (n = 6, 32%) and afebrile NORSE (n = 8, 42%). FIRES and afebrile NORSE patients remained without confirmed etiology, but retrospectively two paraneoplastic and two neurodegenerative causes were suspected in the afebrile NORSE group. Viral encephalitis patients were median 64 years old (IQR 55-64), and four (80%) had prodromal fever and abnormal findings in the first brain imaging. FIRES patients were median 21 years old (IQR 19-24), all febrile and had normal brain imaging at onset. In the afebrile NORSE group, median age was 67 (IQR 59-71) and 50% had prodromal cognitive or psychiatric symptoms. FIRES patients differed from other NORSE patients by younger age (p = 0.001), respiratory prodromal symptoms (p = 0.004), normal brain MRI (p = 0.044) and lack of comorbidities (p = 0.011). They needed more antiseizure medications (p = 0.001) and anesthetics (p = 0.002), had a longer hospital stay (p = 0.017) and more complications (p < 0.001). CONCLUSIONS Among febrile NORSE patients, FIRES group was distinctive due to patients' young age, prodromal respiratory symptoms and normal first brain imaging. These features should be confirmed by subsequent studies as basis for selecting patients for early intensive immunotherapy.
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Affiliation(s)
- Anna Haanpää
- grid.15485.3d0000 0000 9950 5666Department of Neurology, Neurocenter, Helsinki University Hospital, PB 372, 00029 HUS Helsinki, Finland ,grid.7737.40000 0004 0410 2071Department of Clinical Neurosciences, University of Helsinki, PB 22, 00014 University of Helsinki Helsinki, Finland
| | - Sini M. Laakso
- grid.15485.3d0000 0000 9950 5666Department of Neurology, Neurocenter, Helsinki University Hospital, PB 372, 00029 HUS Helsinki, Finland ,grid.7737.40000 0004 0410 2071Department of Clinical Neurosciences, University of Helsinki, PB 22, 00014 University of Helsinki Helsinki, Finland
| | - Antti Kinnunen
- grid.15485.3d0000 0000 9950 5666Department of Clinical Neurophysiology, Helsinki University Hospital, PB 340, 00029 HUS Helsinki, Finland
| | - Leena Kämppi
- grid.7737.40000 0004 0410 2071Department of Clinical Neurosciences, University of Helsinki, PB 22, 00014 University of Helsinki Helsinki, Finland ,grid.15485.3d0000 0000 9950 5666Epilepsia Helsinki, Department of Neurology, Neurocenter, Helsinki University Hospital, PB 372, 00029 HUS Helsinki, Finland
| | - Nina Forss
- grid.15485.3d0000 0000 9950 5666Department of Neurology, Neurocenter, Helsinki University Hospital, PB 372, 00029 HUS Helsinki, Finland ,grid.7737.40000 0004 0410 2071Department of Clinical Neurosciences, University of Helsinki, PB 22, 00014 University of Helsinki Helsinki, Finland
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7
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Suomalainen OP, Martinez-Majander N, Sibolt G, Bäcklund K, Järveläinen J, Korvenoja A, Tiainen M, Forss N, Curtze S. Comparative analysis of core and perfusion lesion volumes between commercially available computed tomography perfusion software. Eur Stroke J 2022; 8:259-267. [PMID: 37021148 PMCID: PMC10069177 DOI: 10.1177/23969873221135915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 10/12/2022] [Indexed: 11/19/2022] Open
Abstract
Introduction: Computed tomography perfusion (CTP) imaging has become an important tool in evaluating acute recanalization treatment candidates. Large clinical trials have successfully used RAPID automated imaging analysis software for quantifying ischemic core and penumbra, yet other commercially available software vendors are also on the market. We evaluated the possible difference in ischemic core and perfusion lesion volumes and the agreement rate of target mismatch between OLEA, MIStar, and Syngo.Via versus RAPID software in acute recanalization treatment candidates. Patients and methods: All consecutive stroke-code patients with baseline CTP RAPID imaging at Helsinki University Hospital during 8/2018–9/2021 were included. Ischemic core was defined as cerebral blood flow <30% than the contralateral hemisphere and within the area of delay time (DT) >3s with MIStar. Perfusion lesion volume was defined as DT > 3 s (MIStar) and Tmax > 6 s with all other software. A perfusion mismatch ratio of ⩾1.8, a perfusion lesion volume of ⩾15 mL, and ischemic core <70 mL was defined as target mismatch. The mean pairwise differences of the core and perfusion lesion volumes between software were calculated using the Bland-Altman method and the agreement of target mismatch between software using the Pearson correlation. Results: A total of 1606 patients had RAPID perfusion maps, 1222 of which had MIStar, 596 patients had OLEA, and 349 patients had Syngo.Via perfusion maps available. Each software was compared with simultaneously analyzed RAPID software. MIStar showed the smallest core difference compared with RAPID (−2 mL, confidence interval (CI) from −26 to 22), followed by OLEA (2 mL, CI from −33 to 38). Perfusion lesion volume differed least with MIStar (4 mL, CI from −62 to 71) in comparison with RAPID, followed by Syngo.Via (6 mL, CI from −94 to 106). MIStar had the best agreement rate with target mismatch of RAPID followed by OLEA and Syngo.Via. Discussion and conclusion: Comparison of RAPID with three other automated imaging analysis software showed variance in ischemic core and perfusion lesion volumes and in target mismatch.
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Affiliation(s)
- Olli P Suomalainen
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Finland
| | - Nicolas Martinez-Majander
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Finland
| | - Gerli Sibolt
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Finland
| | - Katariina Bäcklund
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Finland
| | - Juha Järveläinen
- Department of Neuroradiology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Finland
| | - Antti Korvenoja
- Department of Neuroradiology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Finland
| | - Marjaana Tiainen
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Finland
| | - Nina Forss
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Finland
- Department of Neuroscience and Biomedical Engineering, Aalto University, Finland
| | - Sami Curtze
- Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Finland
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8
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Suomalainen OP, Elseoud Abou A, Martinez-Majander N, Tiainen M, Valkonen K, Virtanen P, Forss N, Curtze S. Is infarct core growth linear? Infarct volume estimation by computed tomography perfusion imaging. Acta Neurol Scand 2022; 145:684-691. [PMID: 35187642 DOI: 10.1111/ane.13601] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/08/2022] [Accepted: 02/09/2022] [Indexed: 12/30/2022]
Abstract
OBJECTIVES Current guidelines for recanalization treatment are based on the time elapsed between symptom onset and treatment and visualization of existing penumbra in computed tomography perfusion (CTP) imaging. The time window for treatment options relies on linear growth of infarction although individual infarct growth rate may vary. We aimed to test how accurately the estimated follow-up infarct volume (eFIV) can be approximated by using a linear growth model based on CTP baseline imaging. If eFIV did not fall within the margins of +/- 19% of the follow-up infarct volume (FIV) measured at 24 h from non-enhanced computed tomography images, the results would imply that the infarct growth is not linear. MATERIALS AND METHODS All consecutive endovascularly treated (EVT) patients from 11/2015 to 9/2019 at the Helsinki University Hospital with large vessel occlusion (LVO), CTP imaging, and known time of symptom onset were included. Infarct growth rate was assumed to be linear and calculated by dividing the ischemic core volume (CTPcore ) by the time from symptom onset to baseline imaging. eFIV was calculated by multiplying the infarct growth rate with the time from baseline imaging to recanalization or in case of futile recanalization to follow-up imaging at 24 h, limited to the penumbra. Collateral flow was estimated by calculating hypoperfusion intensity ratio (HIR). RESULTS Of 5234 patients, 48 had LVO, EVT, CTP imaging, and known time of symptom onset. In 40/48 patients (87%), infarct growth was not linear. HIR did not differ between patients with linear and nonlinear growth (p > .05). As expected, in over half of the patients with successful recanalization eFIV exceeded FIV. CONCLUSIONS Infarct growth was not linear in most patients and thus time elapsed from symptom onset and CTPcore appear to be insufficient parameters for clinical decision-making in EVT candidates.
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Affiliation(s)
- Olli P Suomalainen
- Departments of Neurology, Helsinki University Hospital, Helsinki, Finland
| | - Ahmed Elseoud Abou
- Neuroradiology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Helsinki, Finland
| | | | - Marjaana Tiainen
- Departments of Neurology, Helsinki University Hospital, Helsinki, Finland
| | - Kati Valkonen
- Departments of Neurology, Helsinki University Hospital, Helsinki, Finland
| | - Pekka Virtanen
- Neuroradiology, Helsinki University Hospital and Clinical Neurosciences, University of Helsinki, Helsinki, Finland
| | - Nina Forss
- Departments of Neurology, Helsinki University Hospital, Helsinki, Finland.,Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland
| | - Sami Curtze
- Departments of Neurology, Helsinki University Hospital, Helsinki, Finland
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9
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Suomalainen OP, Abou Elseoud A, Martinez-Majander N, Tiainen M, Valkonen K, Virtanen P, Forss N, Curtze S. Abstract WP108: Is Infarct Core Growth Truly Linear? Follow-up Infarct Volume Estimation By Rapid Baseline Infarct Growth Rate And Linear Model. Stroke 2022. [DOI: 10.1161/str.53.suppl_1.wp108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
Current guidelines for recanalization treatment are based on the time window between symptom onset and treatment in addition to ischemic core and perfusion lesion volumes by computed tomography perfusion imaging (CTP). Linear growth of infarction is commonly assumed.The aim was to test, whether measured follow-up infract volume (FIV) could be approximated from the linear growth model (eFIV) based on CTP baseline infarct growth rate.We assumed the infarct growth to stop, when recanalization was achieved or when the eFIV reached the volume of the perfusion lesion (T
max
>6s volume).
Methods:
All consecutive stroke code patients from 11/2015-9/2019 transferred to Helsinki University Hospital as candidates for endovascular treatment (EVT) were screened; patients with large vessel occlusion (LVO), EVT, CTP and known time of symptom onset were included to study.The infarct growth rate was calculated by dividing the CTP
core
by the time from symptom onset to baseline imaging.eFIV was calculated by infarct growth rate multiplied with the time from baseline imaging to recanalization or follow-up imaging. We assumed a performance of +/- 19% for the accuracy of the CTP
core
assessment. FIV was measured from the 24h non-enhanced computed tomography images. Recanalization was defined as modified Treatment in Cerebral Infarction (mTICI) scale as successful (TICI 2b or 3) or futile (TICI 0,1,2a).
Results:
Out of 5234 patients, 48 had LVO and EVT, CTP imaging and known time of symptom onset (Figure 1). In 40/48 (83%) patients, infarct growth was not within the 19% margins of linear growth. eFIV exceeded FIV in 25/42 patients with successful recanalization (median absolute difference 25 mL,7-73).
Conclusions:
eFIV from linearly approximated growth model did not support linear growth of the infarct.
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Affiliation(s)
| | | | | | | | - Kati Valkonen
- Dept. of Neurology, Helsinki Univ Hosp (HUS), Helsinki, Finland
| | - Pekka Virtanen
- Dept. of Neuroradiology, Helsinki Univ Hosp (HUS), Helsinki, Finland
| | - Nina Forss
- Dept. of Neurology, Dept of Neuroscience and Biomedical Engineering, Helsinki Univ Hosp (HUS), Aalto Univ, Helsinki, Finland
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10
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Abstract
The Rolandic beta rhythm, at ∼20 Hz, is generated in the somatosensory and motor cortices and is modulated by motor activity and sensory stimuli, causing a short lasting suppression that is followed by a rebound of the beta rhythm. The rebound reflects inhibitory changes in the primary sensorimotor (SMI) cortex, and thus it has been used as a biomarker to follow the recovery of patients with acute stroke. The longitudinal stability of beta rhythm modulation is a prerequisite for its use in long-term follow-ups. We quantified the reproducibility of beta rhythm modulation in healthy subjects in a 1-year-longitudinal study both for MEG and EEG at T0, 1 month (T1-month, n = 8) and 1 year (T1-year, n = 19). The beta rhythm (13–25 Hz) was modulated by fixed tactile and proprioceptive stimulations of the index fingers. The relative peak strengths of beta suppression and rebound did not differ significantly between the sessions, and intersession reproducibility was good or excellent according to intraclass correlation-coefficient values (0.70–0.96) both in MEG and EEG. Our results indicate that the beta rhythm modulation to tactile and proprioceptive stimulation is well reproducible within 1 year. These results support the use of beta modulation as a biomarker in long-term follow-up studies, e.g., to quantify the functional state of the SMI cortex during rehabilitation and drug interventions in various neurological impairments. NEW & NOTEWORTHY The present study demonstrates that beta rhythm modulation is highly reproducible in a group of healthy subjects within a year. Hence, it can be reliably used as a biomarker in longitudinal follow-up studies in different neurological patient groups to reflect changes in the functional state of the sensorimotor cortex.
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Affiliation(s)
- Mia Johanna Illman
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.,Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Aalto, Espoo, Finland.,Aalto NeuroImaging, Aalto University School of Science, Aalto, Espoo, Finland
| | - Kristina Laaksonen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Aalto, Espoo, Finland.,Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, Neurology, University of Helsinki, Helsinki, Finland
| | - Veikko Jousmäki
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Aalto, Espoo, Finland.,Aalto NeuroImaging, Aalto University School of Science, Aalto, Espoo, Finland
| | - Nina Forss
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Aalto, Espoo, Finland.,Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, Neurology, University of Helsinki, Helsinki, Finland
| | - Harri Piitulainen
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.,Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Aalto, Espoo, Finland
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11
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Illman M, Laaksonen K, Liljeström M, Piitulainen H, Forss N. The effect of alertness and attention on the modulation of the beta rhythm to tactile stimulation. Physiol Rep 2021; 9:e14818. [PMID: 34173721 PMCID: PMC8234481 DOI: 10.14814/phy2.14818] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 03/05/2021] [Indexed: 02/03/2023] Open
Abstract
Beta rhythm modulation has been used as a biomarker to reflect the functional state of the sensorimotor cortex in both healthy subjects and patients. Here, the effect of reduced alertness and active attention to the stimulus on beta rhythm modulation was investigated. Beta rhythm modulation to tactile stimulation of the index finger was recorded simultaneously with MEG and EEG in 23 healthy subjects (mean 23, range 19–35 years). The temporal spectral evolution method was used to obtain the peak amplitudes of beta suppression and rebound in three different conditions (neutral, snooze, and attention). Neither snooze nor attention to the stimulus affected significantly the strength of beta suppression nor rebound, although a decrease in suppression and rebound strength was observed in some subjects with a more pronounced decrease of alertness. The reduction of alertness correlated with the decrease of suppression strength both in MEG (left hemisphere r = 0.49; right hemisphere r = 0.49, *p < 0.05) and EEG (left hemisphere r = 0.43; right hemisphere r = 0.72, **p < 0.01). The results indicate that primary sensorimotor cortex beta suppression and rebound are not sensitive to slightly reduced alertness nor active attention to the stimulus at a group level. Hence, tactile stimulus‐induced beta modulation is a suitable tool for assessing the sensorimotor cortex function at a group level. However, subjects’ alertness should be maintained high during recordings to minimize individual variability.
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Affiliation(s)
- Mia Illman
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,Aalto NeuroImaging, Aalto University School of Science, Espoo, Finland.,Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Kristina Laaksonen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, Neurology, University of Helsinki, Helsinki, Finland
| | - Mia Liljeström
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Harri Piitulainen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Nina Forss
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, Neurology, University of Helsinki, Helsinki, Finland
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12
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Räty S, Martinez-Majander N, Suomalainen O, Sibolt G, Tiainen M, Valkonen K, Sairanen T, Forss N, Curtze S. Is the weekend effect true in acute stroke patients at tertiary stroke center? J Neurol Sci 2021; 427:117557. [PMID: 34214920 DOI: 10.1016/j.jns.2021.117557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/24/2021] [Accepted: 06/22/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND There is contradicting evidence on the outcome of emergency patients treated during weekends versus weekdays. We studied if outcome of ischemic stroke patients receiving intravenous thrombolysis (IVT) differs according to the treatment time. METHODS Our retrospective study included consecutive patients receiving IVT within 4.5 h of stroke onset between June 1995 and December 2018 at the Helsinki University Hospital. The patients were compared based on the treatment initiation either during weekdays (Monday to Friday) or weekend (Saturday and Sunday). The primary outcome was 3-month mortality and secondary outcomes comprised 3-month modified Rankin Scale (mRS) and incidence of symptomatic intracerebral hemorrhage (sICH). Additional analyses studied the effect of IVT treatment according to non-office hours, time of day, and season. RESULTS Of the 3980 IVT-treated patients, 28.0% received treatment during weekends. Mortality was similar after weekend (10.0%) and weekday (10.6%) admissions in the multivariable regression analysis (OR 0.78; 95% CI 0.59-1.03). Neither 3-month mRS (OR 0.98; 95% CI 0.86-1.12), nor the occurrence of sICH (4.2% vs 4.6%; OR 0.87; 95% CI 0.60-1.26) differed between the groups. No outcome difference was observed between the office vs non-office hours or by the time of day. However, odds for worse outcome were higher during autumn (OR 1.19; 95% CI 1.04-1.35) and winter (OR 1.15; 95% CI 1.01-1.30). CONCLUSION We did not discover any weekend effect for IVT-treated stroke patients. This confirms that with standardized procedures, an equal quality of care can be provided to patients requiring urgent treatment irrespective of time.
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Affiliation(s)
- Silja Räty
- Department of Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | | | - Olli Suomalainen
- Department of Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Gerli Sibolt
- Department of Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Marjaana Tiainen
- Department of Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Kati Valkonen
- Department of Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Tiina Sairanen
- Department of Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Nina Forss
- Department of Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Sami Curtze
- Department of Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
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13
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Suomalainen OP, Elseoud AA, Martinez-Majander N, Tiainen M, Forss N, Curtze S. Comparison of automated infarct core volume measures between non-contrast computed tomography and perfusion imaging in acute stroke code patients evaluated for potential endovascular treatment. J Neurol Sci 2021; 426:117483. [PMID: 33989851 DOI: 10.1016/j.jns.2021.117483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Patients with small core infarction and salvageable penumbra are likely to benefit from endovascular treatment (EVT). As computed tomography perfusion imaging (CTP) is not always available 24/7 for patient selection, many patients are transferred to stroke centers for CTP. We compared automatically measured infarct core volume (NCCTcore) from the non-contrast computed tomography (NCCT) with ischemic core volume (CTPcore) from CTP and the outcome of EVT to clarify if NCCTcore measurement alone is sufficient to identify patients that benefit from transfer to stroke centers for EVT. PATIENTS AND METHODS We included all consecutive stroke-code patients imaged with both NCCT and CTP at Helsinki University Hospital during 9/2016-01/2018. NCCTcore and CTPcore volumes were automatically calculated from the acute NCCT images. Follow-up infarct volume (FIV) was measured from 24 h follow-up NCCT to evaluate efficacy of EVT. To study whether NCCTcore could be used to identify patients eligible to EVT, we sub-grouped patients based on NCCTcore volumes (>50 mL and ≥ 70 mL). RESULTS Out of 1743 patients, baseline NCCTcore, CTPcore and follow-up NCCT was available for 288 patients. Median time from symptom onset to baseline imaging was 74 min (IQR 52-118), and time to follow-up imaging 24.15 h (22.25-26.33). Baseline NCCTcore was 20 mL (10-42), CTPcore 4 mL (0-16), and FIV 5 mL (1-49). Out of 288 patients, 23 had NCCTcore ≥ 70 mL and 26 had CTPcore ≥ 70 mL. NCCTcore and CTPcore performed similarly well in predicting large FIV (≥70 ml). CONCLUSION NCCTcore is a promising tool to identify patients that are not eligible to EVT due to large ischemic cores at baseline imaging.
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Affiliation(s)
- Olli P Suomalainen
- Department of Neurology, University of Helsinki and Helsinki University Hospital, Finland.
| | - Ahmed Abou Elseoud
- Department of Neuroradiology, University of Helsinki and Helsinki University Hospital, Finland.
| | | | - Marjaana Tiainen
- Department of Neurology, University of Helsinki and Helsinki University Hospital, Finland.
| | - Nina Forss
- Department of Neurology, University of Helsinki and Helsinki University Hospital, Finland; Department of Neuroscience and Biomedical Engineering, Aalto University, Finland.
| | - Sami Curtze
- Department of Neurology, University of Helsinki and Helsinki University Hospital, Finland.
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14
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Aikio R, Laaksonen K, Sairanen V, Parkkonen E, Abou Elseoud A, Kujala J, Forss N. CMC is more than a measure of corticospinal tract integrity in acute stroke patients. NeuroImage: Clinical 2021; 32:102818. [PMID: 34555801 PMCID: PMC8458977 DOI: 10.1016/j.nicl.2021.102818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 06/06/2021] [Accepted: 08/30/2021] [Indexed: 11/17/2022] Open
Abstract
CMC is weaker and occurs at lower frequencies in acute stroke patients. Both afferent and efferent input signals contribute to CMC. CMC should not be used as a direct measure of corticospinal tract integrity.
In healthy subjects, motor cortex activity and electromyographic (EMG) signals from contracting contralateral muscle show coherence in the beta (15–30 Hz) range. Corticomuscular coherence (CMC) is considered a sign of functional coupling between muscle and brain. Based on prior studies, CMC is altered in stroke, but functional significance of this finding has remained unclear. Here, we examined CMC in acute stroke patients and correlated the results with clinical outcome measures and corticospinal tract (CST) integrity estimated with diffusion tensor imaging (DTI). During isometric contraction of the extensor carpi radialis muscle, EMG and magnetoencephalographic oscillatory signals were recorded from 29 patients with paresis of the upper extremity due to ischemic stroke and 22 control subjects. CMC amplitudes and peak frequencies at 13–30 Hz were compared between the two groups. In the patients, the peak frequency in both the affected and the unaffected hemisphere was significantly (p < 0.01) lower and the strength of CMC was significantly (p < 0.05) weaker in the affected hemisphere compared to the control subjects. The strength of CMC in the patients correlated with the level of tactile sensitivity and clinical test results of hand function. In contrast, no correlation between measures of CST integrity and CMC was found. The results confirm the earlier findings that CMC is altered in acute stroke and demonstrate that CMC is bidirectional and not solely a measure of integrity of the efferent corticospinal tract.
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15
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Elomaa M, Hotta J, de C Williams AC, Forss N, Äyräpää A, Kalso E, Harno H. Symptom reduction and improved function in chronic CRPS type 1 after 12-week integrated, interdisciplinary therapy. Scand J Pain 2020; 19:257-270. [PMID: 30789827 DOI: 10.1515/sjpain-2018-0098] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 10/29/2018] [Indexed: 12/22/2022]
Abstract
Background and aims Complex Regional Pain Syndrome (CRPS) often recovers spontaneously within the first year, but when it becomes chronic, available rehabilitative therapies (pharmacological management, physiotherapy, and psychological intervention) have limited effectiveness. This study examined the effect of a 12-week intensive outpatient rehabilitation on pain relief and function in chronic CRPS patients. Rehabilitation program included memantine and morphine treatment (added to patient's prior pain medication) and concurrent psychological and physiotherapeutic intervention. Primary outcome measure was a change in CRPS symptom count and secondary outcomes were motor performance, psychological factors, pain intensity, and quality of life. Methods Ten patients with chronic upper limb CRPS I (median 2.9 years, range 8 months to 12 years) were recruited to the study and were assessed before and after the intervention. Hand motor function of the patients was evaluated by an independent physiotherapist. There were standardized questionnaires for depression, pain anxiety, pain acceptance, quality of life, and CRPS symptom count. In addition, psychological factors were evaluated by a semi-structured interview. Severity of experienced pain was rated at movement and at rest. In addition, a video experiment of a hand action observation was conducted pre- and post-intervention to study possible change in neuronal maladaptation. Intervention consisted of pharmacological, psychological and physiotherapeutic treatment. First, 10 mg daily morphine was started and increased gradually to 30 mg daily, if tolerated. After 30 mg/day or tolerated dose of morphine was achieved, 5 mg daily memantine was started and increased gradually to 40 mg, if tolerated. Psychological intervention consisted of weekly group sessions, using cognitive and behavioral methods (relaxation, behavioral activation, and exposure) and acceptance and commitment therapy (ACT) and daily home practice. Physiotherapeutic intervention consisted of graded motor imagery and physiotherapy exercises with weekly group sessions and/or individual guidance by the physiotherapist, and individual exercise of the affected upper limb. Results Multimodal intensive intervention resulted in significant decrease in CRPS symptom count. The effect was strongest in motor and trophic symptoms (19% decrease after intervention) and in sensory symptoms (18% decrease). Additionally, improvement was seen in some, but not all, secondary outcomes (movement pain, motor symptoms, change in perceptions during video experiment of hand actions, and summary index with motor functioning, pain, and psychological factors). There were no dropouts. Conclusions Intensive 12-week multimodal intervention reduced some CRPS symptoms but was not sufficient to alter patients' rest pain, distress, or quality of life. Implications These results support the efficacy of an interdisciplinary rehabilitation program for pain and function in chronic CRPS patients. After intervention, some CRPS symptoms reduced and function improved, but distress and quality of life were unchanged. This may be due to the relatively short duration of this program; to delayed effects; to particular cognitive problems of CPRS patients; and/or to low distress levels at baseline that make statistically significant reduction less likely.
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Affiliation(s)
- Minna Elomaa
- Pain Clinic, Department of Anaesthesiology, Intensive Care and Pain Medicine, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Jaakko Hotta
- Clinical Neurosciences, Neurology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
- Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland
| | - Amanda C de C Williams
- Research Department of Clinical, Educational and Health Psychology, University College London, London, UK
| | - Nina Forss
- Clinical Neurosciences, Neurology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
- Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland
| | - Anni Äyräpää
- Pain Clinic, Department of Anaesthesiology, Intensive Care and Pain Medicine, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
- Internal Medicine and Rehabilitation, Physiotherapy, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Eija Kalso
- Pain Clinic, Department of Anaesthesiology, Intensive Care and Pain Medicine, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Hanno Harno
- Pain Clinic, Department of Anaesthesiology, Intensive Care and Pain Medicine, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
- Pain Clinic, Department of Clinical Neurosciences, Neurology, Helsinki University Hospital and University of Helsinki, P.O Box 140, 00029 HUS, Helsinki, Finland, Phone: +358504639469, Fax: +358947175641
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16
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Kaltiainen H, Liljeström M, Helle L, Salo A, Hietanen M, Renvall H, Forss N. Mild Traumatic Brain Injury Affects Cognitive Processing and Modifies Oscillatory Brain Activity during Attentional Tasks. J Neurotrauma 2019; 36:2222-2232. [PMID: 30896274 PMCID: PMC6653790 DOI: 10.1089/neu.2018.6306] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Despite the high prevalence of mild traumatic brain injury (mTBI), current diagnostic tools to objectively assess cognitive complaints after mTBI continue to be inadequate. Our aim was to identify neuronal correlates for cognitive difficulties in mTBI patients by evaluating the possible alterations in oscillatory brain activity during a behavioral task known to be sensitive to cognitive impairment after mTBI. We compared oscillatory brain activity during rest and cognitive tasks (Paced Auditory Serial Addition Test [PASAT] and a vigilance test [VT]) with magnetoencephalography between 25 mTBI patients and 20 healthy controls. Whereas VT induced no significant differences compared with resting state in either group, patients exhibited stronger attenuation of 8- to 14-Hz oscillatory activity during PASAT than healthy controls in the left parietotemporal cortex (p ≤ 0.05). Further, significant task-related modulation in the left superior frontal gyrus and right prefrontal cortex was detected only in patients. The ∼10-Hz (alpha) peak frequency declined in frontal, temporal, and parietal regions during PASAT compared with rest (p < 0.016) in patients, whereas in controls it remained the same or showed a tendency to increase. In patients, the ∼10-Hz peak amplitude was negatively correlated with behavioral performance in the Trail Making Test. The observed alterations in the cortical oscillatory activity during cognitive load may provide measurable neurophysiological correlates of cognitive difficulties in mTBI patients, even at the individual level.
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Affiliation(s)
- Hanna Kaltiainen
- 1 Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,2 Aalto Neuroimaging, MEG Core, Aalto University, Espoo, Finland.,3 Lohja District Hospital, Department of Neurology, Lohja, Finland.,5 Clinical Neurosciences, University of Helsinki, and Department of Neurology, Helsinki University Hospital, BioMag Laboratory, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Mia Liljeström
- 1 Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,2 Aalto Neuroimaging, MEG Core, Aalto University, Espoo, Finland
| | - Liisa Helle
- 1 Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,2 Aalto Neuroimaging, MEG Core, Aalto University, Espoo, Finland.,4 MEGIN (Elekta Oy), Helsinki, Finland
| | - Anne Salo
- 5 Clinical Neurosciences, University of Helsinki, and Department of Neurology, Helsinki University Hospital, BioMag Laboratory, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Marja Hietanen
- 5 Clinical Neurosciences, University of Helsinki, and Department of Neurology, Helsinki University Hospital, BioMag Laboratory, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Hanna Renvall
- 1 Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,2 Aalto Neuroimaging, MEG Core, Aalto University, Espoo, Finland.,5 Clinical Neurosciences, University of Helsinki, and Department of Neurology, Helsinki University Hospital, BioMag Laboratory, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,6 HUS Medical Imaging Center, BioMag Laboratory, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Nina Forss
- 1 Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,2 Aalto Neuroimaging, MEG Core, Aalto University, Espoo, Finland.,5 Clinical Neurosciences, University of Helsinki, and Department of Neurology, Helsinki University Hospital, BioMag Laboratory, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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17
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Kaltiainen H, Helle L, Liljeström M, Renvall H, Forss N. Theta-Band Oscillations as an Indicator of Mild Traumatic Brain Injury. Brain Topogr 2018; 31:1037-1046. [PMID: 30097835 PMCID: PMC6182433 DOI: 10.1007/s10548-018-0667-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 07/28/2018] [Indexed: 11/30/2022]
Abstract
Mild traumatic brain injury (mTBI) patients continue to pose a diagnostic challenge due to their diverse symptoms without trauma-specific changes in structural imaging. We addressed here the possible early changes in spontaneous oscillatory brain activity after mTBI, and their feasibility as an indicator of injury in clinical evaluation. We recorded resting-state magnetoencephalography (MEG) data in both eyes-open and eyes-closed conditions from 26 patients (11 females and 15 males, aged 20–59) with mTBI 6 days–6 months after the injury, and compared their spontaneous oscillatory activity to corresponding data from 139 healthy controls. Twelve of the patients underwent a follow-up measurement at 6 months. Ten of all patients were without structural lesions in MRI. At single-subject level, aberrant 4–7 Hz (theta) band activity exceeding the + 2 SD limit of the healthy subjects was visible in 7 out of 26 patients; three out of the seven patients with abnormal theta activity were without any detectable lesions in MRI. Of the patients that participated in the follow-up measurements, five showed abnormal theta activity in the first recording, but only two in the second measurement. Our results suggest that aberrant theta-band oscillatory activity can provide an early objective sign of brain dysfunction after mTBI. In 3/7 patients, the slow-wave activity was transient and visible only in the first recording, urging prompt timing for the measurements in clinical settings.
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Affiliation(s)
- Hanna Kaltiainen
- Department of Neuroscience and Biomedical Engineering, School of Science, Aalto University, P.O. Box 12200, 00076, Aalto, Espoo, Finland.
- Aalto Neuroimaging, MEG Core, Aalto University, Espoo, Finland.
- Department of Neurology, Lohja District Hospital, Sairaalatie 8, 08200, Lohja, Finland.
- Clinical Neurosciences and Department of Neurology, University of Helsinki and Helsinki University Central Hospital, P.O. Box 340, 00029, HUS, Helsinki, Finland.
| | - Liisa Helle
- Department of Neuroscience and Biomedical Engineering, School of Science, Aalto University, P.O. Box 12200, 00076, Aalto, Espoo, Finland
- Aalto Neuroimaging, MEG Core, Aalto University, Espoo, Finland
- Elekta Oy, P.O. Box 34, 00531, Helsinki, Finland
| | - Mia Liljeström
- Department of Neuroscience and Biomedical Engineering, School of Science, Aalto University, P.O. Box 12200, 00076, Aalto, Espoo, Finland
- Aalto Neuroimaging, MEG Core, Aalto University, Espoo, Finland
| | - Hanna Renvall
- Department of Neuroscience and Biomedical Engineering, School of Science, Aalto University, P.O. Box 12200, 00076, Aalto, Espoo, Finland
- Aalto Neuroimaging, MEG Core, Aalto University, Espoo, Finland
- Clinical Neurosciences and Department of Neurology, University of Helsinki and Helsinki University Central Hospital, P.O. Box 340, 00029, HUS, Helsinki, Finland
| | - Nina Forss
- Department of Neuroscience and Biomedical Engineering, School of Science, Aalto University, P.O. Box 12200, 00076, Aalto, Espoo, Finland
- Aalto Neuroimaging, MEG Core, Aalto University, Espoo, Finland
- Clinical Neurosciences and Department of Neurology, University of Helsinki and Helsinki University Central Hospital, P.O. Box 340, 00029, HUS, Helsinki, Finland
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Hari R, Baillet S, Barnes G, Burgess R, Forss N, Gross J, Hämäläinen M, Jensen O, Kakigi R, Mauguière F, Nakasato N, Puce A, Romani GL, Schnitzler A, Taulu S. IFCN-endorsed practical guidelines for clinical magnetoencephalography (MEG). Clin Neurophysiol 2018; 129:1720-1747. [PMID: 29724661 PMCID: PMC6045462 DOI: 10.1016/j.clinph.2018.03.042] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 03/18/2018] [Accepted: 03/24/2018] [Indexed: 12/22/2022]
Abstract
Magnetoencephalography (MEG) records weak magnetic fields outside the human head and thereby provides millisecond-accurate information about neuronal currents supporting human brain function. MEG and electroencephalography (EEG) are closely related complementary methods and should be interpreted together whenever possible. This manuscript covers the basic physical and physiological principles of MEG and discusses the main aspects of state-of-the-art MEG data analysis. We provide guidelines for best practices of patient preparation, stimulus presentation, MEG data collection and analysis, as well as for MEG interpretation in routine clinical examinations. In 2017, about 200 whole-scalp MEG devices were in operation worldwide, many of them located in clinical environments. Yet, the established clinical indications for MEG examinations remain few, mainly restricted to the diagnostics of epilepsy and to preoperative functional evaluation of neurosurgical patients. We are confident that the extensive ongoing basic MEG research indicates potential for the evaluation of neurological and psychiatric syndromes, developmental disorders, and the integrity of cortical brain networks after stroke. Basic and clinical research is, thus, paving way for new clinical applications to be identified by an increasing number of practitioners of MEG.
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Affiliation(s)
- Riitta Hari
- Department of Art, Aalto University, Helsinki, Finland.
| | - Sylvain Baillet
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Gareth Barnes
- Wellcome Centre for Human Neuroimaging, University College of London, London, UK
| | - Richard Burgess
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Nina Forss
- Clinical Neuroscience, Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Joachim Gross
- Centre for Cognitive Neuroimaging, University of Glasgow, Glasgow, UK; Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Germany
| | - Matti Hämäläinen
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA; Harvard Medical School, Boston, MA, USA; NatMEG, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Ole Jensen
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK
| | - Ryusuke Kakigi
- Department of Integrative Physiology, National Institute of Physiological Sciences, Okazaki, Japan
| | - François Mauguière
- Department of Functional Neurology and Epileptology, Neurological Hospital & University of Lyon, Lyon, France
| | | | - Aina Puce
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | - Gian-Luca Romani
- Department of Neuroscience, Imaging and Clinical Sciences, Università degli Studi G. D'Annunzio, Chieti, Italy
| | - Alfons Schnitzler
- Institute of Clinical Neuroscience and Medical Psychology, and Department of Neurology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Samu Taulu
- Institute for Learning & Brain Sciences, University of Washington, Seattle, WA, USA; Department of Physics, University of Washington, Seattle, WA, USA
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Hari R, Baillet S, Barnes G, Forss N, Gross J, Hämäläinen M, Jensen O, Kakigi R, Mauguière F, Nakasato N, Puce A, Romani GL, Schnitzler A, Taulu S. Reply to "Clinical practice guidelines or clinical research guidelines?". Clin Neurophysiol 2018; 129:2056-2057. [PMID: 30025803 DOI: 10.1016/j.clinph.2018.06.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 06/24/2018] [Indexed: 10/28/2022]
Affiliation(s)
| | - Sylvain Baillet
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
| | - Gareth Barnes
- Wellcome Centre for Human Neuroimaging, University College of London, London, UK.
| | - Nina Forss
- Department of Neurology, Helsinki University Hospital, Helsinki, Finland.
| | - Joachim Gross
- Institute for Biomagnetism and Biosignalanalysis, University of Münster, Germany.
| | - Matti Hämäläinen
- Harvard Medical School and Massachusetts General Hospital, Boston, MA, USA.
| | - Ole Jensen
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK.
| | - Ryusuke Kakigi
- National Institute for Physiological Sciences, Okazaki, Japan.
| | | | | | - Aina Puce
- Psychological & Brain Sciences, Indiana University, Bloomington, IN, USA.
| | - Gian-Luca Romani
- Institute for Advanced Biomedical Technologies, Università degli Studi G. D'Annunzio, Chieti, Italy.
| | - Alfons Schnitzler
- Institute of Clinical Neuroscience and Medical Psychology, Heinrich-Heine-University, Düsseldorf, Germany.
| | - Samu Taulu
- I-LABS MEG Brain Imaging Center, University of Washington, Seattle, WA, USA.
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Piitulainen H, Illman M, Laaksonen K, Jousmäki V, Forss N. Reproducibility of corticokinematic coherence. Neuroimage 2018; 179:596-603. [PMID: 29964185 DOI: 10.1016/j.neuroimage.2018.06.078] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/25/2018] [Accepted: 06/28/2018] [Indexed: 10/28/2022] Open
Abstract
Corticokinematic coherence (CKC) between limb kinematics and magnetoencephalographic (MEG) signals reflects cortical processing of proprioceptive afference. However, it is unclear whether strength of CKC is reproducible across measurement sessions. We thus examined reproducibility of CKC in a follow-up study. Thirteen healthy right-handed volunteers (7 females, 21.7 ± 4.3 yrs) were measured using MEG in two separate sessions 12.6 ± 1.3 months apart. The participant was seated and relaxed while his/her dominant or non-dominant index finger was continuously moved at 3 Hz (4 min for each hand) using a pneumatic movement actuator. Finger kinematics were recorded with a 3-axis accelerometer. Coherence was computed between finger acceleration and MEG signals. CKC strength was defined as the peak coherence value at 3 Hz form a single sensor among 40 pre-selected Rolandic gradiometers contralateral to the movement. Pneumatic movement actuator provided stable proprioceptive stimuli and significant CKC responses peaking at the contralateral Rolandic sensors. In the group level, CKC strength did not differ between the sessions in dominant (Day-1 0.40 ± 0.19 vs. Day-2 0.41 ± 0.17) or non-dominant (0.35 ± 0.16 vs. 0.36 ± 0.17) hand, nor between the hands. Intraclass-correlation coefficient (ICC) values indicated excellent inter-session reproducibility for CKC strength for both dominant (0.86) and non-dominant (0.97) hand. However, some participants showed pronounced inter-session variability in CKC strength, but only for the dominant hand. CKC is a promising tool to study proprioception in long-term longitudinal studies in the group level to follow, e.g., integrity of cortical proprioceptive processing with motor functions after stroke.
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Affiliation(s)
- Harri Piitulainen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, P.O. BOX 12200, 00076 AALTO, Espoo, Finland.
| | - Mia Illman
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, P.O. BOX 12200, 00076 AALTO, Espoo, Finland; Aalto NeuroImaging, Aalto University School of Science, P.O. BOX 12200, 00076 AALTO, Espoo, Finland.
| | - Kristina Laaksonen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, P.O. BOX 12200, 00076 AALTO, Espoo, Finland; Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, Neurology, University of Helsinki, P.O. Box 340, 00029 HUS, Helsinki, Finland.
| | - Veikko Jousmäki
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, P.O. BOX 12200, 00076 AALTO, Espoo, Finland; Aalto NeuroImaging, Aalto University School of Science, P.O. BOX 12200, 00076 AALTO, Espoo, Finland; NatMEG, Department of Clinical Neuroscience, Karolinska Institutet, Nobels väg 9, 171 77, Stockholm, Sweden.
| | - Nina Forss
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, P.O. BOX 12200, 00076 AALTO, Espoo, Finland; Department of Neurology, Helsinki University Hospital and Clinical Neurosciences, Neurology, University of Helsinki, P.O. Box 340, 00029 HUS, Helsinki, Finland.
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Ijas P, Mäkitie L, Kivelä S, Wahlman-Muranen T, Kiukkonen N, Selonen P, Stirbu V, Taivalsaari A, Myyryläinen L, Koskimies O, Honkanen M, Forss N. Abstract WMP62: Remote Home Monitoring of Risk Factors After Stroke or TIA to Improve Secondary Prevention - A Pilot Study. Stroke 2018. [DOI: 10.1161/str.49.suppl_1.wmp62] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
Up to 90% of strokes could be prevented by effective treatment of the risk factors. However, there are major problems with the implementation of prevention. For example, only 40% of patients taking medication have blood pressure (BP) at treatment goals and 60% of patients with atrial fibrillation (AF) use anti-coagulant medication.
Hypothesis:
Remote home monitoring of risk factors after minor stroke or TIA may lead to better control of risk factors by increasing measurements and patient awareness and uncovering undetected risk factors. This pilot study investigates the feasibility of home monitoring of risk factors after minor stroke or TIA.
Methods and Patients:
Patients (n=30, mean age 57 yrs, range 34-79, 37% females) with recent minor stroke or TIA were supplied with a remote home monitoring system at discharge. The system comprised of a cloud backend for data storage and processing, patient user interface (UI), and wireless BP meter and light-weight EKG device with secured connection to clinician UI, through which BP and EKG could be followed real-time and individualized alarm limits could be set. EKG was automatically analyzed in the cloud backend to detect AF. The patients were contacted by phone at two weeks by stroke nurse and they returned the remote home monitoring system at final visit at three months. Additionally they were contacted if AF was detected or their BP required medication adjustment.
Results:
Twenty-nine (97%) patients completed the study. One patient discontinued due to unrelated serious illness. One patient did not follow the monitoring program. Of the remaining 28 patients (93%) with complete monitoring data, BP medication needed adjustment in 11 patients (39%) and new AF was detected in 3 patients (11%). Patients appraised that the home monitoring system was easy to use (score 8.6/10) and most would recommend it to peers (score 8.9/10).
Conclusions:
Remote home monitoring of risk factors after minor stroke or TIA is feasible and may be an efficient way to improve secondary prevention.
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Affiliation(s)
- Petra Ijas
- Dept of Neurology, Helsinki Univ Hosp, Helsinki, Finland
| | - Laura Mäkitie
- Dept of Neurology, Helsinki Univ Hosp, Helsinki, Finland
| | - Satu Kivelä
- Dept of Neurology, Helsinki Univ Hosp, Helsinki, Finland
| | | | | | | | | | | | | | | | | | - Nina Forss
- Dept of Neurology, Helsinki Univ Hosp, Helsinki, Finland
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Ijäs P, Mäkitie L, Kotisaari K, Ristola E, Kälviäinen R, Jäkälä P, Koivisto T, Jääskeläinen J, Majamaa K, Rainesalo S, Numminen H, Roine R, Rinne J, Arvonen S, Hemminki L, Niemelä M, Forss N. Brain hub - digital healthcare services to patients with brain diseases, citizens and professionals. J Neurol Sci 2017. [DOI: 10.1016/j.jns.2017.08.3439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Abstract
INTRODUCTION Many central pathophysiological aspects of complex regional pain syndrome (CRPS) are still unknown. Although brain-imaging studies are increasingly supporting the contribution of the central nervous system to the generation and maintenance of the CRPS pain, the brain's white-matter alterations are seldom investigated. METHODS In this study, we used diffusion tensor imaging to explore white-matter changes in twelve CRPS-type-1 female patients suffering from chronic right upper-limb pain compared with twelve healthy control subjects. RESULTS Tract-based spatial-statistics analysis revealed significantly higher mean diffusivity, axial diffusivity, and radial diffusivity in the CRPS patients, suggesting that the structural connectivity is altered in CRPS. All these measures were altered in the genu, body, and splenium of corpus callosum, as well as in the left anterior and posterior and the right superior parts of the corona radiata. Axial diffusivity was significantly correlated with clinical motor symptoms at whole-brain level, supporting the physiological significance of the observed white-matter abnormalities. CONCLUSIONS Altogether, our findings further corroborate the involvement of the central nervous system in CRPS.
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Affiliation(s)
- Jaakko Hotta
- Department of Neuroscience and Biomedical Engineering Aalto University Espoo Finland.,Aalto NeuroImaging Aalto University Espoo Finland.,Clinical Neurosciences, Neurology University of Helsinki and Department of Neurology, Helsinki University Hospital Helsinki Finland
| | - Guangyu Zhou
- Department of Neuroscience and Biomedical Engineering Aalto University Espoo Finland.,Department of Neurology Northwestern University Chicago IL USA
| | - Hanna Harno
- Clinical Neurosciences, Neurology University of Helsinki and Department of Neurology, Helsinki University Hospital Helsinki Finland.,Pain Clinic Department of Anesthesiology, Intensive Care and Pain Medicine University of Helsinki and Helsinki University Hospital Helsinki Finland
| | - Nina Forss
- Department of Neuroscience and Biomedical Engineering Aalto University Espoo Finland.,Clinical Neurosciences, Neurology University of Helsinki and Department of Neurology, Helsinki University Hospital Helsinki Finland
| | - Riitta Hari
- Department of Neuroscience and Biomedical Engineering Aalto University Espoo Finland.,Department of Art Aalto University Helsinki Finland
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24
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Kotisaari K, Virtanen P, Forss N, Strbian D, Scheperjans F. Emergency computed tomography in patients with first seizure. Seizure 2017; 48:89-93. [DOI: 10.1016/j.seizure.2017.04.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 04/06/2017] [Accepted: 04/14/2017] [Indexed: 10/19/2022] Open
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Parkkonen E, Laaksonen K, Piitulainen H, Pekkola J, Parkkonen L, Tatlisumak T, Forss N. Strength of ~20-Hz Rebound and Motor Recovery After Stroke. Neurorehabil Neural Repair 2017; 31:475-486. [PMID: 28164736 DOI: 10.1177/1545968316688795] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Stroke is a major cause of disability worldwide, and effective rehabilitation is crucial to regain skills for independent living. Recently, novel therapeutic approaches manipulating the excitatory-inhibitory balance of the motor cortex have been introduced to boost recovery after stroke. However, stroke-induced neurophysiological changes of the motor cortex may vary despite of similar clinical symptoms. Therefore, better understanding of excitability changes after stroke is essential when developing and targeting novel therapeutic approaches. OBJECTIVE AND METHODS We identified recovery-related alterations in motor cortex excitability after stroke using magnetoencephalography. Dynamics (suppression and rebound) of the ~20-Hz motor cortex rhythm were monitored during passive movement of the index finger in 23 stroke patients with upper limb paresis at acute phase, 1 month, and 1 year after stroke. RESULTS After stroke, the strength of the ~20-Hz rebound to stimulation of both impaired and healthy hand was decreased with respect to the controls in the affected (AH) and unaffected (UH) hemispheres, and increased during recovery. Importantly, the rebound strength was lower than that of the controls in the AH and UH also to healthy-hand stimulation despite of intact afferent input. In the AH, the rebound strength to impaired-hand stimulation correlated with hand motor recovery. CONCLUSIONS Motor cortex excitability is increased bilaterally after stroke and decreases concomitantly with recovery. Motor cortex excitability changes are related to both alterations in local excitatory-inhibitory circuits and changes in afferent input. Fluent sensorimotor integration, which is closely coupled with excitability changes, seems to be a key factor for motor recovery.
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Affiliation(s)
- Eeva Parkkonen
- 1 Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,2 Department of Neurology, Helsinki University Hospital, Helsinki, Finland.,3 Clinical Neurosciences, University of Helsinki, Helsinki, Finland
| | - Kristina Laaksonen
- 1 Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,2 Department of Neurology, Helsinki University Hospital, Helsinki, Finland.,3 Clinical Neurosciences, University of Helsinki, Helsinki, Finland
| | - Harri Piitulainen
- 1 Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Johanna Pekkola
- 4 HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, Finland
| | - Lauri Parkkonen
- 1 Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Turgut Tatlisumak
- 2 Department of Neurology, Helsinki University Hospital, Helsinki, Finland.,3 Clinical Neurosciences, University of Helsinki, Helsinki, Finland.,5 Department of Neurology, Sahlgrenska University Hospital, Gothenburg, Sweden.,6 Department of Clinical Neurosciences, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Nina Forss
- 1 Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,2 Department of Neurology, Helsinki University Hospital, Helsinki, Finland.,3 Clinical Neurosciences, University of Helsinki, Helsinki, Finland
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26
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Hotta J, Saari J, Koskinen M, Hlushchuk Y, Forss N, Hari R. Abnormal Brain Responses to Action Observation in Complex Regional Pain Syndrome. J Pain 2016; 18:255-265. [PMID: 27847313 DOI: 10.1016/j.jpain.2016.10.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 08/30/2016] [Accepted: 10/28/2016] [Indexed: 12/29/2022]
Abstract
Patients with complex regional pain syndrome (CRPS) display various abnormalities in central motor function, and their pain is intensified when they perform or just observe motor actions. In this study, we examined the abnormalities of brain responses to action observation in CRPS. We analyzed 3-T functional magnetic resonance images from 13 upper limb CRPS patients (all female, ages 31-58 years) and 13 healthy, age- and sex-matched control subjects. The functional magnetic resonance imaging data were acquired while the subjects viewed brief videos of hand actions shown in the first-person perspective. A pattern-classification analysis was applied to characterize brain areas where the activation pattern differed between CRPS patients and healthy subjects. Brain areas with statistically significant group differences (q < .05, false discovery rate-corrected) included the hand representation area in the sensorimotor cortex, inferior frontal gyrus, secondary somatosensory cortex, inferior parietal lobule, orbitofrontal cortex, and thalamus. Our findings indicate that CRPS impairs action observation by affecting brain areas related to pain processing and motor control. PERSPECTIVE This article shows that in CRPS, the observation of others' motor actions induces abnormal neural activity in brain areas essential for sensorimotor functions and pain. These results build the cerebral basis for action-observation impairments in CRPS.
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Affiliation(s)
- Jaakko Hotta
- Systems and Clinical Neuroscience, Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland; Aalto NeuroImaging, Aalto University School of Science, Espoo, Finland; Department of Neurology, Helsinki University Hospital, and Clinical Neurosciences, Neurology, University of Helsinki, Finland.
| | - Jukka Saari
- Systems and Clinical Neuroscience, Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Miika Koskinen
- Systems and Clinical Neuroscience, Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland; Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Yevhen Hlushchuk
- Systems and Clinical Neuroscience, Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland; HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Nina Forss
- Systems and Clinical Neuroscience, Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland; Department of Neurology, Helsinki University Hospital, and Clinical Neurosciences, Neurology, University of Helsinki, Finland
| | - Riitta Hari
- Systems and Clinical Neuroscience, Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland; Department of Art, Aalto University School of Arts, Design and Architecture, Helsinki, Finland
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27
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Mäkitie L, Korja M, Kangasniemi M, Kallela M, Forss N, Niemelä M, Lindsberg PJ. Headache as symptom of intracranial hemorrhage. Duodecim 2016; 132:1993-1999. [PMID: 29190051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The most important signs of danger of a headache patient include exceptionally intense or acute headache, transient loss or progressive impairment of consciousness, and neurological deficit symptoms. These patients are referred to an urgent assessment by a physician. Computed tomography scanning of the head is carried out in the case of suspected hemorrhage of a headache patient. Routine diagnosis employing cerebrospinal fluid analysis can be abandoned when excluding subarachnoid hemorrhage in a patient with headache symptoms, if blood is with certainty not observed in the CT scan of the head and no more than six hours have passed after the onset of the symptom. If subarachnoid hemorrhage is detected, cerebral CT angiography will be performed at the same time and a neurosurgeon consulted about the need of operative treatment.
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28
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Parkkonen E, Laaksonen K, Piitulainen H, Parkkonen L, Forss N. Modulation of the ∽20-Hz motor-cortex rhythm to passive movement and tactile stimulation. Brain Behav 2015; 5:e00328. [PMID: 25874163 PMCID: PMC4396160 DOI: 10.1002/brb3.328] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 12/21/2014] [Accepted: 01/25/2015] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Integration of afferent somatosensory input with motor-cortex output is essential for accurate movements. Prior studies have shown that tactile input modulates motor-cortex excitability, which is reflected in the reactivity of the ∽ 20-Hz motor-cortex rhythm. ∽ 20-Hz rebound is connected to inhibition or deactivation of motor cortex whereas suppression has been associated with increased motor cortex activity. Although tactile sense carries important information for controlling voluntary actions, proprioception likely provides the most essential feedback for motor control. METHODS To clarify how passive movement modulates motor-cortex excitability, we studied with magnetoencephalography (MEG) the amplitudes and peak latencies of suppression and rebound of the ∽ 20-Hz rhythm elicited by tactile stimulation and passive movement of right and left index fingers in 22 healthy volunteers. RESULTS Passive movement elicited a stronger and more robust ∽ 20-Hz rebound than tactile stimulation. In contrast, the suppression amplitudes did not differ between the two stimulus types. CONCLUSION Our findings suggest that suppression and rebound represent activity of two functionally distinct neuronal populations. The ∽ 20-Hz rebound to passive movement could be a suitable tool to study the functional state of the motor cortex both in healthy subjects and in patients with motor disorders.
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Affiliation(s)
- Eeva Parkkonen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science Espoo, Finland ; Aalto NeuroImaging, MEG-Core, Aalto University School of Science Espoo, Finland ; Clinical Neurosciences, Neurology, University of Helsinki and Helsinki University Hospital Finland
| | - Kristina Laaksonen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science Espoo, Finland ; Aalto NeuroImaging, MEG-Core, Aalto University School of Science Espoo, Finland ; Clinical Neurosciences, Neurology, University of Helsinki and Helsinki University Hospital Finland
| | - Harri Piitulainen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science Espoo, Finland ; Aalto NeuroImaging, MEG-Core, Aalto University School of Science Espoo, Finland
| | - Lauri Parkkonen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science Espoo, Finland ; Aalto NeuroImaging, MEG-Core, Aalto University School of Science Espoo, Finland
| | - Nina Forss
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science Espoo, Finland ; Aalto NeuroImaging, MEG-Core, Aalto University School of Science Espoo, Finland ; Clinical Neurosciences, Neurology, University of Helsinki and Helsinki University Hospital Finland
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Hotta J, Harno H, Nummenmaa L, Kalso E, Hari R, Forss N. Patients with complex regional pain syndrome overestimate applied force in observed hand actions. Eur J Pain 2015; 19:1372-81. [DOI: 10.1002/ejp.669] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/29/2014] [Indexed: 02/02/2023]
Affiliation(s)
- J. Hotta
- Department of Neuroscience and Biomedical Engineering; Aalto University; Espoo Finland
- Clinical Neurosciences, Neurology; University of Helsinki and Helsinki University Hospital; Finland
| | - H. Harno
- Clinical Neurosciences, Neurology; University of Helsinki and Helsinki University Hospital; Finland
- Pain Clinic; Department of Anaesthesiology, Intensive Care and Pain Medicine; University of Helsinki and Helsinki University Hospital; Finland
| | - L. Nummenmaa
- Department of Neuroscience and Biomedical Engineering; Aalto University; Espoo Finland
- Turku PET Centre; University of Turku; Finland
| | - E. Kalso
- Pain Clinic; Department of Anaesthesiology, Intensive Care and Pain Medicine; University of Helsinki and Helsinki University Hospital; Finland
| | - R. Hari
- Department of Neuroscience and Biomedical Engineering; Aalto University; Espoo Finland
| | - N. Forss
- Department of Neuroscience and Biomedical Engineering; Aalto University; Espoo Finland
- Clinical Neurosciences, Neurology; University of Helsinki and Helsinki University Hospital; Finland
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Saver JL, Strbian D, Michel P, Seiffge DJ, Numminen H, Meretoja A, Murao K, Weder B, Forss N, Parkkila AK, Eskandari A, Cordonnier C, Davis SM, Engelter ST, Jones PG, Spertus JA, Tatlisumak T. Abstract 62: GRASPS Score to Predict Risk of Clinically Relevant Symptomatic Intracranial Hemorrhage after Intravenous Tissue Plasminogen Activator. Stroke 2015. [DOI: 10.1161/str.46.suppl_1.62] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
The NINDS Study definition of symptomatic hemorrhage (sICH) after intravenous tissue plasminogen activator (tPA), requiring only minimal early worsening and minimal petechial hemorrhage, is now widely recognized as overly inclusive. Clinically relevant sICH is better defined by at least moderate worsening and parenchymal hematoma. The 6-item GRASPS scale for predicting sICH was derived from the national US Get with the Guidelines - Stroke registry based on the NINDS Study definition. For use in clinical practice, it is desirable to recalibrate the GRASPS scale to predict more stringently defined symptomatic hemorrhage.
Methods:
We merged prospectively collected data of patients with consecutive ischemic stroke who received tPA in 7 stroke centers. We applied the GRASPS (glucose at presentation, race [Asian], age, sex [male], systolic blood pressure at presentation, and severity of stroke at presentation [NIH Stroke Scale]) to predict Safe Implementation of Thrombolysis in Stroke (SITS)-defined sICH. To derive a monotonic predictive model, we used a generalized additive model framework and fit 6 different transformations of the GRASPS score: linear scale, log scale, without and with splines, and without and with local smoothing (“loess”) to identify any non-parametric patterns.
Results:
The final cohort comprised 5274 eligible patients, of whom 143 (2.7%) had symptomatic ICH per SITS criteria. Based on favorable residual deviance scores and Akaike's information criterion scores, the linear transformation of raw GRASPS scores provided the best fit. With this model, the area under the curve for predicting SITS sICH was 0.68 (95% CI 0.63-0.72). Risk score values for cardinal GRASPS scale points included 0.6% for GRASPS 50, 2.4% for GRASPS 70, and 9.5% for GRASPS 90.
Conclusions:
The GRASPS scale showed moderate performance in predicting SITS-defined symptomatic intracerebral hemorrhage after IV tPA. With the predictive values available from this study, the GRASPS score can be used to assess risk of clinically relevant symptomatic hemorrhage following thrombolytic therapy.
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Affiliation(s)
| | | | - Patrik Michel
- Cntr Hospier Universitaire Vaudois, Lausanne, Switzerland
| | | | | | | | - Kei Murao
- Univ Lille Nord de France, Lille, France
| | - Bruno Weder
- Kantonsspital St Gallen, St Gallen, Switzerland
| | - Nina Forss
- Helsinki Univ Central Hosp, Helsinki, Finland
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31
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Kirveskari E, Vartiainen NV, Kallio-Laine K, Kalso E, Forss N. Normal laser-evoked cortical responses in patients with chronic hemibody pain. Eur J Pain 2014; 19:1168-76. [PMID: 25523148 DOI: 10.1002/ejp.642] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2014] [Indexed: 11/07/2022]
Abstract
BACKGROUND Patients with widespread unilateral chronic pain associated with recurrent herpes simplex virus (HSV) infections show functional and/or structural changes in the insula, anterior cingulate cortex, frontal and prefrontal cortices, as well as the thalamus, suggesting central dysfunction of the pain system in these patients. Central pain has been associated with attenuated laser-evoked cortical responses. We aimed to clarify whether the observed deficient activation of these areas to acute nociceptive stimuli is due to a lesion at a lower level of pain processing pathways. METHODS We explored the functional integrity of the ascending nociceptive pathways by recording the cortical-evoked responses to noxious laser stimulation using magnetoencephalography and electroencephalography in eight patients (age 41-51 years, mean 46) with recurrent HSV infections and a history of chronic, spontaneous, widespread unilateral pain, and in nine age-matched healthy control subjects. RESULTS The cortical-evoked fields of the HSV patients originating from the secondary somatosensory and posterior parietal cortices, as well as the evoked potentials recorded from the midline, did not differ from those of the control subjects, indicating functionally intact ascending nociceptive pathways. CONCLUSIONS The present results show that our patients with chronic hemibody pain do not show signs of spinothalamic tract lesion. This indicates normal processing of sensory aspects of painful stimuli, while higher pain processing areas show altered activation. We conclude that normal laser-evoked magnetic fields (LEF) or laser-evoked potentials (LEP) may not exclude central pain condition.
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Affiliation(s)
- E Kirveskari
- Brain Research Unit and MEG Core, O.V. Lounasmaa Laboratory, Aalto Neuroimaging, School of Science, Aalto University, Espoo, Finland.,Department of Clinical Neurophysiology, HUS Medical Imaging Center, Helsinki University Central Hospital, Finland.,Department of Neurological Sciences, University of Helsinki, Finland
| | - N V Vartiainen
- Brain Research Unit and MEG Core, O.V. Lounasmaa Laboratory, Aalto Neuroimaging, School of Science, Aalto University, Espoo, Finland
| | - K Kallio-Laine
- Department of Anaesthesia and Intensive Care Medicine, Pain Clinic, Helsinki University Central Hospital, Finland
| | - E Kalso
- Department of Anaesthesia and Intensive Care Medicine, Pain Clinic, Helsinki University Central Hospital, Finland.,Institute of Clinical Medicine, Faculty of Medicine, University of Helsinki, Finland
| | - N Forss
- Brain Research Unit and MEG Core, O.V. Lounasmaa Laboratory, Aalto Neuroimaging, School of Science, Aalto University, Espoo, Finland.,Department of Neurological Sciences, University of Helsinki, Finland.,Department of Neurology, Helsinki University Central Hospital, Finland
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32
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Rajamaeki R, Parkkonen E, Laaksonen K, Kujala J, Forss N. P523: Changes in corticomuscular coherence after acute stroke. Clin Neurophysiol 2014. [DOI: 10.1016/s1388-2457(14)50621-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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33
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Kirveskari E, Vartiainen N, Kallio-Laine K, Kalso E, Forss N. P989: Normal laser-evoked cortical responses in patients with unilateral chronic pain. Clin Neurophysiol 2014. [DOI: 10.1016/s1388-2457(14)51025-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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34
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Tolonen J, Häme A, Forss N, Harjola VP, Luosujärvi R, Mattila J. SAT0005 Sle Patients in Emergency. the Evaluation of SLE Patients in Helsinki University Central Hospital Emergency during 2003-2012. Ann Rheum Dis 2014. [DOI: 10.1136/annrheumdis-2014-eular.2234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Parkkonen E, Laaksonen K, Parkkonen L, Forss N. P528: Modulation of the 20-Hz motor cortex rhythm to passive movement and tactile stimulation. Clin Neurophysiol 2014. [DOI: 10.1016/s1388-2457(14)50626-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Strbian D, Michel P, Seiffge DJ, Saver JL, Numminen H, Meretoja A, Murao K, Weder B, Forss N, Parkkila AK, Eskandari A, Cordonnier C, Davis SM, Engelter ST, Tatlisumak T. Symptomatic Intracranial Hemorrhage After Stroke Thrombolysis. Stroke 2014; 45:752-8. [DOI: 10.1161/strokeaha.113.003806] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Daniel Strbian
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - Patrik Michel
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - David J. Seiffge
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - Jeffrey L. Saver
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - Heikki Numminen
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - Atte Meretoja
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - Kei Murao
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - Bruno Weder
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - Nina Forss
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - Anna-Kaisa Parkkila
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - Ashraf Eskandari
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - Charlotte Cordonnier
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - Stephen M. Davis
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - Stefan T. Engelter
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
| | - Turgut Tatlisumak
- From the Departments of Neurology and Stroke Units, Helsinki University Central Hospital, Helsinki, Finland (D.S., A.M., N.F., T.T.); Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland (P.M., A.E.); University Hospital Basel, Basel, Switzerland (D.J.S., S.T.E.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA (J.L.S.); Tampere University Hospital, Tampere, Finland (H.N., A.-K.P.); The Royal Melbourne Hospital, Parkville,
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Vartiainen N, Forss N. [Imaging of brain changes in chronic pain]. Duodecim 2014; 130:1507-1514. [PMID: 25211820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Modern methods of brain imaging have enabled objective measurements of functional and structural brain changes associated with chronic pain conditions. According to recent investigations, chronic pain is not only associated with abnormally strong or prolonged activity of regions processing acute pain, but also with activation of brain networks that are characteristic for each pain state, changes in cortical remodeling, as well as local reduction of grey matter in several regions of the brain. Brain changes associated with chronic pain facilitate the understanding of mechanisms of various chronic pain conditions.
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Laaksonen K, Helle L, Parkkonen L, Kirveskari E, Mäkelä JP, Mustanoja S, Tatlisumak T, Kaste M, Forss N. Alterations in spontaneous brain oscillations during stroke recovery. PLoS One 2013; 8:e61146. [PMID: 23593414 PMCID: PMC3623808 DOI: 10.1371/journal.pone.0061146] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 03/07/2013] [Indexed: 11/18/2022] Open
Abstract
Amplitude or frequency alterations of spontaneous brain oscillations may reveal pathological phenomena in the brain or predict recovery from brain lesions, but the temporal evolution and the functional significance of these changes is not well known. We performed follow-up recordings of spontaneous brain oscillations with whole-head MEG in 16 patients with first-ever stroke in the middle cerebral artery territory, affecting upper limb motor function, 1-7 days (T0), 1 month (T1), and 3 months (T2) after stroke, with concomitant clinical examination. Clinical test results improved significantly from T0 to T1 or T2. During recovery (at T1 and T2), the strength of temporo-parietal ≈ 10-Hz oscillations in the affected hemisphere (AH) was increased as compared with the unaffected hemisphere. Abnormal low-frequency magnetic activity (ALFMA) at ≈ 1 Hz in the AH was detected in the perilesional cortex in seven patients at T0. In four of these, ALFMA persisted at T2. In patients with ALFMA, the lesion size was significantly larger than in the rest of the patients, and worse clinical outcome was observed in patients with persisting ALFMA. Our results indicate that temporo-parietal ≈ 10-Hz oscillations are enhanced in the AH during recovery from stroke. Moreover, stroke causes ALFMA, which seems to persist in patients with worse clinical outcome.
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Affiliation(s)
- Kristina Laaksonen
- Brain Research Unit, O.V. Lounasmaa Laboratory and MEG Core, Aalto Neuroimaging, Aalto University, Aalto, Espoo, Finland.
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Abstract
Botulism is a muscle-paralyzing disease caused by neurotoxins (types A-G) produced by the bacteria Clostridium botulinum. Symptoms of food-borne botulism most commonly appear 12-36 h after eating contaminated food, but the earliest neurological symptoms may in some cases start abruptly. Here, we report the cases of two patients with food-borne botulism who were admitted to the neurological emergency room as candidates for intravenous thrombolysis for acute stroke.
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Affiliation(s)
- Nina Forss
- Departments of Neurology, Helsinki University Central Hospital, Helsinki, Finland
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Strbian D, Engelter S, Michel P, Meretoja A, Sekoranja L, Ahlhelm FJ, Mustanoja S, Kuzmanovic I, Sairanen T, Forss N, Cordier M, Lyrer P, Kaste M, Tatlisumak T. Symptomatic intracranial hemorrhage after stroke thrombolysis: the SEDAN score. Ann Neurol 2012; 71:634-41. [PMID: 22522478 DOI: 10.1002/ana.23546] [Citation(s) in RCA: 207] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE A study was undertaken to develop a score for assessing risk for symptomatic intracranial hemorrhage (sICH) in ischemic stroke patients treated with intravenous (IV) thrombolysis. METHODS The derivation cohort comprised 974 ischemic stroke patients treated (1995-2008) with IV thrombolysis at the Helsinki University Central Hospital. The predictive value of parameters associated with sICH (European Cooperative Acute Stroke Study II) was evaluated, and we developed our score according to the magnitude of logistic regression coefficients. We calculated absolute risks and likelihood ratios of sICH per increasing score points. The score was validated in 828 patients from 3 Swiss cohorts (Lausanne, Basel, and Geneva). Performance of the score was tested with area under a receiver operating characteristic curve (AUC-ROC). RESULTS Our SEDAN score (0 to 6 points) comprises baseline blood Sugar (glucose; 8.1-12.0 mmol/l [145-216 mg/dl] = 1; >12.0 mmol/l [>216 mg/dl] = 2), Early infarct signs (yes = 1) and (hyper)Dense cerebral artery sign (yes = 1) on admission computed tomography scan, Age (>75 years = 1), and NIH Stroke Scale on admission (≥10 = 1). Absolute risk for sICH in the derivation cohort was: 1.4%, 2.9%, 8.5%, 12.2%, 21.7%, and 33.3% for 0, 1, 2, 3, 4, and 5 score points, respectively. In the validation cohort, absolute risks were similar (1.0%, 3.5%, 5.1%, 9.2%, 16.9%, and 27.8%, respectively). AUC-ROC was 0.77 (0.71-0.83; p < 0.001). INTERPRETATION Our SEDAN score reliably assessed risk for sICH in IV thrombolysis-treated patients with anterior- and posterior circulation ischemic stroke, and it can support clinical decision making in high-risk patients. External validation of the score supports its generalization.
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Affiliation(s)
- Daniel Strbian
- Department of Neurology, Helsinki University Central Hospital, Finland.
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Lioumis P, Mustanoja S, Bikmullina R, Vitikainen AM, Kičić D, Salonen O, Tatlisumak T, Kaste M, Forss N, Mäkelä JP. Probing modifications of cortical excitability during stroke recovery with navigated transcranial magnetic stimulation. Top Stroke Rehabil 2012; 19:182-92. [PMID: 22436366 DOI: 10.1310/tsr1902-182] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To follow cortical excitability changes during recovery from stroke with navigated transcranial magnetic stimulation (nTMS), in particular, to characterize changes of short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF), to correlate them with recovery of upper extremity function, and to detect possible shifts of cortical hand representations. METHODS Single and paired pulse nTMS were delivered to the hemisphere with infarction and to the hemisphere without infarction in 14 first-ever stroke patients at 1 (T1) and 3 months (T2) after stroke. Electromyographic responses to nTMS stimulation were recorded from the first dorsal interosseus muscles. nTMS was used to ensure an accurate coil repositioning in repeated measurements. Hand function recovery was clinically evaluated using the Action Research Arm Test (ARAT) and 9-hole peg test (9-HPT). RESULTS SICI and ICF were modulated in both hemispheres during recovery. Inhibition in the hemisphere without infarction correlated significantly with the affected hand performance at T2; stronger disinhibition (poor inhibition) was associated with worse hand performance. Location of hand muscle representations was shifted in 3 well-recovered patients out of 14 patients at T2. CONCLUSIONS In line with earlier studies, disinhibition in the hemisphere without infarction may be related to poor recovery of the affected hand. Usage of the affected hand during stroke recovery seems to influence these cortical excitability changes. nTMS is a valuable tool for tracking muscle cortical representation changes during brain reorganization.
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Strbian D, Meretoja A, Michel P, Engelter S, Sekoranja Bianchi L, Ahlhelm FJ, Mustanoja S, Kuzmanovic I, Sairanen T, Forss N, Lyrer P, Kaste M, Tatlisumak T. Abstract 67: Risk of Symptomatic Intracerebral Hemorrhage in Ischemic Stroke Thrombolysis: the SEDAN Score. Stroke 2012. [DOI: 10.1161/str.43.suppl_1.a67] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objectives
To develop a score for assessing the risk of symptomatic intracerebral hemorrhage (sICH) in ischemic stroke patients treated with iv thrombolysis.
Methods
The score was derived from a cohort of acute ischemic stroke patients treated with iv thrombolysis (n=972) at the Helsinki University Central Hospital (1995-2008). The predictive value of parameters associated with development of sICH (ECASS-2 criteria) was evaluated, and the score was developed according to the magnitude of logistic regression coefficients. The accuracy of the model was evaluated with 1000 bootstrap replicates. To test the performance of the score, we calculated area under receiver operating characteristic curve (AUC-ROC). We calculated absolute risks and likelihood ratios of sICH per increasing score points. The score was validated externally in merged cohort from 3 Swiss cities (Lausanne, Basel, and Geneva) including 828 ischemic stroke patients treated with iv thrombolysis.
Findings
The SEDAN score (0 to 6 points) consists of blood
S
ugar (glucose) at baseline [8.1-12.0 mmol/L (145-216 mg/dL)=1; >12.0 mmol/L (>216 mg/dL)=2],
E
arly infarct signs (yes=1) and (hyper)
D
ense cerebral artery sign (yes=1) on admission CT scan,
A
ge (>75=1), and
N
IH Stroke Scale on admission (>9=1). Accuracy of the score based on 1000 bootstrap replicates was 93.1% (91.4%-94.5%). AUC-ROC was 0.73 (0.67-0.79; p<0.001). Absolute risk for sICH in patients with increasing score points was: 1.4%, 2.9%, 8.5%, 12.2%, 21.7%, and 33.3% for 0, 1, 2, 3, 4, and 5 score points, respectively. Likelihood ratios were 0.19 (0.06-0.59), 0.40 (0.21-0.76), 1.23 (0.85-1.79), 1.85 (1.26-2.72), 3.68 (2.10-6.45), and 5.66 (2.40-13.40), respectively. Absolute risks in external validation were similar (1.0%, 3.5%, 5.1%, 9.2%, 16.9%, and 27.8%, respectively), and AUC-ROC was 0.77 (0.71-0.83; p<0.001).
Conclusions
The SEDAN score reliably assesses the risk of sICH in iv thrombolysis treated ischemic stroke patients and can support clinical decision-making in the high-risk patients. External validation of the score in the three Swiss cohorts supports its generalizibility.
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Affiliation(s)
| | | | - Patrik Michel
- Cntr Hospier Universitaire Vaudois and Univ of Lausanne, Lausanne, Switzerland
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Kolho E, Lindström M, Forss N. [Botulism]. Duodecim 2012; 128:1963-1969. [PMID: 23155747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Botulism is a rare but potentially life-threatening disease caused by Clostridium botulinum neurotoxin. In Finland only a few cases have been diagnosed during the past ten years but mild cases may be underdiagnosed. The diagnosis of botulism is clinical. Patients present with weakness in muscles innervated by the cranial nerves. In more severe cases the paralysis gradually progresses in a descending order and may affect respiratory muscles leading to mechanical ventilation. Routine laboratory tests or radiology are unhelpful in initial diagnostics. A practicing physician should administrate botulinum antitoxin immediately when food-borne botulism is suspected since it may be life-saving.
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Jalava K, Selby K, Pihlajasaari A, Kolho E, Dahlsten E, Forss N, Bäcklund T, Korkeala H, Honkanen-Buzalski T, Hulkko T, Derman Y, Järvinen A, Kotilainen H, Kultanen L, Ruutu P, Lyytikaïnen O, Lindström M. Two cases of food-borne botulism in Finland caused by conserved olives, October 2011. ACTA ACUST UNITED AC 2011; 16:20034. [PMID: 22172330 DOI: 10.2807/ese.16.49.20034-en] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In October 2011 in Finland, two persons fell ill with symptoms compatible with botulism after having eaten conserved olives stuffed with almonds. One of these two died. Clostridium botulinum type B and its neurotoxin were detected in the implicated olives by PCR and mouse bioassay, respectively. The olives were traced back to an Italian manufacturer and withdrawn from the market. The public and other European countries were informed through media and Europe-wide notifications.
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Affiliation(s)
- K Jalava
- Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare, Helsinki, Finland.
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Abstract
The clinical differential diagnosis between ischemic stroke and postictal deficit is sometimes challenging. If the clinical presentation is inconclusive, perfusion imaging can help to identify stroke patients for thrombolysis therapy. However, also epileptic phenomena may alter cerebral perfusion. Hypoperfusion spreading beyond the borders of cerebrovascular territories is usually considered suggestive of an etiology other than stroke. We present a patient whose clinical symptoms suggested a postictal deficit rather than an acute stroke. CT perfusion imaging showed hypoperfusion of the entire left cerebral hemisphere covering all vascular territories. CT angiography revealed occlusions in the ipsilateral internal carotid artery and in the circle of Willis as the cause of the global hypoperfusion. The patient was treated with i.v. thrombolysis and recovered with moderate disability. This is the first description of hyperacute ischemia of an entire cerebral hemisphere and its treatment with thrombolysis. It demonstrates the potential of modern neuroimaging in identifying atypically presenting strokes and shows that i.v. thrombolysis can be effectively and safely used to treat such potentially fatal insults.
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Affiliation(s)
- Filip Scheperjans
- Department of Neurology, Helsinki University Central Hospital, Helsinki, Finland
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Forss N, Mustanoja S, Roiha K, Kirveskari E, Mäkelä JP, Salonen O, Tatlisumak T, Kaste M. Activation in parietal operculum parallels motor recovery in stroke. Hum Brain Mapp 2011; 33:534-41. [PMID: 21425393 DOI: 10.1002/hbm.21230] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 10/21/2010] [Accepted: 11/18/2010] [Indexed: 11/08/2022] Open
Abstract
Motor recovery after stroke requires continuous interaction of motor and somatosensory systems. Integration of somatosensory feedback with motor programs is needed for the automatic adjustment of the speed, range, and strength of the movement. We recorded somatosensory evoked fields (SEFs) to tactile finger stimulation with whole-scalp magnetoencephalography in 23 acute stroke patients at 1 week, 1 month, and 3 months after stroke to investigate how deficits in the somatosensory cortical network affect motor recovery. SEFs were generated in the contralateral primary somatosensory cortex (SI) and in the bilateral parietal opercula (PO) in controls and patients. In the patients, SI amplitude or latency did not correlate with any of the functional outcome measures used. In contrast, the contralateral PO (cPO) amplitude to the affected hand stimuli correlated significantly with hand function in the acute phase and during recovery; the weaker the PO activation, the clumsier the hand was. At 1 and 3 months, enhancement of the cPO activation paralleled the improvement of the hand function. Whole-scalp magnetoencephalography measurements revealed that dysfunction of somatosensory cortical areas distant from the ischemic lesion may affect the motor recovery. Activation strength of the PO paralleled motor recovery after stroke, suggesting that the PO area is an important hub in mediating modulatory afferent input to motor cortex.
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Affiliation(s)
- Nina Forss
- Brain Research Unit, Low Temperature Laboratory, Aalto University, Espoo, Finland.
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Roiha K, Kirveskari E, Kaste M, Mustanoja S, Mäkelä JP, Salonen O, Tatlisumak T, Forss N. Reorganization of the primary somatosensory cortex during stroke recovery. Clin Neurophysiol 2011; 122:339-45. [DOI: 10.1016/j.clinph.2010.06.032] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 06/02/2010] [Accepted: 06/21/2010] [Indexed: 10/19/2022]
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Forss N, Roiha K, Kirveskari E, Makela J, Mustanoja S, Tatlisumak T, Kaste M. P25-24 Modulation of the 20-Hz mu rhythm by somatosensory input during stroke recovery. Clin Neurophysiol 2010. [DOI: 10.1016/s1388-2457(10)61046-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kirveskari E, Vartiainen NV, Gockel M, Forss N. Motor cortex dysfunction in complex regional pain syndrome. Clin Neurophysiol 2010; 121:1085-91. [PMID: 20185362 DOI: 10.1016/j.clinph.2010.01.032] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2009] [Revised: 01/25/2010] [Accepted: 01/27/2010] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Most patients with complex regional pain syndrome (CRPS) exhibit debilitating motor symptoms. The effect of continuous pain on motor system in CRPS, however, is not well known. We searched for signs of motor cortex dysfunction in chronic CRPS type 1 patients with motor impairment. METHODS We recorded rhythmic brain activity with magnetoencephalography (MEG) during noxious thulium-laser stimulation of both hands in eight CRPS patients and eight control subjects. We measured excitability of the motor cortex by monitoring the reactivity of the approximately 20-Hz motor cortex rhythm to laser stimuli. The reactivity was defined as a sum of the stimulus-induced suppression and the subsequent rebound of the approximately 20-Hz rhythm. RESULTS In CRPS, the reactivity of the approximately 20-Hz rhythm in the hemisphere contralateral to the painful hand was significantly weaker than in control subjects. The reactivity correlated with the mean level of the spontaneous pain (r=-0.64, P=0.04). Suppression of the approximately 20-Hz rhythm correlated with the grip strength in the painful hand (r=0.66, P=0.04). CONCLUSION Continuous pain in CRPS is associated with attenuated motor cortex reactivity. SIGNIFICANCE Abnormal motor cortex reactivity may be linked with motor dysfunction of the affected hand in CRPS.
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Affiliation(s)
- Erika Kirveskari
- Brain Research Unit, Low Temperature Laboratory, Aalto University, School of Science and Technology, Finland.
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Vartiainen N, Kirveskari E, Kallio-Laine K, Kalso E, Forss N. Cortical reorganization in primary somatosensory cortex in patients with unilateral chronic pain. J Pain 2009; 10:854-9. [PMID: 19638329 DOI: 10.1016/j.jpain.2009.02.006] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Revised: 01/02/2009] [Accepted: 02/26/2009] [Indexed: 11/15/2022]
Abstract
UNLABELLED Bodily representations of the primary somatosensory (SI) cortex are constantly modified according to sensory input. Increased input due to training as well as loss of input due to deafferentation are reflected as changes in the extent of cortical representations. Recent studies in complex regional pain syndrome (CRPS) patients have indicated that the chronic pain itself is associated with cortical reorganization. However, it is unclear whether the observed reorganization is specific for CRPS or if it can be detected also in other types of chronic pain. We therefore searched for signs of cortical reorganization in a group of 8 patients who suffered from chronic pain associated with herpes simplex virus infections. The pain was widespread but restricted to unilateral side of the body and included the upper limb. We recorded neuromagnetic responses to tactile stimulation of fingers of both hands in patients and in a group of healthy, matched control subjects. In the patients, the distance between the thumb (D1) and little finger (D5) representations in SI cortex was statistically significantly smaller in the hemisphere contralateral to painful side than in the hemisphere contralateral to healthy side. In the control subjects, the D1-D5 distance was the same in both hemispheres. PERSPECTIVE The present results indicate that cortical reorganization occurs in chronic neuropathic pain patients even without peripheral nerve damage. It is possible that cortical reorganization is related to chronic pain, regardless of its etiology. Causality between reorganization and chronic pain should be examined further to develop therapeutic approaches for chronic pain.
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Affiliation(s)
- Nuutti Vartiainen
- Brain Research Unit, Low Temperature Laboratory, Helsinki University of Technology, Espoo, Finland.
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