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Grijalva C, Hale D, Wu L, Toosizadeh N, Laksari K. Hyper-acute effects of sub-concussive soccer headers on brain function and hemodynamics. Front Hum Neurosci 2023; 17:1191284. [PMID: 37780960 PMCID: PMC10538631 DOI: 10.3389/fnhum.2023.1191284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 08/29/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction Sub-concussive head impacts in soccer are drawing increasing research attention regarding their acute and long-term effects as players may experience thousands of headers in a single season. During these impacts, the head experiences rapid acceleration similar to what occurs during a concussion, but without the clinical implications. The physical mechanism and response to repetitive impacts are not completely understood. The objective of this work was to examine the immediate functional outcomes of sub-concussive level impacts from soccer heading in a natural, non-laboratory environment. Methods Twenty university level soccer athletes were instrumented with sensor-mounted bite bars to record impacts from 10 consecutive soccer headers. Pre- and post-header measurements were collected to determine hyper-acute changes, i.e., within minutes after exposure. This included measuring blood flow velocity using transcranial Doppler (TCD) ultrasound, oxyhemoglobin concentration using functional near infrared spectroscopy imaging (fNIRS), and upper extremity dual-task (UEF) neurocognitive testing. Results On average, the athletes experienced 30.7 ± 8.9 g peak linear acceleration and 7.2 ± 3.1 rad/s peak angular velocity, respectively. Results from fNIRS measurements showed an increase in the brain oxygenation for the left prefrontal cortex (PC) (p = 0.002), and the left motor cortex (MC) (p = 0.007) following the soccer headers. Additional analysis of the fNIRS time series demonstrates increased sample entropy of the signal after the headers in the right PC (p = 0.02), right MC (p = 0.004), and left MC (p = 0.04). Discussion These combined results reveal some variations in brain oxygenation immediately detected after repetitive headers. Significant changes in balance and neurocognitive function were not observed in this study, indicating a mild level of head impacts. This is the first study to observe hemodynamic changes immediately after sub-concussive impacts using non-invasive portable imaging technology. In combination with head kinematic measurements, this information can give new insights and a framework for immediate monitoring of sub-concussive impacts on the head.
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Affiliation(s)
- Carissa Grijalva
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, United States
| | - Dallin Hale
- Department of Physiology, University of Arizona, Tucson, AZ, United States
| | - Lyndia Wu
- Department of Mechanical Engineering, University of British Columbia, Vancouver, BC, Canada
| | - Nima Toosizadeh
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, United States
- Arizona Center for Aging, Department of Medicine, University of Arizona, Tucson, AZ, United States
| | - Kaveh Laksari
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ, United States
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ, United States
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Slessarev M, Mahmoud O, McIntyre CW, Ellis CG. Cerebral Blood Flow Deviations in Critically Ill Patients: Potential Insult Contributing to Ischemic and Hyperemic Injury. Front Med (Lausanne) 2021; 7:615318. [PMID: 33553208 PMCID: PMC7854569 DOI: 10.3389/fmed.2020.615318] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 12/14/2020] [Indexed: 11/27/2022] Open
Abstract
Background: Ischemic and hyperemic injury have emerged as biologic mechanisms that contribute to cognitive impairment in critically ill patients. Spontaneous deviations in cerebral blood flow (CBF) beyond ischemic and hyperemic thresholds may represent an insult that contributes to this brain injury, especially if they accumulate over time and coincide with impaired autoregulation. Methods: We used transcranial Doppler to measure the proportion of time that CBF velocity (CBFv) deviated beyond previously reported ischemic and hyperemic thresholds in a cohort of critically ill patients with respiratory failure and/or shock within 48 h of ICU admission. We also assessed whether these CBFv deviations were more common during periods of impaired dynamic autoregulation, and whether they are explained by concurrent variations in mean arterial pressure (MAP) and end-tidal PCO2 (PetCO2). Results: We enrolled 12 consecutive patients (three females) who were monitored for a mean duration of 462.6 ± 39.8 min. Across patients, CBFv deviated by more than 20–30% from its baseline for 17–24% of the analysis time. These CBFv deviations occurred equally during periods of preserved and impaired autoregulation, while concurrent variations in MAP and PetCO2 explained only 13–21% of these CBFv deviations. Conclusion: CBFv deviations beyond ischemic and hyperemic thresholds are common in critically ill patients with respiratory failure or shock. These deviations occur irrespective of the state of dynamic autoregulation and are not explained by changes in MAP and CO2. Future studies should explore mechanisms responsible for these CBFv deviations and establish whether their cumulative burden predicts poor neurocognitive outcomes.
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Affiliation(s)
- Marat Slessarev
- Department of Medicine, Western University, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada.,Brain & Mind Institute, Western University, London, ON, Canada
| | - Ossama Mahmoud
- Department of Computer Science, Western University, London, ON, Canada
| | - Christopher W McIntyre
- Department of Medicine, Western University, London, ON, Canada.,Department of Medical Biophysics, Western University, London, ON, Canada
| | - Christopher G Ellis
- Department of Medical Biophysics, Western University, London, ON, Canada.,Robarts Research Institute, Western University, London, ON, Canada
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Impact of Type 2 Diabetes Mellitus on the Cerebral Blood Vessels in Asymptomatic Patients in Egypt (Ultrasonographic Study). ARCHIVES OF NEUROSCIENCE 2020. [DOI: 10.5812/ans.105600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background: Diabetes is an important risk factor of extra and intracranial stenosis and hence can cause cerebrovascular stroke. In Egypt, prevalence of asymptomatic extra and intracranial blood vessels stenosis in diabetic patients is still unknown. Objectives: To estimate the prevalence of asymptomatic extra and intracranial vessels stenosis. Methods: 100 Patients with Type-2 Diabetes (T2D) were recruited consecutively from diabetes clinic of the department of internal medicine at Assiut University Hospitals in the period from 1st January 2016 to 31st January 2017. A detailed history was obtained for all participant. As well, thorough-out physical and neurologic examination were carried out for patients. All patients underwent extra cranial and transcranial colour coded ultrasound by two independent investigators. Patients with history of cerebrovascular stroke and transient ischemic attacks were excluded. Results: 36% of patients had increased IMT, 6% had stenosis 50-69% and 2% had stenosis ≥ 70%. There was a positive correlation between age and increased IMT (r = 0.272) (P = 0.006) and between uncontrolled DM and increased IMT (r = 0.211) (P = 0.035). 26% of patients had stenosis of < 50% in vertebral artery (21% in V0 segment, 5% in V1 segment); being male and uncontrolled diabetes escalate the stenosis risk. MCA pulsatility index was found to be higher among old diabetics in comparison to younger diabetics and control group (r = -0.225) (P = -0.025). Also, the longer the time since T2D onset, the higher was MCA PSV (r = 0.244) (P = 0.014). Conclusions: The cerebral blood vessels atherosclerotic changes (mainly extracranial) are higher among diabetics in comparison to healthy controls.
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The Role of Transcranial Doppler as a Monitoring Tool in the Neurocritical Care Unit. Neurocrit Care 2019. [DOI: 10.1017/9781107587908.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Yan L, Zhou X, Zheng Y, Luo W, Yang J, Zhou Y, He Y. Research progress in ultrasound use for the diagnosis and treatment of cerebrovascular diseases. Clinics (Sao Paulo) 2019; 74:e715. [PMID: 30864640 PMCID: PMC6438134 DOI: 10.6061/clinics/2019/e715] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 10/15/2018] [Indexed: 11/18/2022] Open
Abstract
Cerebrovascular diseases pose a serious threat to human survival and quality of life and represent a major cause of human death and disability. Recently, the incidence of cerebrovascular diseases has increased yearly. Rapid and accurate diagnosis and evaluation of cerebrovascular diseases are of great importance to reduce the incidence, morbidity and mortality of cerebrovascular diseases. With the rapid development of medical ultrasound, the clinical relationship between ultrasound imaging technology and the diagnosis and treatment of cerebrovascular diseases has become increasingly close. Ultrasound techniques such as transcranial acoustic angiography, doppler energy imaging, three-dimensional craniocerebral imaging and ultrasound thrombolysis are novel and valuable techniques in the study of cerebrovascular diseases. In this review, we introduce some of the new ultrasound techniques from both published studies and ongoing trials that have been confirmed to be convenient and effective methods. However, additional evidence from future studies will be required before some of these techniques can be widely applied or recommended as alternatives.
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Affiliation(s)
- Li Yan
- Department of Ultrasonography, Xijing Hospital, The Fourth Military Medical University, Xi’an , China
- Department of Ultrasonography, Xi’an Central Hospital, The Third Affiliated Hospital of JiaoTong University, Xi’an, China
| | - Xiaodong Zhou
- Department of Ultrasonography, Xijing Hospital, The Fourth Military Medical University, Xi’an , China
- Corresponding author. E-mail:
| | - Yu Zheng
- Department of Ultrasonography, Xi’an Central Hospital, The Third Affiliated Hospital of JiaoTong University, Xi’an, China
| | - Wen Luo
- Department of Ultrasonography, Xijing Hospital, The Fourth Military Medical University, Xi’an , China
| | - Junle Yang
- Department of CT & MRI, Xi’an Central Hospital, The Third Affiliated Hospital of JiaoTong University, Xi’an, China
| | - Yin Zhou
- Department of Ultrasonography, Xi’an Central Hospital, The Third Affiliated Hospital of JiaoTong University, Xi’an, China
| | - Yang He
- Department of General Surgery, Xi'an Medical University, Xi'an, China
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Thorpe SG, Thibeault CM, Canac N, Wilk SJ, Devlin T, Hamilton RB. Decision Criteria for Large Vessel Occlusion Using Transcranial Doppler Waveform Morphology. Front Neurol 2018; 9:847. [PMID: 30386287 PMCID: PMC6199366 DOI: 10.3389/fneur.2018.00847] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 09/21/2018] [Indexed: 01/23/2023] Open
Abstract
Background: The current lack of effective tools for prehospital identification of Large Vessel Occlusion (LVO) represents a significant barrier to efficient triage of stroke patients and detriment to treatment efficacy. The validation of objective Transcranial Doppler (TCD) metrics for LVO detection could provide first responders with requisite tools for informing stroke transfer decisions, dramatically improving patient care. Objective: To compare the diagnostic efficacy of two such candidate metrics: Velocity Asymmetry Index (VAI), which quantifies disparity of blood flow velocity across the cerebral hemispheres, and Velocity Curvature Index (VCI), a recently proposed TCD morphological biomarker. Additionally, we investigate a simple decision tree combining both metrics. Methods: We retrospectively compare accuracy/sensitivity/specificity (ACC/SEN/SPE) of each method (relative to standard CT-Angiography) in detecting LVO in a population of 66 subjects presenting with stroke symptoms (33 with CTA-confirmed LVO), enrolled consecutively at Erlanger Southeast Regional Stroke Center in Chattanooga, TN. Results: Individual VCI and VAI metrics demonstrated robust performance, with area under receiver operating characteristic curve (ROC-AUC) of 94% and 88%, respectively. Additionally, leave-one-out cross-validation at optimal identified thresholds resulted in 88% ACC (88% SEN) for VCI, vs. 79% ACC (76% SEN) for VAI. When combined, the resultant decision tree achieved 91% ACC (94% SEN). Discussion: We conclude VCI to be superior to VAI for LVO detection, and provide evidence that simple decision criteria incorporating both metrics may further optimize. Performance: Our results suggest that machine-learning approaches to TCD morphological analysis may soon enable robust prehospital LVO identification. Registration: Was not required for this feasibility study.
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Affiliation(s)
| | | | - Nicolas Canac
- Neural Analytics, Inc., Los Angeles, CA, United States
| | - Seth J Wilk
- Neural Analytics, Inc., Los Angeles, CA, United States
| | - Thomas Devlin
- Erlanger Medical Center, Chattanooga, TN, United States
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Thorpe SG, Thibeault CM, Wilk SJ, O'Brien M, Canac N, Ranjbaran M, Devlin C, Devlin T, Hamilton RB. Velocity Curvature Index: a Novel Diagnostic Biomarker for Large Vessel Occlusion. Transl Stroke Res 2018; 10:475-484. [PMID: 30293170 PMCID: PMC6733810 DOI: 10.1007/s12975-018-0667-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/06/2018] [Accepted: 09/24/2018] [Indexed: 11/25/2022]
Abstract
Despite being a conveniently portable technology for stroke assessment, Transcranial Doppler ultrasound (TCD) remains widely underutilized due to complex training requirements necessary to reliably obtain and interpret cerebral blood flow velocity (CBFV) waveforms. The validation of objective TCD metrics for large vessel occlusion (LVO) represents a first critical step toward enabling use by less formally trained personnel. In this work, we assess the diagnostic utility, relative to current standard CT angiography (CTA), of a novel TCD-derived biomarker for detecting LVO. Patients admitted to the hospital with stroke symptoms underwent TCD screening and were grouped into LVO and control groups based on the presence of CTA confirmed occlusion. Velocity curvature index (VCI) was computed from CBFV waveforms recorded at multiple depths from the middle cerebral arteries (MCA) of both cerebral hemispheres. VCI was assessed for 66 patients, 33 of which had occlusions of the MCA or internal carotid artery. Our results show that VCI was more informative when measured from the cerebral hemisphere ipsilateral to the site of occlusion relative to contralateral. Moreover, given any pair of bilateral recordings, VCI separated LVO patients from controls with average area under receiver operating characteristic curve of 92%, which improved to greater than 94% when pairs were selected by maximal velocity. We conclude that VCI is an analytically valid candidate biomarker for LVO diagnosis, possessing comparable accuracy, and several important advantages, relative to current TCD diagnostic methodologies.
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Affiliation(s)
- Samuel G Thorpe
- Neural Analytics, Inc., 2440 S. Sepulveda Blvd. Suite 115, Los Angeles, CA, 90064, USA.
| | - Corey M Thibeault
- Neural Analytics, Inc., 2440 S. Sepulveda Blvd. Suite 115, Los Angeles, CA, 90064, USA
| | - Seth J Wilk
- Neural Analytics, Inc., 2440 S. Sepulveda Blvd. Suite 115, Los Angeles, CA, 90064, USA
| | - Michael O'Brien
- Neural Analytics, Inc., 2440 S. Sepulveda Blvd. Suite 115, Los Angeles, CA, 90064, USA
| | - Nicolas Canac
- Neural Analytics, Inc., 2440 S. Sepulveda Blvd. Suite 115, Los Angeles, CA, 90064, USA
| | - Mina Ranjbaran
- Neural Analytics, Inc., 2440 S. Sepulveda Blvd. Suite 115, Los Angeles, CA, 90064, USA
| | - Christian Devlin
- Cardiac Biomechanics Group, University of Virginia, Charlottesville, VA, USA
| | - Thomas Devlin
- Department of Neurology, Erlanger Medical Center, Chattanooga, TN, USA
| | - Robert B Hamilton
- Neural Analytics, Inc., 2440 S. Sepulveda Blvd. Suite 115, Los Angeles, CA, 90064, USA
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Saqqur M, Khan K, Derksen C, Alexandrov A, Shuaib A. Transcranial Doppler and Transcranial Color Duplex in Defining Collateral Cerebral Blood Flow. J Neuroimaging 2018; 28:455-476. [DOI: 10.1111/jon.12535] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Accepted: 06/18/2018] [Indexed: 12/31/2022] Open
Affiliation(s)
- Maher Saqqur
- Division of Neurology, Department of Medicine; University of Alberta; Edmonton AB Canada
- Neuroscience Institute; Hamad General Hospital Doha Qatar
| | - Khurshid Khan
- Division of Neurology, Department of Medicine; University of Alberta; Edmonton AB Canada
| | - Carol Derksen
- Division of Neurology, Department of Medicine; University of Alberta; Edmonton AB Canada
| | - Andrei Alexandrov
- Department of Neurology; University of Tennessee Health Science Center; Memphis TN USA
| | - Ashfaq Shuaib
- Division of Neurology, Department of Medicine; University of Alberta; Edmonton AB Canada
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9
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Flat-head positioning increases cerebral blood flow in anterior circulation acute ischemic stroke. A cluster randomized phase IIb trial. Int J Stroke 2017; 13:600-611. [DOI: 10.1177/1747493017711943] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background Whether lying-flat improves blood flow in patients with acute ischemic stroke is unknown. Our aim was to investigate if lying-flat “changes” cerebral blood flow velocities assessed by transcranial Doppler in acute ischemic stroke patients. Methods In a multicenter cluster clinical trial, we randomly assigned patients within 12 h from onset of a neurological deficit due to cerebral ischemia of the anterior circulation to lying-flat or upright head positioning. The primary outcome was a change of 8 cm/s or more in mean cerebral blood flow velocities on transcranial Doppler to the middle cerebral artery at 1 and 24 h post-randomization, adjusted for imbalance in baseline variables. Secondary outcomes included serious adverse events and physical functioning at 90 days. Results Ninety-four of 304 patients screened were recruited. The primary outcome occurred in 11 (26%) of 43 patients in the lying-flat group and in 6 (12%) of 51 in the upright group at 1 h (adjusted odds ratio, 3.81; 95% CI, 1.07 to 13.54), and in 23 (53%) and 18 (36%) patients in these respective groups at 24 h (adjusted odds ratio, 3.04; 95% CI, 1.08 to 8.53). There were no between-group differences in serious adverse events, including pneumonia, heart failure or mortality, nor in functional outcome at 3 months (adjusted common odds ratio, 1.38; 95% CI 0.64 to 3.00). Conclusion The lying-flat head position was associated with a significant increase in cerebral blood flow velocities at one and 24 h within the ipsilateral hemisphere of anterior circulation acute ischemic stroke, without serious safety concerns. Clinical trial registration-URL: http://www.clinicaltrials.gov . Unique identifier: NCT01706094.
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Del Brutto OH, Mera RM, de la Luz Andrade M, Espinosa V, Castillo PR, Zambrano M, Nader JA. Temporal bone thickness and texture are major determinants of the high rate of insonation failures of transcranial Doppler in Amerindians (the Atahualpa Project). JOURNAL OF CLINICAL ULTRASOUND : JCU 2016; 44:55-60. [PMID: 26178311 DOI: 10.1002/jcu.22284] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 04/03/2015] [Accepted: 06/05/2015] [Indexed: 06/04/2023]
Abstract
PURPOSE To assess the role of temporal bone characteristics in transcranial Doppler (TCD) insonation failures in Amerindians living in rural Ecuador. METHODS We evaluated thickness and texture of temporal bones in community-dwelling Amerindians ≥65 years old undergoing TCD. Using receiver operator characteristics curve analysis and generalized estimating equations, we investigated factors associated with insonation failures. RESULTS Of 65 participants (mean age 74.7 ± 6.7 years, 60% women), 32 (49%) had uni- or bilateral insonation failure through temporal windows. Considering temporal bones independently, 57 of 130 (44%) had poor insonation. Mean thickness was higher (4.7 ± 1.2 versus 2.7 ± 0.9, p < 0.0001), and texture more often heterogeneous (93% versus 22%, p < 0.0001) in bones with poor acoustic windows. Thickness, better predicting poor insonation, was ≥3.6 mm if used alone, and ≥2.7 mm if used together with heterogeneous texture. For every millimeter of increase in thickness, subjects were 2.9 times more likely to have insonation failures. Per se, heterogeneous texture increased by 3.2 times the odds for poor insonation. In all models, being woman increased the odds for poor insonation by six to nine times. CONCLUSIONS Temporal bone thickness and texture are independent predictors of TCD insonation failure in Amerindians.
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Affiliation(s)
- Oscar H Del Brutto
- School of Medicine, Universidad Espíritu Santo-Ecuador, Guayaquil, Ecuador
| | - Robertino M Mera
- Gastroenterology Department, Vanderbilt University, Nashville, TN
| | | | | | - Pablo R Castillo
- Sleep Disorders Center, Mayo Clinic College of Medicine, Jacksonville, FL
| | | | - Juan A Nader
- Department of Neurology, Hospital Medica Sur, Mexico City, Mexico
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Transcranial Doppler Examination. Neuroophthalmology 2016. [DOI: 10.1007/978-3-319-28956-4_26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Castillo PR, Del Brutto OH, Andrade MDLL, Zambrano M, Nader JA. The association of sleep-disordered breathing with high cerebral pulsatility might not be related to diffuse small vessel disease. A pilot study. BMC Res Notes 2015; 8:500. [PMID: 26420374 PMCID: PMC4588689 DOI: 10.1186/s13104-015-1481-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 09/21/2015] [Indexed: 11/10/2022] Open
Abstract
Background
In a population-based sampling study conducted in community-dwelling older adults living in rural Ecuador, we aimed to assess the relation among sleep-disordered breathing, cerebral pulsatility index, and diffuse small vessel disease.
Methods Of 25 participants, 9 (36 %) had moderate-to-severe sleep-disordered breathing, characterized by an apnea/hypopnea index ≥15 per hour, and 10 (40 %) had moderate-to-severe white matter hyperintensities, graded according to the modified Fazekas scale. Mean (SD) pulsatility index in the middle cerebral artery was 1.18 (0.19) and positively correlated with the apnea/hypopnea index (R = .445, P = .03, [Pearson’s correlation coefficient]). The middle cerebral artery pulsatility index was increased in persons with moderate-to-severe sleep-disordered breathing compared with persons who had none-to-mild sleep-disordered breathing (mean [SD] 1.11 [0.12] vs. 1.3 [0.23], P = .01). No significant differences were found in the prevalence of moderate-to-severe white matter hyperintensities across groups of sleep-disordered breathing (P = .40) or in the mean apnea/hypopnea index across groups of persons with none-to-mild or moderate-to-severe white matter hyperintensities (P = .16).
Conclusions This pilot study shows that moderate-to-severe sleep-disordered breathing correlates with cerebral pulsatility, but such association might be independent of diffuse small vessel disease.
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Affiliation(s)
- Pablo R Castillo
- Division of Sleep Medicine, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL, 32224, USA.
| | - Oscar H Del Brutto
- School of Medicine, Universidad Espíritu Santo-Ecuador, Guayaquil, Ecuador.
| | | | | | - Juan A Nader
- Department of Neurology, Hospital Médica Sur, Mexico City, Mexico.
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Nader JA, Andrade MDLL, Espinosa V, Zambrano M, Del Brutto OH. Technical difficulties due to poor acoustic insonation during transcranial Doppler recordings in Amerindians and individuals of European origin. A comparative study. Eur Neurol 2015; 73:230-232. [PMID: 25790759 DOI: 10.1159/000380819] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 02/08/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND There is no information on transcranial Doppler (TCD) failures due to poor insonation among native inhabitants of Latin America. METHODS Seventy Ecuadorian natives and 70 age- and sex-matched individuals of European origin underwent TCD. The same investigators performed all exams using the same equipment and protocol. Using the McNemar's test for correlated proportions, we compared TCD failures related to poor insonation across ethnic groups. RESULTS Out of 140 participants, 56 (40%) had one or more suboptimal/absent acoustic windows. These persons were older (p = 0.01) and were more often women (p < 0.0001) than those with all optimal windows (irrespective of race/ethnicity). In the matched-pair analysis, Amerindians were more likely to have suboptimal/absent acoustic windows than individuals of European origin (OR: 2.8, 95% CI: 1.3-6.5, p = 0.006). CONCLUSION Amerindians are almost three times more likely to have insonation failures related to poor acoustic windows than their European counterparts.
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Brunser AM, Lavados PM, Cárcamo DA, Hoppe A, Olavarría VV, López J, Muñoz P, Rivas R. Accuracy of Power Mode Transcranial Doppler in the Diagnosis of Brain Death. J Med Ultrasound 2015. [DOI: 10.1016/j.jmu.2014.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Microembolic signal monitoring and the prediction of thromboembolic events following coil embolization of unruptured intracranial aneurysms: diffusion-weighted imaging correlation. Neuroradiology 2014; 57:189-96. [DOI: 10.1007/s00234-014-1451-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 10/01/2014] [Indexed: 10/24/2022]
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Kim JS, Lee SW, Eun MY, Seo WK. Power motion-mode Doppler signature: a useful tool for assessing middle cerebral artery stenosis. JOURNAL OF CLINICAL ULTRASOUND : JCU 2014; 42:348-354. [PMID: 24449334 DOI: 10.1002/jcu.22134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 09/27/2013] [Accepted: 12/16/2013] [Indexed: 06/03/2023]
Abstract
PURPOSE To identify power motion-mode Doppler (PMD) patterns and assess their diagnostic value for the diagnosis of middle cerebral artery (MCA) stenosis. METHODS Retrospective analyses of PMD data were performed for the identification of specific patterns related to MCA stenosis. The interrater reliability and the validity of these patterns were studied, using magnetic resonance angiography and conventional transcranial Doppler sonography as gold standards. RESULTS Three PMD patterns were identified: the so-called black-hole, the white-hole, and the diastolic-band patterns in 58 among 178 MCAs. The mean flow velocity was significantly higher in arterial segments with the black-hole patterns and lower in segments with the diastolic-band pattern compared with the segments with normal patterns. The interrater reliability was good for each pattern. The black-hole pattern or its combination with the white-hole pattern showed the highest validity. CONCLUSION Despite some limitations, the black-hole PMD pattern or its combination with the white-hole pattern appeared as a reliable and valid marker for the diagnosis of MCA stenosis.
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Affiliation(s)
- Ji-Sun Kim
- Department of Neurology, College of Medicine, Korea University, Seoul, Korea
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Soeding P, Hoy S, Hoy G, Evans M, Royse C. Effect of phenylephrine on the haemodynamic state and cerebral oxygen saturation during anaesthesia in the upright position. Br J Anaesth 2013; 111:229-34. [DOI: 10.1093/bja/aet024] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Regan RE, Duffin J, Fisher JA. Instability of the middle cerebral artery blood flow in response to CO2. PLoS One 2013; 8:e70751. [PMID: 23936248 PMCID: PMC3728315 DOI: 10.1371/journal.pone.0070751] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 06/26/2013] [Indexed: 01/09/2023] Open
Abstract
Background The middle cerebral artery supplies long end-artery branches to perfuse the deep white matter and shorter peripheral branches to perfuse cortical and subcortical tissues. A generalized vasodilatory stimulus such as carbon dioxide not only results in an increase in flow to these various tissue beds but also redistribution among them. We employed a fast step increase in carbon dioxide to detect the dynamics of the cerebral blood flow response. Methodology/Principal Findings The study was approved by the Research Ethics Board of the University Health Network at the University of Toronto. We used transcranial ultrasound to measure the time course of middle cerebral artery blood flow velocity in 28 healthy adults. Normoxic, isoxic step increases in arterial carbon dioxide tension of 10 mmHg from both hypocapnic and normocapnic baselines were produced using a new prospective targeting system that enabled a more rapid step change than has been previously achievable. In most of the 28 subjects the responses at both carbon dioxide ranges were characterised by more complex responses than a single exponential rise. Most responses were characterised by a fast initial response which then declined rapidly to a nadir, followed by a slower secondary response, with some showing oscillations before stabilising. Conclusions/Significance A rapid step increase in carbon dioxide tension is capable of inducing instability in the cerebral blood flow control system. These dynamic aspects of the cerebral blood flow responses to rapid changes in carbon dioxide must be taken into account when using transcranial blood flow velocity in a single artery segment to measure cerebrovascular reactivity.
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Affiliation(s)
- Rosemary E. Regan
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - James Duffin
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Anaesthesia, University of Toronto, and University Health Network, Toronto, Ontario, Canada
- * E-mail:
| | - Joseph A. Fisher
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Anaesthesia, University of Toronto, and University Health Network, Toronto, Ontario, Canada
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19
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Image-guided transcranial Doppler sonography for monitoring of defined segments of intracranial arteries. J Neurosurg Anesthesiol 2013; 25:55-61. [PMID: 23027224 DOI: 10.1097/ana.0b013e31826b3d55] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Transcranial Doppler sonography (TCD) is widely used in neurointensive care. Image guidance (IG) could simplify secure vessel identification and reduce interinvestigator and intrainvestigator variability. The present study was purposed to investigate the precision and reproducibility of image-guided TCD. METHODS The Kolibri IG system (Brainlab AG, Feldkirchen, Germany) was used to track a hand-held Doppler probe of a DWL Multi-Dop® T digital device (Compumedics Germany GmbH, Singen, Germany). The patient's head was registered noninvasively to the IG system. Distance between predefined vascular target and optimal Doppler signal was evaluated to assess spatial accuracy of image-guided TCD. To investigate reproducibility, spatial accuracy of trajectories acquired during an initial examination using the IG system was analyzed in serial examinations. Furthermore, stability of noninvasive registration of the patient's head to the IG system was analyzed. Data are presented as mean±SD for descriptive statistics. Twelve patients were included. RESULTS Using IG, a Doppler signal was recorded immediately in all cases for middle cerebral artery (MCA) (29 examinations), in 81% for carotid-T (27 examinations), and in 90% for basilar tip (29 examinations). The optimal Doppler signal was found within 2.64±1.15 mm (94 preplanned targets). At serial examinations, a spatial deviation of 2.75±1.20 mm was found (56 trajectories acquired in 19 serial examinations). Examination time did not influence accuracy of noninvasive patient registration. CONCLUSIONS Data suggest that image-guided TCD allows for accurate examinations with high intraprocedural and high interprocedural reproducibility. It facilitates identification of specific vessel segments and generation of standardized examination protocols for serial examinations.
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20
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Topcuoglu MA. Transcranial Doppler ultrasound in neurovascular diseases: diagnostic and therapeutic aspects. J Neurochem 2012; 123 Suppl 2:39-51. [PMID: 23050641 DOI: 10.1111/j.1471-4159.2012.07942.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Albeit no direct anatomical information can be obtained, neurosonological methods provide real-time determination of velocity, and spectral waveform of blood flow in basal intracranial arteries adds significant benefit to the care of the patients with neurovascular diseases. Several features, such as relative simplicity in terms of interpretation and performance, significantly low cost, totally non-invasiveness, portability, and excellent temporal resolution, make neurosonology increasingly popular tool for evaluation, planning, and monitoring of treatment, and for determining prognosis in various neurovascular diseases. Usefulness of transcranial Doppler in diagnosing/monitoring subarachnoid hemorrhage related vasospasm and sickle cell vasculopathy is already well known. Utility in diagnosis of intracranial arterial stenosis, acute occlusion and recanalization, intracranial hemodynamic effect of the cervical arterial pathologies, intracranial pressure increase, and cerebral circulatory arrest are also well established. Neurosonological determination of vasomotor reactivity, cerebral autoregulation, neurovascular coupling, and micro-embolic signals detection are useful in the assessment of stroke risk, diagnosis of right-to-left shunting, and monitoring during surgery and interventional procedures. Transcranial Doppler is also an evolving ultrasound method with a therapeutic potential such as augmentation of clot lysis and cerebral delivery of thrombolytic or neuroprotective agent loaded nanobubbles in neurovascular diseases. The aim of this study is to give an overview of current usage of the different ultrasound modalities in different neurovascular diseases.
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Affiliation(s)
- M Akif Topcuoglu
- Hacettepe University Hospitals, Department of Neurology, Neurosonology Laboratory, Neurological Intensive Care Unit, Ankara, Turkey.
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21
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Gujjar AR, William R, Jacob PC, Jain R, Al-Asmi AR. Transcranial Doppler ultrasonography in acute ischemic stroke predicts stroke subtype and clinical outcome: a study in Omani population. J Clin Monit Comput 2011; 25:121-8. [PMID: 21713538 DOI: 10.1007/s10877-011-9288-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Accepted: 06/11/2011] [Indexed: 12/01/2022]
Abstract
BACKGROUND Transcranial Doppler ultrasonography (TCD) is being increasingly used for its ability to provide cerebral hemodynamic information in stroke. Few studies have explored its association with cerebral arteriographic changes and stroke subtype. This study explored the relation of TCD changes in acute stroke with stroke subtypes, MR cerebral arteriography and clinical outcome in Omani population. METHODS Adult patients presenting with acute ischemic stroke within 4 days of stroke onset were subjected to TCD through the temporal and suboccipital windows using a 2 MHz probe; flow velocities, pulsatility and direction of flow were recorded from arteries at the skull base. MR arteriographic (MRA) changes on corresponding arteries were graded on a scale of 1-4. ANOVA, student's t test and ROC analysis were used to evaluate TCD in relation to stroke type, outcome and stenosis on MRA. RESULTS Of 60 patients recruited, 52 (M:F::36:16; mean age: 60 + 13 years) had adequate bone window for TCD study. Large artery stroke occurred in 30 (58%) patients; lacunar stroke-11 (21%); cardioembolic and mixed groups 9 (17%), other specificed causes-2 (4%). 86.5% had evidence of intracranial disease. 10/52 patients (19%) died while 33 (63%) had good outcome (modified Rankin Score 0-3). Of the 186 arteries studied by the two methods, 52 had TCD evidence of stenosis while 42 were abnormal on MRA, giving a sensitivity of 60%, specificity: 81.25%; positive likelihood ratio: 3.18 and negative likelihood ratio: 0.5. 29/52 (56%) of patients had TCD changes in the arteries corresponding to stroke location. Abnormal TCD was associated with large artery strokes (p = 0.007), poor outcome (p = 0.038) and mortality (p = 0.01). CONCLUSION This study of TCD in acute stroke in Omani population demonstrates a relatively higher burden of intracranial arterial disease. TCD changes are associated with type of stroke and outcome in this population. TCD is a simple and fairly useful method of evaluation in patients with acute stroke. Adopting TCD in evaluation of stroke patients may provide useful information regarding the pathophysiology which could enhance patient management.
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Affiliation(s)
- Arunodaya R Gujjar
- Department of Medicine (Neurology), College of Medicine and Health Sciences, Sultan Qaboos University, PO Box 35, PC 123 Muscat, Oman.
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22
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Choi Y, Saqqur M, Asil T, Jin A, Stewart E, Stephenson C, Ibrahim M, Roy J, Boulanger JM, Coutts S, Khan F, Demchuk AM. A combined power m-mode and single gate transcranial doppler ultrasound microemboli signal criteria for improving emboli detection and reliability. J Neuroimaging 2011; 20:359-67. [PMID: 19912481 DOI: 10.1111/j.1552-6569.2009.00446.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Single gate transcranial Doppler spectrogram (sgTCD) has a high variability in the detection of microembolic signals (MES), Adding Power M-mode Doppler (PMD) information may improve MES detection. Our study's aim is to derive combined PMD/sgTCD microemboli criteria to overcome this limitation. METHODS Patients with symptomatic carotid disease were prospectively enrolled within 24 h of symptom onset underwent 1 hour TCD emboli monitoring. We reviewed disparity between PMD MES criteria and sgTCD MES criteria. We compared combined PMD/sgTCD criteria to sgTCD alone criteria by measuring the intraclass correlation coefficient (ICC). RESULTS Of 92 patients, 28 patients had evidence of MES on sgTCD or PMD. Total MES count was 269 based on sgTCD criteria, and 326 based on combined PMD/sgTCD criteria (P= 0.005). Combined PMD/sgTCD criteria revealed 17 MESs (4.8%) based on sgTCD criteria to represent artifacts and 57 MESs (17.5%) not to be detected by sgTCD criteria. Overall ICC based on sgTCD criteria was 0.67 [95% confidence interval (CI): 0.58-0.74]; however, introducing combined PMD/sgTCD criteria resulted in a significant increase in the ICC, 0.91 (95% CI: 0.88-0.93). CONCLUSION Our combined PMD/sgTCD criteria for MES appeared to improve the yield of MES detection. Reliability in MES detection interpretation was improved when combined PMD/sgTCD criteria was applied.
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Affiliation(s)
- Youngbin Choi
- Department of Neurology, Catholic University of Korea, Seoul, South Korea
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23
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Alvarez-Fernández JA, Pérez-Quintero R. [Some uncommon applications of transcranial Doppler in the intensive care unit]. Med Intensiva 2009; 33:97-9. [PMID: 19401112 DOI: 10.1016/s0210-5691(09)70689-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
We present the case of a 64-year old woman with shock related to ischemic colitis associated with paradoxical embolism through a foramen ovale. Some utilities of transcranial Doppler ultra-sonography applied in this case that could have an usual interest in intensive and intermediate care are discussed. These include analysis of the regional distribution of cerebral blood flow, intracranial arterial continuous monitoring for detection of spontaneous microembolisms and injection of microbubbles to detect right to left shunts. The added value of using power M-mode Doppler in transcranial Doppler evaluations is highlighted.
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Affiliation(s)
- J A Alvarez-Fernández
- Unidad de Neurosonología y Hemodinámica Cerebral, Hospital Hospiten-Rambla, Santa Cruz de Tenerife, Islas Canarias, España.
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24
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Barreto AD, Sharma VK, Lao AY, Schellinger PD, Amarenco P, Sierzenski P, Alexandrov AV, Molina CA. Safety and dose-escalation study design of Transcranial Ultrasound in Clinical SONolysis for acute ischemic stroke: the TUCSON Trial. Int J Stroke 2009; 4:42-8. [PMID: 19236498 DOI: 10.1111/j.1747-4949.2009.00252.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rationale Transcranial Doppler (TCD) monitoring during intravenous tissue plasminogen activator (i.v.-tPA) infusion increases recanalization rates in acute ischemic stroke. Addition of perflutren-lipid microspheres MRX-801 (microS) may further enhance the process of recanalization. This article describes the design of the Transcranial Ultrasound in Clinical SONolysis (TUCSON) trial. Aims and Design TUCSON is a phase I-II, randomized, placebo-controlled, open-label, safety, dose-escalation clinical trial of microS+TCD ultrasound (sonolysis). Patients with acute ischemic stroke and arterial intracranial occlusions are enrolled within 3 h of symptom onset. All patients receive standard i.v.-tPA and will be randomized to 90 min of continuous 2-MHz TCD+microS or 90 min of saline+brief TCD vessel assessments. The safety profile of four escalating dose tiers will be assessed. Arterial occlusions and recanalization are defined with the Thrombolysis in Brain Ischemia flow grades. Study Outcomes Safety is determined by the rates of symptomatic intracerebral hemorrhage within 36 h. Neurological deficits and outcomes are measured with the National Institute of Health Stroke Scale and modified Rankin Scale (mRS). The signal-of-efficacy is determined by rates of recanalization, dramatic or early clinical recovery within 2 h, clinical recovery at 24-36 h and independent outcome (mRS 0-2) at 90 days.
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Affiliation(s)
- Andrew D Barreto
- Department of Neurology, University of Texas-Houston Stroke Team, Houston, TX, USA
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25
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Brunser AM, Lavados PM, Hoppe A, Lopez J, Valenzuela M, Rivas R. Accuracy of transcranial Doppler compared with CT angiography in diagnosing arterial obstructions in acute ischemic strokes. Stroke 2009; 40:2037-41. [PMID: 19359640 DOI: 10.1161/strokeaha.108.542704] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Patients with acute ischemic stroke and intracranial arterial obstructions have a poor prognosis and a high probability of deteriorating at 24 hours. We aimed to evaluate the diagnostic accuracy of power motion mode Doppler (PMD-TCD) compared with CT angiography as standard in diagnosing intracranial arterial obstructions in patients presenting with ischemic stroke of <24 hours. METHODS Consecutive patients presenting with acute ischemic stroke to the emergency department underwent high-resolution brain CT angiography and PMD-TCD within a 6-hour difference. RESULTS A total of 100 patients were included. PMD-TCD demonstrated 34 intracranial occlusions and CTA 33. There were 6 false-positives and 4 false-negative diagnoses with PMD-TCD. PMD-TCD had a positive likelihood ratio of 13.7, a negative likelihood ratio of 0.19, sensitivity of 81.8%, and specificity of 94% for detecting an arterial occlusion in any specific artery. Results for the middle cerebral artery were: positive likelihood ratio 24.6, negative likelihood ratio 0.045, sensitivity 95.6%, and specificity 96.2%. For the anterior circulation, the results were: positive likelihood ratio 18.5, negative likelihood ratio 0, sensitivity 100%, and specificity 94.5%. For the posterior circulation, the results were: positive likelihood ratio >1000, negative likelihood ratio 0.42, sensitivity 57.1%, and specificity 100%. The post-test probability for any occluded artery when PMD-TCD was positive increased for any admission National Institutes of Health Stroke Scale score but was especially remarkable for National Institutes of Health Stroke Scale scores between 7 and 15 points. CONCLUSIONS PMD-TCD is valid compared with CT angiography for the diagnosis of arterial occlusions in patients with acute ischemic stroke, especially in middle cerebral artery obstructions.
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Affiliation(s)
- Alejandro M Brunser
- Department of Medicine, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana-Universidad del Desarrollo Santiago Chile, Av Manquehue Norte 1410, Vitacura 7630000, Santiago, Chile.
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26
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Hong JM, Joo IS, Huh K, Sheen SS. Simultaneous vasomotor reactivity testing in the middle cerebral and basilar artery with suboccipital probe fixation device. J Neuroimaging 2009; 20:83-6. [PMID: 19226344 DOI: 10.1111/j.1552-6569.2008.00353.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND We assess the feasibility of using the newly designed suboccipital probe fixation device (SPFD) as a convenient and reliable tool for simultaneous measurement of vasomotor reactivity (VMR) in the middle cerebral artery (MCA) and basilar artery (BA). METHODS We analyzed 30 healthy volunteers' VMR values by using both SPFD and conventional handheld method. The VMR values were measured as percentage increase of the mean flow velocity on transcranial Doppler (TCD) in response to hypercapnia induced by the rebreathing method. The VMR tests were performed three times: (1) for both MCAs, (2) for the index MCA (the better signal window) and the BA by using the SPFD, and (3) for the index MCA and the BA by using the handheld technique. RESULTS The VMR values of the right and left MCAs were similar (P > .05). Although the VMR values of the index MCA and the BA obtained by SPFD application and the handheld technique were similar (P > .05), the correlation coefficient of VMR values obtained by using the SPFD was higher (r= .827, P < .001 vs. r= .568, P= .001). CONCLUSION The SPFD is a convenient and reliable tool for the evaluation of relative VMR between the MCA and BA during TCD monitoring.
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Affiliation(s)
- Ji Man Hong
- Department of Neurology, Ajou University School of Medicine, Suwon-sī, kyunggi-do, South Korea.
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27
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Abstract
Transcranial Doppler ultrasonography (TCD) is the only noninvasive real-time neuroimaging modality for the evaluation of characteristics of blood flow in basal intracerebral vessels that adds physiologic information to structural imaging. TCD has been rapidly evolving from a simple noninvasive diagnostic tool to an imaging modality with a broad spectrum of clinical applications. In acute stroke, TCD can provide rapid information about vascular stenosis and occlusion, the hemodynamic status of the cerebral circulation, and real-time monitoring of recanalization. Extended applications such as vasomotor reactivity testing, emboli monitoring, and right-to-left shunt detection help clinicians ascertain stroke mechanisms at the bedside, plan and monitor treatment, and determine prognosis. In the neurointensive care unit, TCD is useful for detecting increased intracranial pressure and confirming cerebral circulatory arrest. TCD is of established value for screening children with sickle cell disease and detecting and monitoring vasospasm after spontaneous subarachnoid hemorrhage.
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28
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Tsivgoulis G, Man BL, Lao AY, Sharma VK, Kotsis V, Vadikolias K, Alexandrov AV. A Spectrum of Knock-Type Doppler Signals in the Intracranial Vessels. Stroke 2009; 40:644-7. [DOI: 10.1161/strokeaha.108.517797] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Knock-type Doppler signals (KTDS) are detectable by transcranial Doppler, and it has been hypothesized that they are related to an occlusion of a small perforating artery and microvascular ischemia. However, the nature of KTDS has not been prospectively defined. We aimed at describing the spectral and power motion Doppler characteristics of KTDS and ultrasound exposure conditions that lead to their appearance.
Methods—
Consecutive patients referred with symptoms of stroke or transient ischemic attacks to our cerebrovascular ultrasound laboratory were screened for the presence of KTDS. The presence of microvascular ischemia was assessed using brain MRI.
Results—
Among 327 patients with cerebrovascular symptoms, 46 (14%) had KTDS. KTDS were found more frequently in posterior circulation vessels (55% vertebral artery, 21.5% basilar artery, and 6% posterior cerebral artery). There was no association between ultrasound identification of KTDS and the presence of brain ischemia in the distribution of any vessel (OR, 0.37; 95% CI, 0.09–1.53;
P
=0.171) on univariate logistic regression analyses. KTDS was not related to the presence of microvascular ischemia on brain MRI (OR, 1.12; 95% CI, 0.55–2.29;
P
=0.761). We described the range of spectral and power motion Doppler appearances of KTDS and experimentally demonstrated the most likely underlying mechanism being a large vessel wall movement artifact.
Conclusions—
Although KTDS can be distinguished from other spectral flow signals, they can be found in normal vessels, they do not seem to be associated with the vessel affected by ischemia, and they should not be overinterpreted.
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Affiliation(s)
- Georgios Tsivgoulis
- From Comprehensive Stroke Center (G.T., A.V.A.), Department of Neurology, University of Alabama at Birmingham, Birmingham, Ala; Barrow Neurological Institute (G.T., B.L.M., A.Y.L., V.K.S., A.V.A.), St. Joseph’s Hospital and Medical Center, Phoenix, Ariz; Division of Neurology (B.L.M.), Department of Medicine and Therapeutics, the Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China; Division of Neurology (V.K.S.), National University Hospital, Singapore; 3rd Department of
| | - Bing L. Man
- From Comprehensive Stroke Center (G.T., A.V.A.), Department of Neurology, University of Alabama at Birmingham, Birmingham, Ala; Barrow Neurological Institute (G.T., B.L.M., A.Y.L., V.K.S., A.V.A.), St. Joseph’s Hospital and Medical Center, Phoenix, Ariz; Division of Neurology (B.L.M.), Department of Medicine and Therapeutics, the Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China; Division of Neurology (V.K.S.), National University Hospital, Singapore; 3rd Department of
| | - Annabelle Y. Lao
- From Comprehensive Stroke Center (G.T., A.V.A.), Department of Neurology, University of Alabama at Birmingham, Birmingham, Ala; Barrow Neurological Institute (G.T., B.L.M., A.Y.L., V.K.S., A.V.A.), St. Joseph’s Hospital and Medical Center, Phoenix, Ariz; Division of Neurology (B.L.M.), Department of Medicine and Therapeutics, the Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China; Division of Neurology (V.K.S.), National University Hospital, Singapore; 3rd Department of
| | - Vijay K. Sharma
- From Comprehensive Stroke Center (G.T., A.V.A.), Department of Neurology, University of Alabama at Birmingham, Birmingham, Ala; Barrow Neurological Institute (G.T., B.L.M., A.Y.L., V.K.S., A.V.A.), St. Joseph’s Hospital and Medical Center, Phoenix, Ariz; Division of Neurology (B.L.M.), Department of Medicine and Therapeutics, the Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China; Division of Neurology (V.K.S.), National University Hospital, Singapore; 3rd Department of
| | - Vassilios Kotsis
- From Comprehensive Stroke Center (G.T., A.V.A.), Department of Neurology, University of Alabama at Birmingham, Birmingham, Ala; Barrow Neurological Institute (G.T., B.L.M., A.Y.L., V.K.S., A.V.A.), St. Joseph’s Hospital and Medical Center, Phoenix, Ariz; Division of Neurology (B.L.M.), Department of Medicine and Therapeutics, the Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China; Division of Neurology (V.K.S.), National University Hospital, Singapore; 3rd Department of
| | - Konstantinos Vadikolias
- From Comprehensive Stroke Center (G.T., A.V.A.), Department of Neurology, University of Alabama at Birmingham, Birmingham, Ala; Barrow Neurological Institute (G.T., B.L.M., A.Y.L., V.K.S., A.V.A.), St. Joseph’s Hospital and Medical Center, Phoenix, Ariz; Division of Neurology (B.L.M.), Department of Medicine and Therapeutics, the Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China; Division of Neurology (V.K.S.), National University Hospital, Singapore; 3rd Department of
| | - Andrei V. Alexandrov
- From Comprehensive Stroke Center (G.T., A.V.A.), Department of Neurology, University of Alabama at Birmingham, Birmingham, Ala; Barrow Neurological Institute (G.T., B.L.M., A.Y.L., V.K.S., A.V.A.), St. Joseph’s Hospital and Medical Center, Phoenix, Ariz; Division of Neurology (B.L.M.), Department of Medicine and Therapeutics, the Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China; Division of Neurology (V.K.S.), National University Hospital, Singapore; 3rd Department of
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Ozdemir AO, Tamayo A, Munoz C, Dias B, Spence JD. Cryptogenic stroke and patent foramen ovale: clinical clues to paradoxical embolism. J Neurol Sci 2008; 275:121-7. [PMID: 18822432 DOI: 10.1016/j.jns.2008.08.018] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Revised: 08/10/2008] [Accepted: 08/12/2008] [Indexed: 01/19/2023]
Abstract
BACKGROUND Patent foramen ovale (PFO) is an independent risk factor for cerebral infarction. Since ~25% of the population have a PFO, the simple association of PFO with stroke is not enough to establish the diagnosis of paradoxical embolism. We evaluated possible clinical clues to the diagnosis of paradoxical embolism. METHODS Among patients with cryptogenic ischemic stroke (CS) who were investigated for a right-to-left shunt (RLS), we compared clinical, coagulation and biochemical parameters in patients with PFO versus without PFO. RESULTS Among 1689 new patients referred for TIA/non-disabling stroke between 2001 and 2007, 175 with cryptogenic stroke (CS) were investigated for RLS by transcranial Doppler (TCD) bubble studies; 89 (5.5%) with positive TCD had a PFO confirmed by TEE. In multivariate logistic regression, a history of DVT or pulmonary embolism (OR, 4.39; 95% CI, 1.23-15.69; p=0.023), prolonged travel (OR, 8.77; 95% CI, 1.775-43.3; p=0.008) , migraine (OR, 2.30: 95% CI, 1.07-4.92; p=0.031), a Valsalva maneuver preceding the onset of focal neurological symptoms (OR, 3.33; 95% CI, 1.15-9.64; p=0.026) and waking up with stroke/TIA (OR, 4.53, 95% CI, 1.26-16.2; p=0.018) were independently associated with PFO-associated cerebrovascular events. Patients with PFO had higher plasma total homocysteine levels than patients without PFO (8.9+/-3 versus 7.9+/-2.6 micromol/L respectively; p=0.021). CONCLUSIONS A history of DVT or pulmonary embolism, migraine, recent prolonged travel, sleep apnea, waking up with TIA or stroke or a Valsalva maneuver preceding the event are clinical clues to the diagnosis of paradoxical embolism among patients with CS.
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Affiliation(s)
- A Ozcan Ozdemir
- Eskisehir Osmangazi University, Department of Neurology, Eskisehir, Turkey.
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Jesurum JT, Fuller CJ, Moehring MA, Renz J, Harley M, Spencer MP. Unilateral versus bilateral middle cerebral artery detection of right-to-left shunt by power M-mode transcranial doppler. J Neuroimaging 2008; 19:235-41. [PMID: 18826441 DOI: 10.1111/j.1552-6569.2008.00280.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Comparison was performed between unilateral and bilateral power M-mode transcranial Doppler to detect right-to-left circulatory shunt (RLS). METHODS Recorded Doppler data from 87 patients with confirmed RLS referred for transcatheter closure of patent foramen ovale were reanalyzed for embolic tracks (ET) counted from left and right temporal bone windows during bubble study. Unilateral counts were obtained by multiplying each side by 2; bilateral counts were obtained by summing left and right ET. Both unilateral and bilateral ET were converted to a 6-point logarithmic grade. Sex and age group subanalyses were performed. RESULTS At rest, significantly more ET were detected with bilateral versus unilateral detection (P= .01), but not following Valsalva (P= .13). Unilateral and bilateral detection were equally able to detect large RLS (grades IV or V) following Valsalva (P= 1.00). For the group aged > or =55 years, the right-hand side yielded greater ET than the left-hand side (mean difference 9%+/- 37; 95% confidence interval -3 to 21%) at rest (P= .01), but not following Valsalva (mean difference 1%+/- 25; 95% confidence interval -7 to 9%, P= .10). CONCLUSIONS Unilateral detection of ET by power M-mode transcranial Doppler is equivalent to bilateral detection to assess RLS.
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Affiliation(s)
- Jill T Jesurum
- Department of Cardiovascular Scientific Development, Swedish Medical Center, Seattle, Washington 98122, usa.
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Tsivgoulis G, Sharma VK, Hoover SL, Lao AY, Ardelt AA, Malkoff MD, Alexandrov AV. Applications and Advantages of Power Motion-Mode Doppler in Acute Posterior Circulation Cerebral Ischemia. Stroke 2008; 39:1197-204. [PMID: 18323502 DOI: 10.1161/strokeaha.107.499392] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Evaluation of posterior circulation with single-gate transcranial Doppler (TCD) is technically challenging and yields lower accuracy parameters in comparison to anterior circulation vessels. Transcranial power motion-mode Doppler (PMD-TCD), in addition to spectral information, simultaneously displays in real-time flow signal intensity and direction over 6 cm of intracranial space. We aimed to evaluate the diagnostic accuracy of PMD-TCD against angiography in detection of acute posterior circulation stenoocclusive disease.
Methods—
Consecutive patients presenting to the emergency room with symptoms of acute (<24 hours) cerebral ischemia underwent emergent neurovascular evaluation with PMD-TCD and angiography (computed tomographic angiography, magnetic resonance angiography, or digital subtraction angiography). Previously published diagnostic criteria were prospectively applied for PMD-TCD interpretation independent of angiographic findings.
Results—
A total of 213 patients (119 men; mean age 65±16 years; ischemic stroke 71%, transient ischemic attack 29%) underwent emergent neurovascular assessment. Compared with angiography, PMD-TCD showed 17 true-positive, 8 false-negative, 6 false-positive, and 182 true-negative studies in posterior circulation vessels (sensitivity 73% [55% to 91%], specificity 96% [93% to 99%], positive predictive value 68% [50% to 86%], negative predictive value 95% [92% to 98%], accuracy 93% [90% to 96%]). In 14 patients (82% of true-positive cases), PMD display showed diagnostic flow signatures complementary to the information provided by the spectral display: reverberating or alternating flow, distal basilar artery flow reversal, high-resistance flow, emboli tracks and, bruit flow signatures.
Conclusions—
PMD-TCD yields a satisfactory agreement with urgent brain angiography in the evaluation of patients with acute posterior circulation cerebral ischemia. PMD display can depict flow signatures that are complimentary to and can increase confidence in standard single-gate TCD spectral findings.
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Affiliation(s)
- Georgios Tsivgoulis
- From the Comprehensive Stroke Center (G.T., A.A.A., A.V.A.), University of Alabama at Birmingham Hospital, Birmingham, Ala; the Neurosonology and Stroke Research Program (G.T., V.K.S., S.L.H., A.Y.L., M.D.M., A.V.A.), Barrow Neurological Institute, Phoenix, Az; the Department of Neurology (G.T.), University of Athens School of Medicine, Athens, Greece; the Division of Neurology, Department of Medicine (V.K.S.), National University Hospital, Singapore; and the University of Santo Tomas (A.Y.L.),
| | - Vijay K. Sharma
- From the Comprehensive Stroke Center (G.T., A.A.A., A.V.A.), University of Alabama at Birmingham Hospital, Birmingham, Ala; the Neurosonology and Stroke Research Program (G.T., V.K.S., S.L.H., A.Y.L., M.D.M., A.V.A.), Barrow Neurological Institute, Phoenix, Az; the Department of Neurology (G.T.), University of Athens School of Medicine, Athens, Greece; the Division of Neurology, Department of Medicine (V.K.S.), National University Hospital, Singapore; and the University of Santo Tomas (A.Y.L.),
| | - Steven L. Hoover
- From the Comprehensive Stroke Center (G.T., A.A.A., A.V.A.), University of Alabama at Birmingham Hospital, Birmingham, Ala; the Neurosonology and Stroke Research Program (G.T., V.K.S., S.L.H., A.Y.L., M.D.M., A.V.A.), Barrow Neurological Institute, Phoenix, Az; the Department of Neurology (G.T.), University of Athens School of Medicine, Athens, Greece; the Division of Neurology, Department of Medicine (V.K.S.), National University Hospital, Singapore; and the University of Santo Tomas (A.Y.L.),
| | - Annabelle Y. Lao
- From the Comprehensive Stroke Center (G.T., A.A.A., A.V.A.), University of Alabama at Birmingham Hospital, Birmingham, Ala; the Neurosonology and Stroke Research Program (G.T., V.K.S., S.L.H., A.Y.L., M.D.M., A.V.A.), Barrow Neurological Institute, Phoenix, Az; the Department of Neurology (G.T.), University of Athens School of Medicine, Athens, Greece; the Division of Neurology, Department of Medicine (V.K.S.), National University Hospital, Singapore; and the University of Santo Tomas (A.Y.L.),
| | - Agnieszka A. Ardelt
- From the Comprehensive Stroke Center (G.T., A.A.A., A.V.A.), University of Alabama at Birmingham Hospital, Birmingham, Ala; the Neurosonology and Stroke Research Program (G.T., V.K.S., S.L.H., A.Y.L., M.D.M., A.V.A.), Barrow Neurological Institute, Phoenix, Az; the Department of Neurology (G.T.), University of Athens School of Medicine, Athens, Greece; the Division of Neurology, Department of Medicine (V.K.S.), National University Hospital, Singapore; and the University of Santo Tomas (A.Y.L.),
| | - Marc D. Malkoff
- From the Comprehensive Stroke Center (G.T., A.A.A., A.V.A.), University of Alabama at Birmingham Hospital, Birmingham, Ala; the Neurosonology and Stroke Research Program (G.T., V.K.S., S.L.H., A.Y.L., M.D.M., A.V.A.), Barrow Neurological Institute, Phoenix, Az; the Department of Neurology (G.T.), University of Athens School of Medicine, Athens, Greece; the Division of Neurology, Department of Medicine (V.K.S.), National University Hospital, Singapore; and the University of Santo Tomas (A.Y.L.),
| | - Andrei V. Alexandrov
- From the Comprehensive Stroke Center (G.T., A.A.A., A.V.A.), University of Alabama at Birmingham Hospital, Birmingham, Ala; the Neurosonology and Stroke Research Program (G.T., V.K.S., S.L.H., A.Y.L., M.D.M., A.V.A.), Barrow Neurological Institute, Phoenix, Az; the Department of Neurology (G.T.), University of Athens School of Medicine, Athens, Greece; the Division of Neurology, Department of Medicine (V.K.S.), National University Hospital, Singapore; and the University of Santo Tomas (A.Y.L.),
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Pagola J, Ribo M, Alvarez-Sabín J, Lange M, Rubiera M, Molina CA. Timing of recanalization after microbubble-enhanced intravenous thrombolysis in basilar artery occlusion. Stroke 2007; 38:2931-4. [PMID: 17901389 DOI: 10.1161/strokeaha.107.487454] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Information about early recanalization of basilar artery occlusion after systemic tissue plasminogen activator remains unknown. We aimed to determine the timing of recanalization in basilar artery occlusion treated with systemic thrombolysis, microbubbles, and continuous transcranial Doppler monitoring. METHODS We studied 20 patients with <12 hours basilar artery occlusion treated with intravenous tissue plasminogen activator, 2 hours continuous ultrasound, and 3 boluses of microbubbles. Transcranial Doppler assessed recanalization at different time points. Outcome was assessed using the National Institutes of Health Stroke Scale and modified Rankin scale. Patients were considered to be independent if modified Rankin scale score was <3 at 90 days. RESULTS Median admission National Institutes of Health Stroke Scale was 18.5 (interquartile range 16 to 26.5) and median time to treatment was 180 minutes (range, 80 to 720 minutes). Rate of complete recanalization raised progressively: at 1 hour 10%, at 2 hours 20%, at 6 hours 35%, and at 24 hours 50%. In 10 patients (50%), no recanalization was observed at 24 hours. Median discharge National Institutes of Health Stroke Scale was 14 (interquartile range 1 to 30). Degree of National Institutes of Health Stroke Scale improvement was related to time of recanalization: median discharge National Institutes of Health Stroke Scale--1 for recanalization between 0 and 6 hours, 11 for recanalization between 6 and 24 hours, and 30 if no recanalization occurred (P=0.002). At 3 months, mortality was 35%. Only one patient (10%) who recanalized within 24 hours died as compared with 60% of nonrecanalizers (P=0.029). Rate of independent patients progressively decreased as time to recanalization increased (P=0.006). CONCLUSIONS In acute basilar artery occlusion, endovenous tissue plasminogen activator, microbubbles, and continuous ultrasound leads to early recanalization in a significant number of patients and this is associated with favorable outcome. Immediate intravenous tissue plasminogen activator treatment should be the first therapeutic option in these patients.
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Affiliation(s)
- Jorge Pagola
- Unitat Neurovascular Vall d'Hebron, Hospital Universitari Vall d'Hebron, Departament de Medicina, Universitat Autónoma de Barcelona, Barcelona, Spain
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Popa VN, Spencer MP, Lion CL, Felberg RA. Power M-Mode Doppler and Single-Gate Spectral Analysis Using a 2-MHz Pulsed-Wave Doppler Transducer to Directly Detect Cervical Internal Carotid Artery Stenosis. Stroke 2007; 38:1780-5. [PMID: 17463309 DOI: 10.1161/strokeaha.106.480491] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE We hypothesized that direct cervical investigation with Power M-Mode Doppler (PMD) combined with single-gate Doppler spectral analysis (SGDSA) using a 2-MHz pulsed-wave Doppler transducer would show reasonable accuracy parameters when compared with standard color-coded carotid duplex ultrasound (CDU). METHODS We prospectively screened for cervical internal carotid artery (ICA) stenosis by direct observation using a 2 MHz PMD/SGDSA device. PMD identified the artery (location, depth, flow direction) and SGDSA assessed waveform; peak systolic, end diastolic, and mean flow velocities (MFV) of the common carotid artery; cervical ICA proximally and distally; and external carotid artery. Diagnostic accuracy was compared with concurrent carotid duplex ultrasound. The continuity principle was applied using the proximal/distal cervical ICA MFV ratio. RESULTS We examined 456 vessels (228 patients). Using ICA proximally/ICA distally MFV ratio of 1.5 or greater or absence of ICA signature, for 40% to 59% or greater stenosis (including occlusions), sensitivity was 75.4%, specificity 99.8%, positive predictive value 97.7%, negative predictive value 96.6%, and accuracy 96.7%. For MFV ratio 1.6 or greater or absence of ICA signature and 60% to 79% or greater stenosis (including occlusions), sensitivity was 92.3%, specificity 98.1%, positive predictive value 81.8%, negative predictive value 99.3%, and accuracy 97.6%. CONCLUSIONS Use of combined PMD and SGDSA to directly observe the extracranial ICA is reasonably accurate compared with carotid duplex ultrasound. Using the MFV ratio of proximal/distal extracranial ICA improves accuracy parameters and provides a quick and effective bedside screen for ICA stenosis. This novel technique should be considered part of the standard PMD/transcranial Doppler examination.
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Affiliation(s)
- Vasile N Popa
- Ochsner Stroke Team, Department of Neurology, Ochsner Clinic Foundation, New Orleans, LA 70121, USA.
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Alexandrov AV, Sloan MA, Wong LKS, Douville C, Razumovsky AY, Koroshetz WJ, Kaps M, Tegeler CH. Practice Standards for Transcranial Doppler Ultrasound: Part I-Test Performance. J Neuroimaging 2007; 17:11-8. [PMID: 17238867 DOI: 10.1111/j.1552-6569.2006.00088.x] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Indications for the clinical use of transcranial Doppler (TCD) continue to expand while scanning protocols and quality of reporting vary between institutions. Based on literature analysis and extensive personal experience, an international expert panel started the development of guidelines for TCD performance, interpretation, and competence. The first part describes complete diagnostic spectral TCD examination for patients with cerebrovascular diseases. Cranial temporal bone windows are used for the detection of the middle cerebral arteries (MCA), anterior cerebral arteries (ACA), posterior cerebral arteries (PCA), C1 segment of the internal carotid arteries (ICA), and collateralization of flow via the anterior (AComA) and posterior (PComA) communicating arteries; orbital windows-for the ophthalmic artery (OA) and ICA siphon; the foraminal window-for the terminal vertebral (VA) and basilar (BA) arteries. Although there is a significant individual variability of the circle of Willis with and without disease, the complete diagnostic TCD examination should include bilateral assessment of the M2 (arbitrarily located at 30-40 mm depth), M1 (40-65 mm) MCA [with M1 MCA mid-point at 50 mm (range 45-55 mm), average length 16 mm (range 5-24 mm), A1 ACA (60-75 mm), C1 ICA (60-70 mm), P1-P2 PCA (average depth 63 mm (range 55-75 mm), AComA (70-80 mm), PComA (58-65 mm), OA (40-50 mm), ICA siphons (55-65 mm), terminal VA (40-75 mm), proximal (75-80), mid (80-90 mm), and distal (90-110 mm) BA]. The distal ICA on the neck (40-60 mm) can be located via submandibular windows to calculate the VMCA/VICA index, or the Lindegaard ratio for vasospasm grading after subarachnoid hemorrhage. Performance goals of diagnostic TCD are to detect and optimize arterial segment-specific spectral waveforms, determine flow direction, measure cerebral blood flow velocities and flow pulsatility in the above-mentioned arteries. These practice standards will assist laboratory accreditation processes by providing a standard scanning protocol with transducer positioning and orientation, depth selection and vessel identification for ultrasound devices equipped with spectral Doppler and power motion Doppler.
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35
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Ribo M, Molina CA, Alvarez B, Rubiera M, Alvarez-Sabin J, Matas M. Transcranial Doppler Monitoring of Transcervical Carotid Stenting With Flow Reversal Protection. Stroke 2006; 37:2846-9. [PMID: 17008626 DOI: 10.1161/01.str.0000244781.68371.59] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Transfemoral carotid stenting, despite becoming very frequent, has some limitations such as difficult groin access in few patients, lack of distal protection during filter placement, or embolization despite protection. Transcervical stenting (TCS) is a novel technique during which a common carotid to jugular vein shunt is placed creating a protective reversal flow in the internal carotid artery after proximal common carotid artery (CCA) clamping. We aim to study, with transcranial Doppler (TCD), cerebral flow changes and microemboli detection during transcervical stenting.
Methods—
From September 2005 to March 2006, of 65 consecutive patients eligible for carotid revascularization, 23 were considered high risk (sapphire criteria) and underwent TCS. Neurologic examination was performed before and after the procedure by a neurologist and a preprocedure vascular reactivity TCD examination was done in all patients.
Results—
After CCA clamping, flow inversion was observed in the anterior cerebral artery, supplying blood to the middle cerebral artery (MCA) and internal carotid artery (reversal). TCD did not detect any air/solid emboli during stent deployment and angioplasty confirming the reversal flow protection hypothesis. Mean reversal flow time was 15.4 minutes; in all cases, substantial MCA flow was present during CCA clamping (initial mean velocity 30 cm/s), and a slow gradual increase was observed traducing collateral flow recruitment (mean velocity after 5 minutes 36 cm/s,
P
<0.001). Flow increase was observed in all patients except in those with preprocedural exhausted ipsilateral vascular reactivity (16% versus 2%,
P
=0.036). The only in-procedure complication was one transient ischemic attack. After CCA unclamping, normal antegrade flow was restored in anterior cerebral artery and mean final MCA velocity increased 16% according to preprocedure flow.
Conclusions—
TCS with protective internal carotid artery flow reversal can eliminate showers of micoremboli during stent deployment making it a promising carotid revascularization technique in high-risk patients with carotid stenosis.
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Affiliation(s)
- Marc Ribo
- Unitat Neurovascular, Servei de Neurología, Hospital Vall d'Hebron, Universitat Autonoma de Barcelona, Spain.
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36
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Saqqur M, Hill MD, Alexandrov AV, Roy J, Schebel M, Krol A, Garami Z, Shuaib A, Demchuk AM. Derivation of Power M-Mode Transcranial Doppler Criteria for Angiographic Proven MCA Occlusion. J Neuroimaging 2006; 16:323-8. [PMID: 17032381 DOI: 10.1111/j.1552-6569.2006.00055.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Stringent transcranial Doppler (TCD) criteria for diagnosing occlusion are needed for more reliable TCD performance at bedside in the acute stroke setting. SUBJECTS AND METHODS At three academic stroke centers, we performed TCD examination for patients with symptoms of cerebral ischemia who underwent digital subtraction angiography (DSA). We used a standard insonation protocol with power M-mode Doppler (PMD) TCD (TCD 100 M, Spencer Technologies Inc., Seattle, WA). We collected mean flow velocity (MFV), pulsatility indices (PI), and power M-mode resistance signature (absent, high, or low) in symptomatic middle (MCA), anterior (ACA), posterior (PCA), and in affected (a), ipsilateral (i), and contralateral (c-lat) cerebral arteries. Ratios of aMCA/c-lat MCA, aMCA/iACA, and aMCA/iPCA MFV were subsequently calculated. PMD-TCD flow findings were evaluated with a receiver-operating characteristic (ROC) analysis for angiographically proven MCA occlusion. RESULTS We studied 120 patients with acute cerebral ischemia with PMD-TCD examinations prior to or immediately after DSA. Lower aMCA velocities pointed to higher probability of occlusion (P= .055). The aMCA/iPCA MFV ratio was superior to the aMCA/iACA ratio and strongly predictive of occlusion at a threshold ratio of 0.5 (RR 2.31 CI(95) 2.13-2.51). High resistance or absent M-mode flow signatures in the proximal MCA were present in 87% of M1 and M2 MCA occlusions (probability 87%). In the presence of a low-resistance PMD signature, obtaining the aMCA/iPCA MFV ratio <0.5 increases probability of occlusion to 87%. Normal MFV ratios and low-resistance M-mode signatures are highly predictive of a negative angiogram for MCA occlusion. CONCLUSION In acute cerebral ischemia, reliable criteria for proximal MCA occlusion have been developed based on combination of MFV ratios and M-mode flow resistance signatures. Validation of these criteria will require multicenter studies.
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Affiliation(s)
- Maher Saqqur
- Department of Medicine, University of Alberta, Alberta, Canada
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Azarpazhooh MR, Chambers BR. Clinical application of transcranial Doppler monitoring for embolic signals. J Clin Neurosci 2006; 13:799-810. [PMID: 16908159 DOI: 10.1016/j.jocn.2005.12.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Accepted: 12/20/2005] [Indexed: 12/12/2022]
Abstract
A major advantage of transcranial ultrasound is its suitability for continuous monitoring. Microembolic signals (MES) are brief, high-intensity transients that occur when particulate microemboli or gaseous microbubbles pass through the ultrasound beam. These MES have been detected in several clinical scenarios, but rarely in age-matched controls. The detection of MES provides important pathophysiological information in a variety of disorders, but their clinical importance and possible therapeutic implications are still under debate. The present article summarizes the significance of MES in different clinical settings and outlines some of the problems to be resolved so that transcranial ultrasound can be applied in clinical practice.
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Affiliation(s)
- M R Azarpazhooh
- National Stroke Research Institute, University of Melbourne, Austin Health, Heidelberg Heights, Victoria, Australia
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38
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Delgado-Mederos R, Ribó M, Montaner J, Arenillas JF, Rubiera M, Alvarez-Sabín J, Molina CA. Real-time monitoring of recanalization after intravenous thrombolysis for acute ischemic stroke. Eur J Neurol 2006; 13:426-7. [PMID: 16643326 DOI: 10.1111/j.1468-1331.2006.01172.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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39
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Ribo M, Alvarez-Sabín J, Montaner J, Romero F, Delgado P, Rubiera M, Delgado-Mederos R, Molina CA. Temporal profile of recanalization after intravenous tissue plasminogen activator: selecting patients for rescue reperfusion techniques. Stroke 2006; 37:1000-4. [PMID: 16514102 DOI: 10.1161/01.str.0000206443.96112.d9] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Intravenous thrombolysis in stroke achieves arterial recanalization in approximately 50% of cases. Determining temporal profile of recanalization may address patient selection and potential benefits of further rescue reperfusion techniques. METHODS We studied 179 consecutive intravenous tissue plasminogen activator (t-PA)-treated patients with intracranial artery occlusion. Continuous transcranial Doppler assessed recanalization (none-partial-complete) at 60 minutes (early), 120 minutes (delayed) after t-PA bolus, and 6 hours (late) from symptom onset. Outcomes were determined: National Institutes of Health Stroke Scale (NIHSS; 48-hour NIHSS) and 3-month modified Rankin Scale (mRS). RESULTS On admission, 68% of patients presented proximal middle cerebral artery occlusion, median NIHSS 17. Early recanalization was complete for 30 patients (17%), partial for 50 (28%), and none for 99 (55%). Delayed recanalization was complete for 56 patients (31%), partial for 39 (22%), and none for 84 (47%). Although early flow improvement was observed in up to 45% of patients, only 19% of patients with persistent occlusion (11% of total) presented delayed recanalization (odds ratio [OR] delayed/early recanalization, 0.16; 95% CI, 0.085 to 0.304; P<0.001). Among patients with persistent occlusion at 2 hours, only 13 (7% of total) presented late flow improvement (OR late/early recanalization, 0.09; 95% CI, 0.043 to 0.196; P<0.001). The few patients with late recanalization presented comparable median 48-hour NIHSS to those with early/delayed recanalization (3 versus 4.5; P=0.9) and much lower than those with persistent occlusion after 6 hours (3 versus 15; P=0.005). At 3 months, the rate of mRS < or =2 was not statistically different between patients with early/delayed versus late recanalization (55% versus 86%; P=0.12) but was lower if occlusion persisted 6 hours after onset (22%; P<0.001). CONCLUSIONS The majority of t-PA-induced recanalizations occur during the first hour after treatment. Recanalizations during the following hours are rare but still related to clinical improvement if achieved within 6 hours from onset. Rescue reperfusion techniques should be considered if flow improvement is not observed 60 minutes after t-PA bolus.
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Affiliation(s)
- Marc Ribo
- Unitat Neurovascular Hospital Vall d'Hebron, Barcelona, Spain.
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Topçuoglu MA, Palacios IF, Buonanno FS. Contrast M-Mode Power Doppler Ultrasound in the Detection of Right-to-Left Shunts: Utility of Submandibular Internal Carotid Artery Recording. J Neuroimaging 2006. [DOI: 10.1111/j.1552-6569.2003.tb00198.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Abstract
Transcranial Doppler (TCD) is an evolving neurovascular ultrasound technique that has an established diagnostic and potential therapeutic role in acute stroke management. Angiographically validated criteria for circle-of-Willis occlusion and thrombolysis in brain ischemia classification of residual flow have set the stage for the further development of this technique. TCD has shown its clinical value in thrombolysis monitoring and early emboli detection. The therapeutic effect requires confirmation and may be enhanced further by nanobubble technologies.
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Affiliation(s)
- Andrew M Demchuk
- Department of Clinical Neurosciences, University of Calgary, AB, Canada.
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Dominguez-Roldan JM, Jimenez-Gonzalez PI, Garcia-Alfaro C, Rivera-Fernandez V, Hernandez-Hazañas F. Diagnosis of brain death by transcranial Doppler sonography: Solutions for cases of difficult sonic windows. Transplant Proc 2004; 36:2896-7. [PMID: 15686655 DOI: 10.1016/j.transproceed.2004.10.052] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Delays in diagnosis of brain death have definite consequences for the organ retrieval and transplantation process. It is advisable to use accurate diagnostic methods. Transcranial Doppler sonography is a well-accepted technique for diagnosing cerebral circulatory arrest. However, in some cases, the access to the intracranial circulation via the temporal window is difficult. In 43 brain-dead patients we evaluated the rate of impossibility of insonation of middle cerebral artery using a temporal window and the usefulness of an orbital window for insonation of the carotid siphon. In 39 patients the usual protocol of insonation (temporal window and foramen magnum window) was sufficient to demonstrate cerebral circulatory arrest. In 10 patients, including all the cases in which it was impossible to use a temporal approach, the carotid siphon was successfully insonated, showing in all the cases the existence of a sonographic pattern compatible with cerebral circulatory arrest. It may be concluded that the use of an orbital window for exploring intracranial circulation by transcranial Doppler sonography can be a useful tool in cases of difficult sonic windows.
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Spencer MP, Moehring MA, Jesurum J, Gray WA, Olsen JV, Reisman M. Power M-Mode Transcranial Doppler for Diagnosis of Patent Foramen Ovale and Assessing Transcatheter Closure. J Neuroimaging 2004. [DOI: 10.1111/j.1552-6569.2004.tb00261.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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44
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Navarro JC, Mikulik R, Garami Z, Alexandrov AV. The Accuracy of Transcranial Doppler in the Diagnosis of Stenosis or Occlusion of the Terminal Internal Carotid Artery. J Neuroimaging 2004. [DOI: 10.1111/j.1552-6569.2004.tb00256.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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45
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Alexandrov AV, Wojner AW, Grotta JC. CLOTBUST: Design of a Randomized Trial of Ultrasound-Enhanced Thrombolysis for Acute Ischemic Stroke. J Neuroimaging 2004. [DOI: 10.1111/j.1552-6569.2004.tb00225.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Ribo M, Garami Z, Uchino K, Song J, Molina CA, Alexandrov AV. Detection of Reversed Basilar Flow With Power-Motion Doppler After Acute Occlusion Predicts Favorable Outcome. Stroke 2004; 35:79-82. [PMID: 14671244 DOI: 10.1161/01.str.0000106760.25228.2c] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Power-motion transcranial Doppler PMD-TCD is a new method for simultaneous display of flow at multiple depths. We aimed to determine clinical significance of PMD-TCD demonstration of reversed basilar flow in patients with basilar artery (BA) occlusion.
Methods—
We prospectively evaluated patients with acute vertebrobasilar ischemia using PMD-TCD. Using a predefined set of TCD depth criteria and specific flow findings, occlusion was localized to the proximal, middle, or distal BA stem. The National Institutes of Health Stroke Scale was used to measure stroke severity and the modified Rankin Scale (mRS) to assess outcome at 3 months.
Results—
BA occlusion was diagnosed in 16 patients (3 women, mean age 65, median NIHSS 8, mean time from symptoms onset 8.5 hours). PMD-TCD diagnosis of BA occlusion was confirmed in 11 of 12 patients who underwent invasive angiography. Reversed BA flow on PMD-TCD was identified in 8 patients (50%). Angiography confirmed flow from carotid system in 6 of these 8 patients (κ=0.87). Patients with reversed BA flow showed lower NIHSS scores on admission (median 4 versus 15.5,
P
=0.009), on discharge (2 versus 21.5,
P
=0.03) and did not experience neurological deterioration during hospital stay (n=0 versus 4,
P
=0.05). There was a trend toward better outcome at 3 months (mRS 1 versus 4,
P
=0.07).
Conclusion—
Detection of reversed flow in the distal BA with PMD-TCD is associated with lower stroke severity and better outcome after acute basilar artery occlusion.
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Affiliation(s)
- Marc Ribo
- Stroke Treatment Team, Medical School, The University of Texas-Houston, USA.
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Krams M, Lees KR, Hacke W, Grieve AP, Orgogozo JM, Ford GA. Acute Stroke Therapy by Inhibition of Neutrophils (ASTIN). Stroke 2003; 34:2543-8. [PMID: 14563972 DOI: 10.1161/01.str.0000092527.33910.89] [Citation(s) in RCA: 286] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
UK-279,276 (neutrophil inhibitory factor) reduced infarct volume in a rat middle cerebral artery occlusion reperfusion model. ASTIN (Acute Stroke Therapy by Inhibition of Neutrophils) was an adaptive phase 2 dose-response–finding, proof-of-concept study to establish whether UK-279,276 improves recovery in acute ischemic stroke. The prime objective was to determine the dose that gave a clinically relevant effect in patients.
Methods—
A Bayesian sequential design with real-time efficacy data capture and continuous reassessment of the dose response allowed double-blind, randomized, adaptive allocation to 1 of 15 doses (dose range, 10 to 120 mg) or placebo and early termination for efficacy or futility. The primary end point was change from baseline to day 90 on the Scandinavian Stroke Scale (ΔSSS), adjusted for baseline SSS, aiming for a 3-point additional mean recovery above placebo.
Results—
Nine hundred sixty-six acute stroke patients (887 ischemic, 204 cotreated with intravenous tissue plasminogen activator; mean baseline SSS score, 28; range, 10 to 40) were treated within 6 hours of symptom onset. Mean ΔSSS was approximately +17 points of improvement on SSS for the overall evaluable population. There was no treatment effect for UK-279,276 (posterior probability of futility, 0.89). The trial was stopped early for futility. Post hoc analysis indicated a mean 1.6-point additional improvement on ΔSSS in the tissue plasminogen activator–treated subset (credible interval=0.5, 2.6). UK-279,276 was generally well tolerated, with no increased incidence of infections.
Conclusions—
UK-279,276 did not improve recovery in acute ischemic stroke patients but was devoid of serious side effects. The adaptive design facilitated early termination for futility.
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Affiliation(s)
- Michael Krams
- Pfizer Global Research and Development, Sandwich, UK.
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48
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Estrera AL, Garami Z, Miller CC, Sheinbaum R, Huynh TTT, Porat EE, Winnerkvist A, Safi HJ. Determination of cerebral blood flow dynamics during retrograde cerebral perfusion using power M-mode transcranial Doppler. Ann Thorac Surg 2003; 76:704-9; discussion 709-10. [PMID: 12963182 DOI: 10.1016/s0003-4975(03)00552-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Retrograde cerebral perfusion (RCP) during profound hypothermic circulatory arrest has been used as an adjunct for cerebral protection for repairs of the ascending and transverse aortic arch. Transcranial Doppler ultrasound has been used to monitor cerebral blood flow during RCP with varying success. The purpose of this study was to characterize cerebral blood flow dynamics during RCP using a new mode of monitoring known as transcranial power motion-mode (M-mode) Doppler ultrasound. METHODS Data on pump-flow characteristics and patient outcomes were collected prospectively for patients undergoing ascending and transverse aortic arch repair. Retrograde cerebral perfusion during profound hypothermic circulatory arrest was used for all operations. Intraoperative cerebral blood flow dynamics were monitored and recorded using transcranial power M-mode Doppler ultrasound. RESULTS Between August 2001 and March 2002, we used transcranial power M-mode Doppler ultrasound monitoring for 40 ascending and transverse aortic arch repairs during RCP. Mean RCP time was 32.2 +/- 13.8 minutes. Mean RCP pump flow and RCP peak pressure for identification of cerebral blood flow were 0.66 +/- 0.11 L/min and 31.8 +/- 9.7 mm Hg, respectively. Retrograde cerebral blood flow during RCP was detected in 97.5% of cases (39 of 40 patients) with a mean transcranial power M-mode Doppler ultrasound flow velocity of 15.5 +/- 12.3 cm/s. In the study group, 30-day mortality was 10.0% (4 of 40 patients). The incidence of stroke was 7.6% (3 of 40 patients); the incidence of temporary neurologic deficit was 35.0% (14 of 40 patients). CONCLUSIONS Transcranial power M-mode Doppler ultrasound consistently demonstrated retrograde middle cerebral artery blood flow during RCP. Transcranial power M-mode Doppler ultrasound can provide optimal RCP with individualized settings of pump flow.
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Affiliation(s)
- Anthony L Estrera
- DEPARTMENT OF Cardiothoracic and Vascular Surgery, Houston, Texas 77030, USA.
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49
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Babikian VL, Wijman CA. Brain Embolism Monitoring with Transcranial Doppler Ultrasound. CURRENT TREATMENT OPTIONS IN CARDIOVASCULAR MEDICINE 2003; 5:221-232. [PMID: 12777200 DOI: 10.1007/s11936-003-0006-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Embolism is considered to be the main mechanism leading to brain infarction today; with the introduction of sophisticated neuroimaging tools, its impact is increasingly appreciated. Transcranial Doppler ultrasound allows noninvasive monitoring of in vivo embolism. Acute stroke, internal carotid artery stenosis, several cardiac conditions, internal carotid endarterectomy, and coronary artery bypass graft surgery have been extensively monitored. These investigations and other clinical and neuroimaging studies have expanded the understanding of brain embolism; they suggest it may be appropriate to think of it as a process that occurs in the context of other hemodynamic factors. Differences have been identified among several conditions regarding the temporal profile of embolism and the characteristics of embolic particles. This article presents a brief review of brain embolism monitoring with transcranial Doppler ultrasound.
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Affiliation(s)
- Viken L. Babikian
- Stroke Service, Department of Neurology, Boston University School of Medicine, 715 Albany Street, D-315, Boston, MA 02118, USA.
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