Endothelial receptor proteins in acute venous thrombosis and delayed thrombus resolution in cerebral sinus vein thrombosis

BACKGROUND AND PURPOSE

Cerebral sinus venous thrombosis (CSVT) is a rare but life-threatening disease and its diagnosis remains challenging. Blood biomarkers, including D-Dimer are currently not recommended in guidelines. Soluble endothelial receptor proteins (sICAM-1, sPECAM-1 and sVCAM-1) have been shown to be promising diagnostic biomarkers in deep vein thrombosis (DVT) and pulmonary embolism (PE). Therefore, we examined endothelial receptor proteins as potential biomarkers for detecting CSVT.

METHODS

In this bi-centre, prospective study, we quantified D-Dimer as well as sICAM-1, sPECAM-1 and sVCAM-1 in plasma of patients with clinically suspected CSVT managed in the neurological emergency department (ED) of a tertiary care hospital. All patients underwent cerebral magnetic resonance imaging (MRI) and were followed up after 3, 6 and 12 months to detect thrombus resolution.

RESULTS

Twenty-four out of 75 (32%) patients with clinically suspected CSVT presenting with headache to the ED were diagnosed with acute CSVT. These patients had a mean age of 45 ± 16 years and 78% were female. In patients with CSVT, mean baseline D-dimer (p < 0.001) and sPECAM-1 (p < 0.001) were significantly higher compared to patients without CSVT. The combination of D-Dimer and sPECAM-1 yielded the best ROC-AUC (0.994; < 0.001) with a negative predictive value of 95.7% and a positive predictive value of 95.5%. In addition, higher baseline sPECAM-1 levels (> 198 ng/ml) on admission were associated with delayed venous thrombus resolution at 3 months (AUC = 0.83).

CONCLUSION

sPECAM-1 in combination with D-Dimer should be used to improve the diagnostic accuracy of acute CSVT and sPECAM-1 may predict long-term outcome of CSVT. Confirmatory results are needed in other settings in order to show their value in the management concept of CSVT patients.

Endovascular stroke therapy outside core working hours in a nationwide stroke system

BACKGROUND

Endovascular therapy (EVT) has been established as a major component in the acute treatment of large vessel occlusion stroke. However, it is unclear whether outcome and other treatment-related factors differ if patients are treated within or outside core working hours.

METHODS

We analyzed data from the prospective nationwide Austrian Stroke Unit Registry capturing all consecutive stroke patients treated with EVT between 2016 and 2020. Patients were trichotomized according to the time of groin puncture into treatment within regular working hours (08:00-13:59), afternoon/evening (14:00-21:59) and night-time (22:00-07:59). Additionally, we analyzed 12 EVT treatment windows with equal patient numbers. Main outcome variables included favorable outcome (modified Rankin Scale scores of 0-2) 3 months post-stroke as well as procedural time metrics, recanalization status and complications.

RESULTS

We analyzed 2916 patients (median age 74 years, 50.7% female) who underwent EVT. Patients treated within core working hours more frequently had a favorable outcome (42.6% vs 36.1% treated in the afternoon/evening vs 35.8% treated at night-time; p=0.007). Similar results were found when analyzing 12 treatment windows. All these differences remained significant in multivariable analysis adjusting for outcome-relevant co-factors. Onset-to-recanalization time was considerably longer outside core working hours, which was mainly explained by longer door-to-groin time (p<0.001). There was no difference in the number of passes, recanalization status, groin-to-recanalization time and EVT-related complications.

CONCLUSIONS

The findings of delayed intrahospital EVT workflows and worse functional outcomes outside core working hours in this nationwide registry are relevant for optimization of stroke care, and might be applicable to other countries with similar settings.

Protocol for the Exercise, Cancer and Cognition - The ECCO-Study: A Randomized Controlled Trial of Simultaneous Exercise During Neo-/Adjuvant Chemotherapy in Breast Cancer Patients and Its Effects on Neurocognition

Introduction

Epidemiological studies show that increased physical activity is linked to a lower risk of breast cancer and mortality. As a result, physical activity can significantly improve patients' quality of life (QOL) both during and after therapy.Many breast cancer patients demonstrate a decrease in cognitive capacity, referred to as the symptom-complex cancer related cognitive impairment (CRCI). Most frequently reported impairments are mild to moderate deficits in processing speed, attention, memory, and executive functions. Cognitive symptoms persist for months or even years, following medical treatment in roughly 35% of afflicted people, impairing everyday functioning, limiting the ability to return to work, and lowering the overall QOL. Recent studies point toward a key role of inflammatory pathways in the CRCI genesis. Attention to physical activity as a potential supportive care option is therefore increasing. However, evidence for the positive effects of exercise on preventing CRCI is still lacking.

Patients and Methods

Against this background, the prospective, two-arm, 1:1 randomized, controlled trial investigates the influence of first line chemotherapy accompanied by exercise training on preventing CRCI in 126 patients with breast cancer at the local University Hospital. The study will evaluate biomarkers and secondary assessments suspected to be involved in the pathogenesis of CRCI in addition to objective (primary outcome) and subjective cognitive function. CRCI is believed to be connected to either functional and/or morphological hippocampal damage due to chemotherapy. Thus, cerebral magnetic resonance imaging (MRI) and hippocampal volume measurements are performed. Furthermore, a specific neuropsychological test battery for breast cancer patients has been developed to detect early signs of cognitive impairments in patients and to be integrated into practice.

Discussion

This study will explore how a long-term supervised exercise intervention program might prevent CRCI, enables optimization of supportive care and objectifies limits of psychological and physical resilience in breast cancer patients during and after chemotherapy treatment.

Trial Registration

ClinicalTrials.gov: Identifier: NCT04789187. Registered on 09 March 2021.

Caregiver burden in patients with behavioural variant frontotemporal dementia and non-fluent variant and semantic variant primary progressive aphasia

Studies on caregiver burden in patients with frontotemporal lobar degeneration are rare, differ methodologically and show variable results. Single center longitudinal pilot study on caregiver burden and potential risk factors in patients with behavioural variant frontotemporal dementia (bvFTD) and semantic (svPPA) and non-fluent variants (nfvPPA) primary progressive aphasia. Forty-six bvFTD, nine svPPA, and six nfvPPA patients and caring relatives were analysed for up to 2 years using the Mini-Mental State Examination as global measure for cognitive performance, Frontal Assessment Battery (frontal lobe functions), Frontal Behavioural Inventory (personality and behaviour), Neuropsychiatric Inventory (dementia-related neuropsychiatric symptoms), Barthel Index and Lawton IADL Scale (basic and instrumental activities of daily living), the Caregiver Strain Index (CSI), and in most participants also the Zarit Burden Interview (ZBI). CSI baseline sum scores were highest in bvFTD (mean ± SD 5.5 ± 3.4, median 5, IQR 6), intermediate in svPPA (2.9 ± 2.3; 3; 3.5) and low in nfvPPA (1.6 ± 2.1; 1; 2). Similar differences of caregiver burden were found using the ZBI. During follow-up, CSI and ZBI sum scores deteriorated in svPPA, not in bvFTD and nfvPPA, and correlated significantly with personality and behaviour, neuropsychiatric symptoms, caregiver age, and instrumental, but not basic activities of daily living, Mini-Mental State Examination scores or frontal lobe functions. This study reveals differences in caregiver burden in variants of frontotemporal lobar degeneration. Caregivers should be systematically asked for caregiver burden from the time of the diagnosis to provide comprehensive support in time.

Ultrasound Examination of the Pupil - A New Tool for the Neuro-Ophthalmological Assessment

BACKGROUND

 Pupil examination represents a diagnostic and prognostic test in the management of several neurological diseases. Infrared video pupillometry (IVP) is the gold standard, since it is not routinely available, a noninvasive bedside ultrasound assessment has been proposed as an alternative. The aim of this study was to assess the feasibility and reproducibility of ultrasound pupillometry (UP) in comparison with IVP.

MATERIALS AND METHODS

 81 subjects (43 men and 38 women, mean age: 52 ± 20 years and 49 ± 19 years, respectively) with no history of neurophthalmologic disease were enrolled. UP was performed with a 12-MHz linear probe according to current guidelines for orbital insonation. Light and painful stimuli were applied to test pupillary light reflex (PLR) and ciliospinal reflex (CR). In 30 of these subjects IVP examination was performed additionally to obtain intra-observer and inter-observer agreement.

RESULTS

 Increasing age was associated with a decreased pupillary diameter (PD) at rest, after PLR and CR (R -0.728, p < 0.01, R -0.643, p < 0.01, R 0.674, p < 0.001 respectively), while no association was noticed with time to constriction/dilation. UP measurements were reproducible (rate of inter- and intra-observer agreement: R 0.979, p < 0.01, R 0.946, p < 0.01 respectively) and concordant with IVP (PLR R 0.831, p < 0.01; CR R 0.879, p < 0.01).

CONCLUSION

 According to our study, ultrasound pupillometry is a feasible and reliable technique for bedside pupillary function assessment, and is a good alternative to infrared video pupillometry. Moreover, it represents the only way for functional pupillary assessment in patients with periorbital hematoma.

Characteristics and Outcomes in Patients With COVID-19 and Acute Ischemic Stroke: The Global COVID-19 Stroke Registry

Supplemental Digital Content is available in the text.

Recent case-series of small size implied a pathophysiological association between coronavirus disease 2019 (COVID-19) and severe large-vessel acute ischemic stroke. Given that severe strokes are typically associated with poor prognosis and can be very efficiently treated with recanalization techniques, confirmation of this putative association is urgently warranted in a large representative patient cohort to alert stroke clinicians, and inform pre- and in-hospital acute stroke patient pathways. We pooled all consecutive patients hospitalized with laboratory-confirmed COVID-19 and acute ischemic stroke in 28 sites from 16 countries. To assess whether stroke severity and outcomes (assessed at discharge or at the latest assessment for those patients still hospitalized) in patients with acute ischemic stroke are different between patients with COVID-19 and non-COVID-19, we performed 1:1 propensity score matching analyses of our COVID-19 patients with non-COVID-19 patients registered in the Acute Stroke Registry and Analysis of Lausanne Registry between 2003 and 2019. Between January 27, 2020, and May 19, 2020, 174 patients (median age 71.2 years; 37.9% females) with COVID-19 and acute ischemic stroke were hospitalized (median of 12 patients per site). The median National Institute of Health Stroke Scale was 10 (interquartile range [IQR], 4–18). In the 1:1 matched sample of 336 patients with COVID-19 and non-COVID-19, the median National Institute of Health Stroke Scale was higher in patients with COVID-19 (10 [IQR, 4–18] versus 6 [IQR, 3–14]), P=0.03; (odds ratio, 1.69 [95% CI, 1.08–2.65] for higher National Institute of Health Stroke Scale score). There were 48 (27.6%) deaths, of which 22 were attributed to COVID-19 and 26 to stroke. Among 96 survivors with available information about disability status, 49 (51%) had severe disability at discharge. In the propensity score-matched population (n=330), patients with COVID-19 had higher risk for severe disability (median mRS 4 [IQR, 2–6] versus 2 [IQR, 1–4], P<0.001) and death (odds ratio, 4.3 [95% CI, 2.22–8.30]) compared with patients without COVID-19. Our findings suggest that COVID-19 associated ischemic strokes are more severe with worse functional outcome and higher mortality than non-COVID-19 ischemic strokes.

Enhancing and accelerating stroke treatment in Eastern European region: Methods and achievement of the ESO EAST program

Introduction

Despite the availability of prevention and therapies of stroke, their implementation in clinical practice, even of low-cost ones, remains poor. In 2015, the European Stroke Organisation (ESO) initiated the ESO Enhancing and Accelerating Stroke Treatment (EAST) program, which aims to improve stroke care quality, primarily in Eastern Europe. Here, we describe its methods and milestones.

Patients and methods

The ESO EAST program is using an implementation strategy based on a 'detecting-understanding-reducing disparities' conceptual framework: stroke care quality is first measured (after developing a platform for data collection), gaps are identified in the current service delivery, and ultimately feedback is provided to participating hospitals, followed by the application of interventions to reduce disparities. The ESO EAST program is carried out by establishing a stroke quality registry, stroke management infrastructure, and creating education and training opportunities for healthcare professionals.

Results

Program management and leadership infrastructure has been established in 19 countries (Country Representatives in 22 countries, National Steering Committee in 19 countries). A software platform for data collection and analysis: Registry of Stroke Care Quality was developed, and launched in 2016, and has been used to collect data from over 90,000 patients from >750 hospitals and 56 countries between September 2016 and May 2019. Training in thrombolysis, nursing and research skills has been initiated.

Discussion

ESO EAST is the first pan-Eastern European (and beyond) multifaceted quality improvement intervention putting evidence-informed policies into practice. Continuous monitoring of stroke care quality allows hospital-to-hospital and country-to-country benchmarking and identification of the gaps and needs in health care.

Endovascular equipoise shift in a phase III randomized clinical trial of sonothrombolysis for acute ischemic stroke

Background:

Results of our recently published phase III randomized clinical trial of ultrasound-enhanced thrombolysis (sonothrombolysis) using an operator-independent, high frequency ultrasound device revealed heterogeneity of patient recruitment among centers.

Methods:

We performed a post hoc analysis after excluding subjects that were recruited at centers reporting a decline in the balance of randomization between sonothrombolysis and concurrent endovascular trials.

Results:

From a total of 676 participants randomized in the CLOTBUST-ER trial we identified 52 patients from 7 centers with perceived equipoise shift in favor of endovascular treatment. Post hoc sensitivity analysis in the intention-to-treat population adjusted for age, National Institutes of Health Scale score at baseline, time from stroke onset to tPA bolus and baseline serum glucose showed a significant (p < 0.01) interaction of perceived endovascular equipoise shift on the association between sonothrombolysis and 3 month functional outcome [adjusted common odds ratio (cOR) in centers with perceived endovascular equipoise shift: 0.22, 95% CI 0.06–0.75; p = 0.02; adjusted cOR for centers without endovascular equipoise shift: 1.20, 95% CI 0.89–1.62; p = 0.24)]. After excluding centers with perceived endovascular equipoise shift, patients randomized to sonothrombolysis had higher odds of 3 month functional independence (mRS scores 0–2) compared with patients treated with tPA only (adjusted OR: 1.53; 95% CI 1.01–2.31; p = 0.04).

Conclusion:

Our experience in CLOTBUST-ER indicates that increasing implementation of endovascular therapies across major academic stroke centers raises significant challenges for clinical trials aiming to test noninterventional or adjuvant reperfusion strategies.

Pharyngeal electrical stimulation for early decannulation in tracheotomised patients with neurogenic dysphagia after stroke (PHAST-TRAC): a prospective, single-blinded, randomised trial

BACKGROUND

Dysphagia after stroke is common, especially in severely affected patients who have had a tracheotomy. In a pilot trial, pharyngeal electrical stimulation (PES) improved swallowing function in this group of patients. We aimed to replicate and extend this single-centre experience.

METHODS

We did a prospective, single-blind, randomised controlled trial across nine sites (seven acute care hospitals, two rehabilitation facilities) in Germany, Austria, and Italy. Patients with recent stroke who required tracheotomy were randomly assigned to receive 3 days of either PES or sham treatment (1:1). All patients had the stimulation catheter inserted; sham treatment was applied by connecting the PES base station to a simulator box instead of the catheter. Randomisation was done via a computerised interactive system (stratified by site) in blocks of four patients per site. Patients and investigators applying PES were not masked. The primary endpoint was assessed by a separate investigator at each site who was masked to treatment assignment. The primary outcome was readiness for decannulation 24-72 h after treatment, assessed using fibreoptic endoscopic evaluation of swallowing and based on a standardised protocol, including absence of massive pooling of saliva, presence of one or more spontaneous swallows, and presence of at least minimum laryngeal sensation. We planned a sequential statistical analysis of superiority for the primary endpoint. Interim analyses were to be done after primary outcome data were available for 50 patients (futility), 70 patients, and every additional ten patients thereafter, up to 140 patients. Analysis was by intention to treat. This trial is registered with the ISRCTN registry, number ISRCTN18137204.

FINDINGS

From May 29, 2015, to July 5, 2017, of 81 patients assessed, 69 patients from nine sites were randomly assigned to receive PES (n=35) or sham (n=34) treatment. Median onset to randomisation time was 28 days (IQR 19-41; PES 28 [20-49]; sham 28 [18-40]). The Independent Data and Safety Monitoring Board recommended that the trial was stopped early for efficacy after 70 patients had been recruited and primary endpoint data for 69 patients were available. This decision was approved by the steering committee. More patients were ready for decannulation in the PES group (17 [49%] of 35 patients) than in the sham group (three [9%] of 34 patients; odds ratio [OR] 7·00 [95% CI 2·41-19·88]; p=0·0008). Adverse events were reported in 24 (69%) patients in the PES group and 24 (71%) patients in the sham group. The number of patients with at least one serious adverse event did not differ between the groups (ten [29%] patients in the PES group vs eight [23%] patients in the sham group; OR 1·30 [0·44-3·83]; p=0·7851). Seven (20%) patients in the PES group and three (9%) patients in the sham group died during the study period (OR 2·58 [0·61-10·97]; p=0·3059). None of the deaths or serious adverse events were judged to be related to PES.

INTERPRETATION

In patients with stroke and subsequent tracheotomy, PES increased the proportion of patients who were ready for decannulation in this study population, many of whom received PES within a month of their stroke. Future trials should confirm whether PES is beneficial in tracheotomised patients who receive stimulation similarly early after stroke and explore its effects in other cohorts.

FUNDING

Phagenesis Ltd.

Real-life experience with the specific reversal agent idarucizumab for the management of emergency situations in dabigatran-treated patients: a series of 11 cases

Non-vitamin K antagonist oral anticoagulants (NOACs) have a favorable benefit-risk profile compared with vitamin K antagonists. However, the lack of specific reversal agents has made the management of some patients receiving long-term treatment with NOACs problematic in emergency situations such as major bleeding events or urgent procedures. Idarucizumab, a fully humanized Fab antibody fragment that binds specifically and with high affinity to dabigatran, was recently approved for use in adult patients treated with dabigatran when rapid reversal of its anticoagulant effect is required. Clinical experience with idarucizumab is currently limited. We report 11 real-life clinical cases in which idarucizumab was used after multidisciplinary consultation in a variety of emergency situations including severe postoperative bleeding, emergency high-bleeding-risk surgery (hip/spine surgery and neurosurgery), invasive diagnostic testing (lumbar puncture), intracranial bleeding (pre-pontine subarachnoid hemorrhage and lobar intracerebral hemorrhage) and thrombolysis with recombinant tissue plasminogen activator for acute ischemic stroke. This case series illustrates the role of idarucizumab in improving patient safety in rare emergency situations requiring rapid reversal of the anticoagulant effect of dabigatran, while highlighting the importance of information and education about the availability and appropriate use of this recently approved specific reversal agent.

The phoenix from the ashes: cardiovascular autonomic dysfunction in behavioral variant of frontotemporal dementia

BACKGROUND

Patients with autonomic failure may experience postural dizziness, syncope, and falls. Identifying symptomatic dysautonomia in dementia is of importance to ensure appropriate management and reduce risk of falls.

OBJECTIVE

The aim of this prospective study is to identify cardiovascular autonomic dysfunction in patients suffering from behavioral variant of frontotemporal dementia (bvFTD), compared to Alzheimer's disease (AD).

METHODS

Patients were prospectively recruited from 2009 until 2013. Clinical autonomic function tests were carried out in an Autonomic Unit according to Ewing's cardiovascular battery. Parasympathetic tests included resting heart rate variability, deep breathing, and Valsalva. Sympathetic function tests compromised blood pressure regulation on valsalva, cutaneous cold stimulation, and 70° head up tilt including of plasma noradrenaline.

RESULTS

26 patients (17 female) with bvFTD and 18 patients (10 female) with AD were examined. Mean age of bvFTD was 69 ± 11 years, AD 74 ± 9 years. History taking was often not conclusive and did not correlate with autonomic signs. In 42% bvFTD patients and 44% AD patients, autonomic dysfunction was demonstrated. Manifest orthostatic hypotension (OH) was present in 19% of bvFTD and 33% AD patients. Frequency of autonomic dysfunction and orthostatic hypotension did not differ between bvFTD and AD, but were significantly higher than in healthy controls. Autonomic dysfunction was associated with an increased risk of falling (assessed with Tinetti Score).

CONCLUSION

This is the first prospective study to elucidate autonomic dysfunction in bvFTD patients. There is a considerable higher frequency of cardiovascular dysfunction and OH in bvFTD. History taking may be not conclusive thus cannot exclude cardiovascular dysautonomia.

The Peripheral Sympathetic Neuron is Intact in Alzheimer's Disease and Behavioral Variant of Frontotemporal Dementia

INTRODUCTION

The study was undertaken to evaluate the postganglionic sympathetic sudomotor function employing the quantitative sudomotor axon reflex test (QSART) in tauopathies Alzheimer's disease (AD) and behavioral variant of frontotemporal dementia (bvFTD).

METHODS

Patients were recruited in a prospective pilot study. A structured history was taken and QSART was recorded.

RESULTS

In all, 15 patients with AD (7 female) and 14 patients with bvFTD (9 female) were included. Mean age (±standard deviation) of patients with AD and bvFTD was 74 ± 9 and 71 ± 10 years, respectively. Severe sudomotor dysfunction (Composite Autonomic Severity sudomotor score 3) was present in 3 (20%) patients with AD and 0 (0%) patients with bvFTD (P = .037). The upper extremity was only involved in 1 patient with AD and 1 patient with bvFTD. Sweat results of the 4 recording sites did not differ between both groups. Patients' history correlated with severe autonomic symptoms as assessed with QSART.

CONCLUSION

Postganglionic sudomotor involvement in AD and bvFTD is most likely not part of the disease.

Onset of sweating depends on the type of reflex syncope

Reflex syncope is classified based on the efferent autonomic system as vasodepressant type, cardioinhibitory type and mixed type. We employed quantitative sweat testing to assess differences in sudomotor sympathetic activity in relation to the type of reflex syncope. In cardioinhibitory type sweating started in 7/9 patients after and in vasodepressor type in 11/12 patients before syncope. In mixed type sweating in 20 patients started before and in 10 after syncope. The onset of sweating correlated significantly with the onset of syncope symptoms. These results possibly reflect different onsets of emotional sweating.

Acute-onset migrainous aura mimicking acute stroke: MR perfusion imaging features

BACKGROUND AND PURPOSE

In a very limited number of cases, acute migrainous aura may mimic acute brain infarction. The aim of this study was to recognize patterns of MR perfusion abnormalities in this presentation.

MATERIALS AND METHODS

One thousand eight hundred fifty MR imaging studies performed for the suspicion of acute brain infarction were analyzed retrospectively to detect patients with acute migrainous aura not from stroke. All patients were examined clinically by 2 neurologists and underwent a standard stroke MR imaging protocol, including PWI. Two radiologists reviewed the perfusion maps visually and quantitatively for the presence, distribution, and grade of perfusion abnormalities.

RESULTS

Among 1850 MR imaging studies, 20 (1.08%) patients were found to have acute migrainous aura. Hypoperfusion was found in 14/20 patients (70%) with delayed rMTT and TTP, decreased rCBF, and minimal decrease in rCBV. In contrast to the typical pattern in stroke, perfusion abnormalities were not limited to a single vascular territory but extended to >1. Bilateral hypoperfusion was seen in 3/14 cases. In 11/14 cases, hypoperfusion with a posterior predominance was found. TTP and rMTT were the best maps to depict perfusion changes at visual assessment, but also rCBF maps demonstrated significant hypoperfusion in quantitative analysis. In all patients, clinical and imaging follow-up findings were negative for stroke.

CONCLUSIONS

Acute migrainous aura is rare but important in the differential diagnosis among patients with the suspicion of acute brain infarction. Atypical stroke perfusion abnormalities can be seen in these patients.

[Ischemic stroke in the elderly--analysis of the Austrian Stroke Unit Registry]

Epidemiological and benchmarking parameters of patients with ischemic stroke were collected in the Austrian Stroke Unit Registry from January 2003 till February 2007. 13,440 patient-data were analysed. 9509 were under 80 years old, 3931 were older than 80. Old patients showed worse clinical symptoms upon admission (NIHSS 9 vs. 6) and doubled mortality by worse pre-morbid status (mRS 1.27 vs. 0.47) in comparison to younger ones. Numerous other parameters were tested and compared in both groups of patients.

Pravastatin reduces microvascular basal lamina damage following focal cerebral ischemia and reperfusion

Transient ischemia has been shown to damage the basal lamina of the cerebral microvasculature. Other studies proved statins to be beneficial to non-cerebral microvessels. The aim of this study was to determine whether pravastatin pretreatment ameliorates microvascular basal lamina damage following transient ischemia. Using the suture model, we subjected 15 rats to focal ischemia (3 h) and reperfusion (24 h). Rats received pravastatin (20 mg/kg/day) or saline for 4 weeks prior to the experiment. The outcome was determined by a behavior test and the infarct size. Collagen type IV, a marker for an intact basal lamina, and hemoglobin extravasation were measured by Western blot analysis. A ratio (in percentage) between ischemic and contralateral hemispheres was calculated. Pravastatin pretreatment resulted in a significantly better neurological outcome and reduced infarct size (15 +/- 0.5 and 59 +/- 10 mm(3), respectively) compared with controls (12.25 +/- 0.4 and 167 +/- 13 mm(3), respectively, P < 0.01 for both). In controls, loss of collagen type IV was seen in the basal ganglia and in the cortex (43 +/- 4 and 64 +/- 5%, respectively). Pravastatin prevented significant collagen loss (basal ganglia: 106 +/- 17%; cortex: 112 +/- 14%, P < 0.01 for both) and significantly reduced the hemoglobin extravasation compared with controls in the basal ganglia (198 +/- 49 vs. 553 +/- 47%, P < 0.01). Pravastatin pretreatment resulted in a reduction of microvascular basal lamina damage and hemoglobin extravasation following transient ischemia. Pravastatin seems to protect the cerebral microvascular system.

Influence of the duration of ischemia and reperfusion on infarct volume and microvascular damage in mice

OBJECTIVES

Focal cerebral ischemia is responsible for alterations of vascular permeability, and the loss of microvascular integrity is a primary source of subsequent hemorrhages. We evaluated the influence of different durations of ischemia and reperfusion on infarction size and microvascular damage after focal cerebral ischemia in the mouse.

METHODS

C57BL/6 mice (n=39) were subjected to focal cerebral ischemia (I) and reperfusion (R). Consecutive brain sections were analysed for infarction volumes (Nissl-staining) and for collagen type IV (immunohistochemistry and western blot).

RESULTS

Infarction size (percentage of the infarction volume versus ipsilateral hemisphere) increased with total time of ischemia and reperfusion: 19+/-2% (I3R0), 30+/-2% (I3R3), 36+/-4% (I3R12), 41+/-4% (I1R24), 45+/-6% (I2R24) and 58+/-2% (I3R24). The ischemic hemispheres showed a significant progressive reduction of collagen type IV positive vessels (ischemic versus non-ischemic contralateral area): 90+/-3% (I3R0), 88+/-1% (I3R3), 82+/-3% (I3R12), 85+/-3% (I1R24), 79+/-3% (I2R24), 72+/-2% (I3R24).

CONCLUSIONS

Both prolonged ischemia and reperfusion lead to an increased infarction volume, as well as progressive microvascular damage.

Expression pattern of the transcription factor Olig2 in response to brain injuries: implications for neuronal repair

Despite the presence of neural stem cells and ongoing neurogenesis in some regions of the adult mammalian brain, neurons are not replaced in most brain regions after injury. With the aim to unravel factors contributing to the failure of neurogenesis in the injured cerebral cortex, we examined the expression of cell fate determinants after acute brain injuries, such as stab wound or focal ischemia, and in a model of chronic amyloid deposition. Although none of the neurogenic factors, such as Pax6, Mash1, Ngn2, was detected in the injured parenchyma, we observed a strong up-regulation of the bHLH transcription factor Olig2, but not Olig1, upon acute and chronic injury. To examine the function of Olig2 in brain lesion, we injected retroviral vectors containing a dominant negative form of Olig2 into the lesioned cortex 2 days after a stab wound. Antagonizing Olig2 function resulted in a significant number of infected cells generating immature neurons that were not observed after injection of the control virus. These data, therefore, imply Olig2 as a repressor of neurogenesis in cells reacting to brain injury and open innovative perspectives toward evoking endogenous neuronal repair.

A new approach to reduce the number of animals used in experimental focal cerebral ischemia models

We describe a novel experimental set-up that allows biochemical, immunohistochemical and morphometric recording of multiple parameters from a single rat brain. The whole brain was cut (coronal sectioning) in a volumetric manner, and 100 cryo-sections (10 microm) were collected from the region of infarction. By use of a scalpel to dissect the cryosection, crude brain material was obtained from the cortical and basal ganglia areas of ischemic and non-ischemic hemispheres. Material from four 10 microm thick sections of the same animal was pooled. About 30 microg protein lysate was extracted per four sections with various lysis buffers; this sufficed for one biochemical or enzymatic test called "micro-Western-blots" or "micro-zymographies". Scraping brain material from cryosections allows the detection of up to 25 parameters from adjacent brain sections of one single rat brain. Different analysis are possible, we have chosen, e.g. to compare factors affecting the basal lamina of cerebral microvessels like the content of the metalloproteinases-2/-9, their tissue inhibitors, the plasminogen activators, collagen type IV, parameters to test the blood-brain barrier: hemoglobin and the protein of the perfusion solution BSA and the infarction volume. On the basis of these parameters it was possible to compare the interactions of the complex processes in the ischemic brain in the same animal in adjacent sections. Thus, this method increases the validity of data comparisons and reduces significantly the number of animals needed in various experimental settings.

Microvascular basal lamina damage in thromboembolic stroke in a rat model

We investigated microvascular damage in areas with magnetic resonance imaging (MRI)-defined apparent diffusion coefficient reduction (ADC-R) in a rat model of thromboembolic occlusion of the middle cerebral artery. Rats received either intracarotid recombinant tissue plasminogen activator (rt-PA) or saline. Microvascular basal lamina damage was quantified by immunohistochemical staining of collagen type IV and by videoimaging analysis. ADC-R positive basal ganglia (cortical) areas showed a significant reduction of stained microvascular area by 15+/-6% (8+/-7%) and the microvascular density by 13+/-5% (8+/-6%) of that on the non-ischemic control side (P<0.001). There were no significant microvascular differences between rats given rt-PA or saline, or between those with or without angiographically proven recanalization. This study reports for the first time that microvascular basal lamina damage in experimental thromboembolic stroke is confined to regions with ADC-R in MRI.

Microvascular damage following experimental sinus-vein thrombosis in rats

We evaluated effects of thrombosis of the superior sagittal sinus, its bridging and cortical veins (SVT) on the cerebral microvasculature in rats. Cryosections of brains ( n=7) were examined for venous infarction and microvascular basal lamina damage 3 h after SVT by immunohistochemical staining of microtubule-associated protein 2 and collagen type IV. Microvessels in the infarctions showed a decrease in the number (23.5+/-6.1%, P<0.002) and the total area (24.9+/-6.5%, P<0.011) of collagen type IV-positive vessels in contrast to control areas (21.7+/-12.4%, P<0.007; and 26.3+/-15.1%, P<0.026 in contrast to control areas of unoperated animals). This study showed a significant alteration of the cerebral microvasculature in SVT, which might contribute to edema and hemorrhagic transformation.

The Mt. Diwata study on the Philippines 2000-treatment of mercury intoxicated inhabitants of a gold mining area with DMPS (2,3-dimercapto-1-propane-sulfonic acid, Dimaval)

Ninty-five inhabitants of the gold mining area of Mt. Diwata (on Mindanao, Philippines), who were diagnosed to be mercury (Hg) intoxicated, were orally treated with 2 x 200 mg of the chelating agent DMPS (Dimaval, Co. Heyl, Germany) for 14 days in the course of a UNIDO project focusing on mercury pollution abatement. Blood and urine samples before and after treatment, urine after the first application of DMPS and a hair sample were collected and analyzed for Hg. Before and after treatment extensive anamnestic data were collected, medical and neurological investigations and some neuro-psychological tests were performed. In spite of the short time of treatment most of the patients reported a marked improvement of the complaints which were stated by them before the therapy and which are characteristic for a chronic Hg intoxication, for example tremor, loss of memory, sleeplessness, metallic taste, etc. But even in some of the objective neurological parameters like hypo-mimia, Romberg test and tests for tremor/ataxia a statistical significant improvement could be found. Significant improvements could also be found in two neuro-psychological tests (pencil tapping and Frostig). In some cases an extreme high urinary Hg excretion was found under the chelating therapy with DMPS, and by this a distinct reduction of the Hg body burden. Nevertheless, in most cases Hg in blood and urine was not markedly decreased by the treatment. This shows that the duration of the treatment (14 days) was not sufficient for a permanent decrease in Hg. As DMPS excretes Hg mainly through the kidney, it can be concluded that in most cases even after 14 days of treatment there was an ongoing redistribution of Hg from other tissues to the kidney. In conclusion, this study proves that a chelating therapy with DMPS is highly effective even in the case of a mixed chronic and acute intoxication with an unknown combination of Hg vapor, inorganic Hg and organic Hg=methylmercury (MeHg), as characteristic for gold mining areas in the third world. Adverse side effects were rarely reported. Only in one case the medication had to be terminated after the first application due to an allergic skin reaction.

Unique case of eleven Bell's palsy episodes

Bell's palsy (BP) is a peripheral facial nerve paralysis of unknown etiology. It is not a life-threatening condition; however, incomplete recovery may leave an individual stigmatized functionally, occupationally as well as socially. Recurrent paralyses are seldom, noted in 7-8% of all BP cases. More than two BP relapses are even less frequent. Adour et al. (1977) reported only two patients with four BP episodes from 1700 patients. Only one patient with more than four BP recurrences in the group containing 2414 BP cases were reported by Yanagihara et al. (1984). The highest reported number of BP recurrences in the accessible literature has been nine. We are presenting an unusual patient who suffered a total of eleven relapses of an idiopathic facial nerve palsy. Description of the case along with review of the relevant literature are discussed.

Plasminogen activation in experimental permanent focal cerebral ischemia

BACKGROUND

Previous experimental work using in situ zymography has shown very early increased plasminogen activation in ischemic regions after 3 h of ischemia with and without reperfusion. The objective of the present study was to evaluate the time course and extent of plasminogen activation in long-term permanent focal cerebral ischemia.

MATERIAL AND METHODS

The middle cerebral artery in male Fisher rats was irreversibly occluded by electrocoagulation. Duration of ischemia was 48, 72, and 168 h. Occlusion was controlled in vivo by MRI at day 2. Plasminogen activation was detected by in situ zymography of 10 microm cryosections with an overlay containing plasminogen and the plasmin substrate caseine. Areas of plasminogen activation were compared to structural lesions (immunohistochemical loss of microtubule-associated protein 2; MAP 2).

RESULTS

Compared to controls, increased plasminogen activation was observed in the basal ganglia and the cortex of the ischemic hemisphere after 48, 72, and 168 h (affected area of basal ganglia: 44.5+/-21.9, 70.1+/-2.3 and 66.6+/-2.8%, respectively; affected area of cortex: 63.4+/-9.8, 67.7+/-0.7 and 64.0+/-3.7%, respectively). The duration of ischemia had no significant influence on the extent of plasminogen activation. Areas of increased plasminogen activation significantly overlapped with and exceeded areas of MAP 2 loss (P<0.005).

DISCUSSION

Permanent focal cerebral ischemia leads to increased plasminogen activation in ischemic regions. This plasminogen activation remains elevated at persistent levels over days. It may contribute to extracellular matrix (ECM) disruption, secondary hemorrhage, and brain edema in subacute stages of ischemic stroke.

Plasminogen activation in focal cerebral ischemia and reperfusion

In focal cerebral ischemia the plasminogen-plasmin system plays a role in the fibrinolysis of vessel-occluding clots and also in the proteolysis of extracellular matrix components, which potentially contributes to brain edema and bleeding complications. The authors investigated the plasminogen activation after middle cerebral artery occlusion with and without reperfusion (reperfusion intervals 9 and 24 hours) in rats by histologic zymography and compared areas of increased plasminogen activation to areas of structural injury, which were detected immunohistochemically. After 3 hours of ischemia, increased plasminogen activation was observed in the ischemic hemisphere. The affected area measured 5.2%+/-8.5% and 19.4%+/-30.1% of the total basal ganglia and cortex area, respectively. Reperfusion for 9 hours after 3 hours of ischemia led to a significant expansion of plasminogen activation in the basal ganglia (68.8%+/-42.2%, P < 0.05) but not in the cortex (43.0%+/-34.6%, P = 0.394). In the basal ganglia, areas of increased plasminogen activation were related to areas of structural injury (r = 0.873, P < 0.001). No such correlation was found in the cortex (r = 0.299, P = 0.228). In this study, increased plasminogen activation was demonstrated early in focal cerebral ischemia. This activation may promote early secondary edema formation and also secondary hemorrhage after ischemic stroke.

[Leber's hereditary optic nerve neuropathy]

The authors present a case report of 26 years old man with bilateral optic nerve neuropathy. Detection of heteroplasmic mutation of mitochondrial DNA at G3460A site confirmed the suspicion on Lebers hereditary optic nerve neuropathy (LHON). Genetic and environmental factors of the disease and various accompanying neurologic and other symptoms, which can together with the optic nerve defect participate in the development of of the LOHN clinical pattern are discussed. (Ref. 12.)