Endovascular Thrombectomy for Large Ischemic Stroke Across Ischemic Injury and Penumbra Profiles

Importance

Whether endovascular thrombectomy (EVT) efficacy for patients with acute ischemic stroke and large cores varies depending on the extent of ischemic injury is uncertain.

Objective

To describe the relationship between imaging estimates of irreversibly injured brain (core) and at-risk regions (mismatch) and clinical outcomes and EVT treatment effect.

Design, Setting, and Participants

An exploratory analysis of the SELECT2 trial, which randomized 352 adults (18-85 years) with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) and large ischemic core to EVT vs medical management (MM), across 31 global centers between October 2019 and September 2022.

Intervention

EVT vs MM.

Main Outcomes and Measures

Primary outcome was functional outcome-90-day mRS score (0, no symptoms, to 6, death) assessed by adjusted generalized OR (aGenOR; values >1 represent more favorable outcomes). Benefit of EVT vs MM was assessed across levels of ischemic injury defined by noncontrast CT using ASPECTS score and by the volume of brain with severely reduced blood flow on CT perfusion or restricted diffusion on MRI.

Results

Among 352 patients randomized, 336 were analyzed (median age, 67 years; 139 [41.4%] female); of these, 168 (50%) were randomized to EVT, and 2 additional crossover MM patients received EVT. In an ordinal analysis of mRS at 90 days, EVT improved functional outcomes compared with MM within ASPECTS categories of 3 (aGenOR, 1.71 [95% CI, 1.04-2.81]), 4 (aGenOR, 2.01 [95% CI, 1.19-3.40]), and 5 (aGenOR, 1.85 [95% CI, 1.22-2.79]). Across strata for CT perfusion/MRI ischemic core volumes, aGenOR for EVT vs MM was 1.63 (95% CI, 1.23-2.16) for volumes ≥70 mL, 1.41 (95% CI, 0.99-2.02) for ≥100 mL, and 1.47 (95% CI, 0.84-2.56) for ≥150 mL. In the EVT group, outcomes worsened as ASPECTS decreased (aGenOR, 0.91 [95% CI, 0.82-1.00] per 1-point decrease) and as CT perfusion/MRI ischemic core volume increased (aGenOR, 0.92 [95% CI, 0.89-0.95] per 10-mL increase). No heterogeneity of EVT treatment effect was observed with or without mismatch, although few patients without mismatch were enrolled.

Conclusion and Relevance

In this exploratory analysis of a randomized clinical trial of patients with extensive ischemic stroke, EVT improved clinical outcomes across a wide spectrum of infarct volumes, although enrollment of patients with minimal penumbra volume was low. In EVT-treated patients, clinical outcomes worsened as presenting ischemic injury estimates increased.

Trial Registration

ClinicalTrials.gov Identifier: NCT03876457.

Endovascular thrombectomy plus medical care versus medical care alone for large ischaemic stroke: 1-year outcomes of the SELECT2 trial

BACKGROUND

Multiple randomised trials have shown efficacy and safety of endovascular thrombectomy in patients with large ischaemic stroke. The aim of this study was to evaluate long-term (ie, at 1 year) evidence of benefit of thrombectomy for these patients.

METHODS

SELECT2 was a phase 3, open-label, international, randomised controlled trial with blinded endpoint assessment, conducted at 31 hospitals in the USA, Canada, Spain, Switzerland, Australia, and New Zealand. Patients aged 18-85 years with ischaemic stroke due to proximal occlusion of the internal carotid artery or of the first segment of the middle cerebral artery, showing large ischaemic core on non-contrast CT (Alberta Stroke Program Early Computed Tomographic Score of 3-5 [range 0-10, with lower values indicating larger infarctions]) or measuring 50 mL or more on CT perfusion and MRI, were randomly assigned, within 24 h of ischaemic stroke onset, to thrombectomy plus medical care or to medical care alone. The primary outcome for this analysis was the ordinal modified Rankin Scale (range 0-6, with higher scores indicating greater disability) at 1-year follow-up in an intention-to-treat population. The trial is registered at ClinicalTrials.gov (NCT03876457) and is completed.

FINDINGS

The trial was terminated early for efficacy at the 90-day follow-up after 352 patients had been randomly assigned (178 to thrombectomy and 174 to medical care only) between Oct 11, 2019, and Sept 9, 2022. Thrombectomy significantly improved the 1-year modified Rankin Scale score distribution versus medical care alone (Wilcoxon-Mann-Whitney probability of superiority 0·59 [95% CI 0·53-0·64]; p=0·0019; generalised odds ratio 1·43 [95% CI 1·14-1·78]). At the 1-year follow-up, 77 (45%) of 170 patients receiving thrombectomy had died, compared with 83 (52%) of 159 patients receiving medical care only (1-year mortality relative risk 0·89 [95% CI 0·71-1·11]).

INTERPRETATION

In patients with ischaemic stroke due to a proximal occlusion and large core, thrombectomy plus medical care provided a significant functional outcome benefit compared with medical care alone at 1-year follow-up.

FUNDING

Stryker Neurovascular.

Endovascular Thrombectomy Treatment Effect in Direct vs Transferred Patients With Large Ischemic Strokes: A Prespecified Analysis of the SELECT2 Trial

Importance

Patients with large ischemic core stroke have poor clinical outcomes and are frequently not considered for interfacility transfer for endovascular thrombectomy (EVT).

Objective

To assess EVT treatment effects in transferred vs directly presenting patients and to evaluate the association between transfer times and neuroimaging changes with EVT clinical outcomes.

Design, Setting, and Participants

This prespecified secondary analysis of the SELECT2 trial, which evaluated EVT vs medical management (MM) in patients with large ischemic stroke, evaluated adults aged 18 to 85 years with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) as well as an Alberta Stroke Program Early CT Score (ASPECTS) of 3 to 5, core of 50 mL or greater on imaging, or both. Patients were enrolled between October 2019 and September 2022 from 31 EVT-capable centers in the US, Canada, Europe, Australia, and New Zealand. Data were analyzed from August 2023 to January 2024.

Interventions

EVT vs MM.

Main Outcomes and Measures

Functional outcome, defined as modified Rankin Scale (mRS) score at 90 days with blinded adjudication.

Results

A total of 958 patients were screened and 606 patients were excluded. Of 352 enrolled patients, 145 (41.2%) were female, and the median (IQR) age was 66.5 (58-75) years. A total of 211 patients (59.9%) were transfers, while 141 (40.1%) presented directly. The median (IQR) transfer time was 178 (136-230) minutes. The median (IQR) ASPECTS decreased from the referring hospital (5 [4-7]) to an EVT-capable center (4 [3-5]). Thrombectomy treatment effect was observed in both directly presenting patients (adjusted generalized odds ratio [OR], 2.01; 95% CI, 1.42-2.86) and transferred patients (adjusted generalized OR, 1.50; 95% CI, 1.11-2.03) without heterogeneity (P for interaction = .14). Treatment effect point estimates favored EVT among 82 transferred patients with a referral hospital ASPECTS of 5 or less (44 received EVT; adjusted generalized OR, 1.52; 95% CI, 0.89-2.58). ASPECTS loss was associated with numerically worse EVT outcomes (adjusted generalized OR per 1-ASPECTS point loss, 0.89; 95% CI, 0.77-1.02). EVT treatment effect estimates were lower in patients with transfer times of 3 hours or more (adjusted generalized OR, 1.15; 95% CI, 0.73-1.80).

Conclusions and Relevance

Both directly presenting and transferred patients with large ischemic stroke in the SELECT2 trial benefited from EVT, including those with low ASPECTS at referring hospitals. However, the association of EVT with better functional outcomes was numerically better in patients presenting directly to EVT-capable centers. Prolonged transfer times and evolution of ischemic change were associated with worse EVT outcomes. These findings emphasize the need for rapid identification of patients suitable for transfer and expedited transport.

Trial Registration

ClinicalTrials.gov Identifier: NCT03876457.

Safety and Efficacy of Tenecteplase and Alteplase in Patients With Tandem Lesion Stroke: A Post Hoc Analysis of the EXTEND-IA TNK Trials

BACKGROUND AND OBJECTIVES

The safety and efficacy of tenecteplase (TNK) in patients with tandem lesion (TL) stroke is unknown. We performed a comparative analysis of TNK and alteplase in patients with TLs.

METHODS

We first compared the treatment effect of TNK and alteplase in patients with TLs using individual patient data from the EXTEND-IA TNK trials. We evaluated intracranial reperfusion at initial angiographic assessment and 90-day modified Rankin scale (mRS) with ordinal logistic and Firth regression models. Because 2 key outcomes, mortality and symptomatic intracranial hemorrhage (sICH), were few in number among those who received alteplase in the EXTEND-IA TNK trials, we generated pooled estimates for these outcomes by supplementing trial data with estimates of incidence obtained through a meta-analysis of studies identified in a systematic review. We then calculated unadjusted risk differences to compare the pooled estimates for those receiving alteplase with the incidence observed in the trial among those receiving TNK.

RESULTS

Seventy-one of 483 patients (15%) in the EXTEND-IA TNK trials possessed a TL. In patients with TLs, intracranial reperfusion was observed in 11/56 (20%) of TNK-treated patients vs 1/15 (7%) alteplase-treated patients (adjusted odds ratio 2.19; 95% CI 0.28-17.29). No significant difference in 90-day mRS was observed (adjusted common odds ratio 1.48; 95% CI 0.44-5.00). A pooled study-level proportion of alteplase-associated mortality and sICH was 0.14 (95% CI 0.08-0.21) and 0.09 (95% CI 0.04-0.16), respectively. Compared with a mortality rate of 0.09 (95% CI 0.03-0.20) and an sICH rate of 0.07 (95% CI 0.02-0.17) in TNK-treated patients, no significant difference was observed.

DISCUSSION

Functional outcomes, mortality, and sICH did not significantly differ between patients with TLs treated with TNK and those treated with alteplase.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that TNK is associated with similar rates of intracranial reperfusion, functional outcome, mortality, and sICH compared with alteplase in patients with acute stroke due to TLs. However, the CIs do not rule out clinically important differences. TRIAL REGISTRATION INFORMATION: clinicaltrials.gov/ct2/show/NCT02388061; clinicaltrials.gov/ct2/show/NCT03340493.

Trial of Endovascular Thrombectomy for Large Ischemic Strokes

BACKGROUND

Trials of the efficacy and safety of endovascular thrombectomy in patients with large ischemic strokes have been carried out in limited populations.

METHODS

We performed a prospective, randomized, open-label, adaptive, international trial involving patients with stroke due to occlusion of the internal carotid artery or the first segment of the middle cerebral artery to assess endovascular thrombectomy within 24 hours after onset. Patients had a large ischemic-core volume, defined as an Alberta Stroke Program Early Computed Tomography Score of 3 to 5 (range, 0 to 10, with lower scores indicating larger infarction) or a core volume of at least 50 ml on computed tomography perfusion or diffusion-weighted magnetic resonance imaging. Patients were assigned in a 1:1 ratio to endovascular thrombectomy plus medical care or to medical care alone. The primary outcome was the modified Rankin scale score at 90 days (range, 0 to 6, with higher scores indicating greater disability). Functional independence was a secondary outcome.

RESULTS

The trial was stopped early for efficacy; 178 patients had been assigned to the thrombectomy group and 174 to the medical-care group. The generalized odds ratio for a shift in the distribution of modified Rankin scale scores toward better outcomes in favor of thrombectomy was 1.51 (95% confidence interval [CI], 1.20 to 1.89; P<0.001). A total of 20% of the patients in the thrombectomy group and 7% in the medical-care group had functional independence (relative risk, 2.97; 95% CI, 1.60 to 5.51). Mortality was similar in the two groups. In the thrombectomy group, arterial access-site complications occurred in 5 patients, dissection in 10, cerebral-vessel perforation in 7, and transient vasospasm in 11. Symptomatic intracranial hemorrhage occurred in 1 patient in the thrombectomy group and in 2 in the medical-care group.

CONCLUSIONS

Among patients with large ischemic strokes, endovascular thrombectomy resulted in better functional outcomes than medical care but was associated with vascular complications. Cerebral hemorrhages were infrequent in both groups. (Funded by Stryker Neurovascular; SELECT2 ClinicalTrials.gov number, NCT03876457.).

Health Research and Education during and after the COVID-19 Pandemic: An Australian Clinician and Researcher Perspective

Introduction: The COVID-19 pandemic had an unprecedented global effect on teaching and education. This review discusses research, education and diagnostics from the perspectives of four academic clinicians and researchers across different facilities in Australia. Materials and methods: The study adopted a literature review and an Australian researcher's perspective on the impact of the COVID-19 pandemic on health education, research and diagnostics. Results: At the start of the pandemic, medical facilities had to adhere urgently to major work restrictions, including social distancing, mask-wearing rules and/or the closure of facilities to protect staff, students and patients from the risk of COVID-19 infection. Telemedicine and telehealth services were rapidly implemented and adapted to meet the needs of medical education, the teaching of students, trainee doctors, nursing and allied health staff and became a widely accepted norm. The impact on clinical research and education saw the closure of clinical trials and the implementation of new methods in the conducting of trials, including electronic consents, remote patient assessments and the ability to commence fully virtual clinical trials. Academic teaching adapted augmented reality and competency-based teaching to become important new modes of education delivery. Diagnostic services also required new policies and procedures to ensure the safety of personnel. Conclusions: As a by-product of the COVID-19 pandemic, traditional, face-to-face learning and clinical research were converted into online formats. An hybrid environment of traditional methods and novel technological tools has emerged in readiness for future pandemics that allows for virtual learning with concurrent recognition of the need to provide for interpersonal interactions.

Endovascular thrombectomy versus standard bridging thrombolytic with endovascular thrombectomy within 4·5 h of stroke onset: an open-label, blinded-endpoint, randomised non-inferiority trial

BACKGROUND

The benefit of combined treatment with intravenous thrombolysis before endovascular thrombectomy in patients with acute ischaemic stroke caused by large vessel occlusion remains unclear. We hypothesised that the clinical outcomes of patients with stroke with large vessel occlusion treated with direct endovascular thrombectomy within 4·5 h would be non-inferior compared with the outcomes of those treated with standard bridging therapy (intravenous thrombolysis before endovascular thrombectomy).

METHODS

DIRECT-SAFE was an international, multicentre, prospective, randomised, open-label, blinded-endpoint trial. Adult patients with stroke and large vessel occlusion in the intracranial internal carotid artery, middle cerebral artery (M1 or M2), or basilar artery, confirmed by non-contrast CT and vascular imaging, and who presented within 4·5 h of stroke onset were recruited from 25 acute-care hospitals in Australia, New Zealand, China, and Vietnam. Eligible patients were randomly assigned (1:1) via a web-based, computer-generated randomisation procedure stratified by site of baseline arterial occlusion and by geographic region to direct endovascular thrombectomy or bridging therapy. Patients assigned to bridging therapy received intravenous thrombolytic (alteplase or tenecteplase) as per standard care at each site; endovascular thrombectomy was also per standard of care, using the Trevo device (Stryker Neurovascular, Fremont, CA, USA) as first-line intervention. Personnel assessing outcomes were masked to group allocation; patients and treating physicians were not. The primary efficacy endpoint was functional independence defined as modified Rankin Scale score 0-2 or return to baseline at 90 days, with a non-inferiority margin of -0·1, analysed by intention to treat (including all randomly assigned and consenting patients) and per protocol. The intention-to-treat population was included in the safety analyses. The trial is registered with ClinicalTrials.gov, NCT03494920, and is closed to new participants.

FINDINGS

Between June 2, 2018, and July 8, 2021, 295 patients were randomly assigned to direct endovascular thrombectomy (n=148) or bridging therapy (n=147). Functional independence occurred in 80 (55%) of 146 patients in the direct thrombectomy group and 89 (61%) of 147 patients in the bridging therapy group (intention-to-treat risk difference -0·051, two-sided 95% CI -0·160 to 0·059; per-protocol risk difference -0·062, two-sided 95% CI -0·173 to 0·049). Safety outcomes were similar between groups, with symptomatic intracerebral haemorrhage occurring in two (1%) of 146 patients in the direct group and one (1%) of 147 patients in the bridging group (adjusted odds ratio 1·70, 95% CI 0·22-13·04) and death in 22 (15%) of 146 patients in the direct group and 24 (16%) of 147 patients in the bridging group (adjusted odds ratio 0·92, 95% CI 0·46-1·84).

INTERPRETATION

We did not show non-inferiority of direct endovascular thrombectomy compared with bridging therapy. The additional information from our study should inform guidelines to recommend bridging therapy as standard treatment.

FUNDING

Australian National Health and Medical Research Council and Stryker USA.

Clinical outcomes following reperfusion therapy in acute ischemic stroke patients with infective endocarditis: a systematic review

Background

Acute ischemic stroke (AIS) is a common and fatal complication of infective endocarditis (IE); however, there is a lack of understanding regarding treatment efficacy. This systematic review aimed to evaluate the safety and efficacy of intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT) in IE patients experiencing AIS.

Objectives

The aim of this study was to perform a systematic review investigating the outcomes of AIS in IE patients receiving IVT and/or EVT as a treatment method and to evaluate the safety and efficacy of these methods of reperfusion therapy.

Design

A systematic review in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines was conducted.

Data Sources and Methods

The EMBASE, Cochrane, and PubMed databases were searched for literature published between 2005 and 2021 investigating outcomes of reperfusion therapy post-AIS in IE and non-IE patients. Descriptive statistics were used to describe the overall frequency of clinical outcomes, and groupwise comparisons were performed using Fisher’s exact test to assess the significance of groupwise differences.

Results

Three studies were finally included in the systematic review. A total of 13.5% of IE patients compared to 37% of non-IE patients achieved a good functional outcome (modified Rankin Scale score≤ 2) (P < .001). Furthermore, a larger percentage of the IE cohort achieved good functional outcomes after EVT (22.0%) compared to IVT (10.4%) (P = .013). The IE cohort also had a higher 3-month postreperfusion mortality rate (48.8%) compared to the non-IE cohort (24.9%) (P < .001). The rate of intracranial hemorrhage (ICH) postreperfusion was also significantly higher in the IE cohort (23.5%) than in the non-IE cohort (6.5%) (P < .001).

Conclusion

AIS patients with IE, treated with IVT, EVT, or a combination of the two, experience worse clinical and safety outcomes than non-IE patients. EVT yielded better functional outcomes, albeit with higher postreperfusion ICH rates, than IVT.

A Multicentre Study Comparing Cerebrovascular Disease Profiles in Pacific Islander and Caucasian Populations Presenting with Stroke and Transient Ischaemic Attack

INTRODUCTION

In a multicentre study, we contrasted cerebrovascular disease profiles in Pacific Island (PI)-born patients (Indigenous Polynesian [IP] or Indo-Fijian [IF]) presenting with transient ischaemic attack (TIA), ischaemic stroke (IS) or intracerebral haemorrhage (ICH) with those of Caucasians (CSs).

METHODS

Using a retrospective case-control design, we compared PI-born patients with age- and gender-matched CS controls. Consecutive patients were admitted to 3 centres in South Western Sydney (July 2013-June 2020). Demographic and clinical data studied included vascular risk factors, stroke subtypes, and imaging characteristics.

RESULTS

There were 340 CS, 183 (27%) IP, and 157 (23%) IF patients; mean age 65 years; and 302 (44.4%) female. Of these, 587 and patients presented with TIA/IS and 93 (13.6%) had ICH. Both IP and IF patients were significantly more likely to present >24 h from symptom onset (odds ratios [ORs] vs. CS 1.87 and 2.23). IP patients more commonly had body mass indexes >30 (OR 1.94). Current smoking and excess alcohol intake were higher in CS. Hypertension, diabetes, and chronic kidney disease were significantly higher in both IP and IF groups in comparison to CS. IP patients had higher rates of AF and those with known AF were more commonly undertreated than both IF and CS patients (OR 2.24, p = 0.007). ICH was more common in IP patients (OR 2.32, p = 0.005), while more IF patients had intracranial arterial disease (OR 5.10, p < 0.001).

DISCUSSION/CONCLUSION

Distinct cerebrovascular disease profiles are identifiable in PI-born patients who present with TIA or stroke symptoms in Australia. These may be used in the future to direct targeted approaches to stroke prevention and care in culturally and linguistically diverse populations.

Adjuvant immunosuppression for paradoxical deterioration in tuberculous meningitis including one case responsive to cyclosporine. A tertiary referral hospital experience

BACKGROUND

Tuberculous meningitis (TBM) accounts for 1-4% of all tuberculosis (TB) presentations. Paradoxical deterioration in non-HIV patients is a common manifestation of anti-tuberculosis therapy, characterised by clinico-radiological deterioration. We report a case series of TBM admissions to our institution including one case with paradoxical deterioration refractory to corticosteroids who responded to adjuvant cyclosporine.

METHODS

Retrospective review of 12 HIV-negative patients admitted to Liverpool Hospital, Sydney (2005-2016) with laboratory and/or radiologically confirmed TBM.

RESULTS

Median patient age was 40 (range 22-81 years), M:F = 7:5. Eleven patients (92%) were of Asia-Pacific origin. Eleven initially presented with central nervous system manifestations and one had preceding miliary TB. Nine patients had extra-cranial TB involvement including eight with past or current pulmonary disease. Cerebrospinal fluid (CSF) TB PCR/culture was positive in 10 patients. Paradoxical deterioration developed in three patients despite concomitant corticosteroids in two. One patient with paradoxical deterioration was refractory to corticosteroids: A 22-year-old Vietnamese male with TBM developed worsening headaches and altered mentation after seven weeks concomitant anti-TB and corticosteroid treatment. Interval MRI brain demonstrated increased size and number of tuberculomas as well as hydrocephalus. Cyclosporine was added with gradual improvement and ultimately good outcome.

CONCLUSION

Our case series highlights the seriousness of paradoxical deterioration in TBM and the potential role of adjuvant cyclosporine in patients refractory to corticosteroids.

Factors Associated with Stroke Misdiagnosis in the Emergency Department: A Retrospective Case-Control Study

BACKGROUND

Failure to recognise acute stroke may result in worse outcomes due to missed opportunity for acute stroke therapies. Our study examines factors associated with stroke misdiagnosis in patients admitted to a large comprehensive stroke centre.

METHODS

Retrospective review comparing 156 consecutive stroke patients misdiagnosed in emergency department (ED) with 156 randomly selected stroke controls matched for age, gender, language spoken and stroke subtype for the period 2014-2016.

RESULTS

There were 141 ischemic and 15 hemorrhagic misdiagnosed strokes (median age: 77 years, male:female = 1.3: 1). Symptom resolution, altered mental status, nausea/vomiting, dizziness and vertigo favored misdiagnosis (p < 0.05). Hemiparesis and dysarthria favored an accurate diagnosis (p < 0.05). Misdiagnosed patients were more commonly triaged into a lower ED category (62 vs. 42%, p = 0.001), clinically assessed as Face, Arm, Speech and Time (FAST) - negative (78 vs. 22%, p < 0.001) and underwent delayed CT imaging (median 4.1 vs. 1.5 h, p < 0.001). Misdiagnosed patients were more likely to have posterior circulation stroke (PCS; 39 vs. 22%, p = 0.01) and be admitted under non-neurological services (35 vs. 11%, p < 0.001) with worse discharge outcomes including increased mortality.

CONCLUSIONS

Patients with stroke misdiagnosis were commonly FAST-negative with nonspecific symptoms including altered mental status, dizziness and nausea/vomiting often associated with PCS. Improved diagnostic accuracy may increase access to acute therapies.

Frequency, Aetiology, and Outcome of Small Cerebellar Infarction

BACKGROUND AND PURPOSE

Strokes due to small (<2 cm) cerebellar infarction are under-recognised, and their profile and aetiology have not been well characterised. We aimed to determine the frequency, clinical features, aetiology, and outcome of small as compared to large cerebellar infarction.

METHODS

This study is a retrospective analysis of clinical and imaging features of a prospectively assessed series of 108 consecutive patients with acute cerebellar infarction admitted to Liverpool Hospital, Sydney, NSW, Australia, during 2011-2015.

RESULTS

The mean age of the patients was 67 years, and 33 (31%) had small cerebellar infarction. Compared to large cerebellar infarction, those with small cerebellar infarction had a comparable distribution of vascular risk factors but significantly less nausea and vomiting, gait disturbance, limb ataxia, and dysarthria. The posterior (n = 22, 67%) lobe was most commonly affected, followed by the anterior (n = 9, 27%) and flocculonodular (n = 2) lobes. Dizziness, limb ataxia, and nystagmus were significantly more common in patients with anterior lobe infarction. Vertebrobasilar disease was the presumed aetiology in 40 patients (37%), and was less commonly seen in small as compared to large cerebellar infarction. Cardioembolism affected 37% of the patients, irrespective of the size or topography of the cerebellar infarction, and there was no relation of supratentorial white matter lucencies (WMLs) to the size of cerebellar infarction. At 3 months, 65% of the patients were functionally independent (according to modified Rankin Scale scores of 0-2), and having a poor outcome was significantly related to moderate-to-severe supratentorial WML and large cerebellar infarction.

CONCLUSIONS

Small cerebellar infarction accounted for one-third of the ischaemic strokes in this location, most often involved the posterior lobe, causing fewer clinical features, and had a better clinical outcome than large cerebellar infarction. Patients with small cerebellar infarction require appropriate vascular management including investigation for a cardioembolic source.

Can head trauma trigger adult-onset Rasmussen's encephalitis?

Rasmussen's encephalitis (RE) is a rare unilateral inflammatory brain disorder that causes progressive neurocognitive deterioration and refractory epilepsy including epilepsia partialis continua (EPC). We describe a patient with a unique presentation, where right upper limb EPC due to RE began within 2weeks of a concussive left frontal head injury, in a 36-year-old female without other identifiable etiology, no prior neurological deficit nor suggestion of intracranial pathology or infection, and no preceding seizures. The diagnosis of RE followed extensive investigation, excluding confounding diagnoses, with supportive histopathology, and her EPC has proven refractory to treatment. In the absence of a satisfactory alternative etiology and exclusion of differential diagnoses, the most likely cause or precipitant of this patient's RE was head trauma.

Cerebellar Infarction and Factors Associated with Delayed Presentation and Misdiagnosis

Background and Purpose: The diagnosis of cerebellar infarction (CBI) is often challenging due to non-specific or subtle presenting symptoms and signs. We aimed to determine whether a common syndromic cluster of symptoms, signs or vascular risk factors were associated with delayed presentation or misdiagnosis to an Emergency Department (ED). The degree of misdiagnosis between ED and neurology physicians and the influence of delayed presentation or misdiagnosis on outcome were also investigated. Methods: A prospective study of CBI patients at a large tertiary-referral hospital with a comprehensive stroke service. Data are reported with OR and 95% CIs. Results: Of 115 consecutive CBI patients (mean age ± SD 66 ± 14 years, 51% male), infarction was isolated to the cerebellum in 46%; the remainder had additional vascular territory involvement (‘mixed CBI'). Most patients (n = 79, 69%) had a mild stroke (National Institute of Health Stroke Scale score ≤4), and tended to present late to ED (>4.5 h; p = 0.05). Dysarthria (OR 3.9, 95% CI 1.6-9.6, p = 0.003) and prior history of atrial fibrillation (AF; OR 3.0, 95% CI 1.02-9.1, p = 0.047) predicted early presentation (<4.5 h; in 52%). Neurological signs (as determined by neurology physicians) were more commonly absent in patients with isolated CBI (OR 4.0, 95% CI 1.2-13.3, p = 0.03) who were also less likely to receive acute stroke therapy (p = 0.03). ED physicians detected fewer neurological signs than neurology physicians (mean 1 vs. 2 signs, p < 0.001), and 34% of CBI patients were misdiagnosed, with peripheral vestibulopathy being the most common alternative diagnosis. Nausea and vomiting (OR 2.3, 95% CI 1.01-5.5, p = 0.046), absence of neurological signs as determined by ED physicians (OR 3.5, 95% CI 1.5-8.0, p = 0.003) and isolated CBI (OR 2.2, 95% CI 1.01-4.8, p = 0.047) correlated with misdiagnosis. Vascular territory involvement did not correlate with time to presentation or misdiagnosis. At 3 months, 65% of patients were functionally independent (modified Rankin Scale (mRS) score 0-2). History of hypertension (p = 0.008), AF (p = 0.012), mixed CBI (p = 0.004) and in-hospital stroke-related complications (p < 0.001) were associated with patients having a poor outcome (mRS ≥3). At 3 months, mortality was 16%, and AF was the only predictor of death (OR 3.2, 95% CI 1.1-8.9, p = 0.03). Late presentation to ED and misdiagnosis did not significantly influence 3-month functional outcome. Conclusions: Late ED presentation and misdiagnosis are common for CBI. Timely diagnosis of CBI may increase opportunity for acute stroke therapies and reduce risk of stroke-related complications.

The Effect of Biofeedback as a Psychological Intervention in Multiple Sclerosis: A Randomized Controlled Study

BACKGROUND

Relaxation, mindfulness, social support, and education (RMSSE) have been shown to improve emotional symptoms, coping, and fatigue in multiple sclerosis (MS). Biofeedback was trialed as a psychological intervention, designed to improve self-control, in two groups of patients with MS. Both groups received RMSSE, and one group additionally received biofeedback.

METHODS

Forty people with relapsing-remitting MS were recruited from three sites in Sydney, Australia. The mean disability score (Expanded Disability Status Scale; EDSS) was 2.41 ± 1.46 (95% confidence interval [CI], 1.46-3.36); the mean age in years was 45.9 ± 12.42 (95% CI, 41.92-49.87). Participants were randomly assigned to two active treatment groups (n = 20 per group). All participants received one 1-hour session per week for 3 weeks of RMSSE, while biofeedback equipment measured breathing rate and muscle tension. Members of one group used biofeedback screens to regulate physiological response.

RESULTS

Whole-group pre- and post-treatment scores demonstrated a reduction of 38% for anxiety and 39% for depression scores (P = .007 and P = .009, respectively). A post-treatment comparison failed to demonstrate any significant difference between the two active treatment groups in anxiety and depression scores. The biofeedback group showed significant pre- to post-treatment improvement or trends toward improvement in anxiety, fatigue, and stress (P = .05, .02, and .03, respectively). Comparison of pre-post treatment results between groups showed improvements for the biofeedback group in breathing rate and muscle tension (P = .06 and .09).

CONCLUSIONS

For relapsing-remitting MS patients receiving biofeedback in addition to RMSSE, there was a demonstrable reduction in anxiety, fatigue, and stress. There was also a trend toward significant reduction of breathing rate and muscle tension in favor of biofeedback.

Rectal carbamazepine as effective long-acting treatment after cluster seizures and status epilepticus

Carbamazepine (CBZ) is the gold standard antiepileptic drug (AED) for focal onset seizures. Despite CBZ being the benchmark AED, with readily available therapeutic drug monitoring, patients presenting with recurrent secondarily generalized tonic-clonic (or cluster) seizures or generalized tonic-clonic status epilepticus (SE) are primarily treated with other long-acting agents. The aim of the study was to examine the potential use of rectal (PR) CBZ as alternative long-acting treatment to parenteral AEDs following the termination of cluster seizures or SE with acute intravenous therapies. Oral CBZ syrup was given PR using 400-mg equivalent aliquots. Serum CBZ levels were requested after administration to confirm achievement of minimum therapeutic levels (total CBZ>20μmol·L(-1)). Where levels were subtherapeutic, the procedure was repeated using 400-mg CBZ bolus aliquots until therapeutic levels were achieved. Seven patients received PR CBZ to manage cluster seizures or SE following the initial termination of acute seizures with IV therapies including benzodiazepines. Six patients had no prior history of seizures, and 1 patient with a prior history was not taking AED therapy at the time of presentation. All patients subsequently remained seizure-free, and therapeutic CBZ levels were achieved in 6 of the 7 subjects within 5-10h of initial CBZ dosing. In conclusion, the present study reports 7 patients who were safely and effectively treated with PR CBZ, which proved to be a viable and safe alternative to parenteral AEDs for maintenance of seizure freedom.

Rebound exacerbation multiple sclerosis following cessation of oral treatment

BACKGROUND

Multiple sclerosis (MS) management is changing, revolutionized by oral agents. Immune Reconstitution Inflammatory Syndrome (IRIS) describes exaggerated response to both exogenous (infective) and endogenous (non-infective) antigens.

METHODS

This paper reports two cases of MS "rebound" following withdrawal of oral treatments.

RESULTS

Two patients, with suboptimal response to interferons, trialled oral MS treatment (fingolimod and BG12) with excellent response. Upon cessation both experienced MS "rebound" which responded to steroids.

CONCLUSIONS

"Rebound" may occur following withdrawal of oral MS therapies. Patients should be advised accordingly and possibly started on alternative treatment before the immunomodulating effect of therapy has subsided.

Prevalence of positive syphilis serology and meningovascular neurosyphilis in patients admitted with stroke and TIA from a culturally diverse population (2005-09)

The study aims were to determine the prevalence of positive syphilis serology and meningovascular neurosyphilis (NS) in patients admitted with transient ischaemic attack (TIA) and stroke to a tertiary hospital serving a culturally diverse community. A retrospective cohort analysis was conducted using routinely collected administrative data and medical records to identify patients admitted with TIA, stroke and other conditions, with positive syphilis serology, between 2005 and 2009. Direct medical record review confirmed diagnoses of meningovascular NS. Syphilis serology was requested in 27% (893/3270) of all patients with TIA and stroke (2005-09) of whom 4% (38/893) were positive. Thirty-seven patients with positive serology had clinical characteristics consistent with meningovascular NS. Their mean age was 72±13 years; 65% were male and 68% had a recorded place of birth in South-East Asia or the Pacific Islands. One of 12 patients with suspected meningovascular NS with cerebrospinal fluid (CSF) analysis had a positive CSF Venereal Disease Research Laboratory (VDRL) test. Three patients (8%) met diagnostic criteria for "definite or probable" meningovascular NS. All three patients with a "definite or probable" meningovascular NS and 15 (44%) of the remainder who had positive serology without confirmation of NS were treated with intravenous or intramuscular penicillin. Lumbar puncture (LP) and penicillin were underutilised in patients with TIA and stroke with positive serology. In conclusion, syphilis testing should be considered part of the diagnostic work-up of TIA and stroke, particularly in ethnically diverse populations. In patients with TIA and stroke with positive syphilis serology, it would seem appropriate to further pursue diagnosis and treatment and in patients unable to undergo LP, empiric treatment for NS should be considered.

Small-vessel disease in patients with Parkinson's disease: a clinicopathological study

Few studies have examined the relationship between cerebrovascular disease, vascular risk factors, and Parkinson's disease (PD), although 1 study found small-vessel disease (SVD) to be the main subtype of cerebrovascular disease. In this study we compared the extent and topography of SVD and assessed associated vascular risk factors in autopsy-proven PD cases and community-dwelling controls. Seventy-seven PD and 32 control brains from the Sydney Brain Bank were assessed microscopically by a single examiner blinded to the diagnosis. SVD was assessed by grading perivascular pallor, gliosis, hyaline thickening, and enlargement of perivascular spaces in the white matter underlying the superior frontal and primary motor cortices, basal ganglia, and white matter tracts. A history of vascular risk factors (hypertension, heart disease, diabetes, and cigarette smoking) was obtained. Groups were compared using stepwise multiple regression analysis. There was significantly greater frontal pallor (P = .004) and widening of perivascular spaces in the globus pallidus interna (P = .007) in controls compared with PD. Hyaline thickening and widening of perivascular spaces in the frontal white matter, hyaline thickening in the motor white matter, and widening of perivascular spaces in the caudate nucleus were more common in the control group, but did not reach significance. The prevalence of vascular risk factors and SVD pathology was significantly lower in autopsy-proven PD compared with controls (P = .03) living in the same community. The results of this study support the need for further research in this area.

Changed constitution without change in brand name--the risk of generics in epilepsy

PURPOSE

Lamotrigine (LTG) is an anti epileptic medication (AEM) for which blood levels are helpful for optimal dosing. In late 2010, patients attending an epilepsy clinic were becoming toxic without obvious cause. This paper reports altered levels without change in regimen and provides unexpected findings.

METHODS

Patients with elevated LTG blood levels were assessed to determine change in AEM regimen or generic substitution. Method of blood level determination was reviewed and the company (GlaxoSmithKline) contacted regarding change in source of medication.

PRINCIPAL RESULTS

The sample comprised 18 patients; mean age 40±16 years, mean daily LTG dose 493±218 mg. Mean serum LTG concentrations from August 2010 to February 2011 [91.8±17.7 μmolL(-1), range 69.9-133.7 μmolL(-1)] were significantly higher than those from January 2010 to July 2010 [50.3±9.1 μmolL(-1), range 32-60.1 μmolL(-1)), p<0.0001]. All patients received parent product (Lamictal(®)) and the method of LTG blood level determination was unchanged. GlaxoSmithKline confirmed that Lamictal(®) was sourced from a different site.

CONCLUSIONS

These results indicate that, even using a parent compound, AEM levels can fluctuate if the product source has changed, resulting in toxicity. It also highlights the value of determining AEM levels and the risks attached to generic substitution.

Basilar artery occlusion in a 14-year old female successfully treated with acute intravascular intervention: case report and review of the literature

Basilar artery occlusion (BAO) is a rare cause of paediatric stroke that may result in severe neurological disability including a 'locked-in' state. Acute interventional therapy for paediatric BAO is limited to a small number of published case reports. Of 13 previously published cases that have undergone acute intravascular therapy, six made a full neurological recovery, six had residual deficits ranging from mild dysarthria and ataxia to vegetative state and one patient died. The time from symptom onset to intervention was ≥ 12 h in 77% (10/13). We reported a 14-year-old female patient presenting with altered sensorium that progressed to a 'locked-in' state due to idiopathic BAO who made a full clinical recovery after successful mechanical thrombectomy at 24 h following symptom onset. Acute neuro-interventional therapy for paediatric BAO can result in complete neurological recovery despite the presence of severe neurological deficits and a prolonged period of time from symptom onset to clinical diagnosis.

Glyphosate-surfactant herbicide-induced reversible encephalopathy

Glyphosate-surfactant (GlySH) is a commonly used herbicide that has been used in attempted suicide. Most reports of GlySH toxicity in patients have followed ingestion of the commercial product "Round-up" (Monsanto Ltd; Melbourne, Victoria, Australia), which consists of a mixture of glyphosate (as a isopropylanine salt) and a surfactant (polyoxyethyleneamine). Ingestion of Round-up is reported to cause significant toxicity including nausea, vomiting, oral and abdominal pain. Renal and hepatic impairment and pulmonary oedema may also occur. Impaired consciousness and encephalopathy have been reported as sequelae but there are limited data on the central nervous system (CNS) effects of Round-up toxicity. We report a 71-year-old male who attempted suicide with GlySH and developed a prolonged but reversible encephalopathy suggestive of acute CNS toxicity.

Validation of emergency and final diagnosis coding in transient ischemic attack: South Western Sydney transient ischemic attack study

BACKGROUND

It is important to establish the validity of diagnostic coding in administrative datasets used in stroke and transient ischemic attack (TIA) research. This study examines the accuracy of emergency department (ED) TIA diagnosis and final diagnostic coding after hospital admission.

METHODS

Using administrative datasets, we identified all patients with an ED TIA diagnosis (435.9; ICD-9) admitted to Liverpool Hospital from January 2003 to December 2007. ED and hospital admission records were matched and final diagnosis codes (ICD-10-AM) recorded. All records were expertly reviewed to determine coding validity.

RESULTS

570 patients were admitted with an ED TIA diagnosis. According to ICD-10-AM coding, 46% had TIA, 29% stroke and 25% TIA mimic diagnoses. Expert review determined final diagnoses of TIA in 51.4%, stroke in 26.1% and TIA mimic in 22.5% of the patients. The positive predictive value of a final TIA diagnosis (ICD-10-AM) was 88.2% when subjected to expert review. TIA mimic disorders diagnosed after admission included serious conditions.

CONCLUSIONS

Half of the emergency diagnoses retained a TIA diagnosis after hospital admission. In the setting of neurological admission there were small percentage differences between coded final diagnosis for TIA, stroke and mimic and diagnoses at expert review. Admission of ED TIA cases permitted identification of TIA mimics with serious conditions requiring non-TIA management.

Decreasing presentations of seizures to emergency departments in a large Australian population

This study was designed (1) to compare the prevalence of emergency department (ED) presentations in Western Zone Sydney South West Area Health Service (WZS) between 1998-2002 and 2003-2007 for epilepsy (including status epilepticus (SE) and convulsions), hospital admission rates, and proportion of first seizure presentations; and (2) to compare these data with those for New South Wales (NSW) and Australia-wide figures. Using health department data sets, we found 19,834 presentations to WZS EDs between 1998 and 2007 (24.85/10,000 population/year). When the periods 2003-2007 and 1998-2002 in WZS are compared, ED presentations fell by 3% (P=0.03) and hospital admissions fell by 6% (P=0.001). The prevalence of ED presentations for seizures in NSW did not change (P=0.92), but hospital admissions fell by 3% (P<0.0001). When 1999/2000-2002/2003 was compared with 2003/2004-2006/2007, the prevalence of hospital admissions in Australia fell by 1% (P=0.0002). Rates of presentation for epilepsy in WZS have fallen over the last decade. Most presentations were first seizures rather than recurrences. The reason for this is speculative, but may reflect improved levels of education and health care delivery.

Post-vaccination encephalomyelitis: literature review and illustrative case

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system that is usually considered a monophasic disease. ADEM forms one of several categories of primary inflammatory demyelinating disorders of the central nervous system including multiple sclerosis, optic neuropathy, acute transverse myelitis, and neuromyelitis optica (Devic's disease). Post-infectious and post-immunisation encephalomyelitis make up about three-quarters of cases, where the timing of a febrile event is associated with the onset of neurological disease. Post-vaccination ADEM has been associated with several vaccines such as rabies, diphtheria-tetanus-polio, smallpox, measles, mumps, rubella, Japanese B encephalitis, pertussis, influenza, hepatitis B, and the Hog vaccine. We review ADEM with particular emphasis on vaccination as the precipitating factor. We performed a literature search using Medline (1976-2007) with search terms including "ADEM", "acute disseminated encephalomyelitis", "encephalomyelitis", "vaccination", and "immunisation". A patient presenting with bilateral optic neuropathies within 3 weeks of "inactivated" influenza vaccination followed by delayed onset of ADEM 3 months post-vaccination is described.

Outcomes of patients with transient ischaemic attack after hospital admission or discharge from the emergency department

OBJECTIVE

To compare outcomes at 28 days and 1 year between patients admitted to hospital and those discharged after presenting to the emergency department (ED) with transient ischaemic attack (TIA).

DESIGN AND SETTING

All TIA presentations to EDs in a large metropolitan and rural region of Sydney and its surroundings, New South Wales, between 2001 and 2005 were extracted from state health department databases and followed up over 1 year. Admission and discharge data and subsequent TIA or stroke presentations were identified.

MAIN OUTCOME MEASURES

TIA recurrence or stroke.

RESULTS

Of 2535 presentations to an ED with TIA during the 5-year period, 1816 patients were admitted to hospital (71.6%) and 719 were discharged from the ED (28.4%). At 28 days, the discharged group had significantly higher rates of recurrence than the admitted group for all events (TIA or stroke) (5.3% v 2.3%, P < 0.001), stroke (2.1% v 0.7%, P = 0.002), and recurrent TIA (3.2% v 1.6%, P = 0.01). During the 29-365-day follow-up period, there was no significant difference between the discharged and admitted groups for all events (4.2% v 5.1%; P = 0.37), stroke (1.3% v 2.5%; P = 0.06) or recurrent TIA (2.9% v 2.6%; P = 0.65).

CONCLUSION

Patients with an ED diagnosis of TIA may benefit from admission to hospital through a reduced risk of early stroke.

Dysphagia: causes, assessment, treatment, and management

Dysphagia, or difficulty in swallowing, is a condition with a strong age-related bias. Rates of dysphagia vary due to differences in method between studies; eg, clinical history of "swallowing difficulty," evidence of aspiration, or dysphagia confirmed by swallowing investigations. In general, the rate is lower in the community than in nursing home facilities. The management and treatment of dysphagia among geriatric patients is complicated by cognitive decline, lowered immunity, malnutrition, and end-of-life decisions. This article reviews the current assessment, treatment, and management techniques for dysphagia; covers new developments in research and pilot studies; and reviews the ethical issues related to treatment when prognosis is poor.

Management for motor and non-motor complications in late Parkinson's disease

The prevalence of neurodegenerative diseases such as Parkinson's disease (PD) increases with age. In an aging population, an understanding of the management of late complications of PD is becoming ever more important. Drug treatment for Parkinson's disease is largely symptomatic and relies primarily on levodopa (L-dopa) and adjuvant therapies including dopamine agonists and catechol-O-methyltransferase (COMT) inhibitors. Rehabilitation and allied health input also constitutes a core part of successful management. Most subjects who are symptomatic for more than 5 years are prone to late complications of PD. Some of these are related to the treatment, such as motor fluctuations, including the "on-off" phenomenon and levodopa-related peak dose dyskinesia. Others, such as postural hypotension, falls, psychosis, and dementia, although well-recognized problems in the elderly, often require different treatment strategies if occurring in the context of PD. The practical evidence-based management of motor and non-motor complications in late PD is discussed.

Endovascular treatment of an acute left middle cerebral artery >6 h post stroke in a patient presenting with dysphasia and dense right hemiplegia

This paper describes the case of a 32-year-old man presenting with dense right hemiplegia and global aphasia caused by an acute left middle cerebral artery infarct that underwent successful endovascular therapy after being determined ineligible for intravenous tissue plasminogen activator. Clot transversion and balloon disruption followed by intra-arterial Alteplase resulted in successful re-canalization of his middle cerebral artery at 7 h 30 min. At 3 months post stroke, the patient had moderately severe expressive dysphasia but was mobilizing independently with normal right upper and lower limb strength. In conclusion, the 3 month outcome suggests that the therapeutic time window for endovascular therapy might exceed 6 h post stroke.

Genetics and Parkinson's disease

Idiopathic Parkinson's disease is a neurodegenerative disorder that affects 1-2% of the population over the age of 65 years. Its aetiology is most likely a combination of complex genetic and environmental factors. Although Mendelian inheritance is seen in less than 5% of cases, recent studies have identified three genes mutations causing Parkinson's disease with a Mendelian inheritance pattern: autosomal dominantly inherited mutations of the alpha-synuclein gene on chromosome 4q21-q23, autosomal recessively inherited mutations of the parkin gene on chromosome 6q25.2-q27 and an autosomal dominantly inherited mutation of the Ubiquitin C-terminal hydrolase L1 (UCH-L1) gene on chromosome 4p14-15.1. A number of other candidate gene polymorphisms including cytochrome P450 2D6, N-acetyltransferase 2, monoamine oxidase-B and glutathione-s-transferase M1 are implicated in sporadic and familial cases and may also play a minor role in the aetiology of Parkinson's disease.

Post-cranial irradiation syndrome with migraine-like headaches, prolonged and reversible neurological deficits and seizures

Two adult patients with a background history of astrocytomas treated with resection and cranial irradiation, 18 and 16 years previously, presented with acute onset of headache associated with prolonged neurological deficits, including dysphasia and right hemiparesis. The first patient also developed seizures while in hospital. In both patients, magnetic resonance imaging brain scans failed to show evidence of acute ischaemia or tumour recurrence and symptoms reversed completely after 1 month and 7 days, respectively. A single photon emission computed tomography scan, performed on the first patient at day 8 post-admission, showed hyperperfusion in the left parieto-occipital region (in the same region as his previous tumour). The clinical histories and outcomes are consistent with the diagnosis of post-cranial irradiation syndrome with migraine-like headaches and prolonged and reversible neurological deficits. Recognition of this disorder is useful in providing reassurance of a favourable prognosis and may also help avoid invasive investigations.

Utility of magnetic resonance imaging in diagnosing ulnarneuropathy at the elbow

OBJECTIVE

Magnetic resonance imaging (MRI) of the ulnar nerve is being increasingly employed in the diagnosis of ulnar neuropathy at the elbow (UNE). Our aims were to: (i) assess the sensitivity of MRI in diagnosing UNE, especially in cases where neurophysiologic studies were non-localizing, (ii) determine the spectrum of MRI abnormalities in patients presenting with symptoms and signs of ulnar neuropathy, (iii) assess whether MRI findings differ between grades of UNE severity, and (iv) to see if MRI findings give an input into the pathological mechanisms of UNE.

METHODS

Clinical, neurophysiologic, and radiologic (MRI) records were reviewed in 52 patients with symptoms and signs of ulnar neuropathy. Ulnar nerve MRI studies were assessed by an unblinded observer.

RESULTS

The sensitivity of MRI at diagnosing UNE was higher than conventional nerve conduction studies, 90 versus 65%, respectively. In patients with non-localizing neurophysiologic studies (n=19), MRI disclosed changes consistent with UNE in 16 (84%) cases. The most frequent MRI findings included a combination of high signal intensity and nerve enlargement (63%), followed by nerve compression (27%) and isolated high signal intensity (23%), and isolated nerve enlargement (2%). There was no significant difference between patients with localizing and non-localizing neurophysiologic testing. Lastly, there were no differences between different grades of UNE, suggesting that UNE may be a neurophysiologically heterogeneous disorder.

CONCLUSIONS

MRI studies proved to be more sensitive than conventional nerve conduction studies at diagnosing UNE. In addition, the MRI studies were highly sensitive in patients with non-localizing UNE.

SIGNIFICANCE

Our study shows that MRI of the ulnar nerve should be used in patients with clinical features of UNE especially in those with non-localizing neurophysiologic testing.

Acute and reversible micrographia in a patient possibly due to cerebral ischaemia

We report a patient who developed acute and reversible micrographia, presumably due to cerebral ischaemia, on a background of mutism following a pharyngo-laryngectomy 10 years earlier. Magnetic resonance (MR) imaging showed chronic small vessel disease without evidence of an acute ischaemic lesion on diffusion-weighted sequences. Our patient's micrographia improved significantly within 12 days of symptom onset. The MR imaging was performed within 5 days of symptom onset, suggesting that the lesion was either too small for detection or had resolved on diffusion-weighted sequences.

Comparison of Stroke Risk Factors and Outcomes in Patients with English-Speaking Background versus Non-English-Speaking Background

This study examined stroke risk factor profiles, management and outcomes for elderly patients with English-speaking background (ESB) and non-English-speaking background (NESB). This is an observational cohort study with both retrospective and prospective components. In total, 186 consecutive acute stroke patients aged > or =65 years admitted to our hospital were recruited over a 12-month period. Patient characteristics, stroke risk factors and management, in-hospital mortality, functional independence measurement scores before admission and at discharge, and discharge destination were recorded. On admission, NESB patients with atrial fibrillation (AF) were less likely to be taking warfarin than ESB patients (1 out of 19 with NESB vs. 19 out of 41 with ESB, p = 0.001). More NESB patients had a history of diabetes mellitus (DM) than ESB patients (41.4 vs. 10.2%, respectively; p = 0.001). However, ESB and NESB patients were comparable in terms of age, gender, preadmission functional status as well as other stroke risk factors (including smoking and alcohol drinking pattern, prevalence of hypertension and lipid disorder) and their management. In-hospital mortality was similar between ESB and NESB patients (10.2 vs. 8.6%). In conclusion, we found an association with our population of elderly NESB patients and an underutilization of warfarin for AF as well as a higher frequency of DM. Determination of the underlying reasons for such differences may be of value in the primary health care of NESB patients.

Positional vomiting due to a thoracic spinal dural arteriovenous fistula

✓ The authors report the unique case of a patient with a thoracic spinal dural arteriovenous fistula (DAVF) causing remote brainstem symptoms of positional vomiting and minimal vertigo. Magnetic resonance (MR) imaging of the brain demonstrated high signal abnormality in the medulla, presumably related to venous hypertension, and spinal MR imaging revealed markedly dilated veins along the dorsal aspect of the cord. Spinal angiography confirmed the presence of a thoracic spinal DAVF. Disconnection of the DAVF from the spine resulted in a marked improvement in symptoms and resolution of the preoperative MR imaging—documented abnormalities. The authors highlight the rare syndrome of positional vomiting as a brainstem symptom and conclude that spinal DAVFs should be considered in the differential diagnosis of high signal MR imaging abnormalities localized to the brainstem.

Stereochemistry in clinical medicine: a neurological perspective

Stereoisomers are compounds that have identical sets of atoms configured in the same positions but are arranged differently spatially. Approximately 25% of contemporary drugs are marketed and used as racemates (i.e., as equimolar mixtures of stereoisomers). This may have major clinical implications, as stereoisomers may possess qualitative and/or quantitative differences in pharmacological effects, plasma protein and tissue binding, metabolic and renal clearance. There are many examples of racemic drugs manufactured and used as single stereoisomers in the field of neurology including the anti-Parkinsonian drugs levodopa, selegiline, apomorphine and entacapone, the antiepileptic drugs tiagabine and levetiracetam, the secondary stroke prevention agent clopidogrel and the acetylcholinesterase inhibitor rivastigmine. The role of drug stereochemistry in the re-evaluation of established drugs and the production of new agents is becoming increasingly important as pharmaceutical companies endeavour to show proof of "no penalty" for the introduction of a racemic new drug over one or other of its single stereoisomers.

Barbiturates for acute neurological and neurosurgical emergencies--do they still have a role?

A number of clinical studies have reported poor clinical outcomes for patients treated with barbiturate therapy in acute neurological and neurosurgical emergencies. Barbiturate therapy, as currently practised with thiopentone and pentobarbitone at least, is also associated with a prolonged post-infusion period of clinical unresponsiveness. Hence, the popularity of barbiturate therapy for sedation of critically ill neurological and neurosurgical patients has declined over the past decade. A retrospective study of traumatic brain injury patients treated at the Royal North Shore Hospital, Sydney, with high-dose thiopentone therapy between 1987 and 1997 has found disappointing results with a 1-month mortality outcome of 50% (14 of 28 patients). Nevertheless, barbiturate therapy remains a consideration for patients with severe cranial trauma in whom preferred treatments have failed to control intracranial or cerebral perfusion pressures. More favourable results ( approximately 10% 1-month mortality rate) were encountered for patients with refractory vasospasm complicating subarachnoid haemorrhage or intracerebral haemorrhage complicating supratentorial arteriovenous malformation resection. A well designed, prospective and randomised controlled trial may be of value in further determining the role of barbiturate therapy in acute neurovascular emergencies refractory to standard therapy.

Focal myoclonus-dystonia of the leg secondary to a lesion of the posterolateral putamen: clinical and neurophysiological features

We report on a patient with spontaneous and stimulus-sensitive myoclonic jerks and dystonia of the right leg that had been present since infancy. Magnetic resonance imaging showed a linear area of gliosis confined to the left posterolateral putamen. This is the first report of focal myoclonus-dystonia of the lower limb secondary to a putaminal lesion.

Evoked potentials elicited by stimulation of the lateral and anterior femoral cutaneous nerves in meralgia paresthetica

Seventy-five consecutive patients with clinical symptoms and signs of meralgia paresthetica underwent bilateral somatosensory evoked potential (SEP) studies involving stimulation of skin areas innervated by the lateral and anterior femoral cutaneous nerves of the thighs. The most common abnormality was an absolute lateral femoral cutaneous SEP latency > 40 ms in 35 patients (47%), followed by an absent response in 14 patients (19%), an absolute latency < 40 ms but amplitude reduction > 50% compared with the contralateral response in 8 patients (11%), and an absolute latency < 40 ms but > 5 ms interside latency difference in 5 patients (7%). Anterior femoral cutaneous SEPs were of value in distinguishing meralgia paresthetica from a proximal lumbar radiculopathy in an additional 4 patients and confirming bilateral meralgia paresthetica in 10 patients.

Prolonged thiopentone infusion for neurosurgical emergencies: usefulness of therapeutic drug monitoring

Serial serum thiopentone concentrations were measured during and following completion of an intravenous infusion of thiopentone in 20 patients with neurosurgical emergencies. The concentration data from a further 55 patients who had had some such measurements were reviewed retrospectively. The patients received an infusion for longer than 24 hours at a rate adjusted to maintain EEG burst suppression. The data were interpreted in terms of thiopentone pharmacokinetics and used to produce statistical models relating to clinical outcomes. In these patients, the one-month mortality rate following commencement of thiopentone treatment was 20%; the mean durations of pupillary and motor unresponsiveness following cessation of an infusion were 22 and 91 hours, respectively. Predictors of a prolonged duration of motor unresponsiveness included a prolonged duration of pupillary unresponsiveness, a low thiopentone clearance and a high maximum serum concentration of thiopentone. From pooled logistic regression, median effective serum thiopentone concentrations (EC50) were found to be 50 mg x l(-1) for recovery of pupillary responsiveness and 12 mg x l(-1) for the recovery of motor responsiveness. Because prolonged high-dose thiopentone leads to prolonged residual serum concentrations, it is difficult to distinguish the residual pharmacological effects of thiopentone from the clinical condition. This study suggests that, based on EC50 values for responses, monitoring of post-infusion serum thiopentone concentrations may help determine whether a patient's clinical state is due to residual thiopentone pharmacological effects.

Postoperative seizure outcome in a series of 114 patients with supratentorial arteriovenous malformations

The incidence of de novo and ongoing postoperative seizures and factors implicated in an increased likelihood of seizures following supratentorial cerebral arteriovenous malformation (AVM) resection remain controversial. We investigated the frequency, severity and variables associated with postoperative seizures in 114 consecutive patients who underwent complete surgical excision of supratentorial AVMs at our institution. The minimal follow up period was 24 months. The incidence of seizures post-AVM surgery was 21% (less than half that found preoperatively). The incidence of postoperative seizures first manifesting >12 months post-AVM resection was 6.3%. A history of preoperative seizures was associated with an increased likelihood of multiple (> or =4) seizures >1 month post-AVM resection (chi2 = 4.38, P = 0.04). Poor functional neurological outcome at 12 months was also a risk factor for the development of > or =1 postoperative seizure using logistic regression analysis (P = 0.04, odds ratio 1.52, 95% CI 1.01-2.28). Cessation of AED therapy in all patients who remain seizure-free at 12 months post-AVM resection is appropriate due to a low risk of new seizure onset or seizure recurrence.

Pharmacokinetics of thiopental enantiomers during and following prolonged high-dose therapy

BACKGROUND

Thiopental is used as a racemate; however, this is not generally recognized. During conditions of prolonged high-dose therapy, the pharmacokinetics of thiopental may become nonlinear, but whether this derives from one or both enantiomers has not been evaluated. The authors determined the pharmacokinetics of R- and S-thiopental and serum concentrations of R- and S-pentobarbital from prolonged high-dose infusion of thiopental for neuroprotection.

METHODS

Twenty patients received a mean thiopental dose of 41.2 g over a mean duration of 95 h. R- and S-thiopental enantiomer serum concentration-time data from 18 patients were fitted with two models: a linear one-compartment model with first-order output, and a nonlinear one-compartment model with Michaelis-Menten output.

RESULTS

Nonlinear models were preferred in 16 of 18 patients. Paired analysis indicated that steady state clearance (Clss) and volume of distribution (Vd) were higher for R-thiopental (0.108 vs. 0.096 l/min, P < 0.0001; and 313 vs. 273 l, P < 0.0005, respectively); maximal rate of metabolism (Vm) was higher for S- than for R-thiopental (1.01 vs. 0.86 mg x l(-1) x h(-1), P = 0.02); elimination half-lives did not differ (14.6 vs. 14.7 h, P = 0.8); unbound fractions (f(u)) of R- and S-thiopental were 0.20 and 0.18, respectively, P < 0.0001). The differences in mean Clss, Vd and Vm were not significant when adjusted by f(u). Plasma concentrations of R- and S-pentobarbital were relatively small and unlikely to be of clinical significance.

CONCLUSION

The pharmacokinetics of R- and S-thiopental became nonlinear at these doses. The pharmacokinetic differences between R- and S-thiopental, although small, were statistically significant and were influenced by the higher f(u) of R-thiopental.

Stereoselective interaction of thiopentone enantiomers with the GABA(A) receptor

1. As pharmacokinetic differences between the thiopentone enantiomers seem insufficient to explain the approximately 2 fold greater potency for CNS effects of (-)-S- over (+)-R-thiopentone, this study was performed to determine any enantioselectivity of thiopentone at the GABA(A) receptor, the primary receptor for barbiturate hypnotic effects. 2. Two electrode voltage clamp recording was performed on Xenopus laevis oocytes expressing human GABA(A) receptor subtype alpha1beta2gamma2 to determine relative differences in potentiation of the GABA response by rac-, (+)-R- and (-)-S-thiopentone, and rac-pentobarbitone. Changes in the cellular environment pH and in GABA concentrations were also evaluated. 3. With 3 microM GABA, the EC50 values were (-)-S-thiopentone (mean 26.0+/-s.e.mean 3.2 microM, n=9 cells) >rac-thiopentone (35.9+/-4.2 microM, n=6, P=0.1) >(+)-R-thiopentone (52.5+/-5.0 microM, n=8, P<0.02) >rac-pentobarbitone (97.0+/-11.2 microM, n=11, P<0.01). Adjustment of environment pH to 7.0 or 8.0 did not alter the EC50 values for (+)-R- or (-)-S-thiopentone. 4 Uninjected oocytes responded to >100 microM (-)-S- and R-thiopentone. This direct response was abolished by intracellular oocyte injection of 1,2-bis(2-aminophenoxy)ethane-N, N,N1,N1-tetraacetic acid (BAPTA), a Ca2+ chelating agent. With BAPTA, the EC50 values were (-)-S-thiopentone (20.6+/-3.2 microM, n=8) <(+)-R-thiopentone (36.2+/-3.2 microM, n=9, P<0.005). 5 (-)-S-thiopentone was found to be approximately 2 fold more potent than (+)-R-thiopentone in the potentiation of GABA at GABA(A) receptors expressed on Xenopus oocytes. This is consistent with the differences in potency for CNS depressant effects found in vivo.