Marc E. Wolf

Gender Differences in Acute Ischemic Stroke: Etiology, Stroke Patterns and Response to Thrombolysis

Background and Purpose— Differences between women and men in relation to stroke are increasingly being recognized. Methods— From July 2004 until June 2007, 237 acute ischemic stroke (AIS) patients were treated with recombinant tissue plasminogen activator (rtPA) within 3 hours after onset of symptoms in our stroke unit. Baseline characteristics, etiology, CT/MRI stroke patterns, clinical outcome, and complications of women were compared to those of men. Results— Of 237 AIS patients (mean age 70.7 years), 111 (46.8%) were women and 126 (53.2%) were men. Women were older (P=0.001), but history of hyperlipidemia (P=0.03), smoking (P=0.03), and coronary heart disease (P<0.001) was less frequent than in men. Internal carotid artery disease occurred more often in men (P=0.02), whereas atrial fibrillation was observed more often in women (P=0.002). In men borderzone/small embolic and lacunar stroke was found more frequently (39.7 versus 27.2%), whereas women showed a higher percentage of large territorial stroke (72.8 versus 60.3%, P=0.09). Baseline National Institute of Health Stroke Scale scores (12.5 versus 11.3), NIHSS score at discharge (11.0 versus 9.5), 3-month-outcome modified Rankin Scale score, thrombolysis-related (17.1% versus 13.5%) or independent complications (32.4% versus 30.2%), and mortality after 3 months (13.5% versus 9.5%) were similar. Conclusion— Differences of stroke lesion patterns in genders are paralleled by differences in etiology and risk factor profiles (women, cardioembolism; men, large and small vessel disease). Baseline characteristics, rates of rtPA-related and independent complications, as well as clinical outcomes were not different between women and men with AIS.

Clinical and MRI characteristics of acute migrainous infarction

Objective: Migrainous infarction is considered a rare complication of migraine. Although several studies reported silent brain lesions on neuroimaging in patients with migraine with aura, knowledge about lesion patterns in acute migrainous infarction is scarce. We investigated clinical and MRI characteristics in a series of patients with migraine-associated acute cerebral ischemia. Methods: Seventeen patients among 8,137 stroke patients over an 11-year period were included. All had undergone a dedicated stroke workup including diffusion-weighted imaging (DWI) and a detailed assessment of clinical features and of vascular risk factors. Results: The majority of patients presented with prolonged aura symptoms (visual aura 82.3%, sensory dysfunction 41.2%, and aphasia 5.9%; median NIH Stroke Scale score 2). Presentation at hospital was significantly delayed after symptom onset (mean 33 hours). A total of 70.6% had acute ischemic lesions in the posterior circulation; the middle cerebral artery territory was affected in 29.4%. Small lesions were present in 64.7%; multiple lesions were found in 41.2%. No overlapping ischemic lesions of different vascular territories were found. The prevalence of a patent foramen ovale was high (64.7%). Conclusions: This study supports previous observations that migrainous infarction mostly occurs in the posterior circulation, and in younger women with a history of migraine with aura. Acute ischemic lesions were often multiple and located in distinct arterial territories. As there were no overlapping ischemic lesions, hemodynamic compromise during the development of migraine is unlikely the cause of infarction. Differentiation between migrainous infarction and prolonged migraine aura is difficult and associated with delayed admission of patients.

Comparison of the new ASCO classification with the TOAST classification in a population with acute ischemic stroke

Precise analysis of stroke subtypes is important for clinical treatment decisions, the prognostic evaluation of patients, as well as defining stroke populations in clinical studies. The TOAST classification is the most widely used and approved form for etiologic subtyping. Increasing knowledge about stroke mechanisms and the introduction of new diagnostic techniques have supported the promotion of the new ASCO phenotypic classification, which aims to characterize patients using different grades of evidence for stroke subtypes. We prospectively assigned 103 consecutive patients from our stroke center for subtype classification using ASCO and TOAST. Clinical features and complementary investigations were recorded according to our standardized acute stroke care protocol. Evidence grade 1 with ASCO was assessed in 12.62% for large artery disease (A), 23.30% small-vessel disease (S), 36.89% cardiac source (C) and 1.94% another cause (O). Evidence grades 1–3 were identified in 60.19% A, 75.73% S, 49.51% C, and 3.88% O. A total of 68.93% of the patients were classified in more than one category, and only 3.88% remained completely undetermined. The κ value for inter-rater agreement was 0.92–1. Using TOAST, the distribution was 9.71% A, 23.30% S, 34.95% C, 1.94% O, and 30.10% undetermined. The ASCO classification showed a good concordance with TOAST. The inter-rater agreement was high. The comprehensive character of ASCO allows the recording of important additional information. This may be helpful for a specific treatment adaptation in each individual patient and creation of different etiological profiles in view of adapted clinical trials.

Investigation of leptomeningeal enhancement in MS: a postcontrast FLAIR MRI study.

Objective: To investigate possible leptomeningeal contrast enhancement using postcontrast fluid-attenuated inversion recovery (FLAIR) MRI as an additional marker of inflammation in patients with multiple sclerosis (MS). Methods: A cohort of 112 patients (73 women) with clinically definitive MS or a clinically isolated syndrome suggestive of CNS demyelination were included. A pathologic control group of 5 stroke patients was also examined. MRI was performed on a 3T system including FLAIR, T2-weighted, T1-weighted–contrast injection, followed by T1-weighted and FLAIR. Results: Of the 112 patients, 39 had an acute relapse at the time of MRI. In total, 96 contrast-enhancing lesions were identified on postcontrast T1-weighted images. The pathologic control group demonstrated the sensitivity of postcontrast FLAIR images demonstrating leptomeningeal enhancement in all cases. In contrast, only 1 out of 112 examined patients with MS showed a single area of abnormal leptomeningeal contrast enhancement. Conclusions: In contrast to intraparenchymal blood–brain barrier (BBB) dysfunction that is frequently seen in patients with MS, BBB dysfunction of leptomeningeal vessels is usually not detectable in patients with early MS.

Changes in functional vasomotor reactivity in migraine with aura

Migraine with aura (MA) is associated with cerebral hyper- and hypoperfusion during and after the attacks. Several attempts to estimate individual perfusion changes and asymmetries in patients with MA using transcranial Doppler (TCD) have not been consistent. In 70 patients with MA and 40 controls with migraine without aura (MoA) or without any history of migraine, interictally recorded TCD sequences were prospectively analysed. Formal curve analysis of the visually evoked flow response (VEFR) was performed semiautomatically. As a main parameter for functional vasomotor reactivity (fVMR), the visually evoked flow rate (VEFR%) was calculated. The VEFR% showed a significantly higher mean difference of 14.7 ± 12% in MA patients vs. 5.8 ± 4.4% (P < 0.001) in controls. The significant asymmetry of fVMR in MA patients is suggested to reflect interattack persisting vasomotor changes which are of pathophysiological interest and may be used as a monitoring tool under prophylactic medication.

Multimodal assessment of optokinetic visual stimulation response in migraine with aura.

This study aimed to assess activation patterns and the hemodynamic response to optokinetic stimulation in migraine with aura patients compared with controls.

Dynamic Susceptibility Contrast Perfusion MRI Identifies Persistent Vessel Pathology in Acute Pontine Stroke

Background: In large territorial stroke of the anterior and the posterior circulation, the extent of affected tissue can be characterized by the demonstration of vessel occlusion on MR angiography (MRA), while the extent of hypoperfusion can be shown on dynamic susceptibility contrast perfusion-weighted MRI (PWI). The ability of MRA and conventional MRI sequences to demonstrate branches of the basilar artery (BA) is very limited. This study analyzes the value of the combined use of diffusion-weighted MRI (DWI), MRA and PWI in acute pontine stroke. Methods: A series of 24 consecutive patients with acute pontine stroke received an extensive MRI stroke workup including DWI, PWI and MRA. Results: In 11/24 patients visual analysis of PWI demonstrated persisting hypoperfusion, and in 1/24 patients indication of hyperperfusion was found. Vessel abnormalities were seen in 19/24 patients (15/24 hypoplastic vertebral artery, 9/24 stenosis or occlusion of the BA, 1/20 ectatic BA). Persistent pontine hypoperfusion was more frequently associated with BA pathology (9/11 vs. 1/13, p = 0.001), large-vessel disease (8/11 vs. 1/13; p = 0.001) and a more pronounced clinical deficit (NIHSS score on day 1: 7 vs. 3, p = 0.01). Conclusions: In pontine ischemia areas of hypoperfusion can be identified due to the strong contrast induced by ischemia on PWI and can be easily related to DWI lesion size. This is of use particularly as small vessels are frequently missed by MRA and occlusion of the BA can be better characterized with the help of PWI.

Asymptomatic and Symptomatic Carotid Stenosis: An Obsolete Classification?

Since many years, clinical decisions about the management of patients with carotid stenosis have been based on the distinction between “asymptomatic” and “symptomatic” presentations. This was also reflected by the design of previous studies on the surgical versus conservative treatment and of current studies on interventional treatment versus surgery. Both terms, however, only address different phases of activity of the one and the same condition and blur the significant message that carotid stenosis is a most important marker of systemic atherosclerosis, which is accompanied by a much higher risk of cardiovascular events rather than stroke. As a consequence, early diagnosis and followup during best medical treatment, life-style management, regular cardiovascular assessment, and good control of all vascular risk factors should be recommended in all patients with carotid stenosis—whether identified in the long-lasting “silent” or short-lasting “vulnerable” period lasting only a few weeks after cerebral ischemia. Patients in this short time window benefit from additional carotid intervention, under the condition of an individually favorable benefit-risk ratio (“individual vulnerability”).

Pearls & Oy-sters: Dynamics of altered cerebral perfusion and neurovascular coupling in migraine aura

A 37-year-old woman presented 90 minutes after acute onset of mild motor aphasia with word-finding difficulties and hypesthesia of the right arm. MRI was immediately performed as she presented within the 3-hour time window for IV thrombolysis. Diffusion-weighted images (DWI) were normal, but perfusion MRI (dynamic susceptibility contrast) sequences showed marked hypoperfusion in the left hemisphere affecting both middle cerebral artery and posterior cerebral artery (PCA) territories. These findings were considered compatible with migraine aura. The patient subsequently developed a mild left-sided headache. Clinical symptoms gradually improved to full recovery after 6 hours without specific treatment. Follow-up MRI perfusion scans were obtained 24 hours and 2 months after the episode. Functional transcranial Doppler (fTCD) from the P2-segments of the PCA during visual stimulation was performed at the same time points as MRI (figure). The first follow-up MRI showed only mild residual hypoperfusion in the left hemisphere, and in the asymptomatic state 2 months later, no perfusion abnormality was detected. Correspondingly, initial severe changes of neurovascular coupling on fTCD …

Heterogeneity of acute multiple sclerosis lesions on sodium (23Na) MRI

Background: Advanced magnetic resonance imaging (MRI) techniques provide a window into pathological processes in multiple sclerosis (MS). Nevertheless, to date only few studies have performed sodium MRI in MS. Objectives: We analysed total sodium concentration (TSC) in hyperacute, acute and chronic lesions in MS with 23Na MRI. Methods: 23Na MRI and 1H MRI were performed in 65 MS patients and 10 healthy controls (HC). Mean TSC was quantified in all MS lesions with a diameter of >5 mm and in the normal appearing white and grey matter (NAWM, NAGM). Results: TSC in the NAWM and the NAGM of MS patients was significantly higher compared to HC (WM: 37.51 ± 2.65 mM versus 35.17 ± 3.40 mM; GM: 43.64 ± 2.75 mM versus 40.09 ± 4.64 mM). Acute and chronic MS lesions showed elevated TSC levels of different extent (contrast-enhancing lesions (49.07 ± 6.99 mM), T1 hypointense lesions (45.06 ± 6.26 mM) and remaining T1 isointense lesions (39.88 ± 5.54 mM)). However, non-enhancing hyperacute lesions with a reduced apparent diffusion coefficient showed a TSC comparable to the NAWM (37.22 ± 4.62 mM). Conclusions: TSC is not only a sensitive marker of the severity of chronic tissue abnormalities in MS but is also highly sensitive to opening of the blood–brain barrier and vasogenic tissue oedema in contrast-enhancing lesions.