Alexander Y. Gur

Is Impaired Cerebral Vasomotor Reactivity a Predictive Factor of Stroke in Asymptomatic Patients

BACKGROUND AND PURPOSE Identification of the subgroup of asymptomatic patients with severe internal carotid artery stenosis and high risk of stroke has important clinical implications. Cerebral vasomotor reactivity provides information regarding intracranial hemodynamic features and might have a prognostic value in predicting cerebrovascular ischemic events, especially in patients with carotid stenosis. The aim of our study was to assess the cerebral vasomotor reactivity in asymptomatic patients with carotid stenosis and evaluate its role in stroke occurrence. METHODS Cerebral vasomotor reactivity was assessed using transcranial Doppler ultrasonology and the Diamox test (intravenous administration of 1.0 g acetazolamide) in 44 asymptomatic patients with severe (> 70%) internal carotid artery stenosis. Patients were followed up prospectively (mean, 2 years). RESULTS Cerebral vasomotor reactivity was estimated as good (> 40% increase of blood flow velocity in the middle cerebral artery ipsilateral to the carotid stenosis after undergoing the Diamox test) in 23 patients; it was impaired in the other 21. During the follow-up period, the overall annual rate for ipsilateral stokes was 2.3%; it was 7.9% for all ischemic cerebral events. No strokes or transient ischemic attacks occurred in the former group, but there were 7 cerebral ischemic events (2 strokes [1 fatal] and 5 transient ischemic attacks) in the latter group. There was a statistically significant correlation between cerebral ischemic events and impaired cerebral vasomotor reactivity (P = .009). CONCLUSIONS The data of this preliminary study suggest an important role of impaired cerebral vasomotor reactivity in predicting ischemic cerebral events. Preventive vascular surgery might be considered in this high-risk subgroup of asymptomatic patients with severe carotid stenosis.

Inflammatory Bowel Disease Is Not Associated With Increased Intimal Media Thickening

OBJECTIVES:Several studies have suggested that chronic inflammatory diseases might be associated with an acceleration of the atherosclerotic process. There is little information on the effect of chronic inflammation in patients with inflammatory bowel disease (IBD) on the presence of increased intimal media thickening (IMT), a surrogate marker for atherosclerotic diseases. In this work our aim was to determine whether IBD is a risk factor for increased IMT.METHODS:IMT was measured by ultrasound of the carotid arteries; a computer software program was used to analyze 80–100 independent IMT samples from each carotid artery segment in 61 patients with IBD (45 with Crohns disease and 16 with ulcerative colitis) and in 61 controls matched for age (±2 yr), sex, body mass index (BMI, ±2 kg/m2), and smoking status.RESULTS:Inflammatory markers (erythrocyte sedimentation rate, fibrinogen, high−sensitive C-reactive protein) were significantly (P < 0.001) elevated in IBD patients compared with controls. Even though there was a disease duration of 8.7 ± 8.5 yr, the mean IMT of IBD patients was similar to that of the control group (0.66 ± 0.09 vs 0.64 ± 0.07 mm; P > 0.05).CONCLUSIONS:Despite chronic inflammation, IBD patients had IMT values similar to those of the controls. Thus, unlike other inflammatory diseases, IBD appears not to be a risk factor for accelerated atherosclerosis.

Stroke in Hospitalized Patients: Are There Special Risk Factors?

Background and Purpose: The occurrence of stroke in patients hospitalized for various illnesses remains a particular challenge for neurologists. Determining the potential causes for these particular cerebrovascular events may help to define the population at risk and to take measures in order to prevent stroke during hospitalization. The aim of our study was to evaluate the potential risk factors associated with stroke, which occurred in patients hospitalized for other illnesses. Methods: This retrospective case-control study based on data of patients who underwent an ischemic stroke while being hospitalized not because of stroke and a control group of patients admitted during the same period who were matched for age and sex to the study patients. Common vascular risk factors, e.g. fever, leukocytosis, blood pressure, hemoglobin, cardiac arrhythmia and dehydration, were compared between the study and control groups. Results: Of 2,247 consecutive patients with ischemic stroke, the stroke had occurred during hospitalization not related to any surgical procedure in 80 (3.5%). Six parameters were found as being significant independent risk factors for in-hospital stroke: fever and leukocytosis during hospitalization, elevated diastolic and unstable blood pressure, dehydration and past history of myocardial infarction. Conclusion: Careful monitoring of temperature, blood count, blood pressure, and clinical and laboratory signs of dehydration is needed to prevent in-hospital stroke.

Stroke-in-Evolution: Infarct-Inherent Mechanisms versus Systemic Causes

Background: It is uncertain whether deterioration after acute ischemic stroke is neurological and/or systemic (somatic) in origin. Methods: 442 consecutive patients admitted with first-ever ischemic stroke (FIS) were assessed by the Unified Neurological Stroke Scale (UNSS) at admission, on hospitalization days 1, 2 and 3 and before discharge. Results: Among 71/442 (16.1%) patients deteriorated during hospitalization, the worsening from stroke onset was early (≤72 h) in 67 (94.4%) of them. The majority (57/71, 80.3%) had CT-confirmed cerebral causes and 14/71 (19.7%) had systemic causes. The causes of late deterioration were exclusively systemic. In the logistic regression analysis the initial mean UNSS score was the only significant independent predictor of stroke deterioration (p < 0.0001). Conclusions: Early clinical deterioration in FIS patients results from infarct-inherent mechanisms while late stroke deterioration is due primarily to systemic factors. An initially severe neurological deficit might predict further decline.

Stroke during Sleep: Epidemiological and Clinical Features

Stroke during sleep is an unexplored area of vascular neurology and its pathogenesis; clinical significance and prevention still remain uncertain. The aim of our study was to determine the epidemiological and clinical patterns of ischemic stroke occurring during sleep. Consecutive patients (n = 1822) with acute ischemic stroke recorded in the Tel Aviv Stroke Register were studied. Stroke during sleep was determined whenever focal neurological deficit was verified to have occurred while the patient had been asleep. The comparisons between patients with stroke during sleep and while awake were performed using the t test with Bonferroni correction and the χ2 test for age, sex, vascular risk factors (i.e. ischemic heart disease, myocardial infarction, atrial fibrillation, arterial hypertension, hyperlipidemia, diabetes mellitus, peripheral vascular disease, smoking), vascular distribution (carotid versus vertebrobasilar) and severity of stroke (mild, moderate or severe). Data regarding the onset of stroke (during sleep or while awake) were available for 1,671 patients. A minority of strokes occurred during sleep (n = 311, 18.6%), and stroke during sleep was severer (χ2 = 11.9, p < 0.002). No significant differences were found in terms of age, sex and vascular distribution between the two groups. None of the vascular risk factors was found to be more frequent in stroke during sleep. Strokes occurring during sleep were found to be severer than those with onset while awake. However, no specific clinical patterns of risk factor profiles could be identified in these patients. Hemodynamic factors may play an important role in the occurrence of stroke during sleep, and this issue should be further investigated.

A new scale for assessing patients with vertebrobasilar stroke—the Israeli Vertebrobasilar Stroke Scale (IVBSS): Inter-rater reliability and concurrent validity

OBJECTIVES Most of existing stroke scoring systems have limited ability to evaluate patients with cerebrovascular events in the vertebrobasilar territory. We devised a new scale, the Israeli Vertebrobasilar Stroke Scale (IVBSS) in order to directly and more accurately assess clinical deficits of patients with vertebrobasilar stroke. The present study measured the reliability and validity of the IVBSS. PATIENTS AND METHODS Forty-three patients (mean age+/-S.D., 70.9+/-8.8 years, 27 males) with vertebrobasilar stroke were evaluated with the IVBSS (11 items), the NIH Stroke Scale (NIHSS) and the disability modified Rankin Scale (mRS) by independent examiners. Interobserver agreement was rated by weighted kappa statistics for each item and the total IVBSS score. Validity was examined with Spearman rank coefficients to compare the IVBSS with NIHSS and mRS. RESULTS Excellent reliability was demonstrated between the examiners for almost each item and the total score of the IVBSS (kappa>0.75). The total IVBSS score was strongly associated with NIHSS and mRS results (r=0.80 and 0.76, respectively; P<0.0002). CONCLUSIONS The IVBSS is a valid instrument that allows the assessment of patients with vertebrobasilar stroke with high reliability. Further observations are warranted to determine the predictive value of the IVBSS for stroke outcome.

Cerebral vasomotor reactivity of patients with acute ischemic stroke: Cortical versus subcortical infarcts: An Israeli–Turkish collaborative study

BACKGROUND Cerebral hemodynamic features of patients with different types of acute ischemic stroke are still obscure. We compared cerebral vasomotor reactivity (VMR) in acute cortical (CI) and subcortical (SI) brain infarcts. METHODS Acute stroke patients (within 72 h of stroke onset) underwent transcranial Doppler and the Diamox test (1 g acetazolamide IV). The percent difference between blood flow velocities in the middle cerebral arteries before and after acetazolamide was defined as VMR%. CI and SI infarcts were confirmed by computerized tomography and/or magnetic resonance imaging. Clinical status and disability were assessed by means of the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) respectively.VMR% values and stroke severity and disability parameters were compared between CI and SI groups using ANOVA and Pearsons correlation (r) coefficients. RESULTS VMR% values of the ipsilateral side to the brain infarct in the CI group were significantly lower as compared with SI group (12.2+/-15.9% and 25.6+/-24.4% respectively, P=0.03). VMR% values in both groups were not correlated with stroke severity and disability (P<0.2). CONCLUSIONS Our results suggest greater vulnerability of resistance arterioles in the setting of cortical gray matter infarcts. Although gray matter VMR is physiologically higher than white matter VMR, patients with acute CI have impaired cerebral vascular reserve.

Characteristics of first ever ischemic stroke in the very elderly: Profile of vascular risk factors and clinical outcome

PURPOSE Age is the most significant non-modifiable risk factor for ischemic stroke (IS). With increasing expectancy of life, the majority of IS patients will be elderly subjects. We studied the epidemiological, clinical and rehabilitation features of patients aged ≥85 years with first-ever IS. METHODS Demographic data, prevalence of risk factors, etiology of stroke, severity of neurological deficit, major complications and mortality rates were collected from a hospital-based stroke registry and compared between patients at the age of 65-84 and ≥85. Clinical assessment was performed by means of the National Institutes of Health Stroke Scale (NIHSS) and Modified Rankin Scale (mRS). RESULTS Among 216 patients aged ≥85 years there was significantly higher proportion of a history of atrial fibrillation than in 128 patients at the age of 65-84 years and lower prevalence of hypertension, diabetes mellitus, hyperlipidemia and smoking. Large artery atherosclerosis was more frequently identified in the older patients (49% vs. 32%, p=0.002). Although NIHSS scores on admission were lower in the older patients they were more disabled at discharge. CONCLUSIONS With respect to the patients aged <85 years very old IS patients showed different vascular risk factors profile, clinical and rehabilitation course. These findings suggest specializing stroke care in the very elderly.

EEG as predictor of dementia following first ischemic stroke.

Introduction– Predictive factors for occurrence of vascular dementia may help identify patients at increased risk of developing this condition. Our purpose was to evaluate the prognostic value of early EEG findings in patients after first ischemic cerebral stroke on the development of dementia. Material and methods– We performed routine EEG recordings in 199 consecutive non‐demented patients with first‐ever ischemic stroke, within 48 h of the event. The patients were subsequently followed for their mental state for 2 years. Survival analysis, wherein onset of dementia was the end‐point, was performed on the total sample population and conducted separately on those who had normal EEG at time of the event and on those who had abnormal EEG findings (focal or diffuse slowing). Results– Patients with abnormal EEG at baseline had 2.6 times the risk of developing dementia than those who had normal EEG; this odds ratio was statistical significant (CL: 1.3–5.1, p = 0.003). Development of dementia was not related to any specific EEG abnormal pattern. Conclusions– Abnormal EEG performed close to the first ischemic stroke appears to be an indicator of subsequent cognitive decline, probably because it indicates cortical involvement by the stroke or an underlying indolent cerebral degeneration.

Does Carotid Endarterectomy Modify Cerebral Vasomotor Reactivity

The effects of carotid endarterectomy (CEA) on cerebral hemodynamics in certain groups of patients with severe carotid stenosis still remain unclear. Cerebral vasomotor reactivity (CVR) is an important indicator of intracranial blood supply and cerebral autoregulation. Symptomatic and asymptomatic patients with severe carotid stenosis and impaired CVR were evaluated before and after CEA. Transcranial Doppler ultrasonography (TCD) and the Diamox test (i.v. administration of 1.0 g acetazolamide) before and 3 months after CEA were performed in 42 patients (21 symptomatic, 21 asymptomatic) with severe (70–99%) carotid stenosis. CVR was assessed as the difference between peak blood flow velocities in the middle cerebral artery ipsilateral to the carotid stenosis before and after acetazolamide injection and as percent increase of blood flow velocity after acetazolamide (ANOVA). Three months after CEA there was statistically significant improvement of CVR in asymptomatic compared with symptomatic patients (p < 0.05, ANOVA). CEA improves CVR mostly in asymptomatic patients. TCD combined with the Diamox test appears to be a useful tool in assessing cerebral hemodynamics prior to carotid surgery, and might be an additional criterion for selecting asymptomatic patients for CEA.