Modified activation of somatosensory cortical network in patients with right-hemisphere stroke.
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To study the effects of parietal lesions on activation of the human somatosensory cortical network, we measured somatosensory evoked fields to electric median nerve stimuli, using a whole-scalp 122-channel neuromagnetometer, from six patients with cortical right-hemisphere stroke and from seven healthy control subjects. In the control subjects, unilateral stimuli elicited responses which were satisfactorily accounted for by modelled sources in the contralateral primary (SI) and bilateral secondary (SII) somatosensory cortices. In all patients, stimulation of the right median nerve also activated the SI and SII cortices of the healthy left hemisphere. However, the activation pattern was altered, suggesting diminished interhemispheric inhibition via callosal connections after right-sided stroke. Responses to left median nerve stimuli showed large interindividual variability due to the different extents of the lesions. The strength of the 20-ms response, originating in the SI cortex, roughly reflected the severity of the tactile impairment. Right SII responses were absent in patients with abnormal right SI responses, whereas the left SII was active in all patients, regardless of the responsiveness of the right SI and/or SII. Our results suggest that the human SI and SII cortices may be sequentially activated within one hemisphere, whereas SII ipsilateral to the stimulation may receive direct input from the periphery, at least when normal input from SI is interrupted. (+info)
Balloon angioplasty for embolic total occlusion of the middle cerebral artery and ipsilateral carotid stenting in an acute stroke stage.
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A 66-year-old man suffering from neurologic symptoms caused by acute embolic total occlusion of the left middle cerebral artery was treated successfully with balloon angioplasty, and an ipsilateral carotid stenosis subsequently was dilated with stenting. The patient's clinical outcome 30 days later was favorable. This therapeutic option may prove to be a useful means of treating a patient with acute stroke, embolic total occlusion of the middle cerebral artery, and an ipsilateral carotid stenosis. (+info)
Reports of randomized trials in acute stroke, 1955 to 1995. What proportions were commercially sponsored?
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BACKGROUND AND PURPOSE: Research in acute stroke has expanded rapidly. Many potentially important interventions lack commercial potential (eg, admission to a stroke unit). We therefore wished to examine the frequency of reports of randomized trials of interventions for acute stroke over the past 40 years, the source of support for such trials, the reporting of the commercial involvement, and whether the proportion of commercially supported trials had changed. METHODS: Eligible trials were identified from the Cochrane Stroke Group's specialized register of controlled clinical trials. We included all randomized trials in patients with acute stroke which published a full text report, in English, between 1955 and 1995. Two reviewers independently extracted data on the involvement of the pharmaceutical industry in all eligible trials. RESULTS: There was a substantial increase in the number of acute stroke trials published per year between 1955 and 1995. The description of pharmaceutical industry involvement in each trial report was poor. Only a minority of supported trials made explicit statements about the role of the sponsoring company. The proportion of trials apparently supported by the pharmaceutical industry has increased substantially. CONCLUSIONS: The increasingly important role of the pharmaceutical industry in evaluating new treatments gives substantial scope for bias and may not be in the interests of public health. Poor reporting of the sponsor's involvement suggests that modifications to the guidelines for the reporting of randomized controlled trials to include more details of the sponsor's involvement in the design, conduct, management, analysis, and reporting of the trial are justified. (+info)
Risk factors and 20-year stroke mortality in men and women in the Renfrew/Paisley study in Scotland.
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BACKGROUND AND PURPOSE: The aim of this study was to relate risk factors in middle-aged men and women to stroke mortality over a long follow-up period. METHODS: In the early to mid 1970s, 7052 men and 8354 women from the Renfrew/Paisley prospective cohort study in Scotland were screened when aged 45 to 64 years. Risk factors measured included blood pressure, blood cholesterol and glucose, respiratory function, cardiothoracic ratio, smoking habit, height, body mass index, age, preexisting coronary heart disease, and diabetes. These were related to stroke mortality over 20 years of follow-up. RESULTS: Women's stroke mortality rates were similar to men's, unlike coronary heart disease mortality, in which case women's rates were lower than men's. Diastolic and systolic blood pressure, smoking, cardiothoracic ratio, preexisting coronary heart disease, and diabetes were positively related to stroke mortality for men and women, while adjusted forced expiratory volume in 1 second and height were negatively related. Cholesterol and body mass index were not related to stroke mortality. Glucose in nondiabetics was positively related to stroke mortality for women but not men, and there was evidence of a threshold effect at the highest levels of glucose. Former smokers had mortality rates that were similar to those of never-smokers. In sex-specific multivariate models, most variables retained a statistically significant association with stroke mortality, illustrating the multifactorial etiology of stroke. CONCLUSIONS: Overall, findings for women were similar to those for men. Control of risk factors for reduction of stroke mortality should be targeted at men and women in a similar fashion, particularly with reference to smoking cessation and blood pressure control. (+info)
What determines good recovery in patients with the most severe strokes? The Copenhagen Stroke Study.
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BACKGROUND AND PURPOSE: Even patients with the most severe strokes sometimes experience a remarkably good recovery. We evaluated possible predictors of a good outcome to search for new therapeutic strategies. METHODS: We included the 223 patients (19%) with the most severe strokes (Scandinavian Stroke Scale score <15 points) from the 1197 unselected patients in the Copenhagen Stroke Study. Of these, 139 (62%) died in the hospital and were excluded. The 26 survivors (31%) with a good functional outcome (Barthel Index >/=50 points) were compared with the 58 survivors (69%) with a poor functional outcome (Barthel Index <50 points). The predictive value of the following factors was examined in a multivariate logistic regression model: age; sex; a spouse; work; home care before stroke; initial stroke severity; blood pressure, blood glucose, and body temperature on admission; stroke subtype; neurological impairment 1 week after onset; diabetes; hypertension; atrial fibrillation; ischemic heart disease; previous stroke; and other disabling disease. RESULTS: Decreasing age (odds ratio [OR], 0.50 per 10-year decrease; 95% CI, 0.25 to 0.99; P=0.04), a spouse (OR, 3.1; 95% CI, 1.1 to 8. 8; P=0.03), decreasing body temperature on admission (OR, 1.8 per 1 degrees C decrease; 95% CI, 1.1 to 3.1; P=0.01), and neurological recovery after 1 week (OR, 3.2 per 10-point increase in Scandinavian Stroke Scale score; 95% CI, 1.1 to 7.8; P=0.01) were all independent predictors of good functional outcome. CONCLUSIONS: Patients with the most severe strokes who achieve a good functional outcome are generally characterized by younger age, the presence of a spouse at home, and early neurological recovery. Body temperature was a strong predictor of good functional outcome and the only potentially modifiable factor. We suggest that a randomized controlled trial be undertaken to evaluate whether active reduction of body temperature can improve the generally poor prognosis of patients with the most severe strokes. (+info)
Should stroke victims routinely receive supplemental oxygen? A quasi-randomized controlled trial.
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BACKGROUND AND PURPOSE: We sought to test the hypothesis that breathing 100% oxygen for the first 24 hours after an acute stroke would not reduce mortality, impairment, or disability. METHODS: Subjects admitted to the Central Hospital of Akershus, Norway, with stroke onset <24 hours before admittance were allocated to 2 groups by a quasi-randomized design using birth numbers. All patients with acute stroke admitted to hospital within 24 hours after a stroke were included and enrolled. Patients were allocated to a group that received supplemental oxygen treatment (100% atmospheres, 3 L/min) for 24 hours (n=292) or to the control group, which did not receive additional oxygen. Main outcome measures were 1-year survival, neurological impairment (Scandinavian Stroke Scale), and disability (Barthel Index) 7 months after stroke. RESULTS: One-year survival was 69% in the oxygen group and 73% in the control group (OR 0.82; 95% CI 0.57 to 1.19; P=0.30). Impairment scores and disability scores were comparable 7 months after stroke. Among patients with Scandinavian Stroke Scale (SSS) scores of >/=40, 82% in the oxygen group and 91% in the control group survived (OR 0. 45; 95% CI 0.23 to 0.90; P=0.023). For patients with SSS scores of <40, 53% in the oxygen group and 48% in the control group survived (OR 1.26; 95% CI 0.76 to 2.09; P=0.54). CONCLUSIONS: Supplemental oxygen should not routinely be given to nonhypoxic stroke victims with minor or moderate strokes. Further research is needed to give conclusive advice concerning oxygen supplementation for patients with severe strokes. (+info)
Trends in the incidence, severity, and short-term outcome of stroke in perth, Western Australia.
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BACKGROUND AND PURPOSE: This report describes trends in the key indices of cerebrovascular disease over 6 years from the end of the 1980s in a geographically defined segment of the city of Perth, Western Australia. METHODS: Identical methods were used to find and assess all cases of suspected stroke in a population of approximately 134 000 residents in a triangular area of the northern suburbs of Perth. Case fatality was measured as vital status at 28 days after the onset of symptoms. Data for first-ever strokes and for all strokes for equivalent periods of 12 months in 1989-1990 and 1995-1996 were compared by age-standardized rates and proportions and Poisson regression. RESULTS: There were 355 strokes in 328 patients and 251 first-ever strokes (71%) for 1989-1990 and 290 events in 281 patients and 213 first-ever strokes (73%) for 1995-1996. In Poisson models including age and period, overall trends in the incidence of both first-ever strokes (rate ratio=0.75; 95% confidence limits, 0.63, 0.90) and all strokes (rate ratio=0.73; 95% confidence limits, 0.62, 0.85) were obviously significant, but only the changes in men were independently significant. Case fatality did not change, and the balance between hemorrhagic and occlusive strokes in 1995-1996 was almost indistinguishable from that observed in 1989-1990. CONCLUSIONS: Our results, which are the only longitudinal population-based data available for Australia for key indices of stroke, suggest that it is a change in the frequency of stroke, rather than its outcome, that is chiefly responsible nationally for the fall in mortality from cerebrovascular disease. (+info)
"Task-oriented" exercise improves hamstring strength and spastic reflexes in chronic stroke patients.
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BACKGROUND AND PURPOSE: Despite the belief that after cerebral infarction only limited functional gains are possible beyond the subacute period, we tested the hypothesis that a 12-week program of "task-oriented" treadmill exercise would increase muscle strength and decrease spastic reflexes in chronic hemiparetic patients. METHODS: Fourteen subjects, aged 66+/-3 (mean+/-SEM) years, with residual gait deviations due to remote stroke (>6 months), underwent repeated measures of reflexive and volitional (concentric and eccentric) torque with use of isokinetic dynamometry on the hamstring musculature bilaterally. Torque output was measured at 4 angular velocities (30(o), 60(o), 90(o), and 120(o)/s). RESULTS: After 3 months of 3 times/wk low-intensity aerobic exercise, there were significant main effects (2 legs [P<0.01]x2 times [P<0. 01]x4 angular velocities [P<0.05]) for concentric torque production. Torque/time production in the concentric mode also improved significantly in the paretic (50%, P<0.01) and nonparetic hamstrings (31%, P<0.01). Eccentric torque/time production increased by 21% (P<0.01) and 22% (P<0.01) in the paretic and nonparetic hamstrings, respectively. Passive (reflexive) torque/time generation in the paretic hamstrings decreased by 11% (P<0.027). Reflexive torque/time was unchanged in the nonparetic hamstrings (P=0.45). CONCLUSIONS: These findings provide evidence that progressive treadmill aerobic exercise training improves volitional torque and torque/time generation and reduces reflexive torque/time production in the hemiparetic limb. Strength changes associated with improved functional mobility in chronic hemiparetic stroke survivors after treadmill training will be reported in future articles. (+info)