Patrick Weller | PubMed Health

PubMed2006

Motor recovery as assessed with isometric finger movements and perfusion magnetic resonance imaging after acute ischemic stroke.

OBJECTIVE: Recovery from hemiparetic stroke is variable. An important goal for clinicians and clinical researchers is to identify predictors of recovery. The initial phase after acute ischemic stroke is considered to be of major importance for neurological outcome. The authors sought to determine in patients with acute ischemic stroke whether early motor recovery, as measured by repetitive isometric index-thumb oppositions, is correlated with ischemic lesion volume. METHODS: Thirty-six acute hemiparetic stroke patients with residual hand function were investigated. The European Stroke Scale (ESS) score was determined on admission and at discharge. Performance of repetitive index finger-thumb pinch movements was measured daily during the 1st 8 days after stroke onset. Brain ischemia volume was determined digitally in time-to-peak magnetic resonance images of per-fusion. RESULTS: The recovery of patients with (P = 0.002) and without (P < 0.001) thrombolysis as assessed with the ESS was paralleled by an increase in isometric grip force and movement rate (P < 0.05). Recovery was predicted by the area of moderately impaired perfusion indicated by the per-fusion mismatch volume (r = 0.578, P < 0.001). CONCLUSIONS: In acute stroke, recovery of hand function is predicted by the volume of salvageable ischemic tissue, as determined by the perfusion mismatch.

Aged↗

PubMed2005

Initial ischemic event: perfusion-weighted MR imaging and apparent diffusion coefficient for stroke evolution.

PURPOSE: To prospectively determine if the degree of acute perfusion or diffusion abnormalities measured prior to treatment onset help predict the evolution of brain infarction on magnetic resonance (MR) images. MATERIALS AND METHODS: Local ethics committee approval and informed consent were obtained. On parametric maps obtained in 64 patients (mean age, 64 years +/- 13 [standard deviation]; 37 men and 27 women) with acute middle cerebral artery infarction, lesion volumetry was performed to determine time to peak, mean transit time, cerebral blood volume, and apparent diffusion coefficient obtained within 3 hours of symptom onset. The infarct lesions were assessed on T2-weighted MR images obtained at follow-up on day 8. Cerebrovascular changes were determined on MR angiograms. Inferential and correlation statistics were used. RESULTS: A perfusion delay of more than 6 seconds relative to the nonaffected hemisphere on time-to-peak maps helped to predict the lesion volume on T2-weighted images (r = 0.686, P < .001). In contrast, neither the volume nor the degree of the diffusion abnormality helped to predict the infarct volume (r < 0.46). This was because in one subgroup of patients there was an increase and in one subgroup there was a decrease in infarct volume on the T2-weighted images (P < .001). There was a greater prevalence (P < .02) of cerebral artery abnormalities in the patients with larger infarcts. Clinically, the neurologic impairment was more severe (P < .01) and the mean arterial pressure higher (P < .04) in these patients. CONCLUSION: The results suggest that in acute stroke the severity of the initial ischemic event as determined on time-to-peak maps indicates hemodynamic compromise in addition to internal carotid artery or middle cerebral artery occlusion, because of abnormalities in other cerebral arteries.

Adult↗