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Affected Hemisphere (affected + hemisphere)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Ictal Pattern of EEG and Muscular Activation in Symptomatic Infantile Spasms: A Videopolygraphic and Computer Analysis

EPILEPSIA, Issue 12 2002
Francesca Bisulli
Summary: ,Purpose: To investigate ictal muscular phenomena characterizing symptomatic infantile spasms (ISs) and their relation to ictal EEG. Methods: Four children with severe encephalopathy, neurologic impairment, and refractory ISs related to different dysplastic lesions, underwent videopolygraphic recordings collecting surface electromyogram (EMG) activity from several cranial and limb muscles to evaluate the pattern of muscular recruitment, duration, and side-to-side asymmetry of ISs. Acquired data were stored for off-line analysis by a computerized polygraphic system. Results: Spasms were characterized by a complex pattern of muscular activation. A constant or rostrocaudal propagation pattern was lacking in all patients. Intervals between the onset of EMG activity in different muscles in each spasm were very long: ,100,200 ms. Two patients, with hemispheric cortical dysplasia and agenesis of the corpus callosum, had asymmetric and asynchronous spasms in which the EMG onset of the muscles contralateral to the affected hemisphere constantly anticipated that of the ipsilateral ones. Backaveraging of EEG activity disclosed a high-amplitude EEG complex on the same side as the dysplastic lesion, preceding or succeeding the contralateral muscle activity onset. In the other two patients with diffuse cortical dysplasia, no EEG transient was related to EMG activity onset. Conclusions: Despite clinical similarity between spasms in the same patient, our data demonstrate the complexity and heterogeneity of these motor phenomena. Our findings cannot be explained simply in terms of cortical or reticular generators like other motor phenomena such as cortical myoclonus or startle reflex. [source]

Assessment of corticodiaphragmatic pathway and pulmonary function in acute ischemic stroke patients

EUROPEAN JOURNAL OF NEUROLOGY, Issue 3 2000
E. M. Khedr
This study investigates the effect of stroke on the corticodiaphragmatic pathway and attempts to clarify the relationship between neurophysiological data and degree of motor disability, site of infarction in computerized tomography (CT) scan, diaphragmatic excursion, blood gases and pulmonary function in stroke patients. Using magnetic stimulation of the scalp sites and cervical roots, an assessment of corticodiaphragmatic pathway was made. The study included 34 sequentially selected patients from a total of 250 patients with acute ischemic stroke. Twenty-five (age- and sex-matched) volunteers served as controls. Sixteen patients had cortical infarction, 13 had subcortical infarction and five had both cortical and subcortical infarction. The mean according to the Scandinavian Stroke Scale was 32.2. Decreased diaphragmatic excursion was observed in 41% of the patients. Twenty-four patients (70.5%) had abnormal magnetic evoked potentials (MEPs) in the affected hemisphere. In five patients MEPs could not be elicited from the affected hemisphere; the remaining 19 patients had abnormal values of both cortical latency and central conduction time (CCT). Cortical latency, CCT, amplitude of compound muscle action potentials (CMAPs) and excitability threshold of the affected hemisphere were significantly altered compared with both the unaffected hemisphere and the control group. Those patients with hemiplegia had a greater degree of hypoxia, hypocapnia and decreased serum bicarbonate level compared with the control group. Also, hemiplegic patients had different degree of respiratory dysfunction. A statistically significant association was found between neurophysiological data and disability score, diaphragmatic excursion, site of infarction in CT scan and degree of respiratory dysfunction. Central diaphragmatic impairment may occur in acute stroke and could contribute to the occurence of hypoxia in those patients. [source]

Multimodal microglia imaging of fiber tracts in acute subcortical stroke,

ANNALS OF NEUROLOGY, Issue 6 2009
Basia A. Radlinska BSc
Objective Case series with 11C-PK11195 and positron emission tomography (PET) in stroke patients suggest that activated microglia may be detected in remote brain regions with fiber tract connections to the lesion site as an indicator of poststroke neuroinflammation. However, the specificity of these imaging findings remains to be demonstrated. Methods In a prospective controlled study, we measured microglia activity using 11C-PK11195-PET along the pyramidal tract, as defined by diffusion tensor imaging, in 21 patients with first-time acute subcortical ischemia within 2 weeks of stroke. Uptake ratios (affected vs unaffected side) were determined for a set of standardized volumes of interest along the pyramidal tracts (PT). Uptake ratios from patients in whom the PT was affected were compared with those in whom the PT was not affected. Uptake ratios were related to motor deficit and lesion size according to correlation analyses. Results Increased uptake ratios were only found in patients in whom the PT was affected by stroke. In the affected hemisphere, uptake was increased at the level of pons, midbrain, and internal capsule, but not in the oval center. The extent of remote microglia activation was independent of infarct size or clinical measures of stroke severity. Interpretation A specific activation of microglia was only found in patients in whom the PT was affected by the stroke and only caudal (anterograde) to the lesion; no activation was found in the retrograde direction or in those patients in whom the PT was not affected. These findings were independent of infarct size and may represent changes secondary to early Wallerian degeneration. Ann Neurol 2009;66:825,832 [source]

Long-term effect of repetitive transcranial magnetic stimulation on motor function recovery after acute ischemic stroke

ACTA NEUROLOGICA SCANDINAVICA, Issue 1 2010
E. M. Khedr
Objective,,, Although there is evidence for short term benefits of rTMS in stroke, longer term effects have not been reported. The aim of the study was to evaluate the effect of two different frequencies of rTMS on motor recovery and on cortical excitability up to 1 year post-treatment. Methods,,, Forty-eight patients with acute ischemic stroke were randomly classified into three groups. The first two groups received real rTMS over motor cortex (3 and 10 Hz respectively) of the affected hemisphere and the third group received sham stimulation of the same site, daily for five consecutive days. Disability was assessed before, after fifth sessions, and then after 1, 2, 3 and 12 months. Cortical excitability was assessed for both hemispheres before and after the second and fifth sessions. Results,,, A significant ,rTMS × time' interaction was obtained indicating that real and sham rTMS had different effects on rating scales. This was because real rTMS produced greater improvement than sham that was evident even at one year follow-up. These improvements were associated with changes in cortical excitability over the period of treatment. Conclusion,,, These results confirm that real rTMS over motor cortex can enhance and maintain recovery and may be a useful add on therapy in treatment of acute stroke patients. [source]