Ipsilateral Motor-Related Hyperactivity in Patients With Cerebral Occlusive Vascular Disease

Abstract

Background and Purpose-Cerebral occlusive vascular disease is an established risk factor for ischemic stroke; however, little is known about its effects on brain function in patients without stroke. To detect possible functional alterations, we used magnetoencephalography and evaluated cerebral cortical activity during hand motor tasks in a group of such patients. Method-Event-related desynchronization (ERD) during hand-grasping and self-paced finger-tapping tasks was examined in 38 right-hand-dominant patients with occlusive disease of the internal carotid or middle cerebral artery caused by diverse pathologies (atherosclerosis, 28; others, 10) and in 8 control subjects. All patients had no apparent motor impairments. The spatial distribution and the intensity (t value) of ERD in the beta band were analyzed with synthetic aperture magnetometry. According to the laterality index calculated from the ratios of peak t values on ipsilateral vs contralateral (with respect to the hand movement) hemispheres, the distribution of ERD was classified into 3 patterns: contralateral, bilateral, and ipsilateral. Results-Abnormal ipsilateral dominant distribution of beta ERD was observed significantly more often during contralesional hand grasping in patients with atherosclerotic vascular lesion. It was accompanied by significantly higher t values on the ipsilateral hemisphere, without a decrease in those on the contralateral side. The age, the rating scores of periventricular hyperintensity, and ventricular size were all significantly higher in patients who showed the ipsilateral-dominant pattern. Conclusion-Abnormal

Study of Repetitive Movements Induced Oscillatory Activities in Healthy Subjects and Chronic Stroke Patients

“…6 demonstrate the dominance of unaffected hemisphere in stroke patients. Unlike the LI s in hand movements of healthy subjects and the non-paretic hands in stroke patients, the LI s of paretic hand movements in stroke patients showed laterality dominance in ipsilateral hemisphere both in alpha and beta bands which is in line with the observation in other literatures2434. In addition, it might be worthy to notice that the laterality of beta PAmp resp s was inclined more contralaterally in the hand movements of healthy subject and the non-paretic hands in stroke patients.…”

“…It was reported that ipsilateral motor-related hyperactivity was observed in patients with cerebral occlusive disease24. Therefore, the laterality index ( LI ) was used to quantitatively describe the inter-hemispheric asymmetry25.…”

Ipsilateral hemiparesis in ischemic stroke patients

“…Studying ipsilateral hemiparesis may contribute to our investigations of post‐stroke plastic reorganization, especially the compensatory function of the corticospinal tract contralateral to the injury. Post‐stroke plastic reorganization has been assessed by functional neuroimaging studies including positron emission tomography, transcranial magnetic stimulation (TMS), functional MRI (fMRI), magnetoencephalography, and diffusion tensor imaging . Case‐control studies or serial observation studies, in which ordinary stroke patients were examined by these functional neuroimaging methods, have provided only indirect evidence about the reorganization system because it is uncertain that atypical regions activated neurophysiologically actually work to compensate for damaged function in the stroke patients.…”

Implied functional crossed cerebello-cerebral diaschisis and interhemispheric compensation during hand grasping more than 20 years after unilateral cerebellar injury in early childhood

“…Simple one-handed movements are controlled mainly by the contralateral SM1 hand area with critical regulatory input from the cerebellum contralateral to the SM1 [ 23 , 24 ]. In MEG, the beta ERD appeared in the right SM1 during left hand grasping, the typical response of healthy adults [ 8 , 11 , 13 ], but in the bilateral SM1 with slight right-side dominance during ataxic right hand grasping. This beta ERD pattern is consistent with that reported in patients with gliomas around the central sulcus or with occlusive disease in the arteries providing blood supply to the cerebrum during contralesional hand grasping [ 11 , 13 ], presumably due to compensatory cortical activity by the contralesional (ipsilateral) SM1.…”

“…Event-related desynchronization in the beta oscillation (beta ERD), a robust electrophysiological correlate of movement, was measured by MEG during left and right hand grasping using a 64-channel whole head magnetometer (NeuroSQUID Model 100, CTF Systems Inc., Canada). In healthy adults, the beta ERD is detected by MEG dominantly in the contralateral SM1 during hand grasping [ 8 , 11 , 13 ]. During data collection, the patient sat on a chair in a magnetically shielded room.…”