[Asymmetries in the central alpha activity (my-rhythm) at rest and during activation in patients with cerebrovascular lesions (author's transl)].

Eleven patients with a history of ischemic lesion and weak hemiparesis were used in this study. Bipolar EEG recordings were made from the central region at rest and during voluntary infrequent first-clenching. After computer analysis, percentage alpha power, alpha power decrease during movement (ERD: event-related desynchronization) and alpha-peak frequency were calculated and compared for symmetry in homologeous derivations. As reference a collectiv of 33 normals was used. In 8 out of 11 patients a significant (p < 0.05) alpha-asymmetry was found and in 2 out of 11 a significant (p < 0.05) asymmetry in the ERD. Summarizing all results, 9 out of 11 patients showed significant asymmetry within the central alpha activity. Computer EEG was done on average 18 days after onset of infarction. In clinical EEG, recorded within one week after infarction, 3 out of 11 patients were reported with pathological findings.