뇌경색 후 운동피질 영역의 기능적 재구성

Abstract

Background & Purpose : Focal transcranial magnetic stimulation(TMS) can be used for mapping of the somatotopical organization of the motor cortex. We aimed to investigate the functional reorganization of hand motor areas after monohemispheric ischemic stroke. Methods : Ten patients (six men and four women, age = 57.1 (±11.4 years) with complete hand palsy and no motor evoked potential (MEP) on abductor digiti minimi (ADM) within a week of ischemic stroke were included. TMS was also performed at subacute stage (3 weeks after onset). Motor maps were constructed after 12 months from onset by recording MEPs from bilateral ADM muscles via focal TMS in affected hemisphere (AH) and unaffected hemisphere (UH). Medical Research Council (MRC) Scale, modified Rankin Scale, and Barthel index were evaluated as well. Ten healthy control subjects were also studied to establish normative data. Results : Three different patterns of functional reorganization were observed. First, medially distributed maps in AH compared to UH (‘medially distributed group’) were found in 5 patients: MEP at subacute stage was absent in 3 and present in 2. Second, symmetrically distributed maps between AH and UH (‘symmetric group’) were found in 3 patients: MEP at subacute stage was present in all patients. Third, no MEP was observed in AH (‘no potential group’) in 2 patients: MEP at subacute stage was absent in both patients.‘No potential group’ showed poorer functional outcome compared to the other groups (p < 0.05). Conclusions : Our data shows the different patterns of motor maps in chronic stroke patients. In ‘symmetric group’, the functional recovery may be based on the reestablishment of previously damaged corticospinal connections. The observed neurophysiological findings are correlated with clinical improvement. Korean Journal of Stroke 2001;3(1): 79~84