IDEOMOTOR APRAXIA - BEHAVIORAL DIMENSIONS AND NEUROANATOMICAL BASIS

Ideomotor apraxia, disordered movement execution to command, commonly follows left-hemisphere damage, implying left-hemisphere dominance for certain kinds of movements. To delineate this dominance we used diffe rent command modalities to elicit meaningful movements and tested imit ation of nonsense movements. Twenty-seven patients with unilateral hem ispheric stroke and 10 age-matched controls were evaluated. Patients w ith left-hemisphere damage performed both meaningful and nonsense move ments poorer than the other study groups; thus, the meaningfulness of the movements is irrelevant for the left-hemisphere motor dominance. T he performance varied, however, with the command modality and movement type. Based on this and earlier studies we posit that the left-hemisp here motor dominance is determined by the artificiality of the test si tuation (it concerns movements performed to command and out of the nat ural context) and increased spatial and temporal complexity of the dem anded movements. No association between the lesion locus within the le ft hemisphere and the severity of the ideomotor apraxia was found. (C) 1997 Academic Press.