Disentangling the Alien and Anarchic Hand

Abstract

''Anarchic hand'' is the term by which we propose to identify complex goaldirected movements of a hand, which are performed against the patient's will, and that cannot be voluntarily inhibited. This phenomenon should be differentiated from the feeling of nonbelonging of a hand, known in the literature since the report of Brion and Jedinak (1972), to which the term ''alien hand'' should be retained. Anarchic hand, which is linked with anterior lesions of the corpus callosum and the supplementary motor area contralateral to the wayward hand, should be conceived as s ''frontal'' sign. Alien hand, which has been reported after posterior lesions of the corpus callosum, probably encroaching upon the parietal cortex, should be thought of as a partial hemisomatognosia, that is, a unilateral ''loss of the knowledge or sense of one's own body and bodily condition'' (Beaumont, Kenealy, & Rogers, 1996, p. 108). This distinction will ease the description and the interpretation of new cases of alien and anarchic hand and will avoid some of the confusion currently present in the field.