Impairment of motor planning in patients with Parkinson's disease: evidence from ideomotor apraxia testing.

TLDR

Patients with Parkinson’s disease may experience increased interference between successive items, worsening copying of movement sequences. The study proposes that impaired visuospatial encoding and central processing disrupt movement memory, hindering accurate imitation. Parkinson’s patients scored lower on ideomotor apraxia tests, with sequence imitation more impaired than single movements, and deficits correlated with visuospatial ability rather than motor disability severity.

Abstract

Compared with a group of age matched controls, patients with Parkinson9s disease scored significantly lower in testing for ideomotor apraxia. Imitation of movement sequences was affected more severely than performance of single movements. The degree of impairment was not related to severity of motor disability, but correlated strongly with the results of tests that measured visuospatial and visuoperceptive abilities. It is suggested that defective encoding and central processing of visuospatial information impairs memory for movement which is necessary for correct imitation of movements. Enhanced vulnerability to interference between successively presented items may cause further deterioration of performance in the copying of movement sequences.