Ideomotor apraxia in patients with Alzheimer disease: Why do they use their body parts as objects?

Objective: Difficulty in pantomiming the use of tools is observed in patien ts with Alzheimer disease. Patients with Alzheimer disease tend to use thei r body parts as objects when they try to pantomime the use of tools. The bo dy-parts-as-objects phenomenon was thought to consist of appropriate gross movement of patients' arms despite inappropriate patterns of handling tools with their hands. However, the mechanism has not been investigated fully. Methods: The authors examined 11 healthy individuals and 24 patients with A lzheimer disease for ability to recognize tools, to pantomime the use of to ols, to use actual tools, and to select an appropriate photograph of a hand ling pattern of the tool. Results: In comparison with the patients with Alz heimer disease, the healthy individuals had higher scores for all tasks. Th e authors classified the patients into group A (patients with higher pantom ime scores), group B (patients with middle level scores), and group C (pati ents with lower scores). Frequency of use of body parts as objects for pati ents in group B was higher than that of patients in group A and in group C. The mean Mini-Mental State Examination score for patients in group A was h igher than that of patients in group B and in group C. In comparison with p atients in group A, patients in group B showed lower scores on the hand-pos ture discrimination task without a tool, even after controlling the Mini-Me ntal State Examination score. Conclusions: The authors conclude that body-p arts-as-objects responses in patients with Alzheimer disease occur because general cognition is lowered or because retrieval ability of the appropriat e holding posture for tools is impaired.