A case with dressing apraxia

A 56 year old right handed man developed a persistent dressing apraxia after a cerebral infarction. On examination eight months after the onset, he showed an extreme difficulty in dressing, which did not improve even after repeated trials. He also showed poor judgement of line orientation, impaired ability on constructive task, and prominent difficulty in right left discrimination of objects placed in front of him. Interestingly, his right left orientation about his own body was not impaired. Mild left unilateral neglect and left sided visual extinction on double simultaneous stimuli were also present. No other neuropsychological signs including aphasia, apraxia, agnosia, asomatognosia and amosognosia were present. The detailed experimental investigations showed that his visual imagery and its mental operation were severely impaired. For instance, he was unable to rotate an imagery object in his mind. We concluded that his dressing impairment was inherently related with this difficulty in rotating an imagery object in the mind. A MRI study showed high signal areas in T₂ weighted images in the superior parietal lobule, angular gyrus, occipital cortex, and corona radiata of the right cerebral hemisphere. Also a small lesion was detected in the ventral midbrain through the upper pons.