[Limited paralysis of the hand caused by metastasis in the motor cortex].

A 66-year old man presented a progressive motor deficit of the left hand mimicking radial and ulnar paralysis. Clinical examination, laboratory investigations, and post mortem findings, demonstrated a single metastasis in the contralateral motor cortex. The interest of this case lies in the discrepancy between the extent of the motor deficit and the size of the lesion. This finding could help to interpret current theories concerning the somatotopic representation on the motor cortex in man.