A 62-year-old man presented with monoballism of the right leg. Magneti
c resonance images revealed a small hemorrhagic focus confined to the
caudal portion of the left subthalamic nucleus. The monoballism disapp
eared after a short time, without treatment. This is the first report
of lower monoballism with single subthalamic lesion. The findings in t
his case support the theory of somatotopic correspondence in the subth
alamic nucleus.