General description

Diabetic hemiballism is a neurological condition seen in patients with poorly controlled diabetes during episodes of non-ketotic hyperglycemia, characterized by involuntary, large-amplitude flinging movements of the limbs (hemiballism or chorea). It typically presents acutely, more frequently in elderly women, and may affect one or both sides of the body.

The condition is thought to result from hyperosmolarity and hyperviscosity-induced brain injury, which reduces blood flow to certain brain regions. Lesions are commonly observed in the putamen or caudate nucleus, causing contralateral hemiballism, though cases involving the subthalamic nucleus have also been reported. The abnormal movements usually improve as blood glucose levels are normalized.

Radiographic features

MRI shows T1WI hyperintensity and CT high attenuation in the unilateral putamen, and occasionally in the caudate nucleus, globus pallidus, and subthalamic nucleus contralateral to the symptomatic side. T2*WI may show hypointensity, suggesting microbleeds.