Hypoglycemia-induced hemichorea in a patient with Fahr's syndrome.

Non-ketotic hyperglycemia may be a cause of hemiballism-hemichorea. We present an elderly female type II diabetic patient with right-sided hemiballism-hemichorea of acute onset during hypoglycemia following insulin overtreatment of non-ketotic hyperglycemia. Brain computerized tomography and magnetic resonance imaging scans revealed characteristic hyperdensity and T1 hyperintensity, respectively, in the left basal ganglia, in addition to pallido-dentate calcifications, suggestive of Fahr's syndrome. Although extremely rare, hypoglycemia may be a cause of hemiballism-hemichorea especially in the presence of predisposing factors such as previous hyperglycemic episodes and Fahr's syndrome.