Hemiballism due to hyperglycemic hyperosmolar syndrome.

Non-ketotic hyperglycemia has occasionally been associated with various neurological abnormalities including movement disorders. Hyperglycemic hyperosmolar syndrome (HHS) is the second most common cause of hemiballism-hemichorea, which is due to a contralateral putaminal lesion. We describe a 95-year-old woman with HHS who developed hemichorea-hemiballism syndrome due to a putaminal lesion.