Non-ketotic hyperglycemic chorea-hemiballismus mimicking basal ganglia hemorrhage

Radiographic findings of hyperglycemic non-ketotic chorea-hemiballismus and basal ganglia hemorrhage can be highly similar. A 58-year-old female presented with a 1-week history of choreiform and ballistic movements of the left arm. Based on CT imaging, the patient was diagnosed with a basal ganglia hemorrhage. After transfer to our institution, further imaging and work-up led to a diagnosis of non-ketotic hyperglycemic chorea-hemiballismus. Aggressive glycemic control was started and the patient's symptoms resolved. Despite its rarity, non-ketotic hyperglycemic chorea-hemiballismus should be included in the differential diagnosis of basal ganglia hyperdensity on CT scan, as it can mimic basal ganglia hemorrhage. Resolution of this clinical entity and implementation of aggressive glycemic control can lead to complete resolution of symptoms. It is important for neurosurgeons to be aware of this clinical entity as prompt treatment often yields good outcomes.