[Hemichorea induced by diabetic ketoacidosis and striatal hyperdensity on computerized axial tomography]

Hyperglycaemia, usually not ketotic, may cause hemichorea hemiballism. The mechanism of this physiopathological syndrome is still not clear. It usually occurs in elderly ladies and is associated with hyperdensity in the striate area contralateral to the affected side, on CT and MR potentiated in T1.

Three days before hospital admission, and 86 year old woman presented with the acute onset of choreiform movements of her left limbs, particularly her left arm. She had not taken neuroleptic drugs and there was no family history of chorea. On neurological examination there were no other unusual findings. Laboratory tests showed hyperglycemia with metabolic acidosis and ketone bodies in the urine. On the CT scan there was a hyperdense lesion in the right striate area, but this did not act as a space occupying lesion. Treatment was started with intravenous insulin and the symptoms disappeared 48 hours later.

We emphasize the rarity of the association of hemichorea and diabetic ketoacidosis. From the histological studies done in some of these patients, it seems that the hyperdensity of the striate area may be due to the proliferation of hypertrophic astrocytes secondary to small ischemic lesions. When the hyperglycaemia is treated, the chorea disappears within a few days and it is unusual for neuroleptic treatment to be required. In cases of hemichorea, hyperglycaemia should be ruled out, as should structural causes (tumors, infarcts, hematomas, traumatic lesions, etc.).