Clinical vignette: Hyperglycemic hemichorea hemiballismus: a sugar coated movement disorder

Presented at American College Physicians national meeting, 04/11/2014, Orlando, FL. Winner of resident competition. American College of Physicians New Mexico Chapter Scientific Meeting, 10/18/2013, Albuquerque, NM.An 86 year-old man with type II diabetes, coronary artery disease and anxiety presented to the emergency department with insomnia and restlessness for 3 days duration. The patient claimed to be feeling increasingly anxious and initially sought treatment at an outpatient psychiatric urgent care. He was referred to the emergency department when his blood glucose was found to be above 500 mg/dL. The patient claimed to be taking his long-acting insulin at home but his inability to concentrate made him a poor historian. On examination he appeared dehydrated and disheveled. Physical examination was unrevealing except for abnormal jerking, twitching and writhing of his right upper and lower extremities. His inpatient laboratory findings initially revealed serum blood glucose of 348 mg/dL, a hemoglobin A1C greater than 18% and pseudo-hyponatremia at 129 mmol/L. All other labs were unremarkable. The patient was admitted for treatment of non-ketotic hyperglycemia and evaluation of his abnormal involuntary extremity movements. Urine toxicology screen, thyroid stimulating hormone, vitamin B12 and folate levels were normal. His movements were assumed to be due to insomnia and a possible psychiatric illness but failed to resolve with sleep medication and anxiolytics. The patient underwent a brain CT scan and MRI that revealed hyper-attenuation of the left putamen. This finding, with the patient’s unilateral involuntary jerking in the setting of non-ketotic hyperglycemia lead to the diagnosis of hyperglycemic hemichorea hemiballismus. The patient was treated with glycemic control and short-term clonazepam. His hemichorea resolved after 3 weeks of appropriate glycemic control and clonazepam was discontinued. Hemichorea hemiballismus is a rare and fascinating complication of prolonged hyperglycemia. It typically occurs in elderly type II diabetics and is more common with those of Asian decent. The brain image findings described in our patient are classic for this disease. The pathophysiology of this condition is poorly understood but biopsy of the basal ganglion lesions reveals swollen astrocytes. Symptoms are usually unilateral and typically resolve completely with glucose control, as do the findings on brain imaging. This striking disorder is diagnosed by typical MRI findings in the setting of hyperglycemia. Because it is reversible, physicians should be aware of this rare and disabling form of chorea so as not to mistake it for psychiatric disease or more serious forms of chorea such as Huntington's