Hemichorea-hemiballism (HCHB) can be the solely presentation of a wide range of non-neurological clinical pictures, such as metabolic or hydro-electrolyte derangements. HCHB as the first presentation of type 2 diabetes mellitus has been rarely described [1][2][3] . The case depicted herein reinforces this association highlighting that especially in elder patients with newly diagnosed HCHB, non-ketotic hyperglycemia should promptly be recognized.
caseA 70-year-old white man presented with one month history of involuntary movements of the left upper and lower limbs. He also noticed polyuria and polydipsia for the last 2 months and lost 10 kg within this period. His past medical history included controlled hypertension and a heart attack three years before. He used to take on a regular basis and at the time of presentation to our emergency department captopril 50 mg per day, hydrochlorothiazide 25 mg per day, propranolol 120 mg per day, aspirin 200 mg per day, and digoxin 0.25 mg per day. He used to be a heavy drinker (stopped 15 years ago) and smoker (stopped 3 years ago). There was no history of diabetes mellitus, other diseases or exposure to neuroleptic medication. No family history of movement disorders was obtained.On admission, he was fully alerted and oriented. He had HCHB involving his left upper and lower limb with normal muscle strength, but mild hypotonia. The movements were almost continuous during wakefulness, and disappeared during sleep. Fasting blood glucose was obtained (560 mg/dL) and type 2 diabetes mellitus was diagnosed. Glycosylated hemoglobin A1c was 6.6%. No ketones were detected in urinalysis and urine pH was normal. Corrected sodium concentration was 140 mmol/L, and estimated serum osmolality was 332 mOsm/L. Other routine blood tests including calcium, potassium, magnesium, and phosphate concentrations, and thyroid and parathyroid hormone tests were normal as well liver and kidney functional status. A brain computer tomography (CT) showed a slight hyperdense lesion on the right putamen. T1-weighted brain magnetic resonance imaging (MRI) showed a right hyperintense lesion on putamen with iso-signal intensity on T2-weighted and Flair images.With the administration of haloperidol (10 mg per day) and glycemia control (10 IU bed time NPH insulin) and 6 mg per day glimepiride his movement disorder decreased in severity and completely disappeared 15 days after the first medical appointment. A nine-month re-scan with MRI showed a normal putamen without the previously seen hyperintense lesion (Figure).The patient signed an informed consent to allow his data publication.
discussionThe underlying mechanisms of brain alterations in patients with non-ketotic hyperglycemia-induced HCHB are not known yet, but they have been attributed to base ganglia cerebral blood flow reduction, petechial hemorrhage, depletion of both GABA and acetylcholine, or metabolic acidosis 4 . Interestingly, among neuronal subtypes, striatal medium spiny neurones are highly vulnerable to energy depletion and this might explain ...