Hemichorea induced by non-ketotic hyperglycemia evaluated with 18F-FDG and 11C-CFT PET/CT

Abstract

A 54-year-old female, with a history of recently diagnosed diabetes and poorly controlled hyperglycemia, presented with acute onset of progressive choreiform movements started from the upper right limb then diffused to the whole right limb and her face. Declined muscle strength and tension were found in the right limb, and decreased jerk reflex was observed in bilateral knees. Laboratory examinations on urine ketone, electrolyte, ceruloplasmin, thyroid function, and autoantibody were normal, except for the elevated blood glucose level (416 mg/dL), positive urine glucose (+++), and HbA1c of 9% (N, 4.3–6.3) without ketoacidosis. Brain images revealed hyperdensity on computed tomography (CT) (Fig. 1a, white arrow), hyperintensity on T1-weighted magnetic resonance imaging (T1WI MRI) (Fig. 1b, white arrow), decreased glucose metabolism on F-fluorodeoxyglucose positron emission tomography/CT (F-FDG PET/CT) (Fig. 1c, red arrow), and decreased binding of C-2β-carbomethoxy3β-(4-fluorophenyl) tropane (C-CFT) on PET/CT in the striatum (Fig. 1d and e, red arrows). Therefore, she was diagnosed as hemichorea associated with non-ketotic hyperglycemia (HCNH), and treated with haloperidol and insulin. After 4 months, choreiform movements of the patient were significantly improved along with decreased area and increased signal intensity in the left striatum abnormality (Fig. 1f, white arrow) on brain T1WIMR images, which was consistent with the previous reports [1, 2]. HCNH is a rare complication of diabetes mellitus [3], which is characterized by the triad of symptoms (hyperglycemia, hemichorea, specific findings on CT or MRI), and frequently reported false-negative findings on CT and MRI [4]. Thus, PET imaging with combined glucose metabolism and dopamine transporter may serve as an important approach for precise diagnosis of this disease. Further studies are needed to evaluate feasibility of PET for the initial diagnosis and monitoring of treatment in patients with HCNH [1].