Case Presentation: A 62-year-old man with history of end-stage renal disease and poorly controlled type 2 diabetes mellitus presents to the hospital after a fall due to unsteady gait and was noted to have facial movements similar to tardive dyskinesia, whole body chorea, and hyperkinesis of torso and bilateral extremities. On admission, he had an elevated serum osmolarity to 311 Osm/L and glucose to 500 mg/dL. The magnetic resonance imaging (MRI) of the brain showed T2 hyperintense signal abnormality in the bilateral lentiform nuclei with vague associated restricted diffusion concerning for diabetic striatopathy and most likely secondary to prolonged hyperglycemia. The hyperkinetic movements persisted after glycemic control. Treatment with risperidone 0.5 mg twice a day led to improvement of the choreiform movements.
Discussion: Hospitalists frequently see patients with diabetes mellitus and associated complications in the inpatient setting. Diabetic striatopathy is a rare neurologic complication that occurs in the context of non-ketotic hyperglycemia and may be the first manifestation of uncontrolled type 2 diabetes mellitus. The diagnosis is based on clinical and imaging findings, characterized by abnormalities of the basal ganglia on brain MRI with associated hyperkinesis. The basal ganglia inhibit unwanted movements and removal of this inhibition results in unsuppressed excitatory output leading to hyperkinesis, specifically chorea. Similar movement disorders from this loss of inhibition are Huntingtons disease, dystonia, and hemiballismus. Most published cases of diabetic striatopathy report hemichorea as the clinical presentation with putamen involvement on MRI. While there have been multiple case reports describing this syndrome, the pathophysiology of this rare neurologic sequelae has not fully been elucidated. The theories of pathophysiology are based on the effects to the lentiform nucleus within the basal ganglia. One theory is due to lack of flow there is depletion of inhibitory gamma-aminobutyric acid (GABA). Another theory is hyperviscosity secondary to hyperglycemia resulting in a regional blood-brain barrier disruption. Why this affects the basal ganglionic vessels specifically is unknown. In some cases, resolution of the chorea can be achieved with glycemic control although therapy targeting hyperkinesis, such as haloperidol and risperidone, may be needed in refractory cases.
Conclusions: This case vignette illustrates a rare complication that can occur in decompensated diabetic patients that are not able to achieve glycemic control.