Paroxysmal Hemidystonia as the Presenting Manifestation of Previously Undiagnosed Diabetes Mellitus

TL;DR

A 72-year-old man with unexplained paroxysmal dystonia was found to have undiagnosed diabetes, showing that dystonia can be a rare early sign of hyperglycemia.

Contribution

This case expands the known movement disorders associated with hyperglycemia to include paroxysmal hemidystonia as a possible initial sign of diabetes.

Findings

The patient's abnormal movements resolved after correcting hyperglycemia.

Brain imaging showed no acute striatal lesion, but subtle hypometabolism in the left cerebellum was observed post-recovery.

The case emphasizes the importance of glucose testing in patients with new-onset paroxysmal hyperkinetic movements.

Abstract

Hyperglycemia-related movement disorders classically present as hemichorea-hemiballismus, whereas dystonia is far less common and may occasionally precede the recognition of diabetes mellitus.

A 72-year-old man presented with a 3-month history of recurrent, stereotyped dystonic spells involving the right side of the face, arm, and leg. These episodes occurred approximately twice per minute and lasted about 5 seconds each. Initial laboratory testing revealed a plasma glucose level of 494 mg/dL and an HbA1c of 16.1%, consistent with previously unrecognized diabetes mellitus. Electrolyte levels, electroencephalography, cerebrospinal fluid analysis, and evaluation for autoimmune encephalopathy were unremarkable. Brain MRI showed only a chronic lacunar infarct in the left basal ganglia, with no evidence of an acute striatal lesion. The abnormal movements resolved completely within 3 days after correction of hyperglycemia. Follow-up 18F-FDG PET/CT performed after clinical recovery demonstrated subtle relative hypometabolism in the left cerebellum, with preserved uptake in the basal ganglia and cerebral cortex.

This case broadens the phenomenologic spectrum of hyperglycemia-related movement disorders and highlights paroxysmal hemidystonia as a potential presenting manifestation of previously undiagnosed diabetes mellitus. Bedside glucose testing should therefore be routinely performed in the evaluation of new-onset paroxysmal hyperkinetic movements. In addition, isolated extra-striatal metabolic abnormalities detected after symptom resolution should be interpreted with caution.

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