An 82-year-old man with a past medical history of coronary artery disease, atrial fibrillation, heart failure with reduced ejection fraction, stroke, non insulin-dependent diabetes mellitus and chronic kidney disease stage III presented to the hospital with uncontrollable movements of his right-side upper and lower extremities. His symptoms began spontaneously two weeks earlier and his symptoms waxed and waned in severity. He denied other neurological symptoms except for occasional right-sided headaches. Vital signs were normal, and neurological exam was notable for spontaneous choreiform movements of the right arm and leg, but strength and sensation were intact. Labs were significant for elevated blood glucose (500 mg/dl) without ketones in the serum or urine. CT of the head revealed only a pituitary macroadenoma without hemorrhage or infarct; cranial nerves were intact and serum levels of pituitary hormones were unremarkable. Weight-based insulin therapy was begun to rapidly correct hyperglycemia, and neurological signs and symptoms resolved rapidly after glycemic control was achieved.
Discussion:
Ballism is a neurological phenomenon characterized by uncontrollable, involuntary movements of extremities, typically affecting only one side of the body (hemiballism). Hemiballism differs from typical chorea as it involves large amplitude movements that are fidgeting/kicking in nature. It is most commonly attributed to dysfunction of the basal ganglia, specifically the subthalamic nucleus. Whereas acute stroke is felt to be the most common cause of this dysfunction, a less common and underreported etiology of hemiballism is nonketotic hyperglycemia. The pathophysiology of this phenomenon is poorly understood, but the prevailing theory is that decreased glucose metabolism reduces perfusion of the basal nuclei, leading to cytotoxic edema of astrocytes. Another theory is that hypoperfusion may deplete the inhibitory neurotransmitter GABA, leading to uninhibited movement of the extremities. Imaging of the brain by CT or MRI may reveal contralateral striatal hyperintensities; however, the absence of this finding does not exclude the diagnosis. The preferred treatment of this condition is aggressive glycemic control, and patients typically experience rapid resolution of symptoms as seen in our case above.
Conclusions:
Hospitalists frequently encounter nonketotic hyperglycemia, but rarely see hemiballism. In the absence of evidence of acute stroke, hospitalists should consider nonketotic hyperglycemia high on the differential diagnosis of etiologies of hemiballism. Rapid correction of hyperglycemia frequently results in complete resolution of this unusual movement disorder.