Chorea-ballism associated with ketotic hyperglycemia

Chorea-ballism is a rare movement disorder characterized by irregular, poorly patterned, and involuntary movements, which are usually unilateral but may be bilateral or involve the extremities. The most common metabolic cause of transient chorea-ballism is nonketotic or ketotic hyperglycemia (NKHG or KHG, respectively). A meta-analysis and several reviews have identified clinical characteristics of NKHG-associated chorea-ballism; however, the characteristics of KHG-associated chorea-ballism remain unknown. We performed a search for studies of patients with KHG-associated chorea-ballism, published in MEDLINE between 1960 and May 2014, and identified 13 studies of 15 patients. Despite the limited number of cases, we identified some significant differences in the clinical and radiological characteristics between patients with KHG- or NKHG-induced chorea-ballism. Patients with KHG were significantly younger than patients with NKHG, and a higher percentage of patients with KHG had atypical or negative brain imaging findings for chorea-ballism compared to patients with NKHG. We recommend that blood glucose levels be tested on admission as a key diagnostic measure, to improve the early diagnosis of chorea-ballism. The best treatment for KHG-induced chorea-ballism is rapid glucose control with an insulin drip and, possibly, neuroleptics. The mechanisms of the disease are unclear, although the GABA theory, cerebrovascular insufficiency, and alterations of dopaminergic activity in the striatum might play important roles.