Atypical onset of diabetes in a teenage girl: a case report

Chorea, hemichorea-hemiballismus and severe partial seizures may be the presenting feature of nonketotic hyperglycemia in older adults with type 2 diabetes, but cases in children with type 1 diabetes are rare, since the most easily recognized symptoms of type 1 diabetes in children are secondary to hyperglycemia, glycosuria, and ketoacidosis. A previously healthy 15-year-old girl presents with sudden onset of right-sided chorea. Brain CT did not detect any abnormal density areas. A T1-weighted image of brain MRI was normal. Investigations revealed hyperglycemia with absent ketones and normal serum osmolality. Achievement of normoglycemia with insulin therapy determined the involuntary movements to regress completely within a day. The direct effect of hyperglycemia could be the pathogenesis of the chorea in our patient. Severe hyperglycemia without ketosis at the clinical onset of insulin-dependent diabetes mellitus (type 1) has been reported in children and adolescents, but nonketotic hyperglycemia is an unusual cause of chorea-ballismus in children, and chorea-ballismus is also a rare manifestation of primary diabetes mellitus. The importance of clinical evaluation, laboratory testing and neuroimaging for the differential diagnostics of chorea is emphasized.