P0872 - An unusual cause of acute onset movement disorder in an adolescent: a rare pediatric presentation of Chorea-Hyperglycemia-Basal Ganglia syndrome

Introduction: Chorea or hemiballismus secondary to hyperglycemic changes in the basal ganglia (C-H-BG syndrome), also called diabetic striatopathy and hyperglycemic nonketotic hemichorea/hemiballism, is a rare condition most commonly described in elderly women with T2DM. Here, we present a rare case in an adolescent male.

Case report: An 18 year old male with a history of type 1 DM and unspecified psychotic disorder presented to a pediatric ER with involuntary movements. The patient reported that the movements began with twitching of his right hand five days prior to presentation, but had since progressed to involve his right arm and face, and at times his entire body. Past medical history was significant for T1DM diagnosed at age 5, and an unspecified psychiatric disorder diagnosed at age 13. Of note, the patient discontinued antipsychotic medication several years prior. Physical exam was remarkable only for involuntary movements, which were characterized as right arm ballismus with underlying akathisia and associated mouth chewing dyskinesia, as well as subtle athetoid movements on the left side. Point of care blood glucose was 492. Given the broad differential of new onset movement disorder in a child, initial workup included: Strep test (Sydenham Chorea), Copper, Ceruloplasmin (Wilson's Disease), Vitamin B12, CMP, HIV, TFTs (Hashimoto's Thyroiditis), ANA (Lupus), and a toxicology screen. Since the patient presented with hyperglycemia and a history of poorly controlled diabetes, C-H-BG syndrome was also considered, along with other rare causes of pediatric movement disorder such as Juvenile Huntington's Disorder, Neurodegeneration with Brain Iron Accumulation (NBIA), and a basal ganglia infarct or mass. Lab results revealed a Hgb A1c above 14 and elevated glucose in urinalysis, but were otherwise unremarkable. MRI results (Figure 1) revealed a symmetric, T1 hyperintense signal within the caudate nuclei and putamen. With tight glycemic control, the patient’s movements improved, with almost complete resolution within 24 hours. The patient was diagnosed with hemiballismus and chorea secondary to hyperglycemic changes in the basal ganglia (C-H-BG), and discharged with a plan for tight glycemic control, close follow-up with both endocrinology and neurology, and a scheduled repeat MRI.

Discussion: This case illustrates an uncommon phenomenon in a very unusual patient population, since most reports of this rare condition describe elderly adults with T2DM. C-H-BG syndrome is characterized by T1 hyperintense changes in the basal ganglia on MRI. Symptoms may resolve with glycemic control, or may persist, requiring long-term medical or even surgical treatment. This case, therefore, emphasizes the importance of tight glycemic control in Diabetes management, while also illustrating that, although rare even in elderly adults, C-H-BG syndrome should be considered in pediatric patients as a potentially reversible cause of involuntary movements.