P3D197: A Unique Presentation of Diabetic Striatopathy (DS) in an Adolescent with Type 1 Diabetes Mellitus (T1DM)

Introduction: DS, previously described as nonketotic hyperglycemic hemichorea-hemiballismus, is characterized by involuntary movements due to striatal injury most commonly in the setting of acute hyperglycemia. We are reporting the first case of DS in an adolescent male with T1DM and excellent antecedent glycemic control.

Case Description: A 16-year-old Hispanic male with T1DM located in Guam presented with right lower leg muscle cramping and involuntary movements. Child Neurology was virtually consulted via the Global Telehealth Portal (GTP), a unique physician-to-physician military specific consulting platform. GTP discussion led to a synchronous video consult with Child Neurology. Movements on video were jerking, arrhythmic, and uncomfortable. Overall, movements had features of chorea and dystonia without being clearly consistent with either. MRI showed increased T1 signal in the left caudate head and lentiform nuclei with sparing of the thalamus.

In the three months prior to imaging, Dexcom G6 continuous glucose monitor data showed well controlled glycemia, with an average blood sugar of 142 +|- 49, time in range 63% (>70%), above range 34% ( < 25%), below range 3% ( < 4%) with actual range of 61 to 205.

Discussion: DS prevalence is 1:100,000 and more common in females, Asians, and Type 2 Diabetics (T2DM). To date only eleven pediatric cases have been reported, nine associated with T1DM. Seven cases were reported at the time of initial diagnosis and four were established. All were associated with severe hyperglycemia (300 or higher) or severe A1C (10% or higher).

Severe non-ketotic hyperglycemia induced metabolic acidosis is thought to injure the basal ganglia secondary to GABA depletion that ultimately leads to hemichorea-hemiballismus. Non-GABA associated basal ganglia injury is likely to be the cause in poorly controlled T1DM as ketones can be converted to GABA in the brain.

Our patient had excellent glycemic control which likely represents long-term neurologic sequela from initial T1DM three months prior or other recent unexplained basal ganglia injury.

This case was complicated by lack of access to Child Neurology or Pediatric Endocrinology in the host nation. Satisfactory care was accomplished through a combination of synchronous and asynchronous telemedicine.

Conclusion: This unique case of DS in an adolescent with empiric maintenance of goal glycemic control highlights the importance of awareness of this rare condition. With the recent increase in pediatric T1DM and T2DM cases, associated DS is likely to rise. Even without typical risk factors, childhood diabetics with new onset involuntary movements should raise a high index of suspicion for DS.