Monophasic Autoimmune Chorea in a Pediatric Patient

Introduction: Sydenham chorea is the most common parainfectious chorea in children and may be the only presenting symptom of acute rheumatic fever in children. However, choreiform movement disorders in children may also be the result of nonspecific immune processes or other non-immune-mediated disorders. We present the case of an otherwise healthy 10-year-old girl with a nonspecific immune-mediated chorea that resolved with immunomodulatory therapy. Clinical Findings: The patient's exam results indicated orolingual dyskinesia and blepharospasm. The patient had intermittent choreiform movements of the neck, trunk, and extremities (including a ``milk maid's grasp'') that persisted even when she was asleep. Her coordination was impaired due to chorea and included dysmetria and dysgraphia. Her laboratory results were positive for immunoglobulin G and immunoglobulin M of Mycoplasma pneumoniae antibodies, anti-streptolysin O, anti-DNAse B titers, anti-thyroid peroxidase, and anti-glutamate decarboxylase-65 antibodies. Her erythrocyte sedimentation rate was also elevated at presentation. Clinical Course: The patient's symptoms did not improve with low-dose risperidone or empiric treatment for both Strep pyogenes and Mycoplasma pneumoniae. Her dyskinetic movements also did not improve with time and persisted for 17 days after her initial discharge. She was subsequently readmitted to the hospital and treated with high-dose methylprednisolone and intravenous immunoglobulin, which resulted in long-term resolution of her dyskinetic movements. Conclusions: Immune-mediated choreiform movement disorders may be nonspecific and involve etiologies other than Sydenham chorea/acute rheumatic fever. Empiric immunomodulation should be considered for other autoimmune or parainfectious etiologies of chorea in childhood.