Chorea as a non-thrombotic manifestation in an adolescent with systemic lupus erythematosus, antiphospholipid syndrome and heterozygous prothrombin G20210A gene mutation: a case report

Introduction: Chorea is a rare movement disorder in the context of systemic lupus erythematosus (SLE). Although basal ganglia thrombosis, autoimmune injury or neuronal direct lesion have been proposed as possible explanations, its mechanism is still unknown. It is important to understand its pathogenesis so that the best treatments can be identified. Case presentation: A 12-year-old female adolescent with choreoathetoid movements of the trunk and four limbs, slurred speech, hypophonia and orofacial dyskinesia with 14 days of evolution. Brain magnetic resonance imaging revealed recent subcortical ischemic lesions in both frontal and parietal lobes. Basal ganglia lesions were not found. She started acetylsalicylic acid (ASA) and tetrabenazine, with chorea improvement. Transcranial Doppler ultrasound identified a microembolic sign between the left middle cerebral and anterior cerebral arteries. Therefore, ASA was switched to enoxaparin. Antinuclear antibodies and lupus anticoagulant (LAC) antibody were positive, with heterozygous prothrombin G20210A gene mutation being found. Five-day methylprednisolone pulses 1g/day were performed, followed by prednisolone 60mg/day. Intravenous immunoglobulin was administered, and hydroxychloroquine was initiated. Due to progressive microscopic hematuria and non-nephrotic proteinuria, kidney biopsy was performed, being compatible with class V lupus nephritis. Consequently, mycophenolate mofetil and enalapril were started. Chorea resolved five days later. After discharge, LAC remained positive, but no more neurologic symptoms occurred. Conclusions: Basal ganglia thrombosis does not seem to be the most likely mechanism of SLE-related chorea. Antiphospholipid antibodies alone do not seem to be enough to trigger chorea. Further studies are needed to clarify the mechanisms that trigger this movement disorder.