Case Presentation: A 22 year old female with a history of migraines and anxiety was admitted to our general medicine service after presenting with a 3 month history of progressive chorea, cognitive decline, and intermittent visual changes. Her physical exam was notable for bilateral, severe orofacial and extremity chorea. Her exam was otherwise unremarkable and her vitals were within normal limits. Her only medications were paroxetine and a combined oral contraceptive pill. She did not have a history of alcohol or drug use, sexual activity, or known environmental exposures. Her family history was negative for neurologic, autoimmune, or rheumatic disease. Initial hospital work up was extensive but revealed only ANA positivity at 1:640, positive lupus anticoagulant (LAC), and negative beta2 glycoprotein and anti-cardiolipin antibodies. Brain MRI showed a nonspecific small focus of T2/FLAIR hyperintensity in the right precentral area of the frontal lobe and in the periphery of the superior left cerebellum. Ophthalmologic exam showed right optic neuropathy. A working diagnosis of autoimmune chorea associated with antiphospholipid antibody (APLA) was made, although the patient did not meet criteria for antiphospholipid syndrome (APS). She had no known history of thrombosis or recurrent pregnancy loss, and did not have a history of LAC positivity in the past. The patient’s oral contraceptive was discontinued and she was started on IV solumedrol. She was also treated symptomatically with benztropine, cyclobenzaprine, risperidone, and diazepam. After 6 days of treatment without clinical improvement steroids were discontinued and the patient began plasma exchange (PLEX). She received five cycles of PLEX which resulted in significant clinical improvement. Incidentally, the patient was found to have a small chronic subclavian DVT on a Doppler performed for PLEX line placement. Ultimately, the patient was discharged on rivaroxaban and hydroxychloroquine for DVT and probable APS. At the time of discharge, the patient was able to converse freely, ambulate independently, and complete her activities of daily living with minimal assistance.

Discussion: Chorea is rare presentation of antiphospholipid syndrome (APS), seen in 1-4% of patients, and is even more rare in patients with anti-phospholipid antibodies (APLA) who do not meet Sydney criteria commonly used to diagnose APS. In our case, chorea was the only obvious presenting feature in a patient who likely has APS. It would be prudent for providers to consider APLA as a cause of chorea, even in patients without other signs of APS or other autoimmune disease.
In previous literature, most cases of chorea secondary to APLA were treated with corticosteroids with variable response. In our case, this patient responded only minimally to corticosteroids, but had dramatic improvement with plasma exchange. This case provides support for direct activity of anti-phospholipid antibodies in mediating this disease process as well as for plasma exchange as a management option for these patients.

Conclusions: This was a case of severe autoimmune chorea due to anti-phospholipid antibodies in a patient without any known history of thrombosis or autoimmune disorder. Our case supports the role of direct antibody mediated, non-ischemic pathology in patients with anti-phospholipid antibodies. It also provides support for the role of plasmapheresis in patients with neurologic symptoms due to antiphospholipid antibodies who have not responded to steroids.