P15.01 Anti-Ri syndrome presenting with bilateral CN VI palsy and jaw dystonia

Abstract

Paraneoplastic neurological syndromes are rare disorders associated by various onconeuronal antibodies, which usually precede tumor diagnosis. Anti-RI antibodies (ANNA-2) are directed against ectopic antigens and are typically found in patients with Opsoclonus-Myoclonus Syndrome. We present a 77-year old woman with a subacute progressive bilateral CN VI palsy and jaw dystonia. The patient already underwent surgery of the left breast due to breast cancer 11 years before and subsequent radiation. In addition, a consecutive angiosarcoma of the left breast was diagnosed and resected 6 months before admission. MRI of the brain showed increased signal activity on T2 bitemporally without gadolinium enhancement, consistent with limbic encephalitis. Cerebrospinal fluid examination showed a slightly elevated cell count of 13 cells/μl and an elevated protein level at 54mg/dl (normal range 15-45mg/dl). Oligoclonal bands were detected in the CSF. There was no evidence of malignant cells. Tests regarding an infectious origin remained without positive results (HIV, CMV, HSV, VZV, EBV, TB, Tetanus, Borreliosis, Tickborne encephalitis, Mycoplasma, and Syphilis). Due to the previous history of malignancy, immunofluorescence analysis searching for paraneoplastic antibodies was conducted and revealed anti-Ri antibodies both in serum and CSF (1:10.000). Right after diagnosis we initially administered methylprednisolone and subsequently IVIG (30g per day for 5 days). Staging for cancer disease revealed a newly diagnosed ductal carcinoma of the right breast. A quadrantectomy was performed and anticancer treatment with anastrazole was initiated. To reduce in particular the jaw dystonia to enable the patient to eat and speak we applied botulinum toxin to the masseter muscle 30MU each side). Neurological follow up investigation 6 months after diagnosis showed marked improvement of neurological symptoms. Anti-Ri associated paraneoplastic syndrome usually is associated with Opsoklonus-Myoclonus, as well as with ataxia. This is an unusual and rare presentation of an anti-Ri Syndrome with cranial nerve involvement and mandibular dystonia. Due to the various clinical presentations of paraneoplastic neurological syndromes also unusual combinations of neurological signs and symptoms should be considered as potentially paraneoplastic in the diagnostic workup.