Breast Cancer Associated Opsoclonus-Myoclonus Syndrome: A Case Report

Abstract

\n BackgroundParaneoplastic neurological syndromes constitute rare neurological complications of malignant disease, manifesting in <1% of patients with cancer. Opsoclonus-myoclonus syndrome (OMS) presents with chaotic ocular saccades (opsoclonus), spontaneous muscular jerking (myoclonus) that may be accompanied by ataxia, strabismus, aphasia, or mutism. Its paraneoplastic variant in the adult is most commonly associated with small-cell lung cancer, followed by breast cancer. Importantly, neurological symptoms usually precede the diagnosis of breast cancer and tend to recure after its treatment.Case presentationA 43-year-old premenopausal Caucasian woman with a medical history of hypertension was admitted following an episode of focal seizure. On the day of admission, the initial focal seizure progressed to generalised tonic-clonic seizures and she was subsequently loaded with phenytoin, valproate, and levetiracetam. Initial work up included whole body CT scan, viral and autoimmune serology. The CT scan revealed an enhancing right axillary lymph node, which in combination with Anti-Ri antibody positivity raised the spectre of paraneoplastic opsoclonus-myoclonus syndrome. All other tested antibodies were found negative. MRI of the head revealed subtle nonspecific white matter signal change within the centrum semiovale without any mass lesions, while MRI of spine showed no cord lesions. A right mastectomy and axillary lymph node clearance was performed without any complications. Two months later she was admitted again due to near permanent vertigo, intermittent diplopia, facial weakness, and ataxia. She was clinically diagnosed with a recurrence of her anti-Ri syndrome. MDT recommended mammogram and ultrasound of left breast which was normal. Subsequently, four months after initial discharge, she suffered another neurological recurrence; due to concomitant abdominal pain, PET-CT was performed demonstrating a hypermetabolic right ovarian focus. Bilateral salpingo-oophorectomy was performed as per gynaecology MDT and final histology showed normal tubes and ovaries. She has remained on remission since then, with negative annual mammogram follow-up. ConclusionsIn conclusion, we report a case of OMS associated with breast cancer anti anti-Ri onconeural antibody. Its manifestations preceded the diagnosis of malignancy and it persisted after cancer treatment, underlining the importance for high clinical suspicion in cases of classical paraneoplastic neurological syndromes as well as the need for long-term clinical follow-up.Trial registration:Not applicable