Contribution of immune-mediated paraneoplastic syndromes to neurological manifestations of neuroendocrine tumours: a retrospective study

Abstract

Introduction Neurological symptoms associated with neuroendocrine tumours (NETs) may be related to metastatic disease or paraneoplastic syndromes (PNSs); these last are often associated with autoantibodies targeting various onconeural antigens. To better characterize neurological PNSs related to NETs, we report the largest case-series study to date. Methods We retrospectively reviewed the charts of all patients diagnosed with NETs of the gastrointestinal tract who presented with neurological symptoms at either of 2 tertiary academic hospitals (Henri Mondor and Beaujon, France) between 1994 and 2016. All patients underwent extensive neurological tests including clinical, laboratory, and radiological investigations. The clinical response to immunomodulating agents was recorded. Results In the 13 identified patients, the most common presentations were peripheral neuropathy (46.2%) and encephalopathy (26.6%). Of the 6 (53.3%) patients whose serum anti-neuronal antibodies were assayed, 5 had high titres. Short-term oral corticosteroid and immunosuppressant drug therapy was given to 4 of these patients, of whom 3 had a clinical response and 1 no response. Repeated high-dose intravenous immunoglobulin therapy induced a complete clinical response in 1 patient. Encephalopathy resolved fully after hepatectomy or intrahepatic chemoembolization for liver metastases in another 2 patients. Discussion The neurological symptoms associated with NETs may be due in part to autoimmune PNS. Based…