Case Report Paraneoplastic Opsoclonus Myoclonus in a Patient with Pancreatic Adenocarcinoma Divine C. Nwafor, 1 Ashley B. Petrone, 2 Joseph M. Collins, 3 and Amelia K. Adcock 4 1 Department of Neuroscience, School of Medicine, West Virginia University, Morgantown, WV, USA 2 Department of Pathology, Anatomy and Laboratory Medicine, School of Medicine, West Virginia University, School of Medicine, Morgantown, WV, USA 3 Department of Radiology, Mayo Clinic Arizona, Scottsdale, AZ, USA 4 Department of Neurology, School of Medicine, West Virginia University, Morgantown, WV, USA Correspondence should be addressed to Amelia K. Adcock; akadcock@hsc.wvu.edu Received 18 February 2019; Revised 15 March 2019; Accepted 27 March 2019; Published 16 April 2019 Academic Editor: Isabella Laura Simone Copyright © 2019 Divine C. Nwafor et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Opsoclonus myoclonus syndrome (OMS) is an extremely rare neurological syndrome typically afecting as few as 1 in 10,000,000 people annually. OMS is characterized by the presence of involuntary, saccadic eye movements, as well as ataxia, including gait incoordination, rigidity, and tremor. Te origin of OMS is unclear, but a signifcant percentage of OMS cases are indicative of an underlying malignancy, most commonly neuroblastoma and small cell lung cancer. Here we describe an adult patient with OMS, who was ultimately diagnosed with a small ductal adenocarcinoma of the pancreas. To our knowledge, this is the third published report of an association between OMS and pancreatic malignancy, and the only case where the pancreatic malignancy was detected prior to metastasis or autopsy at death. Tis case report highlights the importance of careful, aggressive malignancy screening with OMS, as the pancreatic duct cut-of sign may be overlooked if pancreatic malignancy is not suspected. 1. Introduction Opsoclonus myoclonus syndrome (OMS) is an extremely rare autoimmune neurological syndrome typically afecting as few as 1 in 10,000,000 people annually. Te etiology of OMS is thought to be paraneoplastic (e.g., malignancies) or nonparaneoplastic (e.g., idiopathic, parainfectious) in origin [1–3]. Te clinical presentation of OMS is characterized by the presence of involuntary and saccadic eye movements, as well as ataxia, including gait incoordination, rigidity, and tremor. Te pathogenesis of OMS remains unclear; however, it has been proposed that it could be the result of dysfunctional motor neurons, specifcally pontine omnipause neurons and/or cerebellar Purkinje cells [4]. Twenty to forty percent of OMS cases in adults and children are indicative of an underlying malignancy [2, 5, 6]. Te tumors most frequently associated with OMS in children and adults are neuroblastoma and small cell lung cancer (SCLC), respec- tively [7]. We describe an adult patient with OMS, who was ultimately diagnosed with ductal adenocarcinoma of the pancreas. To our knowledge, this is the third published report of an association between OMS and pancreatic malignancy, and the only case where the pancreatic malignancy was detected prior to metastasis or autopsy at death [8, 9]. 2. Case Presentation Here we describe, a 72-year-old female with a history of hypothyroidism, hyperlipidemia, hypertension, and 50 pack years of smoking, who presented to an outside facility with a 30-pound weight loss, severe nausea, emesis, mild imbalance which graduated to bedbound instability, and involuntary body “shakes” progressing over 6 months. Initial investi- gations at an outside facility, including contrast enhanced- MRI imaging of the entire neuroaxis, EEG, colonoscopy, and basic hematologic and chemistry panels, were all normal. Te only initial abnormal fndings were as follows: esophagogas- troduodenoscopy (EGD) revealed possible gastritis, thyroid Hindawi Case Reports in Neurological Medicine Volume 2019, Article ID 3601026, 3 pages https://doi.org/10.1155/2019/3601026