Abstracts

Rationale: Background: Paraneoplastic encephalitis can manifest with an array of clinical symptoms, including seizures and psychosis. Diagnosis is often difficult as clinical markers are lacking and symptoms usually precede the diagnosis of cancer. Seizures can be refractory to treatment, and clinical suspicious must remain high in patients with new onset seizures and psychiatric symptoms. Here we present a case of paraneoplastic seizures and psychosis due to antibody-negative testicular germinoma. Methods: Case presentation, information obtained by retrospective chart review. Results: Case Description: A 35 year-old previously healthy Caucasian male presented with 2 weeks of increasing auditory hallucinations, symptoms of mania and intermittent apraxia with increased short term memory loss. He later developed rhythmic flexion of his right hand and arm without alteration of consciousness. No prior history of seizures or malignancy in his family. EEG revealed frequent focal seizures originating from the left parasagittal area, up to 10 per hour, some of which had clinical manifestations, including his auditory hallucinations of music and abnormal movements of his right hand. Seizures persisted despite 3 anti-epileptic medications. Physical exam and laboratory studies were unremarkable, but testicular ultrasound revealed a heterogeneous right testicle with microcalcifications concerning for testicular tumor. Right orchiectomy revealed a PLAP positive/CD-30 seminoma. Immediately post-resection, there was 40-50% reduction in electrographic seizure frequency, with complete resolution of epileptiform abnormalities within 24 hours. Serum and CSF paraneoplastic panels (including anti-Ma) and NMDA Receptor antibody were negative. He has been slowly weaned to monotherapy in the outpatient setting, with no further clinic seizures, with plan to wean of anti-epileptic medications Conclusions: Recognizing the clinical syndromes of paraneoplastic encephalitis can be challenging. Above we describe a patient with primarily psychiatric features with focal motor seizures. Previous studies reported 100% association of anti-Ta (also called anti-Ma2) with testicular tumors and paraneoplastic syndrome. Our patient had no evidence of autoantibodies, but complete resolution of electrographic seizures with removal of testicular mass, and continued to have improvement in his functional abilities and mood after primary source control. References: Voltz R, Dalmau J, et al. A serologic marker of paraneoplastic limbic and brain stem encephalitis in patients with testicular cancer. NEJM 1999; 340: 1788-1795. Gultekin SH, Dalmau J, et al. Paraneoplastic limbic encephalitis: neurological symptoms, immunological findings and tumor association in 50 patients. Brain 2000, 123: 1481-1494. Lancaster, E. The diagnosis and treatment of autoimmune encephalitis. J Clin Neurol 2016; 12: 1-13. Funding: None