CRMP-5-Autoantibodies in Testicular Cancer Associated with Limbic Encephalitis and Choreiform Dyskinesias

Case Report A 40-year-old man presented with agitation, disorientation and optical hallucinations. He had a history of a malignant seminoma that had been treated with orchiectomy 7 years previously. He was admitted to a psychiatric ward of an outside general hospital but was transferred to our neurology service after he had had an epileptic seizure on admission day. At admission in our department, he was mildly disoriented. He also showed moderate amnestic symptoms and mild dysarthria, but neurological examination revealed no other abnormalities. A cranial magnetic resonance imaging study including contrast enhancement with gadolinium and a routine electroencephalogram were both normal. Cerebrospinal fluid (CSF) analysis showed 18 lymphocytes with no other abnormalities. He was treated with aciclovir until herpes simplex virus polymerase chain reaction proved to be negative, and additionally with ampicillin and ceftriaxone. Within 2 days he became increasingly agitated and suffered 2 more epileptic seizures necessitating anticonvulsive therapy with carbamazepine. Within the next few days, he became somnolent and developed severe swallowing and breathing difficulties. In addition, the patient developed Dear Sir, In addition to the well-known paraneoplastic-syndrome-associated antineuronal autoantibodies anti-Hu, anti-Yo and anti-Ri, a variety of different autoantibodies has been described in paraneoplastic neurological syndromes (PNS). One of these antibodies is an autoantibody binding to collapsin-response-mediating protein 5 (anti-CRMP-5) [1] , a phosphoprotein belonging to a group of proteins being important for axonal growth and also expressed in oligodendrocytes [2] . This antibody is most likely identical with the antibody labeled anti-CV-2 some years earlier [3, 4] . There is no distinguishable neurological syndrome related to the presence of anti-CRMP-5, but most patients suffer from peripheral neuropathy, including optic neuropathy or movement disorders [5] . Most cases are associated with small-cell lung cancer, but association with other tumors like thymoma has been reported as well [1] ( table 1 ). An association with germinal cell tumors has not been reported so far. These patients may have anti-Ma autoantibodies, a group of antineuronal nucleolar autoantibodies. We here describe a patient presenting with symptoms of a limbic encephalitis and choreiform dyskinesias associated with anti-CRMP-5 due to a testicular tumor. Received: September 29, 2006 Accepted: November 12, 2006 Published online: March 26, 2007