P/Q-type voltage/gated calcium channel antibodies in paraneoplastic disorders of the central nervous system

Whether P/Q-type voltage-gated calcium channel (VGCC) antibodies are presen t in the serum of patients with paraneoplastic syndromes other than the Lam bert-Eaton myasthenic syndrome (LEMS) and tumors other than small-cell lung cancer (SCLC) is controversial, Using a commercially available radioimmuno precipitation assay kit, we examined the sera of 93 patients with paraneopl astic syndromes of the central nervous system (CNS), including 27 patients with paraneoplastic cerebellar degeneration (PCD) associated with tumors ot her than SCLC and 66 SCLC patients with paraneoplastic encephalomyelitis an d sensory neuronopathy (PEM/SN). All PCD sera from patients with tumors oth er than SCLC were negative for P/Q-type VGCC antibodies. Eight of 66 (12%) SCLC patients with PEM/SN had P/Q-type VGCC antibodies; 4 had LEMS and the other 4 had no symptoms of LEMS or they were overlooked and, therefore, not examined electrophysiologically. In patients with paraneoplastic syndromes of the CNS, the detection of P/Q-type VGCC antibodies supports the diagnos is of LEMS; in our series, only 6% of patients with SCLC and PEM/SN may hav e had a false positive antibody result, or undiagnosed LEMS. (C) 1999 John Wiley & Sons, Inc.