The role of antibodies against the P/Q type voltage-gated calcium channels (VGCC-ab) in the pathogenesis of paraneoplastic cerebellar degeneration (PCD) and lung cancer is unclear. We evaluated in mice the effect of intrathecal injection of IgG purified from serum of a patient with both PCD and Lambert-Eaton myasthenic syndrome (LEMS), and from another patient with isolated LEMS. Mice injected with PCD/LEMS IgG developed marked, reversible ataxia compared with those injected with LEMS or control IgG. These findings suggest that P/Q-type VGCC-ab may play a role in the pathogenesis of ataxia in patients with PCD and SCLC.

This study was supported in part by grants PS09/0193 (FG) and PS11/01780 (JD) from Fondo de Investigaciones Sanitarias, Madrid; grant from Fundació la Marató de TV3 (JD), Barcelona; and grants from the “Ministerio de Ciencia e Innovación” (SAF2007-64062), and “Instituto de Salud Carlos III” (RETICS-Red de Trastornos Adictivos-Redes Temáticas de Investigación Cooperativa en Salud: RD06/0001/0001, RD06/0001/1004) (RM), Spain.The partial support of FEDER funds (EU) is also acknowledged