Calcium channel autoimmunity: Cerebellar ataxia and lambert-eaton syndrome coexisting

Introduction: Neuronal calcium channel antibodies are a biomarker of Lambert-Eaton syndrome (LES) and cerebellar ataxia. We have encountered several patients with LES and cerebellar ataxia coexisting, and we sought to further define this association. Methods: We reviewed records of patients at our institution with a diagnosis of "Lambert-Eaton syndrome" and "cerebellar ataxia." Results: Seventeen patients were identified with LES and ataxia. Presenting symptoms were weakness (8), concurrent weakness and ataxia (4), ataxia (4), and other (1). Nine patients had small-cell lung carcinoma, 3 of whom had survival greater than 100 months. Immunotherapy responses were best among patients without cancer. Nine of 17 (53%) patients were alive at last follow-up (median survival 62 months; range, 8-240). Discussion: Calcium channel autoimmunity should be considered in patients with coexisting cerebellar ataxia and myasthenic weakness. Affected patients may survive small-cell carcinoma or have immunotherapy-responsive neurological symptoms.