[A Lambert-Faton myasthenic syndrome and subacute cerebellar degeneration with a favorable clinical course after resection of small-cell lung cancer]

Abstract

A case of Lambert-Eaton myasthenic syndrome (LEMS) and subacute cerebellar degeneration (SCD) was associated with small-cell lung cancer (SCLC). The patient, a 52-year-old man, who had noticed impotence one year previously, began to have ataxic gait, scanning speech and thirst progressing for 3 months, followed by weakness of the lower limbs, bilateral blepharoptosis, and double vision. Electromyographic studies showed low amplitude of compound muscle action potential (CMAP) and waxing phenomenon in high frequency stimulation of the ulnar nerve. A chest x-ray showed a mass lesion in the left hilar region, and small cell lung cancer was diagnosed on the basis of biopsy specimens. Anti-voltage-gated calcium channel (VGCC) antibody was positive. Anti-Yo and anti-Hu antibodies were negative. The patient was treated by lobectomy and chemotherapy, which resulted in improvement in the LEMS and SCD. Anti-VGCC antibody, the CMAP amplitude, and waxing phenomenon were improved. Operable cases of SCLC are rare. But we propose that anti-neoplastic treatment including resection of the tumor is the first choice for the treatment of paraneoplastic syndrome associated with SCLC.