Ocular autonomic nerve function in Lambert-Eaton myasthenic syndrome.

Autonomic innervation to the eye and ocular adnexae was assessed in seven patients with Lambert-Eaton Myasthenic Syndrome and 50 age-matched control subjects. Pupil responses to light were abnormal in 69% of LEMS patients, compared with 18% of the control group. Reflex tear production--a screening test for parasympathetic innervation to the lacrimal gland--was below the accepted normal limit in 69% of LEMS patients. Parasympathetic and sympathetic denervation hypersensitivity of the iris musculature were individually present in 57% of LEMS patients, compared with 6% of control subjects. The association between autonomic dysfunction and Lambert-Eaton Myasthenic Syndrome is discussed.