Pyramidal tract deficits and polyneuropathy in hyperthyroidism, Combination clinically mimicking amyotrophic lateral sclerosis

Abstract

Generalized weakness, intermittent dysphagia, and a 40-pound weight loss developed in an elderly man over a six-month period. Examination revealed weakness, atrophy and fasciculations of extremity musculature, pseudobulbar speech, hyperactive upper extremity reflexes, and extensor toe signs without sensory loss. Results of electrodiagnostic studies were consistent with an axonal polyneuropathy. Endocrinologic results were compatible with hyperthyroidism. Radioiodine therapy resulted in resolution of clinical neurologic symptoms and signs within seven months. This case illustrates a previously undescribed concurrence of hyperthyroid associated polyneuropathy and pyramidal tract dysfunction that led to an initial clinical diagnosis of amyotrophic lateral sclerosis.