Amyotrophic lateral sclerosis with positive anti-acetylcholine receptor antibodies. Case report and review of the literature.

Myasthenia gravis is a nerve-muscle junction disease, for which the most specific test is an increase in the anti-acetylcholine receptor antibodies (anti-AChR-Abs) titer. Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting both upper and lower motor neurons. Positive AChR-Ab in patients with pure ALS are exceedingly rare.