Abstract
Some of the neuromuscular diseases may cause various pharyngeal and laryngeal muscle dysfunction such as dysphagia, dysphonia and severe dyspnea. In this report the histopath ological features of the muscles in amyotrophic lateral sclerosis (ALS), aquired autoimmune myasthenia gravis (MG) and progressive muscular dystrophies were described. ALS is one of the motor neuron diseases. The cricothyroid muscles and the sternohyoid muscles of the ALS patient were examined. Neurogenic changes such as small grouped atrophy, large grouped atrophy and small angulated fibers were observed. MG is an aquired autoimmune disorder of neuromuscular transmission associated with acetylcholine receptor (AchR) deficiency at the motor end-plate. Ultrastructurally, MG end-plates were characterized by a decrease in thelength of the postsynaptic membrane. In muscular dystrophies various degrees of degenera tion, necrosis and regeneration of the muscle fibers were observed. A cross-sectional view of the muscles showed a fiber size variation by atrophy and hypertrophy of the muscle fibers.
