Case 4 History ---- This patient was well until the sixth decade, when he developed progressive shortness of breath, severe fatigue and excessive daytime somnolence. Respiratory function deteriorated to the point that by age 56, exercise tolerance was less than one-half block of ambulation. There was mild weakness of the proximal muscle groups of the upper extremities and moderate to severe weakness in the proximal lower extremities with diminished muscle mass in buttocks and thighs. There was normal strength of distal musculature. Muscle stretch reflexes were 1+/4+ and symmetrical. Sensory examination was normal. Electrodiagnostic testing (age 56) revealed evidence of myopathy and impaired neuromuscular transmission with normal nerve conduction velocities and borderline sensory nerve amplitudes.
