Also called progressive bulbar atrophy, involves the brain stem—the bulb-shaped region containing lower motor neurons needed for swallowing, speaking, chewing, and other functions. Symptoms include pharyngeal muscle weakness (involved with swallowing), weak jaw and facial muscles, progressive loss of speech, and tongue muscle atrophy.
Individuals are at increased risk of choking and aspiration pneumonia.
Stroke and myasthenia gravis may have certain symptoms that are similar to those of progressive bulbar palsy and must be ruled out prior to diagnosing this disorder.
In about 25 percent of individuals with ALS, early symptoms begin with bulbar involvement.
Some 75 percent of individuals with classic ALS eventually show some bulbar involvement.