||Volume 3, Number 2 Spring-Summer,
Ask The DoctorDear Dr. Belsh: Because my only problem is with my speech and swallowing, I was told that I have “progressive bulbar palsy”. Subsequently, I was told that I have ALS. Which do I have? Is the prognosis any worse for the bulbar palsy type?
Dr. Belsh answers:
Patients with ALS generally present with symptoms referable either to the limb or bulbar muscles. Bulbar complaints will consist of speech difficulty, swallowing difficulty, or a combination of both. Muscles of the throat, tongue, jaw, and face are known as bulbar because the area of the brain that controls these muscles – the lower brainstem – was once known as the bulb. Motor neuron cells in the bulb, just like motor neuron cells in the spinal cord, degenerate and die in ALS, resulting in weakness and wasting of the bulbar muscles. About 25% of ALS patients begin their disease with so-called “bulbar onset”. In classical ALS, typically, 75 – 85% of patients eventually will develop bulbar symptoms and signs.
When a patient presents with bulbar symptoms only, this is often called progressive bulbar palsy (PBP), a condition originally described by the renown French neurologist, G. Duchenne in 1860. Whether it is classified as a separate entity or as a “subtype” of ALS, most clinicians agree that pure PBP, with absolutely no clinical or EMG evidence of abnormalities in the arms or legs, is extremely rare. In other words, most patients who begin with purely bulbar difficulties will eventually develop the more widespread symptoms and signs of typical ALS.
Because patients with bulbar-onset ALS have difficulty swallowing and may choke or aspirate frequently, (with resultant pneumonia) it has been found generally that these patients carry a poorer prognosis than those with more classical ALS. However, much longer courses of bulbar-onset ALS have been reported. In my experience, I have seen many patients with bulbar onset who can manage their disease quite well and do not develop any sign of limb weakness for at least 2-5 years.
As always, an accurate diagnosis of ALS, PBP, and any other neuromuscular disease should be made as early as possible by a physician with experience in these diseases. Only with a correct diagnosis can a plan for appropriate management be outlined.