Progressive Bulbar Palsy - Epidemiology

Epidemiology

Progressive bulbar palsy is slow in onset, with symptoms starting in most patients around 50-70 years of age (Merck 2005). PBP is both progressive and slow, with symptoms lasting around 10 to 20 years until it reaches a fatal ending (Collins 1900). It is debated as to whether PBP is a separate entity or a subtype of amyotrophic lateral sclerosis (ALS). Pure PBP without any EMG or clinical evidence of abnormalities in the legs or arms is possible, albeit extremely rare. Moreover, about twenty-five percent of patients with PBP eventually develop the widespread symptoms common to ALS (Swash 2000).