Bulbar-onset amyotrophic lateral sclerosis in a patient with Chiari I malformation.

We report on a patient with bulbar-onset, clinically defined, sporadic amyotrophic lateral sclerosis (ALS) who also showed a Chiari I malformation. This malformation, otherwise asymptomatic, was detected during the diagnostic work-up for ALS. To our knowledge this is the first report of an association between these two relatively uncommon disorders. Since our patient worked for many years as a bus-driver and because the ALS symptoms began in the brainstem region, we suggest that his hindbrain anomaly, along with the mechanical stress on the spine and cranio-vertebral junction due to the daily driving, might have played a role in the region-specific onset of ALS.