WASHINGTON — Martin A. Samuels, MD, DSc (Hon), MACP, FANA, chair of the department of neurology at Brigham and Women's Hospital and the Miriam Sydney Joseph Professor of Neurology at Harvard Medical School, shared several updates in the field of neurology, including advances in stroke, Parkinson's disease and chronic traumatic encephalopathy.
Samuels discussed a specific theory about Parkinson's disease, and how it may have been validated via research this past year.
"There has been a theory about the cause of Parkinson's disease that was created by the distinguished neurologist and neuroanatomist Heiko Braak, which argues that the agent that causes Parkinson's disease, whatever that agent may be, might be inhaled, damaging the olfactory bulb, and then swallowed into the gastrointestinal tract," he said. "Then it's absorbed into Meissner’s' plexus from the gut and from there it enters the vagus nerve and passes up the vagus nerve, back into the brain stem and then gradually ascends the brain stem from the medulla to the pons to the midbrain. And when it reaches the midbrain, this is when we see the classic triad of Parkinson's disease, of the tremor, the rigidity and the bradykinesia. So there's a long, long presymptomatic phase of Parkinson's disease, according to this theory."
Samuels said that a group of investigators reviewed medical records that spanned multiple decades for patients who had undergone a truncal vagotomy.
"They compared those patients with regard to their risk for Parkinson's disease to people who underwent a superselective vagotomy... and to a control population, and remarkably, those people that had a truncal vagotomy, were protected significantly against the development of Parkinson's disease," he said.
This indicated strong support for the Heiko Braak hypothesis of the etiology of Parkinson's disease and may provide a new approach to thinking about treatment.