My PD Story

2025 Impact Award 

Investigating New Ways to Address Posture Impairment in Parkinson’s 

A common symptom of Parkinson’s disease (PD) is impaired posture. Unfortunately, this symptom is resistant to standard dopamine replacement therapies, and not much is known about the neurological mechanisms that lead to it. Left unchecked, posture impairment can lead to serious falls and other injuries for people with PD. 

Colum MacKinnon, PhD, recipient of a Parkinson’s Foundation Impact Award, suspects that PD affects brainstem neurons responsible for sending posture-related signals to the muscles of the legs and feet. Investigating this potential mechanism behind PD-related posture impairment may contribute to future treatments that could alleviate this debilitating symptom. 

“If successful, this work will be the first to demonstrate that brainstem pathways that control muscle firing properties are altered in people with PD and are associated with postural impairment.” – Dr. MacKinnon 

Dr. MacKinnon, with the help of his coinvestigators Dr. Laura McPherson, PT, DPT, PhD, and Dr. Daniel Free, PhD, will enroll people with and without PD, recording and analyzing their posture and gait (walking manner). He will also use a device to measure muscle activity activity as they point and flex their feet, capturing nerve signals important for balance and posture. 

From this initial data collection, Dr. MacKinnon expects to see reduced postural muscle activity that is controlled by descending brainstem systems in people with PD, and this reduction will correlate with impaired posture and walking ability. 

Next, Dr. MacKinnon will use a noninvasive vagus nerve stimulation device, commonly used to treat migraines and cluster headaches, to stimulate neurons within the brainstem associated with postural control. If his hypothesis is correct, this stimulation will temporarily improve the posture and balance of those with PD as the signals to the ankle muscles are restored. These studies will provide valuable direction for future research and therapeutic development of PD-associated posture impairment, which could significantly improve quality of life for people with PD. 

 “This award provides the unique opportunity to explore the potential contributions of non-dopaminergic pathways to the abnormal muscle activation patterns observed in people with PD, and to conduct exploratory experiments to test the efficacy of using vagus nerve stimulation to upregulate these pathways, improve muscle activation, gait and postural control,” said Dr. MacKinnon. 

Meet more Parkinson’s researchers! Explore our My PD Stories featuring PD researchers.