Imaging the lower limb network in Parkinson's disease

Area of Science:

• Neuroscience
• Movement Disorders
• Brain Imaging

Background:

• Lower limb symptoms significantly impair daily activities in Parkinson's disease (PD).
• Neural underpinnings of these lower limb deficits in PD remain poorly understood.

Purpose of the Study:

• Investigate the neural correlates of lower limb movements in individuals with and without Parkinson's disease.
• Utilize functional magnetic resonance imaging (fMRI) to identify brain activity patterns.

Main Methods:

• fMRI study involving 24 PD patients and 21 controls performing an ankle dorsiflexion task.
• Used a novel MRI-compatible device to limit head motion.
• PD patients were tested in their medication-off state.

Main Results:

• Parkinson's disease patients showed reduced fMRI signal in the contralateral putamen and M1 foot area, and ipsilateral cerebellum during ankle dorsiflexion compared to controls.
• M1 foot area activity negatively correlated with Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS-III) foot symptom severity.

Conclusions:

• Findings provide new evidence of brain alterations associated with motor symptoms in Parkinson's disease.
• Pathophysiology of lower limb symptoms in PD involves both cortico-basal ganglia and cortico-cerebellar motor circuits.