Pathways Mediating Impaired Postural Control in Parkinson's Disease

University of Minnesota120 enrolled

Overview

The purpose of this project is to use transcranial magnetic stimulation (TMS) to explore the state of excitability of corticocortical and corticofugal (cortex to spinal cord, cortex to brainstem to spinal cord) pathways that project to muscles that control the legs and trunk in people with Parkinson's disease. The outcome variables will be further analyzed to understand their relationship to quantitative measures of postural instability and gait dysfunction. As such, the project can be classified as basic physiologic research. The protocol is not designed to determine if measures of corticocortical or corticofugal excitability can be used as a biomarker to predict disease progression.

Study Type

OBSERVATIONAL

Enrollment

120

Conditions

Parkinson Disease

Eligibility

Sex: ALLMin age: 45 YearsMax age: 80 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: Participants with Parkinson's disease * Diagnosis of idiopathic PD or dystonia as determined by a movement disorders neurologist in accordance with the UK Society Brain Bank diagnostic criteria. * Age 45-80 years. * Able to ambulate independently without the use of an assistive device (e.g. cane) for 50 meters. Healthy Older Adults (Control participants) * Age 45-80 years (this group will be age and sex-matched to the PD group) * Able to ambulate independently without the use of an assistive device (cane or walker) Healthy Young Adults * Age 21-44 years (this group will be age and sex-matched to the PD group) * Able to ambulate independently without the use of an assistive device (cane or walker) Exclusion Criteria: * Subjects who describe a history of a frequent vasovagal syncope (fainting) in response to blood, emotional stress, or sensory triggers. * Subjects who are on anti-coagulant medications. * Any musculoskeletal disorder that affects the ability to stand. * History of seizures, epilepsy, stroke, multiple sclerosis, or traumatic brain injury. * Intracranial metallic or magnetic devices. * Pacemaker or any implanted device. * History of surgery on blood vessels, brain or heart. * Unexplained, recurring headaches or concussion within the last six months. * Moderate to severe hearing impairment. * Subjects who are pregnant. * Dementia diagnosis * Other significant neurological disorders that may affect participation or performance in the study * Implanted deep brain stimulator or other neurosurgeries to treat PD.

Outcomes

Primary Outcomes

average gate speed

Participants will walk on an overground pressure walkway (GAITRite, Franklin, NJ) that provides spatiotemporal measures of walking. In addition, they will wear a set of wearable sensors (APDM Inc., Opals) attached to the feet, wrists and trunk (lumbar and sternum) to capture whole-body motion.

Time frame: baseline

stride length

Time frame: baseline

cadence

Time frame: baseline

turn speed

Time frame: baseline

ankle rigidity

Quantitative measures of rigidity will be obtained using a custom-built robotic manipulandum. The manipulandum moves the ankle through a sinusoidal or triangular range of motion (25 deg of plantar flexion to 5 degrees of dorsiflexion; modified as needed for participant's range of motion) while measuring the resistive torque generated by ankle impedance.

Time frame: 25mins

Root mean square of the excursion of the center of pressure

Participants will stand on a set of force platforms that measures the forces and pressures beneath the feet. Primary outcome

Time frame: 5mins

single pulse TMS

A measure of the excitability of corticospinal pathways. Primary outcome variables: Peak-to-peak amplitude of the motor evoked potential (MEP) responses to TMS in lower limb and trunk muscles.

Time frame: 1.5hrs

Paired-Pulse TMS (Intracortical excitability):

A measure of the excitability of intracortical (motor cortex-motor cortex) inhibitory (short-intracortical inhibition, SICI) and excitatory (short-intracortical inhibition, ICF) networks. Primary outcome variables: Peak-to-peak amplitude of the motor evoked potential (MEP) responses to TMS in lower limb and trunk muscles.

Time frame: 1hr

Pathways Mediating Impaired Postural Control in Parkinson's Disease

Overview

Conditions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Central Contacts