Parkinson Disease
Conditions
Keywords
Parkinson Disease, Posture Balance, Learning, Dopamine
Brief summary
The primary goal of this project is to gain a better understanding of whether and how levodopa (a common anti-Parkinson disease medication) alters postural motor learning in people with Parkinson disease. A secondary goal is to assess whether motor cortical excitability, measured via Transcranial magnetic stimulation, is related to postural motor learning. Participants with Parkinson disease will complete between 50 and 100 postural perturbations (via support surface translations), ON and OFF their dopamine replacement therapy (i.e. levodopa). Adaptation of responses to these perturbations will be tracked. Participants will also undergo transcranial magnetic stimulation to capture cortical excitability of the brain (in particular the motor cortex). Cortical excitability will be correlated to adaptation of stepping (i.e. postural motor learning) ON and OFF levodopa. Investigators will also capture postural motor learning and cortical excitability in age-matched healthy adults. Investigators hypothesize that dopamine will have a negative effect on postural motor learning, and the cortical excitability will be correlated to postural motor learning.
Interventions
BEHAVIORALPostural perturbation
Participants will undergo between 50 and 100 postural perturbations (quick movements of the support surface) in multiple directions. These perturbations will be between 9 and 24cm, and between 18 and 56 cm/s depending on participant tolerance.
Sponsors
Oregon Health and Science University
VA Office of Research and Development
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 90 Years
Healthy volunteers
Yes
Inclusion criteria
* Between 18 and 90 years of age. * Individuals with Parkinson Disease * Healthy adults age-matched to PD participants * Participants with PD will be currently taking dopamine replacement (i.e. Levodopa)
Exclusion criteria
All subjects
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Movement of Center of Mass (COM) After Postural Perturbation | Baseline and follow up (24 hours later) both ON and OFF antiparkinson medication | Investigators will assess (via automated and custom Matlab software) the magnitude of COM movement after a postural perturbation is delivered via motion of the support surface. This will be measured throughout the intervention, as well as at follow up (24 hour later). |
| Change in Steps After Postural Perturbation | Baseline and follow up (24 hours later) both ON and OFF antiparkinson medication | Investigators will assess (via automated and custom Matlab software) the number of steps taken after a postural perturbation is delivered via motion of the support surface. This will be measured throughout the intervention, as well as at follow up (24 hour later). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in First Step Length | Baseline and follow up (24 hours later) both ON and OFF antiparkinson medication | Investigators will assess (via automated and custom Matlab software) the length of the first step after a postural perturbation is delivered via motion of the support surface. This will be measured throughout the intervention, as well as at follow up (24 hour later). |
| Cortical Excitability | TMS data was collected ON and OFF medication during one visit. This visit occurred within 3 weeks of the initial postural control assessments. | Investigators will assess the cortical excitability of the primary motor cortex in a subset of participants both ON and OFF levodopa. Specifically, we used transcranial magnetic stimulation to stimulate the motor cortex, where we measure muscular activity of the arm (i.e. motor evoked potentials; MEPs). The primary outcome variable noted below is the lowest stimulation setting (measured as a percentage) which results in an MEP in 5 of 10 trials. |
Countries
United States
Participant flow
Recruitment details
A total of 42 individuals were enrolled in the study (30 people with Parkinson's disease and 12 healthy older adults)
Participants by arm
| Arm | Count |
|---|---|
| Parkinsons Disease Individuals with Parkinsons disease
Postural perturbation: Participants will undergo between 50 and 100 postural perturbations (quick movements of the support surface) in multiple directions. These perturbations will be between 9 and 24cm, and between 18 and 56 cm/s depending on participant tolerance. | 30 |
| Control Age-matched healthy adults
Postural perturbation: Participants will undergo between 50 and 100 postural perturbations (quick movements of the support surface) in multiple directions. These perturbations will be between 9 and 24cm, and between 18 and 56 cm/s depending on participant tolerance. | 12 |
| Total | 42 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Withdrawal by Subject | 2 | 0 |
Baseline characteristics
| Characteristic | Control | Parkinsons Disease | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 9 Participants | 19 Participants | 28 Participants |
| Age, Categorical Between 18 and 65 years | 3 Participants | 11 Participants | 14 Participants |
| Age, Continuous | 68.04 years STANDARD_DEVIATION 6.62 | 66.05 years STANDARD_DEVIATION 9.67 | 67.16 years STANDARD_DEVIATION 7.1 |
| Gender Female | 6 Participants | 10 Participants | 16 Participants |
| Gender Male | 6 Participants | 20 Participants | 26 Participants |
| Region of Enrollment United States | 12 participants | 30 participants | 42 participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 30 | 0 / 12 |
| serious Total, serious adverse events | 0 / 30 | 0 / 12 |
Outcome results
Primary
Change in Movement of Center of Mass (COM) After Postural Perturbation
Investigators will assess (via automated and custom Matlab software) the magnitude of COM movement after a postural perturbation is delivered via motion of the support surface. This will be measured throughout the intervention, as well as at follow up (24 hour later).
Time frame: Baseline and follow up (24 hours later) both ON and OFF antiparkinson medication
Population: We were unable to collect reliable data on some of the people with PD while OFF medication, which is why there is a discrepancy between the Parkinson's disease and Parkinson's disease Off Medication arms.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Parkinsons Disease | Change in Movement of Center of Mass (COM) After Postural Perturbation | Start Train | 0.31 meters | Standard Deviation 0.11 |
| Parkinsons Disease | Change in Movement of Center of Mass (COM) After Postural Perturbation | End Train | 0.26 meters | Standard Deviation 0.1 |
| Control | Change in Movement of Center of Mass (COM) After Postural Perturbation | Start Train | 0.28 meters | Standard Deviation 0.05 |
| Control | Change in Movement of Center of Mass (COM) After Postural Perturbation | End Train | 0.23 meters | Standard Deviation 0.03 |
| Parkinson's Disease Off Medication | Change in Movement of Center of Mass (COM) After Postural Perturbation | Start Train | 0.32 meters | Standard Deviation 0.13 |
| Parkinson's Disease Off Medication | Change in Movement of Center of Mass (COM) After Postural Perturbation | End Train | 0.31 meters | Standard Deviation 0.12 |
Primary
Change in Steps After Postural Perturbation
Investigators will assess (via automated and custom Matlab software) the number of steps taken after a postural perturbation is delivered via motion of the support surface. This will be measured throughout the intervention, as well as at follow up (24 hour later).
Time frame: Baseline and follow up (24 hours later) both ON and OFF antiparkinson medication
Population: We were unable to collect reliable data on some of the people with PD while OFF medication, which is why there is a discrepancy between the Parkinson's disease and Parkinson's disease Off Medication arms.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Parkinsons Disease | Change in Steps After Postural Perturbation | Start Train | 2.22 Number of steps | Standard Deviation 0.9 |
| Parkinsons Disease | Change in Steps After Postural Perturbation | End Train | 1.92 Number of steps | Standard Deviation 1.15 |
| Control | Change in Steps After Postural Perturbation | Start Train | 2.03 Number of steps | Standard Deviation 0.63 |
| Control | Change in Steps After Postural Perturbation | End Train | 1.15 Number of steps | Standard Deviation 0.28 |
| Parkinson's Disease Off Medication | Change in Steps After Postural Perturbation | Start Train | 2.09 Number of steps | Standard Deviation 0.77 |
| Parkinson's Disease Off Medication | Change in Steps After Postural Perturbation | End Train | 2.05 Number of steps | Standard Deviation 1.12 |
Secondary
Change in First Step Length
Investigators will assess (via automated and custom Matlab software) the length of the first step after a postural perturbation is delivered via motion of the support surface. This will be measured throughout the intervention, as well as at follow up (24 hour later).
Time frame: Baseline and follow up (24 hours later) both ON and OFF antiparkinson medication
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Parkinsons Disease | Change in First Step Length | Start of Training | 0.18 meters | Standard Deviation 0.06 |
| Parkinsons Disease | Change in First Step Length | End of Training | 0.20 meters | Standard Deviation 0.08 |
| Control | Change in First Step Length | Start of Training | 0.25 meters | Standard Deviation 0.11 |
| Control | Change in First Step Length | End of Training | 0.27 meters | Standard Deviation 0.08 |
| Parkinson's Disease Off Medication | Change in First Step Length | Start of Training | 0.21 meters | Standard Deviation 0.08 |
| Parkinson's Disease Off Medication | Change in First Step Length | End of Training | 0.21 meters | Standard Deviation 0.08 |
Secondary
Cortical Excitability
Investigators will assess the cortical excitability of the primary motor cortex in a subset of participants both ON and OFF levodopa. Specifically, we used transcranial magnetic stimulation to stimulate the motor cortex, where we measure muscular activity of the arm (i.e. motor evoked potentials; MEPs). The primary outcome variable noted below is the lowest stimulation setting (measured as a percentage) which results in an MEP in 5 of 10 trials.
Time frame: TMS data was collected ON and OFF medication during one visit. This visit occurred within 3 weeks of the initial postural control assessments.
Population: As noted in our protocol, TMS was assessed in a subgroup of participants with PD. Seven of the 28 PD participants and 0 of the control group (healthy adults) were assessed. PD participants were assessed ON and OFF levodopa. We chose this approach because 1) this aim was exploratory in nature, and 2) MEPs of healthy adults are well characterized.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Parkinsons Disease | Cortical Excitability | 40.57 % max stim output | Standard Deviation 8.73 |
| Control | Cortical Excitability | 40.71 % max stim output | Standard Deviation 9.97 |