Biomarkers to Guide Directional DBS for Parkinson's Disease

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to investigate the clinical efficacy of directional DBS electrode technology and whether electrophysiology biomarkers can predict effective contact segments for chronic therapy.

Detailed Description
-----------------
Although deep brain stimulation (DBS) can be remarkable for treating symptoms of Parkinson's disease, improvement varies across clinical trials, individual patients, and over time. A major limitation to the advancement of DBS therapy is that there are no established biomarkers to tailor stimulator settings in individuals. Emerging segmented (directional) lead technology allows current steering, a new opportunity to improve tolerability and efficacy by shaping the DBS electrical field. This novel lead design has 8 contacts rather than the 4 available with currently available leads. How do the investigators optimally adjust stimulation parameters when there are far more potentially useful settings than can be practically evaluated in clinic? How do the investigators know that DBS settings in a given patient are optimal or appropriate? The investigators have pioneered minimally invasive, rapidly acquired biomarkers to solve these important problems. Using electrocorticography, electroencephalography, and subcortical local field potentials, the investigators will measure whether resting or stimulus-evoked electrophysiology can serve as a predictive biomarker to guide activation and adjustment of a directional DBS system. The purpose of this randomized, double-blind crossover study is to measure the clinical efficacy of directional versus omnidirectional stimulation and to explore whether electrophysiology biomarkers can rapidly predict effective, well-tolerated contacts for directional DBS therapy.

Official Title
-----------------
Noninvasive Biomarkers to Advance Emerging DBS Electrode Technologies in Parkinson's Disease (SUNDIAL, SUbthalamic Nucleus DIrectionAL vs Circular Stimulation Study)

Conditions
-----------------
Parkinson Disease

Intervention / Treatment
-----------------
* Device: Boston Scientific Vercise PC IPG with directional DBS lead


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Age ≥18 years and ≤70 years. Clinically definite, advanced idiopathic PD based on at least 2 of 3 cardinal PD features (tremor, rigidity, or bradykinesia). Disease duration of 4 years or more. Participant has elected to undergo DBS surgery as part of routine care, and the subthalamic nucleus (STN) is recommended as the surgical target. Participant agrees to not undergo contralateral DBS for the other side of the brain until ≥ 12 months after initial DBS surgery. Participant is healthy enough to undergo surgery and the research protocol. Normal, or essentially normal, preoperative brain MRI. Willingness and ability to cooperate during awake DBS surgery, as well as during post-operative evaluations, adjustments of medications and stimulator settings. Participant's health insurance and/or Medicare covers DBS surgery as part of routine care. Refractory motor symptoms such as tremor, dyskinesias, wearing off, and/or motor fluctuations, causing significant disability or occupational dysfunction, despite reasonable attempts at medical management, as determined by our consensus DBS committee. Stable doses of PD medications for at least 28 days prior to baseline assessments. Improvement of motor signs ≥30% with dopaminergic medication as assessed with the use of the Movement Disorders - Unified Parkinson's Disease Rating Scale, part III (MDS-UPDRS III; scores range from 0 to 108, with higher scores indicating worse functioning). Disease severity ratings above Hoehn and Yahr stage 1, defined as unilateral involvement only with minimal or no functional disability, with scores ranging from 0 to 5 and higher scores indicating more severe disease. Score of more than 6 for activities of daily living in the worst off medication condition despite medical treatment, as assessed with the use of the MDS-UPDRS II (scores range from 0 to 52, with higher scores indicating worse functioning), or mild-to-moderate impairment in social and occupational functioning (score of 51 to 80% on the Social and Occupational Functioning Assessment Scale with scores ranging from 1 to 100 and lower scores indicating worse functioning). Dementia Rating Scale-2 (DRS-2) score of ≥130 on medications. Beck Depression Inventory II (BDI-II) score of ≤25 on medications. Participant expresses understanding of the consent process, terms of the study protocol, is available for follow-up over the length of the study, and signs informed consent. Exclusion Criteria: Age <18 years or >70 years. Participant's insurance will not cover the costs of surgery with the investigational device. Medical contraindications such as current uncontrolled hypertension, heart disease, coagulopathy, or other conditions contraindicating DBS surgery or stimulation. Duration of disease of <4 years Participant or care team determine that contralateral DBS for the other side of the brain will likely be clinically indicated <12 months after initial DBS surgery. Diagnosis or suspicion of atypical parkinsonism (progressive supranuclear palsy, multiple system atrophy, corticobasal syndrome) or drug-induced parkinsonism, or significant neurological disease other than Parkinson's disease. Disease severity ratings of Hoehn and Yahr stage 1, defined as unilateral involvement only with minimal or no functional disability, with scores ranging from 0 to 5 and higher scores indicating more severe disease. Diagnosis of psychogenic movement disorder based on consensus criteria. Score of >25 on the Beck Depression Inventory II, with scores ranging from 0 to 63 and higher scores indicating worse functioning), or history of suicide attempt. Any current acute psychosis, alcohol abuse or drug abuse. Clinical dementia (score of ≤130 on the Mattis Dementia Rating Scale with scores ranging from 0 to 144 and higher scores indicating better functioning). Ongoing or pervasive impulse control disorder not resolved by reduction of dopaminergic medications. Use of anticoagulant medications that cannot be discontinued during perioperative period. History of hemorrhagic stroke. Current or future risk of immunocompromise that might significantly increase risk of infection. History of recurrent of unprovoked seizures. Lack of clear levodopa responsiveness. Any medical condition requiring repeated MRI. The presence of an implanted device (e.g., cochlear implant, pacemaker, neurostimulators), whether turned on or off. Prior DBS surgery or ablation within the affected basal ganglion. A condition requiring or likely to require the use of diathermy. Structural lesions such as basal ganglionic stroke, tumor or vascular malformation as etiology of the movement disorder. Any medical or psychological problem that would interfere with the conduction of the study protocol A female who is breastfeeding or of child-bearing potential with a positive urine pregnancy test or not using adequate contraception.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: This is a triple blind, randomized crossover study of directional versus omnidirectional unilateral subthalamic deep brain stimulation for Parkinson's disease with motor fluctuations.
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Directional DBS guided by behavior<br>Directional stimulation with the Boston Scientific Vercise PC IPG with directional DBS lead, guided by behavioral assessments during device activation. | Device: Boston Scientific Vercise PC IPG with directional DBS lead<br>* Deep brain stimulation<br>|
| Placebo Comparator: Omnidirectional DBS guided by behavior<br>Omnidirectional (ring mode) stimulation with the Boston Scientific Vercise PC IPG with directional DBS lead, guided by behavioral assessments during device activation. | Device: Boston Scientific Vercise PC IPG with directional DBS lead<br>* Deep brain stimulation<br>|
| Active Comparator: Directional DBS guided by biomarkers<br>Directional unilateral subthalamic stimulation with the Boston Scientific Vercise PC IPG with directional DBS lead, guided by electrophysiology biomarkers measured during surgery (nested exploratory treatment arm). | Device: Boston Scientific Vercise PC IPG with directional DBS lead<br>* Deep brain stimulation<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from preoperative baseline in Movement Disorders Society Unified Parkinson's Disease Rating Scale Part 3 (MDS-UPDRS Part III) off medications | A blinded examiner will measure MDS-UPDRS part 3 motor scores off medications with directional versus omnidirectional unilateral subthalamic brain stimulation. MDS-UPDRS Part III is a motor examination consisting of 18 summed items where the investigator rates each motor symptom based on a scale of 0 - 4, higher values indicating worse function. | 2 months post surgery | 
| Change from preoperative baseline in Movement Disorders Society Unified Parkinson's Disease Rating Scale Part 3 (MDS-UPDRS Part III) off medications | A blinded examiner will measure MDS-UPDRS part 3 motor scores off medications with directional versus omnidirectional unilateral subthalamic brain stimulation. MDS-UPDRS Part III is a motor examination consisting of 18 summed items where the investigator rates each motor symptom based on a scale of 0 - 4, higher values indicating worse function. | 4 months post surgery | 
| Change from preoperative baseline in Movement Disorders Society Unified Parkinson's Disease Rating Scale Part 3 (MDS-UPDRS Part III) off medications | A blinded examiner will measure MDS-UPDRS part 3 motor scores off medications with directional versus omnidirectional unilateral subthalamic brain stimulation. MDS-UPDRS Part III is a motor examination consisting of 18 summed items where the investigator rates each motor symptom based on a scale of 0 - 4, higher values indicating worse function. | 6 months post surgery | 
| Change from preoperative baseline in Movement Disorders Society Unified Parkinson's Disease Rating Scale Part 3 (MDS-UPDRS Part III) off medications | A blinded examiner will measure MDS-UPDRS part 3 motor scores off medications with directional versus omnidirectional unilateral subthalamic brain stimulation. MDS-UPDRS Part III is a motor examination consisting of 18 summed items where the investigator rates each motor symptom based on a scale of 0 - 4, higher values indicating worse function. | 12 months post surgery | 
| Treatment Preference Survey | Based on overall quality of life, participants will select their preference between directional and omnidirectional DBS. | 4 months post surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from preoperative baseline in NIH Toolbox Cognition Battery | The NIH Toolbox Cognition Battery evaluates cognitive function with Dimensional Change Card Sort Test, Flanker Inhibitory Control and Attention Test, List Sorting Working Memory Test, Picture Vocabulary Test, Pattern Comparison Processing Speed Test, Picture Sequence Memory Test, and Oral Reading Recognition. | 2 months post surgery | 
| Change from preoperative baseline in NIH Toolbox Cognition Battery | The NIH Toolbox Cognition Battery evaluates cognitive function with Dimensional Change Card Sort Test, Flanker Inhibitory Control and Attention Test, List Sorting Working Memory Test, Picture Vocabulary Test, Pattern Comparison Processing Speed Test, Picture Sequence Memory Test, and Oral Reading Recognition. | 4 months post surgery | 
| Change from preoperative baseline in NIH Toolbox Cognition Battery | The NIH Toolbox Cognition Battery evaluates cognitive function with Dimensional Change Card Sort Test, Flanker Inhibitory Control and Attention Test, List Sorting Working Memory Test, Picture Vocabulary Test, Pattern Comparison Processing Speed Test, Picture Sequence Memory Test, and Oral Reading Recognition. | 6 months post surgery | 
| Change from preoperative baseline in the Beck Depression Inventory-2 (BDI-2) | The BDI-2 is a self-report inventory which evaluates a person's severity of depression. | 2 months post surgery | 
| Change from preoperative baseline in the Beck Depression Inventory-2 (BDI-2) | The BDI-2 is a self-report inventory which evaluates a person's severity of depression. | 4 months post surgery | 
| Change from preoperative baseline in the Beck Depression Inventory-2 (BDI-2) | The BDI-2 is a self-report inventory which evaluates a person's severity of depression. | 6 months post surgery | 
| Change from preoperative baseline in the Beck Anxiety Inventory (BAI) | The BAI is a self-report inventory which evaluates a person's severity of anxiety. | 2 months post surgery | 
| Change from preoperative baseline in the Beck Anxiety Inventory (BAI) | The BAI is a self-report inventory which evaluates a person's severity of anxiety. | 4 months post surgery | 
| Change from preoperative baseline in the Beck Anxiety Inventory (BAI) | The BAI is a self-report inventory which evaluates a person's severity of anxiety. | 6 months post surgery | 
| Change from preoperative baseline in the Conners Continuous Performance Test Third Edition (Conners CPT-3) | The Conners CPT-3 evaluates attention-related performance in areas of inattentiveness, impulsivity, sustained attention, and vigilance. | 2 months post surgery | 
| Change from preoperative baseline in the Conners Continuous Performance Test Third Edition (Conners CPT-3) | The Conners CPT-3 evaluates attention-related performance in areas of inattentiveness, impulsivity, sustained attention, and vigilance. | 4 months post surgery | 
| Change from preoperative baseline in the Conners Continuous Performance Test Third Edition (Conners CPT-3) | The Conners CPT-3 evaluates attention-related performance in areas of inattentiveness, impulsivity, sustained attention, and vigilance. | 6 months post surgery | 
| Change from preoperative baseline in the Auditory Verbal Learning Test (AVLT) (versions AB, CD, CR, GE) | The AVLT (versions AB, CD, CR, GE) evaluates a person's ability to encode, consolidate, store, and retrieve verbal information. | 2 months post surgery | 
| Change from preoperative baseline in the Auditory Verbal Learning Test (AVLT) (versions AB, CD, CR, GE) | The AVLT (versions AB, CD, CR, GE) evaluates a person's ability to encode, consolidate, store, and retrieve verbal information. | 4 months post surgery | 
| Change from preoperative baseline in the Auditory Verbal Learning Test (AVLT) (versions AB, CD, CR, GE) | The AVLT (versions AB, CD, CR, GE) evaluates a person's ability to encode, consolidate, store, and retrieve verbal information. | 6 months post surgery | 
| Change from preoperative baseline in the 10/36 Spatial Recall Test (forms 1, 2 ,3, 4) | The 10/36 Spatial Recall Test (forms 1, 2 ,3, 4) evaluates visuospatial memory. | 2 months post surgery | 
| Change from preoperative baseline in the 10/36 Spatial Recall Test (forms 1, 2 ,3, 4) | The 10/36 Spatial Recall Test (forms 1, 2 ,3, 4) evaluates visuospatial memory. | 4 months post surgery | 
| Change from preoperative baseline in the 10/36 Spatial Recall Test (forms 1, 2 ,3, 4) | The 10/36 Spatial Recall Test (forms 1, 2 ,3, 4) evaluates visuospatial memory. | 6 months post surgery | 
| Change from preoperative baseline in the Letter Fluency Test (version: CFL, FAS) | The Letter Fluency Test (version: CFL, FAS) evaluates the number of words beginning with the letters C, F, L, A, and S that a participant can produce in one minute. | 2 months post surgery | 
| Change from preoperative baseline in the Letter Fluency Test (version: CFL, FAS) | The Letter Fluency Test (version: CFL, FAS) evaluates the number of words beginning with the letters C, F, L, A, and S that a participant can produce in one minute. | 4 months post surgery | 
| Change from preoperative baseline in the Letter Fluency Test (version: CFL, FAS) | The Letter Fluency Test (version: CFL, FAS) evaluates the number of words beginning with the letters C, F, L, A, and S that a participant can produce in one minute. | 6 months post surgery | 
| Change from preoperative baseline in the D-KEFS Color-Word Interference Test (CWIT) | The CWIT consists of four parts (color naming, word reading, inhibition, and inhibition/switching) and evaluates the ability to inhibit a dominant and automatic verbal response. | 2 months post surgery | 
| Change from preoperative baseline in the D-KEFS Color-Word Interference Test (CWIT) | The CWIT consists of four parts (color naming, word reading, inhibition, and inhibition/switching) and evaluates the ability to inhibit a dominant and automatic verbal response. | 4 months post surgery | 
| Change from preoperative baseline in the D-KEFS Color-Word Interference Test (CWIT) | The CWIT consists of four parts (color naming, word reading, inhibition, and inhibition/switching) and evaluates the ability to inhibit a dominant and automatic verbal response. | 6 months post surgery | 
| Change from preoperative baseline in the Neuropsychiatric Inventory | The Neuropsychiatric Inventory evaluates cognitive function by assessing delusions, hallucinations, agitation/aggression, depression, anxiety, elation/euphoria, apathy/indifference, disinhibition, irritability, and aberrant motor behavior. | 2 months post surgery | 
| Change from preoperative baseline in the Neuropsychiatric Inventory | The Neuropsychiatric Inventory evaluates cognitive function by assessing delusions, hallucinations, agitation/aggression, depression, anxiety, elation/euphoria, apathy/indifference, disinhibition, irritability, and aberrant motor behavior. | 4 months post surgery | 
| Change from preoperative baseline in the Neuropsychiatric Inventory | The Neuropsychiatric Inventory evaluates cognitive function by assessing delusions, hallucinations, agitation/aggression, depression, anxiety, elation/euphoria, apathy/indifference, disinhibition, irritability, and aberrant motor behavior. | 6 months post surgery | 
| Change from preoperative baseline in the Rainbow Passage | The phonetically-balanced Rainbow Passage evaluates speech function by assessing the ability to produce connected speech by measuring average intensity, average fundamental frequency, duration, and cepstral measure of the second sentence. | 2 months post surgery | 
| Change from preoperative baseline in the Rainbow Passage | The phonetically-balanced Rainbow Passage evaluates speech function by assessing the ability to produce connected speech by measuring average intensity, average fundamental frequency, duration, and cepstral measure of the second sentence. | 4 months post surgery | 
| Change from preoperative baseline in the Rainbow Passage | The phonetically-balanced Rainbow Passage evaluates speech function by assessing the ability to produce connected speech by measuring average intensity, average fundamental frequency, duration, and cepstral measure of the second sentence. | 6 months post surgery | 
| Change from preoperative baseline in Spontaneous Speech Production | The Spontaneous Speech Production measure evaluates speech function by assessing the ability to produce spontaneous speech by measuring average intensity, average fundamental frequency, and speech production/articulation. | 2 months post surgery | 
| Change from preoperative baseline in Spontaneous Speech Production | The Spontaneous Speech Production measure evaluates speech function by assessing the ability to produce spontaneous speech by measuring average intensity, average fundamental frequency, and speech production/articulation. | 4 months post surgery | 
| Change from preoperative baseline in Spontaneous Speech Production | The Spontaneous Speech Production measure evaluates speech function by assessing the ability to produce spontaneous speech by measuring average intensity, average fundamental frequency, and speech production/articulation. | 6 months post surgery | 
| Change from preoperative baseline in Acoustic Measures | The acoustic measures evaluate spontaneous speech, maximum phonation time, and voicing formants F1 and F2. | 2 months post surgery | 
| Change from preoperative baseline in Acoustic Measures | The acoustic measures evaluate spontaneous speech, maximum phonation time, and voicing formants F1 and F2. | 4 months post surgery | 
| Change from preoperative baseline in Acoustic Measures | The acoustic measures evaluate spontaneous speech, maximum phonation time, and voicing formants F1 and F2. | 6 months post surgery | 
| Change from preoperative baseline in the Voice Handicap Index | The Voice Handicap Index evaluates speech function with a 30-item self-administered questionnaire that asks participants to describe their voice and the effects of their voice on their lives. | 2 months post surgery | 
| Change from preoperative baseline in the Voice Handicap Index | The Voice Handicap Index evaluates speech function with a 30-item self-administered questionnaire that asks participants to describe their voice and the effects of their voice on their lives. | 4 months post surgery | 
| Change from preoperative baseline in the Voice Handicap Index | The Voice Handicap Index evaluates speech function with a 30-item self-administered questionnaire that asks participants to describe their voice and the effects of their voice on their lives. | 6 months post surgery | 
| Change from preoperative baseline in the Communicative Participation Item Bank (CPIB) | The CPIB evaluates the extent to which communication disorders interfere with communicative participation. | 2 months post surgery | 
| Change from preoperative baseline in the Communicative Participation Item Bank (CPIB) | The CPIB evaluates the extent to which communication disorders interfere with communicative participation. | 4 months post surgery | 
| Change from preoperative baseline in the Communicative Participation Item Bank (CPIB) | The CPIB evaluates the extent to which communication disorders interfere with communicative participation. | 6 months post surgery | 
| Change from preoperative baseline in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (UPDRS) Version 3 Part I | MDS-UPDRS part I is a scale of 13 summed items, which assesses the impact of Parkinson's disease on experiences of daily living. Part 1A is administered by the investigator (6 items) and focuses on complex behaviors. Part 1B is part of the self-administered participant questionnaire that covers 7 items on non-motor experiences of daily living. Each item is rated based on a scale of 0 - 4, higher values indicating worse function. | 2 months post surgery | 
| Change from preoperative baseline in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (UPDRS) Version 3 Part I | MDS-UPDRS part I is a scale of 13 summed items, which assesses the impact of Parkinson's disease on experiences of daily living. Part 1A is administered by the investigator (6 items) and focuses on complex behaviors. Part 1B is part of the self-administered participant questionnaire that covers 7 items on non-motor experiences of daily living. Each item is rated based on a scale of 0 - 4, higher values indicating worse function. | 4 months post surgery | 
| Change from preoperative baseline in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (UPDRS) Version 3 Part I | MDS-UPDRS part I is a scale of 13 summed items, which assesses the impact of Parkinson's disease on experiences of daily living. Part 1A is administered by the investigator (6 items) and focuses on complex behaviors. Part 1B is part of the self-administered participant questionnaire that covers 7 items on non-motor experiences of daily living. Each item is rated based on a scale of 0 - 4, higher values indicating worse function. | 6 months post surgery | 
| Change from preoperative baseline in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (UPDRS) Version 3 Part II | MDS-UPDRS II is a self-evaluated questionnaire of 20 summed items in which the participants answer questions about experiences of daily living. Each item is rated based on a scale of 0 - 4, higher values indicating worse function. | 2 months post surgery | 
| Change from preoperative baseline in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (UPDRS) Version 3 Part II | MDS-UPDRS II is a self-evaluated questionnaire of 20 summed items in which the participants answer questions about experiences of daily living. Each item is rated based on a scale of 0 - 4, higher values indicating worse function. | 4 months post surgery | 
| Change from preoperative baseline in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (UPDRS) Version 3 Part II | MDS-UPDRS II is a self-evaluated questionnaire of 20 summed items in which the participants answer questions about experiences of daily living. Each item is rated based on a scale of 0 - 4, higher values indicating worse function. | 6 months post surgery | 
| Change from preoperative baseline in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (UPDRS) Version 3 Part IV | MDS-UPDRS part IV evaluates complications of therapy, where the investigator uses historical and objective information to assess two motor complications, dyskinesias and motor fluctuations that include OFF-state dystonia. The scale consists of 6 summed items, where each item is rated based on a scale of 0 - 4, higher values indicating worse function. | 2 months post surgery | 
| Change from preoperative baseline in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (UPDRS) Version 3 Part IV | MDS-UPDRS part IV evaluates complications of therapy, where the investigator uses historical and objective information to assess two motor complications, dyskinesias and motor fluctuations that include OFF-state dystonia. The scale consists of 6 summed items, where each item is rated based on a scale of 0 - 4, higher values indicating worse function. | 4 months post surgery | 
| Change from preoperative baseline in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (UPDRS) Version 3 Part IV | MDS-UPDRS part IV evaluates complications of therapy, where the investigator uses historical and objective information to assess two motor complications, dyskinesias and motor fluctuations that include OFF-state dystonia. The scale consists of 6 summed items, where each item is rated based on a scale of 0 - 4, higher values indicating worse function. | 6 months post surgery | 
| Change from preoperative baseline in Activities-Specific Balance Confidence (ABC) Scale | The ABC Scale is a self-report measure that evaluates a person's confidence in performing various ambulatory activities without falling. Possible scores range from 0-1600. Higher scores indicate more self confidence in task completion. | 2 months post surgery | 
| Change from preoperative baseline in Activities-Specific Balance Confidence (ABC) Scale | The ABC Scale is a self-report measure that evaluates a person's confidence in performing various ambulatory activities without falling. Possible scores range from 0-1600. Higher scores indicate more self confidence in task completion. | 4 months post surgery | 
| Change from preoperative baseline in Activities-Specific Balance Confidence (ABC) Scale | The ABC Scale is a self-report measure that evaluates a person's confidence in performing various ambulatory activities without falling. Possible scores range from 0-1600. Higher scores indicate more self confidence in task completion. | 6 months post surgery | 
| Change from preoperative baseline in Activities-Specific Balance Confidence (ABC) Scale | The ABC Scale is a self-report measure that evaluates a person's confidence in performing various ambulatory activities without falling. Possible scores range from 0-1600. Higher scores indicate more self confidence in task completion. | 12 months post surgery | 
| Change from preoperative baseline in the Freezing of Gait Questionnaire (FOG-Q) | The FOG-Q evaluates a person's freezing of gait, a gait disturbance which interrupts walking. The questionnaire consists of 6 summed items; each item is rated based on a scale of 0 - 4, higher values indicating worse function. | 2 months post surgery | 
| Change from preoperative baseline in the Freezing of Gait Questionnaire (FOG-Q) | The FOG-Q evaluates a person's freezing of gait, a gait disturbance which interrupts walking. The questionnaire consists of 6 summed items; each item is rated based on a scale of 0 - 4, higher values indicating worse function. | 4 months post surgery | 
| Change from preoperative baseline in the Freezing of Gait Questionnaire (FOG-Q) | The FOG-Q evaluates a person's freezing of gait, a gait disturbance which interrupts walking. The questionnaire consists of 6 summed items; each item is rated based on a scale of 0 - 4, higher values indicating worse function. | 6 months post surgery | 
| Change from preoperative baseline in the Freezing of Gait Questionnaire (FOG-Q) | The FOG-Q evaluates a person's freezing of gait, a gait disturbance which interrupts walking. The questionnaire consists of 6 summed items; each item is rated based on a scale of 0 - 4, higher values indicating worse function. | 12 months post surgery | 
| Change from preoperative baseline in the 9-Hole Pegboard Test | The 9-Hole Pegboard Test evaluates one's upper extremity motor function. | 2 months post surgery | 
| Change from preoperative baseline in the 9-Hole Pegboard Test | The 9-Hole Pegboard Test evaluates one's upper extremity motor function. | 4 months post surgery | 
| Change from preoperative baseline in the 9-Hole Pegboard Test | The 9-Hole Pegboard Test evaluates one's upper extremity motor function. | 6 months post surgery | 
| Change from preoperative baseline in the 9-Hole Pegboard Test | The 9-Hole Pegboard Test evaluates one's upper extremity motor function. | 12 months post surgery | 
| Change from preoperative baseline in the Time to Walk Test | In the Time to Walk Test, individuals will be timed while they walk 6m at either their comfortable or fastest safe speed. | 2 months post surgery | 
| Change from preoperative baseline in the Time to Walk Test | In the Time to Walk Test, individuals will be timed while they walk 6m at either their comfortable or fastest safe speed. | 4 months post surgery | 
| Change from preoperative baseline in the Time to Walk Test | In the Time to Walk Test, individuals will be timed while they walk 6m at either their comfortable or fastest safe speed. | 6 months post surgery | 
| Change from preoperative baseline in the Time to Walk Test | In the Time to Walk Test, individuals will be timed while they walk 6m at either their comfortable or fastest safe speed. | 12 months post surgery | 
| Change from preoperative baseline in Gait Initiation Test | The gait initiation test evaluates the phase between standing motionless and steady-state locomotion. | 2 months post surgery | 
| Change from preoperative baseline in Gait Initiation Test | The gait initiation test evaluates the phase between standing motionless and steady-state locomotion. | 4 months post surgery | 
| Change from preoperative baseline in Gait Initiation Test | The gait initiation test evaluates the phase between standing motionless and steady-state locomotion. | 6 months post surgery | 
| Change from preoperative baseline in Gait Initiation Test | The gait initiation test evaluates the phase between standing motionless and steady-state locomotion. | 12 months post surgery | 
| Change from preoperative baseline in Stepping Thresholds Test | The stepping thresholds test evaluates a person's compensatory stepping thresholds. | 2 months post surgery | 
| Change from preoperative baseline in Stepping Thresholds Test | The stepping thresholds test evaluates a person's compensatory stepping thresholds. | 4 months post surgery | 
| Change from preoperative baseline in Stepping Thresholds Test | The stepping thresholds test evaluates a person's compensatory stepping thresholds. | 6 months post surgery | 
| Change from preoperative baseline in Stepping Thresholds Test | The stepping thresholds test evaluates a person's compensatory stepping thresholds. | 12 months post surgery | 
| Change from preoperative baseline in Quiet Stance Measure | The quiet stance measure evaluates a person's postural control during quiet standing. | 2 months post surgery | 
| Change from preoperative baseline in Quiet Stance Measure | The quiet stance measure evaluates a person's postural control during quiet standing. | 4 months post surgery | 
| Change from preoperative baseline in Quiet Stance Measure | The quiet stance measure evaluates a person's postural control during quiet standing. | 6 months post surgery | 
| Change from preoperative baseline in Quiet Stance Measure | The quiet stance measure evaluates a person's postural control during quiet standing. | 12 months post surgery | 
| Change from preoperative baseline in the Parkinson's Disease Quality of Life | The PDQ-8 evaluates overall health status consisting of eight questions regarding mobility, activities of daily living, emotional well-being, stigma, social support, cognition, communication, and bodily discomfort. | 2 months post surgery | 
| Change from preoperative baseline in the Parkinson's Disease Quality of Life | The PDQ-8 evaluates overall health status consisting of eight questions regarding mobility, activities of daily living, emotional well-being, stigma, social support, cognition, communication, and bodily discomfort. | 4 months post surgery | 
| Change from preoperative baseline in the Parkinson's Disease Quality of Life | The PDQ-8 evaluates overall health status consisting of eight questions regarding mobility, activities of daily living, emotional well-being, stigma, social support, cognition, communication, and bodily discomfort. | 6 months post surgery | 
| Change from preoperative baseline in the Parkinson's Disease Quality of Life | The PDQ-8 evaluates overall health status consisting of eight questions regarding mobility, activities of daily living, emotional well-being, stigma, social support, cognition, communication, and bodily discomfort. | 12 months post surgery | 
| Change from preoperative baseline in the the Neuro-QOL Item Bank v1.0 Positive Affect and Well-Being short form | The Neuro-QOL Item Bank v1.0 Positive Affect and Well-Being Short Form evaluates feelings that reflect a level of general satisfaction with life as well as a sense that life has purpose and meaning. | 2 months post surgery | 
| Change from preoperative baseline in the the Neuro-QOL Item Bank v1.0 Positive Affect and Well-Being short form | The Neuro-QOL Item Bank v1.0 Positive Affect and Well-Being Short Form evaluates feelings that reflect a level of general satisfaction with life as well as a sense that life has purpose and meaning. | 4 months post surgery | 
| Change from preoperative baseline in the the Neuro-QOL Item Bank v1.0 Positive Affect and Well-Being short form | The Neuro-QOL Item Bank v1.0 Positive Affect and Well-Being Short Form evaluates feelings that reflect a level of general satisfaction with life as well as a sense that life has purpose and meaning. | 6 months post surgery | 
| Change from preoperative baseline in the the Neuro-QOL Item Bank v1.0 Positive Affect and Well-Being short form | The Neuro-QOL Item Bank v1.0 Positive Affect and Well-Being Short Form evaluates feelings that reflect a level of general satisfaction with life as well as a sense that life has purpose and meaning. | 12 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.1 Satisfaction with Social Roles and Activities short form | The Neuro-QOL Item Bank v1.1 Satisfaction with Social Roles and Activities short form short form evaluates one's satisfaction and discontentment with performing usual social roles and activities. | 2 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.1 Satisfaction with Social Roles and Activities short form | The Neuro-QOL Item Bank v1.1 Satisfaction with Social Roles and Activities short form short form evaluates one's satisfaction and discontentment with performing usual social roles and activities. | 4 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.1 Satisfaction with Social Roles and Activities short form | The Neuro-QOL Item Bank v1.1 Satisfaction with Social Roles and Activities short form short form evaluates one's satisfaction and discontentment with performing usual social roles and activities. | 6 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.1 Satisfaction with Social Roles and Activities short form | The Neuro-QOL Item Bank v1.1 Satisfaction with Social Roles and Activities short form short form evaluates one's satisfaction and discontentment with performing usual social roles and activities. | 12 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v2.0 Cognitive Function short form | The Neuro-QOL Item Bank v2.0 Cognitive Function short form evaluates mental acuity, concentration, verbal and nonverbal memory, verbal fluency, and perceived changes in these cognitive functions. | 2 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v2.0 Cognitive Function short form | The Neuro-QOL Item Bank v2.0 Cognitive Function short form evaluates mental acuity, concentration, verbal and nonverbal memory, verbal fluency, and perceived changes in these cognitive functions. | 4 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v2.0 Cognitive Function short form | The Neuro-QOL Item Bank v2.0 Cognitive Function short form evaluates mental acuity, concentration, verbal and nonverbal memory, verbal fluency, and perceived changes in these cognitive functions. | 6 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v2.0 Cognitive Function short form | The Neuro-QOL Item Bank v2.0 Cognitive Function short form evaluates mental acuity, concentration, verbal and nonverbal memory, verbal fluency, and perceived changes in these cognitive functions. | 12 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Lower Extremity Function (Mobility) short form | The Neuro-QOL Item Bank v1.0 Lower Extremity Function (Mobility) short form evaluates functioning of one's lower extremities. | 2 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Lower Extremity Function (Mobility) short form | The Neuro-QOL Item Bank v1.0 Lower Extremity Function (Mobility) short form evaluates functioning of one's lower extremities. | 4 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Lower Extremity Function (Mobility) short form | The Neuro-QOL Item Bank v1.0 Lower Extremity Function (Mobility) short form evaluates functioning of one's lower extremities. | 6 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Lower Extremity Function (Mobility) short form | The Neuro-QOL Item Bank v1.0 Lower Extremity Function (Mobility) short form evaluates functioning of one's lower extremities. | 12 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Upper Extremity Function (Fine Motor, ADL) short form | The Neuro-QOL Item Bank v1.0 Upper Extremity Function (Fine Motor, ADL) short form evaluates functioning of one's upper extremity function in fine motor and ADL capabilities. | 2 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Upper Extremity Function (Fine Motor, ADL) short form | The Neuro-QOL Item Bank v1.0 Upper Extremity Function (Fine Motor, ADL) short form evaluates functioning of one's upper extremity function in fine motor and ADL capabilities. | 4 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Upper Extremity Function (Fine Motor, ADL) short form | The Neuro-QOL Item Bank v1.0 Upper Extremity Function (Fine Motor, ADL) short form evaluates functioning of one's upper extremity function in fine motor and ADL capabilities. | 6 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Upper Extremity Function (Fine Motor, ADL) short form | The Neuro-QOL Item Bank v1.0 Upper Extremity Function (Fine Motor, ADL) short form evaluates functioning of one's upper extremity function in fine motor and ADL capabilities. | 12 months post surgery | 
| Change from preoperative baseline in the Patient-Reported Outcomes Measurement Information System (PROMIS) Scale v1.2 Global Health | The (PROMIS) Scale v1.2 Global Health evaluates one's overall physical and mental health. This is a 10 item scale with scores ranging from 4-20. Higher scores indicate better overall health. | 2 months post surgery | 
| Change from preoperative baseline in the Patient-Reported Outcomes Measurement Information System (PROMIS) Scale v1.2 Global Health | The (PROMIS) Scale v1.2 Global Health evaluates one's overall physical and mental health. This is a 10 item scale with scores ranging from 4-20. Higher scores indicate better overall health. | 4 months post surgery | 
| Change from preoperative baseline in the Patient-Reported Outcomes Measurement Information System (PROMIS) Scale v1.2 Global Health | The (PROMIS) Scale v1.2 Global Health evaluates one's overall physical and mental health. This is a 10 item scale with scores ranging from 4-20. Higher scores indicate better overall health. | 6 months post surgery | 
| Change from preoperative baseline in the Patient-Reported Outcomes Measurement Information System (PROMIS) Scale v1.2 Global Health | The (PROMIS) Scale v1.2 Global Health evaluates one's overall physical and mental health. This is a 10 item scale with scores ranging from 4-20. Higher scores indicate better overall health. | 12 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Stigma short form | The Neuro-QOL Item Bank v1.0 Stigma short form evaluates one's sensitivity of illness-related stigma. | 2 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Stigma short form | The Neuro-QOL Item Bank v1.0 Stigma short form evaluates one's sensitivity of illness-related stigma. | 4 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Stigma short form | The Neuro-QOL Item Bank v1.0 Stigma short form evaluates one's sensitivity of illness-related stigma. | 6 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Stigma short form | The Neuro-QOL Item Bank v1.0 Stigma short form evaluates one's sensitivity of illness-related stigma. | 12 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Scale v1.0 Communication short form | The Neuro-QOL Scale v1.0 Communication short form evaluates one's difficulty with communication. It is a 5 item questionnaire with scores ranging from 5-25. Higher scores indicate better communicative abilities. | 2 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Scale v1.0 Communication short form | The Neuro-QOL Scale v1.0 Communication short form evaluates one's difficulty with communication. It is a 5 item questionnaire with scores ranging from 5-25. Higher scores indicate better communicative abilities. | 4 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Scale v1.0 Communication short form | The Neuro-QOL Scale v1.0 Communication short form evaluates one's difficulty with communication. It is a 5 item questionnaire with scores ranging from 5-25. Higher scores indicate better communicative abilities. | 6 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Scale v1.0 Communication short form | The Neuro-QOL Scale v1.0 Communication short form evaluates one's difficulty with communication. It is a 5 item questionnaire with scores ranging from 5-25. Higher scores indicate better communicative abilities. | 12 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Emotional and Behavioral Dyscontrol short form | Neuro-QOL Item Bank v1.0 Emotional and Behavioral Dyscontrol short form evaluates one's confidence to manage/control symptoms of frustration, disappointment, anger, and other negative emotions. | 2 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Emotional and Behavioral Dyscontrol short form | Neuro-QOL Item Bank v1.0 Emotional and Behavioral Dyscontrol short form evaluates one's confidence to manage/control symptoms of frustration, disappointment, anger, and other negative emotions. | 4 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Emotional and Behavioral Dyscontrol short form | Neuro-QOL Item Bank v1.0 Emotional and Behavioral Dyscontrol short form evaluates one's confidence to manage/control symptoms of frustration, disappointment, anger, and other negative emotions. | 6 months post surgery | 
| Change from preoperative baseline in the Neuro-QOL Item Bank v1.0 Emotional and Behavioral Dyscontrol short form | Neuro-QOL Item Bank v1.0 Emotional and Behavioral Dyscontrol short form evaluates one's confidence to manage/control symptoms of frustration, disappointment, anger, and other negative emotions. | 12 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v2.0 Ability to Participate in Social Roles and Activities short form | The PROMIS v2.0 Ability to Participate in Social Roles and Activities short form evaluates one's perceived ability to perform one's usual social roles and activities. | 2 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v2.0 Ability to Participate in Social Roles and Activities short form | The PROMIS v2.0 Ability to Participate in Social Roles and Activities short form evaluates one's perceived ability to perform one's usual social roles and activities. | 4 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v2.0 Ability to Participate in Social Roles and Activities short form | The PROMIS v2.0 Ability to Participate in Social Roles and Activities short form evaluates one's perceived ability to perform one's usual social roles and activities. | 6 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v2.0 Ability to Participate in Social Roles and Activities short form | The PROMIS v2.0 Ability to Participate in Social Roles and Activities short form evaluates one's perceived ability to perform one's usual social roles and activities. | 12 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Emotional Distress - Anxiety short form | The PROMIS v1.0 Emotional Distress - Anxiety short form evaluates one's feelings of anxiety, such as fear and worry. | 2 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Emotional Distress - Anxiety short form | The PROMIS v1.0 Emotional Distress - Anxiety short form evaluates one's feelings of anxiety, such as fear and worry. | 4 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Emotional Distress - Anxiety short form | The PROMIS v1.0 Emotional Distress - Anxiety short form evaluates one's feelings of anxiety, such as fear and worry. | 6 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Emotional Distress - Anxiety short form | The PROMIS v1.0 Emotional Distress - Anxiety short form evaluates one's feelings of anxiety, such as fear and worry. | 12 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Emotional Distress - Depression short form | The PROMIS v1.0 Emotional Distress - Depression short form evaluates one's feelings of negative mood and depression. | 2 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Emotional Distress - Depression short form | The PROMIS v1.0 Emotional Distress - Depression short form evaluates one's feelings of negative mood and depression. | 4 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Emotional Distress - Depression short form | The PROMIS v1.0 Emotional Distress - Depression short form evaluates one's feelings of negative mood and depression. | 6 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Emotional Distress - Depression short form | The PROMIS v1.0 Emotional Distress - Depression short form evaluates one's feelings of negative mood and depression. | 12 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Fatigue short form | The PROMIS v1.0 Fatigue short form evaluates one's range of symptoms, from mild subjective feelings of tiredness to an overwhelming, debilitating, and sustained sense of exhaustion that likely decreases one's ability to execute daily activities and function normally in family or social roles. | 2 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Fatigue short form | The PROMIS v1.0 Fatigue short form evaluates one's range of symptoms, from mild subjective feelings of tiredness to an overwhelming, debilitating, and sustained sense of exhaustion that likely decreases one's ability to execute daily activities and function normally in family or social roles. | 4 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Fatigue short form | The PROMIS v1.0 Fatigue short form evaluates one's range of symptoms, from mild subjective feelings of tiredness to an overwhelming, debilitating, and sustained sense of exhaustion that likely decreases one's ability to execute daily activities and function normally in family or social roles. | 6 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Fatigue short form | The PROMIS v1.0 Fatigue short form evaluates one's range of symptoms, from mild subjective feelings of tiredness to an overwhelming, debilitating, and sustained sense of exhaustion that likely decreases one's ability to execute daily activities and function normally in family or social roles. | 12 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v2.0 Physical Function short form | The PROMIS v2.0 Physical Function short form measures self-reported capability rather than actual performance of physical activities | 2 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v2.0 Physical Function short form | The PROMIS v2.0 Physical Function short form measures self-reported capability rather than actual performance of physical activities | 4 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v2.0 Physical Function short form | The PROMIS v2.0 Physical Function short form measures self-reported capability rather than actual performance of physical activities | 6 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v2.0 Physical Function short form | The PROMIS v2.0 Physical Function short form measures self-reported capability rather than actual performance of physical activities | 12 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement | The PROMIS v1.0 Pain Interference short form evaluates the consequences of pain on relevant aspects of one's life. This includes the extent to which pain hinders engagement with social, cognitive, emotional, physical, and recreational activities. | 2 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement | The PROMIS v1.0 Pain Interference short form evaluates the consequences of pain on relevant aspects of one's life. This includes the extent to which pain hinders engagement with social, cognitive, emotional, physical, and recreational activities. | 4 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement | The PROMIS v1.0 Pain Interference short form evaluates the consequences of pain on relevant aspects of one's life. This includes the extent to which pain hinders engagement with social, cognitive, emotional, physical, and recreational activities. | 6 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement | The PROMIS v1.0 Pain Interference short form evaluates the consequences of pain on relevant aspects of one's life. This includes the extent to which pain hinders engagement with social, cognitive, emotional, physical, and recreational activities. | 12 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Sleep Disturbance short form | The PROMIS v1.0 Sleep Disturbance short form evaluates one's perceptions of sleep quality. | 2 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Sleep Disturbance short form | The PROMIS v1.0 Sleep Disturbance short form evaluates one's perceptions of sleep quality. | 4 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Sleep Disturbance short form | The PROMIS v1.0 Sleep Disturbance short form evaluates one's perceptions of sleep quality. | 6 months post surgery | 
| Change from preoperative baseline in Patient-Reported Outcomes Measurement Information System PROMIS v1.0 Sleep Disturbance short form | The PROMIS v1.0 Sleep Disturbance short form evaluates one's perceptions of sleep quality. | 12 months post surgery | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Parkinson's, Parkinson Disease