Prism Adaptation Treatment of Parkinson's Disease

Not Applicable

Completed

Conditions: Parkinson

Interventions: Behavioral: Prism adaptation

Registration Number: NCT02380859

Lead Sponsor: Dartmouth-Hitchcock Medical Center

Brief Summary: Subjects diagnosed with Idiopathic Parkinson's Disease, between ages of 40-85 inclusive, who have been referred for gait training. Since there can be subtle differences in the brain organization of left- and right-handed people that may influence some of the measurements, right handed participants are preferred. However, a left handed participant may be considered. Participants will be randomly assigned to one of two groups to undergo two weeks of twice-daily sessions. Group A receiving goggles fitted with lenses that distort vision and Group B patients receiving sham goggles

Detailed Description: The participants will be trained to undergo two daily sessions of visual adaptation at home for 14 consecutive days. For each adaptation session, subject will sit in a chair within reaching distance of a wall or cabinet upon which two dime-sized targets will be placed (one above the other, approximately ten inches apart). While wearing goggles, you will point rapidly to one target then the next, bringing the hand back to his/her torso between each pointing movement. They will be instructed to perform these movements "as quickly as possible" for a total of 50 pointing movements in each treatment session. After performing the 50 pointing movements, they will remove their goggles. Throughout the treatment period they will be asked to keep a diary in which they will log the time and duration of each prism adaptation session. At the first and second site visits, participants will be assessed for posture, gait and activities of daily living which will include some questionnaires. Questionnaires will be sent via mail after post-treatment at one week,1 month and 3 months.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 32

Inclusion Criteria

Diagnosis of idiopathic Parkinson's Disease
Referral for gait training
Aged 40 -85
If the subject is taking CNS-acting medications (benzodiazepines, hypnotics, antidepressants), regimen must be stable for 30 days prior to baseline visit
Subjects with Stage 11.5 - Stage IV (Hoehn and Yahr scale) where stage II.5 is bilateral involvement with axial involvements, but without balance difficulty, to Stage IV where one has severe disability but is still able to walk or stand unassisted
Subjects with any of the following abnormal scores (greater than 0) in the MDS-UPDRS Part III; a) Part III.10 Gait; b) Part III.11 Freezing of gait c) Part III.12 Postural Stability; subjects with Timed up and go test >12 seconds
Right handed participants are preferred due to the cortical lateralization of functions related to sensorimotor adaptation and postural control.
However, we will recruit left-handed participants if there are insufficient right-handed volunteers.

Exclusion Criteria

Subjects with a known psychiatric comorbidity that in the investigator's opinion would compromise participation in the study; subjects with a neurologic diagnosis, other than Parkinson's disease that can cause imbalance and gait impairment (e.g., multiple sclerosis, stroke, subdural hematoma, peripheral neuropathy)
Injury or impairment to the right arm (other than that which is due to Parkinson's disease) that would affect pointing movements; subjects with normal score on UPDRS part III
Classified as legally blind or lacking sufficient visual acuity to view the target and pointing hand during prism adaptation
Lacking sufficient understanding of verbal and written information in English to complete any of the consent screening forms.

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Prism adaptation	Prism adaptation	Patients will undergo twice daily adaptation to upward shifts in vision. Participants will be provided with goggles fitted with prismatic lenses that shift vision upward by 25 dioptres (about 17 degrees). While wearing the lenses, participants point to two 10cm-diameter visual targets positioned one above the other (about 20cm apart) on a wall, returning their pointing arm to their chest between each pointing movement. Participants make 50 pointing movements, as fast and as accurately as possible. Such a procedure induces a downward sensorimotor adaptation of pointing movements. Participants undergo this training twice a day (morning and evening) for two weeks in a self-guided fashion.
Sham adaptation	Prism adaptation	Participants undergo the same treatment protocol as described in the active comparator arm, with the exception that they wear goggles fitted with neutral lenses that do not induce sensorimotor adaptation.

Primary Outcome Measures

Name	Time	Method
Change in Postural Control - Maximum Extension on the Limits of Stability Test (Smart Equitest Balance Master System)	Baseline (Day 0) and Day 15	The participant stood on the platform in front of a monitor. Nine squares were presented on the monitor representing locations relative to the upright starting position: one in the centre of the screen (upright) and the remaining eight forming an ellipse around the central square. The participant's COG was indicated on the screen by the position of a stick figure avatar. At the beginning of each trial the participant was instructed to stand upright, keeping the COG cursor over the central target. A circular target appeared in one of eight other targets. The participant was required to move the COG cursor towards the second target as quickly and as accurately as possible by leaning their body while keeping their feet in the same location, and to then hold a position as close to the target as possible. Maximum extension of the COG over the feet was recorded for 8 trials per location.
Change in Postural Control - Reaction Time on the Limits of Stability Test (Smart Equitest Balance Master System)	Baseline (Day 0) and Day 15	The participant stood on the platform in front of a monitor. Nine squares were presented on the monitor representing locations relative to the upright starting position: one in the centre of the screen (upright) and the remaining eight forming an ellipse around the central square. The participant's COG was indicated on the screen by the position of a stick figure avatar. At the beginning of each trial the participant was instructed to stand upright, keeping the COG cursor over the central target. A circular target appeared in one of eight other targets. The participant was required to move the COG cursor towards the second target as quickly and as accurately as possible by leaning their body while keeping their feet in the same location, and to then hold a position as close to the target as possible. Reacting times were recorded for 8 trials per location. Mean change (post-pre) in seconds
Change in Postural Control - Composite Score on the Sensory Organisation Test SMART EquiTest Balance Master	Baseline (Day 0) and Day 15	The participant is asked to maintain an upright posture under six different conditions of sensory feedback: * Condition 1:Normal vision, fixed support * Condition 2:Absent vision, fixed support * Condition 3:Sway-referenced vision, fixed support * Condition 4:Normal vision, sway-referenced support * Condition 5:Absent vision, sway-referenced support * Condition 6:Sway-referenced vision, sway-referenced support The equilibrium score for each condition compares the subject's anterior/posterior (AP) sway during each trial to the theoretical sway stability limit of 12.5 degrees. A composite equilibrium score (0-100, higher score indicates better outcome) quantifies the overall COG sway or postural stability across the sensory conditions and is calculated by: * Independently averaging the score for conditions 1 and 2; * Adding these two scores to the equilibrium scores from each trial of sensory conditions 3, 4, 5, and 6; and * Dividing that sum by the total number of trials.
Change in Postural Control - Maximum Velocity on the Limits of Stability Test (Smart Equitest Balance Master System)	Baseline (Day 0) and Day 15	The participant stood on the platform in front of a monitor. Nine squares were presented on the monitor representing locations relative to the upright starting position: one in the centre of the screen (upright) and the remaining eight forming an ellipse around the central square. The participant's COG was indicated on the screen by the position of a stick figure avatar. At the beginning of each trial the participant was instructed to stand upright, keeping the COG cursor over the central target. A circular target appeared in one of eight other targets. The participant was required to move the COG cursor towards the second target as quickly and as accurately as possible by leaning their body while keeping their feet in the same location, and to then hold a position as close to the target as possible. Maximum velocity was recorded for 8 trials per location.
Change in Postural Control - Composite Latency Score on the Motor Control Test	Baseline (Day 0) and Day 15	The MCT assesses the ability of the automatic motor system to quickly recover following an unexpected external disturbance. Sequences of small, medium or large platform translations (scaled to the patient's height) in forward and backward directions elicit automatic postural responses. Translation of the surface in one horizontal direction results in displacement of the COG away from center in the opposite direction relative to the base of support. To restore normal balance, a quick movement of the COG back to the center position is required. A composite latency value is provided as the time in milliseconds between the force plate translation and the patient's active corrective responses, averaged across all translation sizes and directions.
Change in Postural Control - Composite Latency Score on the Berg Balance Scale	Baseline (Day 0) and Day 15	Berg Balance Scale. This 14-item test assesses balance during different tasks. Items consist of specific items such as standing with eyes closed, retrieving an object from the floor, and turning to look behind. The assessor rates the patient's performance from 0 ("lowest level of function") to 4 ("highest level of function") and a total is calculated out of a maximum score of 56.
Change in Postural Control - Forward-backward Displacement of Centre of Gravity on the Sensory Organisation Test SMART EquiTest Balance Master	Baseline (Day 0) and Day 15	The participant is asked to maintain an upright posture under different conditions of sensory feedback. Proprioceptive feedback to the feet and joints is manipulated by allowing the platform to tilt to directly follow the participant's anteroposterior body sway (constant proprioception) or by maintaining the standing platform in a fixed horizontal position (normal proprioceptive feedback). Visual feedback is provided by asking the participant to close their eyes (no visual feedback), asking the participant to open their eyes and allowing the visual surround to tilt directly following the participant's anterioposterior body sway (constant visual feedback), or by asking the participant to keep their eyes open and maintaining the visual surround in a fixed position (normal visual feedback). Forward-backward displacement of COG is recorded in degrees.

Secondary Outcome Measures

Name	Time	Method
Change in Gait - Step Length on the Walk Across Test (SMART Equitest Balance Master)	Baseline (Day 0) and Day 15	The WA quantifies characteristics of gait as the patient walks across the length of the force plate. The test characterizes steady state gait by having the patient begin well behind and continuing beyond the force plate. Measured parameters are average step width, average step length, speed and step length symmetry.
Change in Gait - Timed Up and Go Task	Baseline (Day 0) and Day 15	Timed Up and Go Test (TUG). Patients are seated in a chair and instructed to stand up, walk three meters, turn around, walk back, and sit down. The time (in seconds) is recorded.
Change in Gait - Functional Gait Assessment	Baseline (Day 0) and Day 15	Functional Gait Assessment. This 10-item test assesses dynamic balance and postural stability during gait. Items consist of specific walking tasks such as stepping over an obstacle, changing speed of walking upon the assessor's instruction, and walking backwards. The assessor scores the patient's performance from 0 ("severe impairment") to 3 ("normal") and a total is calculated out of 30.
Change in Gait - Step Speed in the Walk Across (SMART Equitest Balance Master)	Baseline (Day 0) and Day 15	The WA quantifies characteristics of gait as the patient walks across the length of the force plate. The test characterizes steady state gait by having the patient begin well behind and continuing beyond the force plate. Measured parameters are average step width, average step length, speed and step length symmetry.