Cognitive Rehabilitation in Parkinson's Disease

We are testing a computer game-style rehabilitation program for people with Parkinson's disease (PD). People with PD often have difficulty with motor planning, such as initiating or starting movements. We believe that our program will improve performance on a movement initiation task as well as on activities of daily living, such as walking, preparing a meal or opening a medicine bottle. We will measure brain function using functional MRI before and after training to identify brain areas that are involved in improved performance. If effective, computer based training will be an inexpensive treatment for motor planning deficits in PD that is free from side effects and easy to administer to a large number of patients.

Our approach is to use PD-based adaptive training to improve performance on IG movement initiation in patients with PD. We have three aims, 1) to systematically evaluate cognitive rehabilitation in people with Parkinson's disease (PD), 2) to examine the neural mechanisms subserving cognitive rehabilitation in PD and 3) to assess the ecological validity of cognitive rehabilitation in PD. We will focus on a single aspect of cognitive function, the decision to initiate a movement. Movements can be internally generated (IG) or externally cued, and motor deficits in PD are typically linked to IG movements. The protocol is designed to drive beneficial neuroplastic changes using a paradigm similar to those that have shown promising results in traumatic brain injury patients. In addition, we will use fMRI to measure activity in underlying basal ganglia-thalamocortical circuits. Finally, because the goal of any research regarding the pathophysiology of disease is to improve the lives of patients with the disease, behavioral and neuropsychological measures will be correlated with fMRI measured functional abnormalities before and after training. Improvement in the initiation of movement has the potential to dramatically improve daily functioning including reducing falls, improving language production and improving proficiency of activities of daily living.

PD subjects who undergo to PC-based neurorehabilitation intervention. This intervention will train research subjects to improve movement initiation in response to visual stimuli.

Age matched controls who undergo to PC-based neurorehabilitation intervention. This intervention will train research subjects to improve movement initiation in response to visual stimuli.

Subjects sit at a computer and type a string of numbers that appears on the screen. As performance improves (# correct), the strings of numbers get longer. They are then instructed to repeat the string from memory. Performing these key entries from memory is a test of internally generated movement initiation.

Before and after computer training outcome measures: left, right, bimanual external cue reaction time; left, right, bimanual external cue error; left, right, bimanual internally generated reaction time; left, right, bimanual internally generated error for four-digit trials.

Modified Emory Functional Ambulatory Profile (mEFAP); mobility test Task 1: 5 meter walk on hard surface; timed. Task 2: 5 meter walk on carpeted surface, timed. Task 3: Timed up and go; rise from chair, walk 3 meters, walk back, sit down in chair, timed. Task 4: Obstacle course, similar to the Timed up and go, with 2 obstacles to be stepped over while walking forward and coming back; timed. Task 5: Ascend and descend 5 steps of stairs; timed.

Functional Dexterity test (FDT): a motor dexterity measurement for hands. Task: Pick up and flip wooden pegs on a 4x4 pegboard in a zig-zag pattern; timed. Task is performed 2 times per hand Modified Task: Interchange 2 columns of of pegs (4 pegs each side) simultaneously. No flipping is required. 5 second penalty to time score for 1.) using the pegboard to help with flipping and 2.) supinating of the hand; per occurrence. 10 second penalty to time score for dropping a peg, per occurrence.

Symbol Digit Modality Test (SDMT): Participants are given a key of numbers (1-9) corresponding to symbols for reference. Task: Participants are given a page of symbols and are instructed to say aloud the number corresponding to each symbol on the page. This task is timed for completion and the score is reported as the number of symbol to number matching correct in 90 seconds.

Inclusion Criteria: Clinical diagnosis of PD dominant on the right side with a Hx of response to dopamine replacement. Exclusion Criteria: Contraindication to MRI History of stroke or significant head trauma Significant vision impairment Hx of brain surgery or claustrophobia Medication change <4 weeks Atypical PD Severe tremor Presence of motor fluctuations or dyskinesia Significantly impaired limb or joint function Significant memory impairment Depression or daytime sleepiness

Disbrow EA, Russo KA, Higginson CI, Yund EW, Ventura MI, Zhang L, Malhado-Chang N, Woods DL, Sigvardt KA. Efficacy of tailored computer-based neurorehabilitation for improvement of movement initiation in Parkinson's disease. Brain Res. 2012 May 3;1452:151-64. doi: 10.1016/j.brainres.2012.02.073. Epub 2012 Mar 9.