An ongoing pilot trial is evaluating a computer-based, non-pharmacological cognitive approach to improve motor function and ease fatigue in people with Parkinson’s disease.
“Study protocol for a randomised pilot study of a computer-based, non-pharmacological cognitive intervention for motor slowing and motor fatigue in Parkinson’s disease,” appeared in the journal Pilot and Feasibility Studies.
Non-pharmacological therapies may offer effective alternatives to the complications and significant cost of dopaminergic treatment. A team of English researchers set out to develop an approach based on cognitive tasks to lessen fatigue and improve motor function in this patient population.
Advances in the understanding of the brain’s anatomy — such as links between motor and cognitive processes — and of Parkinson’s underpinnings provide the required scientific ground to develop such an approach. Also, previous work from the same team and other researchers had shown that people with Parkinson’s have an impairment in visuospatial tasks, such as mental rotation and mental grid navigation. These tasks were found to activate brain regions such as the supplementary motor area, typically involved in motor control.
Mental rotation is the ability to rotate mental representations of two-dimensional and three-dimensional objects and is related to the brain’s capacity for visual representation; mental grid navigation is the ability to compute a series of imagined location shifts in response to directional cues around a mental grid.
Prior work in 16 people with early-stage Parkinson’s showed improved motor performance after a visuospatial intervention task of mental grid navigation, as evidenced by faster mean onset and velocity. Such results, the team said, indicate that cognitive tasks with visuospatial processing can improve resilience to motor slowing and improve motor function. Such a strategy could become a low-cost option for patients and suitable for home use.
But before this intervention can be considered for a large-scale clinical trial, researchers needed to understand whether the computer-based cognitive training intervention (spatial grid navigation) could lead to significant motor benefits. They also wanted to see whether the improvements extend to aspects such as lessened rigidity and increased motor fluency.
The team designed a randomized single-blind (only patients are unaware of which intervention is expected to be beneficial) pilot study (ISRCTN1256549) to evaluate the feasibility of a larger-scale clinical trial. The trial set out to determine the usability of the devices used to capture movement and finger-tapping data. Tests of finger tapping are routinely conducted to assess bradykinesia, or slowness of movement, and may indicate motor fatigue.
Secondary objectives included assessing changes of at least five points in the Unified Parkinson’s Disease Rating Scale Part III (UPDRS-II) motor examination measure, as well as improvements in movement response times and eased motor fatigue over five 45- to 70-minute sessions involving sequential subtraction or spatial memory control tasks.
Patients were tested at home, at local hospitals or at Wales’ School of Psychology, Bangor University. They did not change their medication or other nonpharmacological regimens. Patients’ hand dominance was assessed before starting the study. Evaluations of quality of life, fatigue, sleep quality, and non-motor symptoms were conducted.
In finger tapping, each hand was tested separately, with the number of taps over 15 seconds and the time between taps analyzed. To evaluate measures of velocity and trajectory, patients held down a button on a response box for four seconds and then reached for a green circle on a screen as quickly and accurately as possible. Eighteen trials were conducted per hand. Action completion time, including movement initiation time and reaching time/velocity, were the primary outcome measures on this task.
The spatial grid navigation task includes an empty grid made up of nine squares, shown for 10 milliseconds. Then, a red start square is displayed for 2.5 seconds and participants are asked to memorize its position. A sequence of five screens is then shown, with two, three or four arrows that indicate movement of the red starting square. The participants must track the position of the red square based on the observed sequence.
At the end of the task, a blue target square is shown with a test grid. The patients then decide whether the position of the blue square matches that of the final position of the presented sequence.
“The results of this study will provide information regarding the feasibility of conducting a larger randomized control trial of non-pharmacological cognitive interventions of motor symptoms in [Parkinson’s disease],” the researchers stated.
“The longer-term view is to develop an evidence-based, online or app-based platform that could be accessed by people in their own homes alongside other pharmacological or physical treatments to support maintenance of motor slowing and motor fatigue symptoms,” they said.