Parkinson’s Disease (PD) is diagnosed based on classical motor symptoms, including bradykinesia (slowed movement and loss of spontaneous movement), muscular rigidity, resting tremors and postural instability. In the prodromal phase (an early phase of PD), however, the signs and symptoms shown by patients are often not severe enough for a definitive diagnosis. If physicians can diagnose patients while they are still in the prodromal phase, treatment can be started before the disease begins to significantly affect daily activities.
Gait impairment, brought on by slight motor and cognitive decline, is typically present in the prodromal phase. This symptom is especially pronounced under challenging conditions, such as avoiding or climbing over obstacles or encountering unexpected objects. These challenges require greater interplay between cognitive and motor processes, causing PD patients’ responses in these complex conditions to be more noticeable than when they are walking without obstacles.
A study by a group of Brazilian researchers found that a video game may present a novel tool for early detection of gait impairment in people with Parkinson’s Disease (PD). The study, “Goalkeeper Game: A New Assessment Tool for Prediction of Gait Performance Under Complex Condition in People With Parkinson’s Disease,” showed that a video game could be used to detect gait impairment earlier than existing tests, thus helping people with PD receive treatment sooner.
The Montreal Cognitive Assessment Test and the Dynamic Gait Index are the two clinical tools most widely used for evaluation of cognitive decline and gait impairment.
- The Montreal Cognitive Assessment Test is an evaluation tool used to determine the extent of cognitive impairment in an individual. Physicians, nurses, occupational therapists, psychologists can use this test to help diagnose any disease that involves elements of cognitive decline.
- The Dynamic Gait Index is a clinical tool to assess gait, balance and fall risk. It evaluates both steady-state walking and walking during more challenging tasks, and it assesses the individual’s ability to modify balance while walking in the presence of external demands. Challenges include changing speed while walking, walking while moving one’s head horizontally and vertically, and walking over an obstacle.
The Goalkeeper Game
The goalkeeper game allows players to assume the role of goalkeeper in a soccer penalty shootout, acting as a noninvasive test to assess patients’ gait under complex conditions.
The goalkeeper game’s challenges mimic the decision-making process required when patients encounter unexpected obstacles while walking. Three phases each evaluate distinct motor and cognitive components:
- In the initial phase, patients are told the shooting direction ahead of time. They need only to select the correct direction.
- The learning phase requires patients to identify the correct sequence of shooting direction, an activity with a higher cognitive demand.
- The final phase evaluates learning and memory by asking patients to memorize the sequence of shooting directions before beginning the game.
Study Parameters and Outcome
Seventy-four patients with PD (but without dementia) played the goalkeeper game between 40 and 120 minutes after a dose of levodopa (L-DOPA), the most efficacious drug therapy for PD. L-DOPA is a precursor to dopamine that is taken up by the dopaminergic neurons, which convert L-DOPA to dopamine, and increase dopamine production and storage.
The researchers assessed the patients with the MoCA test and the DGI. MoCA scores were only moderately associated with DGI scores (56% accuracy). But scores in the memory test of the goalkeeper game correlated with the DGI score (65% accuracy). Patients who got more responses wrong in the memory phase had a higher gait impairment in complex situations.
Implications of Early PD Diagnosis
More than 10 million people worldwide are living with PD, and early diagnosis can be crucial to quality of life since treatments such as L-DOPAa are more effective when administered early on in the disease process. Additionally, non-drug treatments such as increased exercise are easier to perform in the early stages of PD and may help slow disease progression.
A video game like the one used in this study may help detect an early decline in gait performance in a noninvasive way, without the need for more expensive screening tools or visits to specialists. Video games could even allow remote detection of gait impairment, giving more patients access to earlier intervention and perhaps even delayed disease progression. Additional studies are warranted to validate video games as a potential tool to detect gait decline in PD patients.
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