Dual-Task Performance Testing As an Indicator of Cognitive Deterioration in Parkinson's Disease: A Pilot Study

Author(s): Dalma Szögedi, Trevor W. Stone, Elek Dinya , Judit Málly

Introduction: The reaction times of Parkinson's disease (PD) patients in dual-task accuracy tests depend on their cognitive ability.

Objective: The non-disabled PD patients’ cognitive ability assessed by dual-task tests deteriorates and is recovered by a short training with dual-task activity. Dual-task training was found to produce improvement sustained for several months in the cognitive function of PD patients.

Method: Forty-six PD patients were compared with 47 age matched healthy controls and 26 patients were followed for one year. Five dual-task tests consisting of a primary cognitive task performed simultaneously with a secondary motor task were repeated for five consecutive days. Testing was repeated after 6 and 12 months. Participants? reaction times, number of Hits and Misses, and other cognitive and motor tests were quantified.

Results: In the initial tests slower reaction times, fewer Hits and more Misses were indicated in the patients? group especially over 65 years, while the other cognitive and movement tests were similar to the normal controls. The decayed cognition of the early PD patients was primarily characterized by the increased number of Misses. The dual-task performances were significantly improved by the training within 3 days, except for Misses. No deterioration up to 6 months was observed.

Conclusion: It is concluded that dual-tasks are objective and sensitive tests reflecting the global cognitive deterioration arising before the appearance of clinical symptoms when the movement is unaffected. Dual-task testing is recommended as an objective measure of cognitive function and as training to reduce cognitive deterioration