Effects of Cognitive Dual-Task on Gait in Parkinson's Disease

The aim of this study is to evaluate gait in individuals diagnosed with PD under tasks involving different cognitive domains, to compare the results with those of age and sex-matched healthy individuals, and to determine which cognitive function has the greatest impact on gait in PD.

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the coexistence of motor and non-motor symptoms, which negatively affect individuals' activities of daily living and quality of life. Although motor symptoms are predominant in PD, impairments in cognitive functions are known to be present from the early stages of the disease and contribute to the clinical picture, thereby limiting functional abilities such as gait. Cognitive functions play a critical role in the planning, initiation, and maintenance of gait. As one of the key determinants of independence, walking is often performed under cognitive load in daily life. The ability to perform motor and cognitive dual tasks simultaneously during walking requires effective attentional allocation and increased information processing speed, and the central nervous system is capable of adapting to these demands. However, in neurodegenerative diseases such as PD, the simultaneous execution of cognitive and motor tasks becomes more challenging, leading to difficulties in maintaining balance during gait and an increased risk of falls. Cognition encompasses multiple domains, including memory, attention, executive functions, language, and visuospatial abilities. Although it is known that cognition affects gait performance in PD, the specific contributions of each cognitive domain to gait are not yet fully understood. Therefore, investigating the effects of cognitive tasks on gait performance in PD represents an important area of research. It is anticipated that the findings of this study will contribute to the development of structured gait training programs aimed at improving functional independence in gait-related activities of daily living in individuals with PD. Furthermore, these findings are expected to support the development of effective and individualized strategies for fall prevention, which remains one of the major challenges in physiotherapy management of PD.

Inclusion Criteria for Individuals with Parkinson's Disease: * A clinical diagnosis of Parkinson's Disease confirmed by a neurologist according to the United Kingdom Parkinson's Disease Society Brain Bank diagnostic criteria * Classified between stages 1 and 3 according to the Modified Hoehn and Yahr Staging Scale * Aged between 40 and 80 years * A score of at least 21 on the Montreal Cognitive Assessment (MoCA) * Ability to walk continuously for at least 10 minutes without interruption and without the use of any assistive walking device * Having received at least 5 years of formal education Exclusion Criteria for Individuals with Parkinson's Disease: * Presence of any neurological disorder other than Parkinson's Disease * Presence of any cardiopulmonary or musculoskeletal condition that may impair safe ambulation * A score of ≥10 for anxiety and ≥7 for depression on the Hospital Anxiety and Depression Scale (HADS) * Presence of visual or auditory impairments that cannot be corrected with assistive devices Inclusion Criteria for Healthy Individuals: * Aged between 40 and 80 years * A score of at least 21 on the Montreal Cognitive Assessment (MoCA) Exclusion Criteria for Healthy Individuals: * Presence of any neurological disorder * Presence of any cardiopulmonary or musculoskeletal condition that may affect safe ambulation * A score of ≥10 for anxiety and ≥7 for depression on the Hospital Anxiety and Depression Scale (HADS) * Presence of visual or auditory impairments that cannot be corrected with assistive devices