P178. The effect of cognitively challenging tasks on walking in Parkinson’s Patients

Abstract

Background The interaction between motor and cognitive functions has an important impact on daily activities, is altered during ageing, and particularly affected in age-associated chronic diseases such as Parkinson’s disease (PD). Therefore, this motor-cognitive interaction has been extensively studied e.g. with dual task paradigms. It has become clear that particularly simultaneously performed cognitive secondary tasks with (an additional) motor aspect (such as carrying a glass of water or checking boxes) lead to impaired walking performance, and increase the risk of falls and injuries in PD patients. Yet, a detailed understanding of the changes which occur in PD when performing dual tasks is still lacking. Methods Fourty-four PD patients in off medication and 44 age- and gender-matched healthy controls were included. Dual tasking effects on gait velocity, number of steps, step duration, gait variability, double limb support and stride asymmetry of the primary task as well as velocity of the secondary tasks (subtracting serial sevens and checking boxes) during a 1 min “as fast as possible” walking condition were investigated. Participants wore a portable quantitative gait assessment system with six sensors (Mobility Lab®, APDM, Oregon, USA). Single as well as dual tasking performances were calculated for each group, and compared among groups. Results During the checking boxes task, all six above-mentioned gait parameters deteriorated in both PD patients and controls. Velocity of checking boxes decreased significantly under the dual tasking condition compared to single task also in both groups. During the subtraction task, four gait parameters deteriorated in PD patients but only two in controls. Velocity of serial subtraction decreased significantly only in PD patients but not in controls. Conclusion Dual tasking affects the quality of the performed tasks differently in PD patients and controls, depending on the kind of the secondary task. To study differences of dual tasking performance between PD patients and controls, a more “cognitive” task such as serial subtraction seems more promising than a secondary task that includes substantial motor aspects.