Gait Patterns in Parkinsonian Patients With or Without Mild Cognitive Impairment

Background: Although in recent years the relationship between cognition and gait in Parkinson’s disease (PD) has received increasing attention, the specific connections between gait patterns and cognitive features are not fully understood. Objective: To describe the gait patterns in patients affected by Parkinson’s disease (PD) with or without mild cognitive impairment (MCI+, MCI-). We also sought to find an association between gait patterns and specific cognitive profiles. Methods: Using a gait analysis system, we compared the gait patterns among MCI+ (n=19), MCI- (n=24) and age- and gender-matched healthy subjects (HS; n=20) in the following conditions: 1) normal gait; 2) motor dual task; 3) cognitive dual task. In PD patients, gait parameters were evaluated in both off and on state. Memory, executive and visuospatial domains were assessed with an extensive neuropsychological battery. Results: Compared with MCI- and HS, MCI+ PD patients displayed reduced step length and swing time, and impairment of measures of dynamic stability; these dysfunctions were only partially reverted by levodopa. We also found that dual task conditions affected several walking parameters in MCI+PD at off and on state with respect to MCI- and HS. Factor analysis revealed two independent factors, namely pace and stability. The latter was strongly and directly correlated with the visuospatial domain. Conclusions: Dysfunctions on specific gait parameters, which were poorly responsive to levodopa and highly sensitive to dual task conditions, were associated with MCI in PD patients. Importantly, visuospatial impairment was strongly associated with the development of instability and more generally with the progression of PD.