ABSTRACT
Cognition and gait appear to be closely related. The chronological interplay between cognitive decline and gait dysfunction is not fully understood. The aim of the present prospective study is investigating whether the dysfunction of specific gait parameters, during specific task and medication conditions, may predict subsequent cognitive impairment in Parkinson's disease (PD). We evaluated cognition and gait in 39 Parkinsonian patients at an initial assessment and after 3 years. Cognitive performance was evaluated with a neuropsychological battery designed to assess memory, executive/attention, and visuospatial domains. Gait was investigated using a gait analysis system during both the off and on states in the following conditions: (1) normal gait; (2) motor dual task; and (3) cognitive dual task. We used regression models to determine whether gait predicts subsequent cognitive dysfunction. Overall, the cognitive test scores were stable over time with the exception of the executive/attention scores, whereas all gait parameters declined. The step length during the cognitive dual task during the on state at the initial evaluation was the only significant predictor of executive/attention domain dysfunction at follow up. The results were confirmed when executive/attention dysfunction at the initial assessment evaluation was included in the regression model as a covariate. Our longitudinal study offers additional insight into the progression of gait dysfunction, and its chronological relationship with cognitive dysfunction in PD patients. In particular, the present study indicates that step length during a cognitive task when on medication is an independent predictor of future executive/attention decline.
Subject(s)
Cognitive Dysfunction/diagnosis , Executive Function , Gait , Parkinson Disease/diagnosis , Parkinson Disease/psychology , Aged , Antiparkinson Agents/therapeutic use , Biomechanical Phenomena , Cognitive Dysfunction/etiology , Cognitive Dysfunction/physiopathology , Disease Progression , Female , Follow-Up Studies , Gait/drug effects , Gait/physiology , Humans , Levodopa/therapeutic use , Longitudinal Studies , Male , Middle Aged , Parkinson Disease/drug therapy , Parkinson Disease/physiopathology , Prognosis , Prospective StudiesABSTRACT
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. The objective of this study was to describe the gait patterns in patients affected by PD with or without mild cognitive impairment (MCI+ and MCI-, respectively). We also sought to find an association between gait patterns and specific cognitive profiles. Using a gait analysis system, we compared the gait patterns among MCI+ patients (n = 19), MCI- patients (n - 24), and age- and sex-matched healthy subjects (HS; n = 20) under the following conditions: (1) normal gait, (2) motor dual task, and (3) cognitive dual task. In PD patients, gait parameters were evaluated in both the off and on states. Memory, executive, and visuospatial domains were assessed using an extensive neuropsychological battery. Compared with MCI- PD and HS, MCI+ PD patients displayed reduced step length and swing time and impairment of measures of dynamic stability; these dysfunctions were only partially reversed by levodopa. We also found that dual-task conditions affected several walking parameters in MCI+ PD in the off and on states relative to MCI- PD and HS. Factor analysis revealed 2 independent factors, namely, pace and stability. The latter was strongly and directly correlated to the visuospatial domain. In conclusion, 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.
