Frontal vs. Posterior cognitive dysfunction: Does greater risk of dementia lead to a differential gait in Parkinson’s disease?

Abstract

Background: Gait impairment is suggested to predict the onset of dementia in Parkinson’s disease (PD). Interestingly, studies have shown that PD patients with cognitive deficits mediated by posterior brain areas are at greater risk of developing dementia than those with frontal deficits. Yet, it remains unknown whether PD patients with posterior cognitive deficits show differences in gait when compared to those with frontal deficits. Aim: This study aimed to compare gait of individuals with PD showing “posterior”, “frontal”, or no cognitive impairment (NCI). Methods: Based on a sample of 64 individuals with PD, median scores were calculated for three neuropsychological tests relying on “frontal” and three relying on “posterior” brain areas. Individuals assigned into the Frontal or Posterior groups showed at least 2 out of 3 scores lower than the median in frontal or posterior tests, respectively. Those with 0 or 1 score lower than the median were classified as NCI. Participants walked under single and dual task conditions. Results: All groups walked slower, with greater variability, wider base of support, and longer double support in the dual task condition.  Interpretation: PD patients with posterior cognitive deficits walk similarly to those with frontal deficits and those with normal cognition.