Abstract
Freezing of Gait (FOG) in Parkinson's disease is described as a sudden inability to initiate or continue walking that can be triggered by narrow spaces. The underlying mechanism of FOG is not well understood, but cognitive decline has been proposed as one aspect related to FOG. The aim of this study was to investigate whether cognitive decline could affect gait and gaze of FOG patients while approaching a doorway. Two FOG patients matched in age, symptom severity and most affected side were assessed on the TMT, Corsi Block Test, Line Bisection and 3MS, followed by performance of ten walking trials through a doorway of normal and narrow width. The cognitively declined (CD) patient pesented slower speed, smaller step length, lower cadence, larger base of support, and larger step length and step time variability as well as more gaze fixations on a greater number of locations, and for a longer mean duration than the non-cognitively declined (NCD) patient in both conditions. In addition, the CD patient had greater number of shifts in gaze toward a more variable choice of locations while the NCD had more shifts within task relevant locations. The results showed that even though the CD patient attempted to extract more visual information from the environment, this gaze behaviour did not appear to impact on his gait. In this context, cognitive decline may play a role in FOG since the CD patient appeared to have difficulty searching for relevant stimulus to guide locomotion.
