Dual-task interference and brain structural connectivity in people with Parkinson's disease who freeze

Abstract

Background Freezing of gait in people with Parkinson’s disease (PD) is likely related to attentional control (ie, ability to divide and switch attention). However, the neural pathophysiology of altered attentional control in individuals with PD who freeze is unknown. Structural connectivity of the pedunculopontine nucleus has been related to freezing and may play a role in altered attentional control; however, this relationship has not been investigated. We measured whether dual-task interference, defined as the reduction in gait performance during dual-task walking, is more pronounced in individuals with PD who freeze, and whether dual-task interference is associated with structural connectivity and/or executive function in this population. Methods We measured stride length in 13 people with PD with and 12 without freezing of gait during normal and dual-task walking. We also assessed asymmetry of pedunculopontine nucleus structural connectivity via diffusion tensor imaging and performance on cognitive tests assessing inhibition and set-shifting, cognitive domains related to freezing. Results Although stride length was not different across groups, change in stride length between normal and dual-task gait (ie, dual-task interference) was more pronounced in people with PD who freeze compared to non-freezers. Further, in people with PD who freeze, dual-task interference was correlated with asymmetry of pedunculopontine nucleus structural connectivity, Go-NoGo target accuracy (ability to release a response) and simple reaction time. Conclusions These results support the hypothesis that freezing is related to altered attentional control during gait, and suggest that differences in pedunculopontine nucleus connectivity contribute to poorer attentional control in people with PD who freeze.

Do executive dysfunction and freezing of gait in Parkinson's disease share the same neuroanatomical correlates?

“…Brugger et al 10 FOG and thus emphasizes the importance of fronto-parietal networks in FOG (11). This is further supported by the notion that FOG is related to abnormal sensory and spatial processing which are considered as parietal lobe functions (23;24).…”

Dual tasking in Parkinson’s disease: should we train hazardous behavior?

“…Up to 79.2% of PD patients in the advanced disease stage reported FOG [13] and 38.2% of patients indicated this symptom to be present even when ONmedication [14]. FOG frequency increases when dual tasking [8], suggesting that patients who freeze have greater loss of automaticity than those who do not [15]. Moreover, FOG was identified as an independent predictor of falling [16].…”

Cortical correlates of susceptibility to upper limb freezing in Parkinson’s disease

“…Congruently, interference of freezers with a second cognitive task was described as an effective procedure to provoke freezing events given the susceptibility of freezers to 'cortical processing conflicts' and 'capacity overloads' (Peterson et al , 2014a, Spildooren et al , 2010.…”