Abstract
Freezing of gait in Parkinson’s disease often occurs during steering of gait (i.e., complex gait) which is thought to arise from executive dysfunction. Our aim was to test whether cognitive cortico-basal ganglia-thalamo cortical circuitry is impaired and whether alternate neural circuits are used for complex gait in Parkinson’s disease with freezing of gait. Methods: Eighteen individuals with idiopathic Parkinson’s disease in the OFF medication state, nine with freezing of gait (aged 68 ± 6) and nine without freezing (aged 65 ± 5) were included. Positron emission tomography was used to measure cerebral glucose metabolism during two gait tasks, steering and straight walking, performed during the radiotracer uptake period. Results: During steering, there was reduced change in cerebral glucose metabolism within the cognitive cortico-thalamic circuit. More specifically, those with freezing of gait had less activation of the posterior parietal cortex, less deactivation of the dorsolateral prefrontal cortex and thalamus, and increased activation in the supplementary motor area. Interestingly, activity in the dorsolateral prefrontal cortex correlated with gait impairment (i.e., reduced stride length) in the freezing of gait group. Conclusion: These results demonstrate decreased parietal control and an alternate control mechanism mediated by prefrontal and supplementary motor areas in Parkinson’s disease with freezing of gait.
- Copyright © 2018 by the Society of Nuclear Medicine and Molecular Imaging, Inc.