title: Altered brain activation in complex walking conditions in patients with Parkinson's disease.
abstract: BACKGROUND
  Behavioral studies suggest that deficits in cognitive domains and sensory-motor processes associated with Parkinson's disease (PD) impair the ability to walk in complex environments. However, the neural correlates of locomotion in complex environments are still unclear.
  
  
  METHODS
  Twenty healthy older adults (mean age 69.7 ± 1.3 yrs) and 20 patients with PD (mean age 72.9 ± 1.6 yrs; disease duration: 6.8 ± 1.3 yrs; UPDRSIII: 29.8 ± 2.4) were asked to imagine themselves walking while in the MRI scanner. Three imagined walking tasks, i.e., usual walking, obstacle negotiation, and navigation were performed. Watching the same virtual scenes without imagining walking served as control tasks. Whole brain analyses were used.
  
  
  RESULTS
  Compared to usual walking, both groups had increased activation during obstacle negotiation in middle occipital gyrus (MOG) (pFWEcorr<0.001), middle frontal gyrus (MFG) (pFWEcorr<0.005), and cerebellum (pFWEcorr<0.001). Healthy older adults had higher activation in precuneus and MOG (pFWEcorr<0.023) during navigation, while no differences were observed in patients with PD. Between group comparisons revealed that patients with PD had a significantly higher activation in usual walking and obstacle negotiation (pFWEcorr<0.039) while during navigation task, healthy older adults had higher activation (pFWEcorr<0.047).
  
  
  CONCLUSIONS
  Patients with PD require greater activation during imagined usual walking and obstacle negotiation than healthy older adults. This increased activation may reflect a compensatory attempt to overcome inefficient neural activation in patients with PD. This increased activation may reduce the functional reserve needed during more demanding tasks such as during navigation which may contribute to the high prevalence of falls and dual tasking difficulties among patients with PD.
authors: Center for the Study of Movement, Cognition, and Mobility, Neurological Institute, Tel Aviv Medical Center, Tel Aviv, Israel; Rivers Lab, Department of Rehabilitation and Movement Science, Rutgers Biomedical and Health Sciences, Newark, USA.
authors: I
authors: I
authors: Maidan
authors: Center for the Study of Movement, Cognition, and Mobility, Neurological Institute, Tel Aviv Medical Center, Tel Aviv, Israel.
authors: K
authors: K
authors: Rosenberg-Katz
authors: Center for the Study of Movement, Cognition, and Mobility, Neurological Institute, Tel Aviv Medical Center, Tel Aviv, Israel.
authors: Y
authors: Y
authors: Jacob
authors: Center for the Study of Movement, Cognition, and Mobility, Neurological Institute, Tel Aviv Medical Center, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel; Department of Neurology, Sackler Faculty of Medicine, Tel Aviv University, Israel.
authors: N
authors: N
authors: Giladi
authors: Rivers Lab, Department of Rehabilitation and Movement Science, Rutgers Biomedical and Health Sciences, Newark, USA.
authors: J E
authors: JE
authors: Deutsch
authors: Center for the Study of Movement, Cognition, and Mobility, Neurological Institute, Tel Aviv Medical Center, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel; Department of Physical Therapy, Sackler Faculty of Medicine, Tel Aviv University, Israel.
authors: J M
authors: JM
authors: Hausdorff
authors: Center for the Study of Movement, Cognition, and Mobility, Neurological Institute, Tel Aviv Medical Center, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel; Department of Neurology, Sackler Faculty of Medicine, Tel Aviv University, Israel. Electronic address: anatmi@tlvmc.gov.il.
authors: A
authors: A
authors: Mirelman
mesh_terms: D000368:Aged; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D058245:Cognitive Reserve / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D020233:Gait Disorders, Neurologic / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology*; D016138:Walking / Q000502:physiology*
keywords: Gait; Motor imagery; Parkinson's disease; Virtual environment; fMRI