title: Resting-state brain connectivity in patients with Parkinson's disease and freezing of gait.
abstract: BACKGROUND
  Freezing of gait is a common cause of disability and falls in patients with Parkinson's disease. We studied brain functional connectivity, by means of resting-state functional magnetic resonance imaging, in patients with Parkinson's disease and freezing of gait.
  
  
  METHODS
  Resting-state functional magnetic resonance imaging at 3 T was collected in 29 patients with Parkinson's disease, of whom 16 presented with freezing of gait as determined by a validated freezing of gait questionnaire, and 15 matched healthy controls. Single-subject and group-level independent component analysis was used to identify the main resting-state networks differing between Parkinson's disease patients with and without freezing of gait. Statistical analysis was performed using BrainVoyager QX.
  
  
  RESULTS
  Between-group differences in resting-state networks revealed that patients with freezing of gait exhibit significantly reduced functional connectivity within both "executive-attention" (in the right middle frontal gyrus and in the angular gyrus) and visual networks (in the right occipito-temporal gyrus) [p < 0.05 corrected for multiple comparisons]. Freezing of gait clinical severity was significantly correlated with decreased connectivity within the two networks. Consistent with their "executive-attention" network impairment, patients with freezing of gait scored lower on tests of frontal lobe functions (phonemic verbal fluency: p = 0.005; frontal assessment battery: p < 0.001; ten point clock test: p = 0.04).
  
  
  CONCLUSIONS
  Our findings suggest that a resting-state functional connectivity disruption of "executive-attention" and visual neural networks may be associated with the development of freezing of gait in patients with Parkinson's disease.
authors.affiliation: Department of Neurological Sciences, Second University of Naples, Naples, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Tessitore
authors.forename: Marianna
authors.initials: M
authors.lastname: Amboni
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Esposito
authors.forename: Antonio
authors.initials: A
authors.lastname: Russo
authors.forename: Marina
authors.initials: M
authors.lastname: Picillo
authors.forename: Laura
authors.initials: L
authors.lastname: Marcuccio
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Pellecchia
authors.forename: Carmine
authors.initials: C
authors.lastname: Vitale
authors.forename: Mario
authors.initials: M
authors.lastname: Cirillo
authors.forename: Gioacchino
authors.initials: G
authors.lastname: Tedeschi
authors.forename: Paolo
authors.initials: P
authors.lastname: Barone
mesh_terms: D000368:Aged; D001931:Brain Mapping; D016022:Case-Control Studies; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D059907:Functional Neuroimaging; D020233:Gait Disorders, Neurologic / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology; D009778:Occipital Lobe / Q000503:physiopathology*; D010296:Parietal Lobe / Q000503:physiopathology*; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology*