Dorsal rather than ventral visual pathways discriminate freezing status in Parkinson's disease

Parkinsonism Relat Disord. 2012 Dec;18(10):1094-6. doi: 10.1016/j.parkreldis.2012.05.016. Epub 2012 Jun 15.


Background: Although visuospatial deficits have been linked with freezing of gait (FOG) in Parkinson's disease (PD), the specific effects of dorsal and ventral visual pathway dysfunction on FOG is not well understood.

Method: We assessed visuospatial function in FOG using an angle discrimination test (dorsal visual pathway bias) and overlapping figure test (ventral visual pathway bias), and recorded overall response time, mean fixation duration and dwell time. Covariate analysis was conducted controlling for disease duration, motor severity, contrast sensitivity and attention with Bonferroni adjustments for multiple comparisons.

Results: Twenty seven people with FOG, 27 people without FOG and 24 controls were assessed. Average fixation duration during angle discrimination distinguished freezing status: [F (1, 43) = 4.77 p < 0.05] (1-way ANCOVA).

Conclusion: Results indicate a preferential dysfunction of dorsal occipito-parietal pathways in FOG, independent of disease severity, attentional deficit, and contrast sensitivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomechanical Phenomena
  • Contrast Sensitivity / physiology
  • Female
  • Gait Disorders, Neurologic / physiopathology*
  • Humans
  • Male
  • Middle Aged
  • Movement Disorders / physiopathology
  • Occipital Lobe / cytology
  • Occipital Lobe / physiology
  • Parietal Lobe / cytology
  • Parietal Lobe / physiology
  • Parkinson Disease / physiopathology*
  • Psychomotor Performance / physiology
  • Space Perception / physiology*
  • Surveys and Questionnaires
  • Visual Pathways / physiopathology*
  • Visual Perception / physiology*