title: Elevated coherent motion thresholds in mild traumatic brain injury.
abstract: OBJECTIVE
  Individuals with mild traumatic brain injury (mTBI) frequently complain of increased sensitivity to visual motion. Thus, the purpose of this study was to assess the coherent motion threshold (CMT) in subjects with mTBI and reported visual motion sensitivity.
  
  
  METHODS
  Fourteen adult subjects with mTBI and symptoms of motion sensitivity were tested. They were compared with 40 age-matched asymptomatic visually normal individuals. CMT was assessed using a 2-alternative, forced choice paradigm. A symptom rating-scale questionnaire related to motion and light sensitivity, vertigo, and self-reported reading ability was also administered to the mTBI group.
  
  
  RESULTS
  Mean CMTs were significantly elevated in the mTBI (8.81%) versus the normal subjects (6.53%). There was a trend for a progressive increase in mean CMT in mTBI with increased symptoms related to visual motion sensitivity and vertigo. However, there was no apparent relation to either light sensitivity or self-reported reading ability in mTBI. There was no significant age effect in either group.
  
  
  CONCLUSIONS
  The elevated CMT in mTBI suggests damage to the magnocellular pathway, such as extrastriate visual cortical area V5, visual area medial temporal, and the medial superior temporal cortex, which is involved directly in various aspects of motion processing. These findings are consistent with the subjects' symptoms of motion sensitivity and vertigo in their natural environments.
authors.affiliation: State University of New York State College of Optometry, New York, NY 10036, USA. rpatel@sunyopt.edu
authors.forename: Reena
authors.initials: R
authors.lastname: Patel
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Ciuffreda
authors.forename: Barry
authors.initials: B
authors.lastname: Tannen
authors.forename: Neera
authors.initials: N
authors.lastname: Kapoor
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001930:Brain Injuries / Q000503:physiopathology* / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009039:Motion Perception; D012684:Sensory Thresholds; D012720:Severity of Illness Index; D014795:Visual Pathways / Q000503:physiopathology; D014796:Visual Perception; D055815:Young Adult