Citation

Piponnier JC, Forget R, Gagnon I, McKerral M, Giguère JF, Faubert J. J. Neurotrauma 2015; 33(2): 242-253.

Affiliation

Université de Montréal, École d'optométrie , 3744, Jean-Brillant , Suite 201-01 , Montreal, Quebec, Canada , H3T 1P1 ; jean-claude.piponnier@umontreal.ca.

Copyright

(Copyright © 2015, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2014.3832

PMID

25950948

Abstract

Mild traumatic brain injury (mTBI) has subtle effects on several brain functions that can be difficult to assess and follow-up. We investigated the impact of mTBI on the perception of sine-wave gratings defined by first-and second-order characteristics. Fifteen adults diagnosed with mTBI were assessed at 15 days, 3 months and 12 months after injury. Fifteen matched controls followed the same testing schedule. Reaction times (RTs) for flicker detection and motion direction discrimination were measured. Stimulus contrast of first- and second-order patterns was equated to control for visibility, and correct-response RT means, standard deviations (SDs), medians, and interquartile ranges (IQRs) were calculated. The level of symptoms was also evaluated to compare it to RT data. In general in mTBI, RTs were longer, and SDs as well as IQRs larger, than those of controls. In addition, mTBI participants' RTs to first-order stimuli were shorter than those to second-order stimuli, and SDs as well as IQRs larger for first- than for second-order stimuli in the motion condition. All these observations were made over the 3 sessions. The level of symptoms observed in mTBI was higher than that of control participants and this difference did also persist up to one year after the brain injury, despite an improvement. The combination of RT measures with particular stimulus properties is a highly sensitive method for measuring mTBI-induced visuomotor anomalies, and provides a fine probe of the underlying mechanisms when the brain is exposed to mild trauma.

Language: en