Abstract

Significance: Concussions or mild traumatic brain injuries (mTBIs) are the most common form of traumatic brain injury. There is lack of reliable, diagnostic tools in healthcare for the treatment of mTBI. A Visual Evoked Potential (VEP) approach will enhance practitioners in diagnosing and treating mTBI.

Purpose: The aim of this study was to evaluate changes in brain function associated mTBI/post-concussion syndrome (PCS) using Visual Evoked Potential (VEP). We examined the effects of mTBI on early visual processing to determine if the signs and symptoms of mTBI reflected the failure of retinal signal latency based on the paradigm that low spatial frequency (LSF) are processed faster than high spatial frequency (HSF) when measured at the primary visual cortex.

Methods: The VEP of participants were measured by biasing the magnocellular pathways using a low Michelson contrast, temporally modulated phase reversing checkerboard stimulus pattern, and successive spatial frequency (SF) from LSF to increasing HSF. The VEP values of participants from the control group where compared with VEP values obtained from the mTBI/ PCS group. Participants from the mTBI/PCS group underwent a 6 week-7 month treatment.

Results: The mTBI/PCS group failed to process the LSF faster than the increasing HSF, which resulted in loss of top-down information that leads to meaningful perception.

Conclusions: The mTBI/PCS subjects resolved their VEP deficits and returned to the proper temporal organization of latency, compared with the results from the control group.

Keywords: Concussion; mTBI; Post-concussion syndrome; Spatial frequency; Thalamus; Vision therapy