Objective assessment of visual attention in mild traumatic brain injury (mTBI) using visual-evoked potentials (VEP)

Abstract

The objective and subjective tests were able to differentiate between those having mTBI with and without an attentional deficit. The proposed VEP protocol can be used in the clinic to detect and assess objectively and reliably a visual attentional deficit in the mTBI population.

Visually Evoked Potential Markers of Concussion History in Patients with Convergence Insufficiency

“…Possible magnocellular deficits have been reported for individuals with a history of mild traumatic brain injury compared with visually normal control subjects based on their P100 visually evoked potential responses to a high-contrast (85%) checkerboard stimulus (1.49-cycle/degree check size) at a very low luminance level (0.3% transmittance; greater P100 latency and smaller amplitude),15 as well as to low-contrast (20%) checkerboard stimuli of varying sizes (smaller P100 amplitude) 16. Observation of magnocellular deficits in mild traumatic brain injury is also consistent with the results of several non–visually evoked potential studies, which found an elevated coherent motion threshold,17 increased visual motion sensitivity,18 and elevated and increased critical flicker frequency threshold values 19,20…”

VEP and Human Attention: Translation from Laboratory to Clinic

“…This system has been approved by the FDA, and it has been used in our laboratory for the last 4 years for a variety of VEP studies. [26][27][28]35,37 The Diopsys company developed a custom-designed software program to measure quantitatively the alpha power responses via power spectrum analysis (Dumermuth and Molinari, 1987). 32 The power spectrum analysis filters and extracts the power (unit = µV2) of each alpha single frequency (i.e., 8, 9, 10, 11, 12, and 13 Hz) that is embedded in the overall complex VEP response waveform using Fourier analysis 38 (Figure 3).…”

“…The OVR consisted of training each of the three oculomotor systems, i.e., version, vergence, and accommodation, with such training indirectly including an attentional component. 34, 35 OVR was performed twice a week for six weeks for a total of 9 hours, 3 hours for each oculomotor system. There was also a similar placebo arm to the protocol (see Thiagarajan [43][44][45][46][47][48] for details).…”

“…Experiment #2: Objective assessment of at ten tion in mild traumatic brain injury (mTBI) using the visualevoked potential (VEP). 35…”

“…26 Experiment #2: Objective assessment of attention in mild traumatic brain injury (mTBI) using the visual-evoked potential (VEP). 35 Experiment #3: Effect of oculomotor vision rehabilitation on the visual-evoked poten tial and visual attention in mild traumatic brain injury (mTBI). 28…”