The value of the visual evoked potentials test in the assessment of the visual pathway in head trauma

Background: the research was done to evaluate the value of the visual evoked potentials test inthe assessment of visual pathways function in cases with head trauma and minimal findings onroutine testing.materials and methods: a prospective case series evaluating use of visual evoked potentialstesting in patients with a history of head trauma and suffering from visual symptoms with nosignificant clinical and neuroimaging findings, referred for further work up.results: thirty-four patients with a history of head trauma and subsequent visual complaints wereincluded. 27 cases (79.4%) were male and 7 cases (20.6%) were female. the mean elapsedtime after the trauma was 47.6 weeks (range: 3.5 to 320 weeks). twenty-five cases hadunilateral and 9 cases had bilateral visual complaints. history of coma with mean duration of 12days was present in 4 cases. the best-corrected visual acuity was less than 1 log mar (legally blind) in 21 eyes. in 4 eyes (12%) the relative afferent papillary defect test was positive. mild tomoderate optic disc pallor was present bilaterally in 4 cases and unilaterally in 3 cases.hemorrhagic patches were reported on mri in 2 cases; no other cases had pathologic mrifindings. in unilateral cases, there was a statistically significant difference between the involvedeye-sided lobe and the sound eye-sided lobe implicit time and amplitude. in patients withbilateral complaints, by testing each eye, the vep amplitudes of both eyes showed significantdifferences with the international society for clinical electrophysiology of vision standards,whereas the implicit times showed not-statistically significant differences.conclusion: the visual evoked potentials test shows not only additional diagnostic value, not seen on routine clinical and neuroimaging testing, but also rather a high validity in tracing visualdisability in traumatic brain injury.