Relationship between visual evoked potentials and intracranial pressure

Abstract

The relationship between intracranial pressure (ICP) and latency of visual evoked potentials (VEP) was investigated in hydrocephalic patients with severe head trauma. A positive correlation of increase in latency of wave N2 (normal latency 71 +/- 9.2 msec) of the VEP with elevations in ICP was observed. A potential role for VEP in both the assessment of shunt function and the monitoring of patients with severe head injury is suggested by these findings.

Noninvasive methods of detecting increased intracranial pressure

“…Several studies have reported a positive correlation between ICP and F-VEP N2 wave latency with correlation coefficients ranging from 0.83 to 0.84 [89,90]. Similarly, Gumerlock et al found that a F-VEP N2 latency >80 ms linearly corresponded to an ICP > 20 cmH 2 O [91].…”

Visual evoked potentials show strong positive association with intracranial pressure in patients with cryptococcal meningitis

“…The positive correlation between ICP and F-VEP wave latency observed in studies of patients with hydrocephalus suggested this method as a mean to provide an early detection of shunt dysfunction 13,14,16,17,18,19 . Changes in the F-VEP latencies of patients with ICH secondary to cerebral edema have also been observed, and the use of F-VEP has been suggested to monitor ICP in head trauma victims 14,16,17,18 .…”

“…Changes in the F-VEP latencies of patients with ICH secondary to cerebral edema have also been observed, and the use of F-VEP has been suggested to monitor ICP in head trauma victims 14,16,17,18 . However, F-VEP in head trauma is biased by other variables as arterial pO 2 , sagittal sinus venous pO 2 and regional cerebral flow and is not an adequate substitute for direct ICP measures 17,19 .…”

“…Prediction and interpretation of changes in the amplitude of the potentials after CSF drainage would be even more complex. The CSF pressure adjacent to the optic nerves tends to reduce the responses, but diffuse brain dysfunction next to it has the opposite effect 11,19 .…”

“…A relationship has been observed between a prolongation of the latency of waves from the diffuse light flash visual evoked potential (F-VEP) test and increased intracranial pressure (ICP) in patients with hydrocephalus, traumatic brain injury or drug-related cerebral oedema 13,14,15,16,17,18,19 . The N2 component exhibits the greatest stability and is the most widely investigated parameter of the F-VEP.…”