Korean J Anesthesiol.  2017 Apr;70(2):127-135. 10.4097/kjae.2017.70.2.127.

Intraoperative monitoring of flash visual evoked potential under general anesthesia

• Hayashi H
• Kawaguchi

• KMID: 2377412
• DOI: http://doi.org/10.4097/kjae.2017.70.2.127

Abstract

In neurosurgical procedures that may cause visual impairment in the intraoperative period, the monitoring of flash visual evoked potential (VEP) is clinically used to evaluate visual function. Patients are unconscious during surgery under general anesthesia, making flash VEP monitoring useful as it can objectively evaluate visual function. The flash stimulus input to the retina is transmitted to the optic nerve, optic chiasm, optic tract, lateral geniculate body, optic radiation (geniculocalcarine tract), and visual cortical area, and the VEP waveform is recorded from the occipital region. Intraoperative flash VEP monitoring allows detection of dysfunction arising anywhere in the optic pathway, from the retina to the visual cortex. Particularly important steps to obtain reproducible intraoperative flash VEP waveforms under general anesthesia are total intravenous anesthesia with propofol, use of retinal flash stimulation devices using high-intensity light-emitting diodes, and a combination of electroretinography to confirm that the flash stimulus has reached the retina. Relatively major postoperative visual impairment can be detected by intraoperative decreases in the flash VEP amplitude.

Keyword

Flash stimulation; General anesthesia; Intraoperative monitoring; Visual evoked potential

MeSH Terms

Anesthesia, General*
Anesthesia, Intravenous
Electroretinography
Evoked Potentials, Visual*
Geniculate Bodies
Humans
Intraoperative Period
Monitoring, Intraoperative*
Neurosurgical Procedures
Occipital Lobe
Optic Chiasm
Optic Nerve
Optic Tract
Propofol
Retina
Retinaldehyde
Vision Disorders
Visual Cortex
Propofol
Retinaldehyde