Intraoperative Flash Visual Evoked Potential Recording and Relationship to Visual Outcome

2019 ◽  
Vol 46 (3) ◽  
pp. 295-302
Author(s):  
David A. Houlden ◽  
Chantal A. Turgeon ◽  
Nathaniel S. Amyot ◽  
Idara Edem ◽  
John Sinclair ◽  
...  
Keyword(s):  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Red Light ◽  
Visual Outcome ◽  
Retinal Stimulation ◽  
Potential Recording ◽  
Flash Visual Evoked Potential ◽  
Surgical Manipulation ◽  
The Relationship ◽  
Visual Evoked

ABSTRACT:Objective: To determine the relationship between intraoperative flash visual evoked potential (FVEP) monitoring and visual function. Methods: Intraoperative FVEPs were recorded from electrodes placed in the scalp overlying the visual cortex (Oz) after flashing red light stimulation delivered by Cadwell LED stimulating goggles in 89 patients. Restrictive filtering (typically 10–100 Hz), optimal reject window settings, mastoid reference site, total intravenous anesthetic (TIVA), and stable retinal stimulation (ensured by concomitant electroretinogram [ERG] recording) were used to enhance FVEP reproducibility. Results: The relationship between FVEP amplitude change and visual outcome was determined from 179 eyes. One eye had a permanent intraoperative FVEP loss despite stable ERG, and this eye had new, severe postoperative visual dysfunction. Seven eyes had transient significant FVEP change (>50% amplitude decrease that recovered by the end of surgery), but only one of those had a decrease in postoperative visual acuity. FVEP changes in all eight eyes (one permanent FVEP loss plus seven transient FVEP changes) were related to surgical manipulation. In each case the surgeon was promptly informed of the FVEP deterioration and took remedial action. The other eyes did not have FVEP changes, and none of those eyes had new postoperative visual deficits. Conclusions: Our FVEP findings relate to visual outcome with a sensitivity and specificity of 1.0. New methods for rapidly acquiring reproducible FVEP waveforms allowed for timely reporting of significant FVEP change resulting in prompt surgical action. This may have accounted for the low postoperative visual deficit rate (1%) in this series.

Visual Evoked potential signal processing and analysis for normal and galucomic eyes

2015 ◽  
Vol 8 (2) ◽  
pp. 2106-2121
Author(s):  
Hamed Ibrahem Abdelkader ◽  
Mona Abdelkader ◽  
Mohammed Kabeel ◽  
Malak Alya
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Optic Tract ◽  
Pattern Reversal ◽  
Blue Color ◽  
Check Size ◽  
Retinal Stimulation ◽  
Normal Individuals ◽  
Visual Evoked

Visual evoked potentials (VEPS) are obtained from optic tract by recording the evoked potentials generated by retinal stimulation. The flash VEP (FVEP) is used less frequently than pattern reversal VEP (PRVEP) because; it shows great variation in both latency and amplitude. The present study was undertaken to evaluate the effect of change of wavelength of flash and change of check size on the parameters of visual evoked potential (amplitude and latency) in normal individuals and glaucoma patients. The group of healthy subjects in the age of 20-45 years while the group of glaucoma subjects where  in the age of 25-50 years.  The two groups were exposed to flash VEP with white light and blue color and they also were exposed to checks subtending a visual angles of 15, 30,60 and 120 minutes of arc. The measured data were statistically analyzed and summarized by histograms. The interindividual and intraindividual in latencies and amplitudes for FVEP were assessed using  the coefficient of variation (COV). In conclusion, monochromatic flash VEP was preferred than white as there were minimal inter and intra individual variation of latencies and amplitudes. The most preferred check size in PRVEP was 120' for  the two groups.  

Multifocal visual evoked potential evaluation for diagnosis of acute optic neuritis and for prediction of visual outcome and ganglion cell layer thinning following optic neuritis

2020 ◽  
pp. 135245852097573
Author(s):  
Gorm Pihl-Jensen ◽  
Benedikte Wanscher ◽  
Jette Lautrup Frederiksen
Keyword(s):  
Optic Neuritis ◽  
Ganglion Cell ◽  
Visual Function ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Conduction Block ◽  
Visual Outcome ◽  
Multifocal Visual Evoked Potential ◽  
Visual Evoked

Background:: While damage to the optic nerve following optic neuritis (ON) is readily quantifiable, the evaluation of prognosis for visual function and neuroaxonal loss in the acute ON is challenging. Objective:: The objective of this study is to investigate the value of multifocal visual evoked potential (mfVEP) in acute ON, diagnostically for acute ON and prognostically for visual outcome and subsequent ganglion cell/inner plexiform layer thickness (GCLIPLt). Methods:: A prospective cohort study of mfVEP and full-field visual evoked potential (ffVEP) in acute, unilateral ON (onset < 31 days) was conducted. Comparisons with healthy controls ( n = 30) and association analysis with follow-up optical coherence tomography (OCT) measurements (of the GCLIPLt) and visual function (Sloan low-contrast visual acuity (LCVA)) were conducted. Results:: Seventy-nine ON patients were included (mean: 17 days from onset). Excluding measurements with conduction block, ffVEP ( n = 54) and mfVEP ( n = 44) showed sensitivities of 89% and 84% to a specificity of 97%. 65/79 patients were re-examined (mean: 200 days follow-up). mfVEP amplitude and latency inter-eye asymmetry in acute ON correlated with GCLIPLt ( r = 0.587 and Spearman’s ρ = 0.597, for both, p < 0.001). mfVEP amplitude correlated with LCVA inter-eye asymmetry at follow-up ( r = 0.421, p < 0.001), mfVEP latency did not. Conclusion: mfVEP may support the prognostic evaluation of acute ON patients and prove valuable in future neuroprotective and remyelinating trials. In acute ON, the increase in diagnostic value of mfVEP to ffVEP may be limited due to widespread conduction block.

Human Intelligence and Power Spectral Analysis of Visual Evoked Potentials

1980 ◽  
Vol 50 (1) ◽  
pp. 192-194 ◽  
Author(s):  
Mariko Osaka ◽  
Naoyuki Osaka
Keyword(s):  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Power Spectra ◽  
Power Spectral Analysis ◽  
Mentally Retarded ◽  
Power Spectral ◽  
The Difference ◽  
Mentally Retarded Children ◽  
The Relationship ◽  
Visual Evoked

The relationship between intelligence and power spectra of visual evoked potential was investigated using 8 normal and 8 mentally retarded children as subjects. The results showed the power spectrum of mentally retarded has a peak at 4 to 6 Hz, whereas that of normal has two apparent peaks at 4 and 12 Hz. It appears the peak at 12 Hz reflects the difference of intelligence.

Sign in / Sign up

Export Citation Format

Share Document