Variability on serial testing of pattern reversal visual evoked potential latencies from full-field, half-field and foveal stimulation in control subjects

1987 ◽  
Vol 66 (4) ◽  
pp. 401-408 ◽  
Author(s):  
S.R Hammond ◽  
S MacCallum ◽  
C Yiannikas ◽  
J.C Walsh ◽  
J.G McLeod
2015 ◽  
Vol 8 (2) ◽  
pp. 2106-2121
Author(s):  
Hamed Ibrahem Abdelkader ◽  
Mona Abdelkader ◽  
Mohammed Kabeel ◽  
Malak Alya

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.  


1985 ◽  
Vol 147 (5) ◽  
pp. 532-539 ◽  
Author(s):  
Graham F. A. Harding ◽  
Christine E. Wright ◽  
Arnold Orwin

The use of the flash and pattern reversal visual evoked potential (VEP) in the diagnosis of primary presenile dementia was investigated. The results from 20 patients with primary presenile dementia were compared with those from a control group of normals of equivalent age and from a control group of 20 patients with cortical atrophy but no dementia. Presenile dementia caused a slowing of the major positive (P2) component of the VEP to flash stimulation. However, the VEP to pattern reversal stimulation (P100) was of normal latency. The difference between these two latencies characterises this unusual combination of results and is found to be a more specific diagnostic indicator of primary presenile dementia than the EEG or CT scan.


2021 ◽  
Vol 58 (2) ◽  
pp. 78-83
Author(s):  
Luan F. B. Almeida ◽  
Marisa Kattah ◽  
Liana O. Ventura ◽  
Adriana L. Gois ◽  
Camilla Rocha ◽  
...  

2020 ◽  
Vol 24 (1) ◽  
pp. 226-234 ◽  
Author(s):  
Rossana Terracciano ◽  
Alessandro Sanginario ◽  
Simona Barbero ◽  
Davide Putignano ◽  
Lorenzo Canavese ◽  
...  

2016 ◽  
Vol 3 (3) ◽  
pp. 107
Author(s):  
Kuldip Singh Bhatia ◽  
Anil Kumar ◽  
Ali Ahanger ◽  
Pradeep Shingal ◽  
Vijay Kumar Roy

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