BACKGROUND To compare the usefulness of the traditional pattern-reversal Visual Evoked Potentials (VEP) with multifocal VEP (mfVEP) and Frequency-Doubling Technology (FDT) perimetry in the evaluation of the ocular abnormalities induced by acute or subacute optic neuritis (ON). MATERIALS AND METHODS The test results of 24 ON patients were compared with those obtained in 40 normal control subje...

A simulation and experimental study has been conducted on equivalent dipole layer imaging (EDLI) of brain electric sources from EEG. Using the three-sphere inhomogeneous head model, the performance of the EDLI was rigorously evaluated for a variety of brain source configurations under different noise levels. The present simulation results demonstrate the excellent performance of the EDLI in map...

To search for a potential negative influence on the central nervous system (CNS) of the electromagnetic field emitted by a mobile phone, the authors performed a pilot experimental study of the influence of a single short acute exposure to the GSM mobile phone Motorola 8700, using visual evoked potentials (VEP) examination as an electrophysiological marker of CNS dysfunction. The study group con...

Most prior visual evoked potential (VEP) research on the development of color vision has employed pattern-reversing stimuli that are not optimal for producing chromatic responses. We measured infant VEPs using low spatial frequency, onset-offset stimuli, modulated along the three axes of a cone-based color space (Derrington et al. [J. Physiol 1984;357, 241-265.]). Three color-normal infants wer...

A case is described in which the latency of the P100 component of the pattern evoked visual response (VEP) was shown in serial recordings to have remained greatly prolonged for three years after an attack of optic neuritis, but had returned to normal after a further three and a half years. A similar pattern was found in one of a group of 21 patients re-examined between 6 and 8 years after abnor...

PURPOSE To compare the Cambridge contrast sensitivity (CS) test and visual evoked potentials (VEP) in detecting visual impairment in a population of visually symptomatic and asymptomatic patients affected by clinically definite multiple sclerosis (MS). METHODS Fifty patients (100 eyes) presenting with MS and 25 healthy subjects (50 eyes) with normal corrected visual acuity were included in th...

BACKGROUND The purpose of this study was to determine the predictive value of flash visual-evoked potentials (VEP), relative afferent pupillary defect, and presence of orbital fractures in patients with traumatic optic neuropathy. METHODS A prospective study was conducted in 15 patients with indirect traumatic optic neuropathy. All patients underwent a thorough ophthalmic examination. Initial...

BACKGROUND The purpose of this study is to validate the use of visual evoked potential (VEP) to objectively quantify visual acuity in normal and amblyopic patients, and determine if it is possible to predict visual acuity in disability assessment to register visual pathway lesions. METHODS A retrospective chart review was conducted of patients diagnosed with normal vision, unilateral amblyopi...

Dynamic random dot correlograms (DRDCs) are binocular stimuli that evoke a percept and a visual evoked potential (VEP) only in case of a mature and functional binocular system. DRDC-VEP is a method extensively used to study cortical binocularity in human infants and nonverbal children. Although the DRDC-VEP was invented 3 decades ago, neither the fundamental parameters, including contrast, of t...

To study components related to parallel processing of information across the visual field, multi-focal pattern reversal visual evoked potentials (VEPs) were recorded using binary m-sequences. Contrast, chromatic, spatial and temporal characteristics of the stimuli were varied in order to favor contributions from either M or P pathways. Responses were decomposed into two additive components whos...