Introduction Retinal input processing in the human visual system involves a phasic and tonic neural response. We investigated the role of the magno- and parvocellular systems by comparing the influence of the active neural population size and its discharge activity on the amplitude and latency of four VEP components. Method We recorded the scalp electric potential of 20 human volunteers viewi...

Between attacks, migraine patients are characterized by potentiation instead of habituation of stimulation-evoked cortical responses. It is debated whether this is due to increased or decreased cortical excitability. We have studied the changes in visual cortex excitability by recording pattern-reversal visual evoked potentials (PR-VEP) after low- and high-frequency repetitive transcranial magn...

Neurology 2012;79:732–733 For 40 years, visual evoked cortical potentials (VEPs) have been used to aid in the diagnosis of demyelinating optic neuropathy.1 Early studies demonstrated an increased latency of the positive peak normally seen at about 100 msec—the P100—in patients with optic neuritis.1 Since the P100 often remains prolonged following recovery from the acute episode, the VEP is usef...

PURPOSE We assessed retinal ganglion cell (RGC) function, and established a correlation between the neural conduction along the visual pathways and the retinal involvement in Leber's hereditary optic neuropathy (LHON). METHODS A total of 39 individuals carrying a LHON mutation (mean age, 33.35 ± 8.4 years), LHON-unaffected (LU, 22 eyes) or LHON-affected (LA, 17 eyes), underwent visual acuity ...

BACKGROUND The aim of our study was to assess the role of laser polarimetry and visual evoked potentials (VEP) as potential biomarkers of disease progression in multiple sclerosis (MS). PARTICIPANTS A total of 41 patients with MS (82 eyes) and 22 age-related healthy volunteers (44 eyes) completed the study. MS patients were divided into two groups, one (ON) with a history of optic neuritis (1...

PURPOSE To describe a visually evoked potential (VEP) examination performed on a patient with a keratoprosthesis. METHODS We report the case of a 60-year-old patient with a Fyodorov-Zuev keratoprosthesis in the right eye complained of gradual visual deterioration in that eye. His past medical history consisted of failed corneal graft procedures due to corneal dystrophy and an Ahmed valve impl...

We congratulate Dr. Azarmina and colleagues on their study investigating the latency of visual evoked potentials (VEPs) among healthy females during and after menstruation.1 The authors found significantly increased latencies in pattern and flash VEP in their subjects. Their findings are particularly remarkable since the mean latency of the P100 wave was increased by approximately 20 ms (mean i...

40 The present investigation documents the electrophysiological occurrence of 41 multisensory stochastic resonance in the human visual pathway elicited by tactile 42 noise. We define multisensory stochastic resonance of brain evoked potentials as 43 the phenomenon in which an intermediate level of input noise of one sensory 44 modality enhances the brain evoked response of another sensory modal...

We study the equilibrium measure on two-dimensional sphere in presence of an external field generated by $$r+1$$ equal point charges that are symmetrically located around north pole. The support is known as droplet. droplet has a motherbody which we characterize means vector problem (VEP) for r measures complex plane. model undergoes two transitions reflected first component minimizer VEP, name...

PURPOSE Visual evoked potentials (VEPs) are widely used to objectively assess visual system function in animal models of ophthalmological diseases. Although use of chronically implanted electrodes is common in longitudinal VEP studies using rodent models, reliability of recordings over time has not been assessed. We compared VEPs 1 and 7 days after electrode implantation in the adult mouse. We ...