Biomaterial Database

[Visual evoked potentials: methodologic problems--variations of stimulus parameters]. 1985

H C Diener, and C Zimmermann

The evaluation of visual potentials (VEP) evoked by pattern reversal includes the latency and amplitude of P100. An increase in the mean brightness or contrast of the checkerboard stimulus results in an increase in amplitude and a decrease in latency of P100. A square edge subtense of 20' in checkerboard pattern or a spatial frequency of 3-4 cyc/degrees in stripe pattern produce maximum responses. Transient VEPs are recorded at low repetition rates (less than 2 Hz), steady state VEPs at temporal frequencies above 8 Hz. In the latter condition the VEP takes the character of a sinusoidal train of waves which, compared to transient stimulation allows for a better measurement of VEP amplitude. The latency of P100 increases with the age of the subject. The influence of the different stimulus parameters and recording techniques must be known and have to be kept constant in order to record reliable and reproducible VEPs.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D009103	Multiple Sclerosis	An autoimmune disorder mainly affecting young adults and characterized by destruction of myelin in the central nervous system. Pathologic findings include multiple sharply demarcated areas of demyelination throughout the white matter of the central nervous system. Clinical manifestations include visual loss, extra-ocular movement disorders, paresthesias, loss of sensation, weakness, dysarthria, spasticity, ataxia, and bladder dysfunction. The usual pattern is one of recurrent attacks followed by partial recovery (see MULTIPLE SCLEROSIS, RELAPSING-REMITTING), but acute fulminating and chronic progressive forms (see MULTIPLE SCLEROSIS, CHRONIC PROGRESSIVE) also occur. (Adams et al., Principles of Neurology, 6th ed, p903)	MS (Multiple Sclerosis),Multiple Sclerosis, Acute Fulminating,Sclerosis, Disseminated,Disseminated Sclerosis,Sclerosis, Multiple
D009902	Optic Neuritis	Inflammation of the optic nerve. Commonly associated conditions include autoimmune disorders such as MULTIPLE SCLEROSIS, infections, and granulomatous diseases. Clinical features include retro-orbital pain that is aggravated by eye movement, loss of color vision, and contrast sensitivity that may progress to severe visual loss, an afferent pupillary defect (Marcus-Gunn pupil), and in some instances optic disc hyperemia and swelling. Inflammation may occur in the portion of the nerve within the globe (neuropapillitis or anterior optic neuritis) or the portion behind the globe (retrobulbar neuritis or posterior optic neuritis).	Neuropapillitis,Retrobulbar Neuritis,Anterior Optic Neuritis,Posterior Optic Neuritis,Anterior Optic Neuritides,Neuritides, Anterior Optic,Neuritides, Optic,Neuritides, Posterior Optic,Neuritides, Retrobulbar,Neuritis, Anterior Optic,Neuritis, Optic,Neuritis, Posterior Optic,Neuritis, Retrobulbar,Neuropapillitides,Optic Neuritides,Optic Neuritides, Anterior,Optic Neuritides, Posterior,Optic Neuritis, Anterior,Optic Neuritis, Posterior,Posterior Optic Neuritides,Retrobulbar Neuritides
D010364	Pattern Recognition, Visual	Mental process to visually perceive a critical number of facts (the pattern), such as characters, shapes, displays, or designs.	Recognition, Visual Pattern,Visual Pattern Recognition
D010775	Photic Stimulation	Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.	Stimulation, Photic,Visual Stimulation,Photic Stimulations,Stimulation, Visual,Stimulations, Photic,Stimulations, Visual,Visual Stimulations
D011930	Reaction Time	The time from the onset of a stimulus until a response is observed.	Response Latency,Response Speed,Response Time,Latency, Response,Reaction Times,Response Latencies,Response Times,Speed, Response,Speeds, Response
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D005074	Evoked Potentials, Visual	The electric response evoked in the cerebral cortex by visual stimulation or stimulation of the visual pathways.	Visual Evoked Response,Evoked Potential, Visual,Evoked Response, Visual,Evoked Responses, Visual,Potential, Visual Evoked,Potentials, Visual Evoked,Response, Visual Evoked,Responses, Visual Evoked,Visual Evoked Potential,Visual Evoked Potentials,Visual Evoked Responses
D005260	Female		Females