Author/Editor		Lowitzsch, K
Title		Visual evoked potentials in neurology: clinical applications in pre- and post-chiasmal lesions
Type		članek
Source		Zdrav Vestn
Vol. and No.		Letnik 62, št. Suppl 1
Publication year		1993
Volume		str. 67-71
Language		eng
Abstract		Pattern-reversal visual evoked potentials (VEP) are often superior to ophthalmological examination, since they fetect clinical as well as subclinical leions of the visual pathways. VEP is affected by a great variety og neuroophthalmological lesions. While retinal and optic disc involvements usualy don't delay VEP, optical nerve and chiasmal leisons change latency and shape of VEP. Several central nervous system (CNS) disease processes lead to segmental demyelination, which causes delays in conduction, increases temporal dispersion, as well as conduction blocks, which is vosualized by VEP alterations. On the other hand, neuronal or axonal degenerations are mostly demonstrated by a decrease of VEP amplitude. The main indication for VEP is the suspicion of a demyelinating process somewhere alomg the vosual pathway, particularly in the pregenicular segment. Additional important indications are optic disc changes, possible pressure on the optic nerve or chiasma, as well as toxic or traumatic optic nerve lesions. Retrogenicular processes along the visual pathway, however, are much more difficult to capture, therefore multichannel recordings and half-field stimulation have to be additionally applied. In some systematic disorders and hereditary diseases the pregenicular parts of the visual system may be affected, therefore VEP is very imporant to clarify differential diagnosis.
Descriptors		VISUAL PATHWAYS OPTIC NEURITIS OPTIC CHIASM OPTIC DISK EVOKED POTENTIALS, VISUAL