Linked Life Data

1375879

Source:http://linkedlifedata.com/resource/pubmed/id/1375879

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1992-7-9
pubmed:abstractText
Transient evoked potentials were recorded simultaneously over 5 electrodes placed in a horizontal row across the occiput. A range of spatial frequencies were presented as either full-field or hemifield stimuli. Subjects were 11 normal observers and 5 patients with lesions causing a homonymous hemianopic field defect. The shortest latency peak response was at approximately 70 msec, a negative potential (N70). For all spatial frequencies, full-field stimuli evoked a lower amplitude N70 at the midline than the sum of N70 amplitudes to two hemifield stimuli, suggesting partial cancellation. The latency and amplitude of N70 increased as spatial frequency increased. N70 and P100 differed in respect to their response to spatial frequency and field size, further suggesting that they may not be subsets of a unitary response. For hemifield stimulation, N70 had an ipsilateral maximum and attenuated or completely reversed in polarity across the midline. Consistent with the data of normals using hemifield stimuli, in 5 patients a full-field stimulus elicited an N70 lateralized contralaterally to the homonymous hemianopia, i.e., the ipsilateral N70 was absent. The absolute amplitude difference between the left and right electrodes was significant for hemifield stimulation in normals and full-field stimulation in the patients, but not for full-field stimulation in normals. Our results imply that the evaluation of N70 hemispheric distribution is useful for the evaluation of paramacular visual field defects.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0013-4694
pubmed:author
pubmed:issnType
Print
pubmed:volume
84
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
201-8
pubmed:dateRevised
2008-9-9
pubmed:meshHeading
pubmed:articleTitle
A short latency cortical component of the foveal VEP is revealed by hemifield stimulation.
pubmed:affiliation
Department of Neurology, Mount Sinai School of Medicine, New York, NY 10029.
pubmed:publicationType
Journal Article