PMID- 7431042
OWN - NLM
STAT- MEDLINE
DCOM- 19810129
LR  - 20190724
IS  - 0022-510X (Print)
IS  - 0022-510X (Linking)
VI  - 48
IP  - 2
DP  - 1980 Nov
TI  - Pattern evoked potentials in human albinism. Evidence of two different 
      topographical asymmetries reflecting abnormal retino-cortical projections.
PG  - 265-86
AB  - In fifteen subjects with oculo-cutaneous or ocular albinism pattern-reversal 
      visual evoked potentials (VEP) were recorded to monocular whole-field (16 degrees 
      radius) and right and left vertical half-field (16 degrees radius) stimulation 
      from an array of occipital electrodes. In all 15 subjects the VEP was of low 
      amplitude and the monocular response to whole-field stimulation showed abnormal 
      asymmetry in scalp topography. This asymmetry was similar to that produced by 
      stimulation of the temporal half-field in the same eye. Two distinct types of VEP 
      asymmetry were readily identified in different subjects. In 5 the major 
      positivity of the response (P100) was distributed in the channels ipsilateral to 
      the stimulated eye or temporal half-field, being similar in distribution to the 
      P100 from the temporal hemifield or normal individuals. In 9 other subjects the 
      converse occurred; the P100 was distributed contralaterally. The remaining 
      subject was unique in that the responses from each eye had a distribution that 
      resembled one of the two main groups. The nasal half-field responses also 
      differentiated the two groups. On stimulation of the nasal field in the first 
      group the P100 was usually absent or attenuated and when present it had the same 
      topography as the temporal half-field P100. In contrast the nasal half-field P100 
      from the second group was always present and, although almost invariably smaller 
      than the temporal half-field P100, it had an identical distribution. There was no 
      correlation between these two patterns of VEP asymmetry and clinical or known 
      genetic features. The findings confirm that in human albinos each hemisphere 
      receives a predominantly monocular input from the contralateral eye; i.e. in 
      addition to the temporal, half-field, approximately 20 degrees of the nasal 
      half-field is projected to the hemisphere contralateral to each eye and not, as 
      in normal subjects, to the ipsilateral hemisphere. Furthermore, the findings of 
      two distinct and in some respects opposite types of VEP topographical asymmetry 
      raises the possibility of two variants of the geniculo-cortical projection 
      patterns existing in human albinos similar to those described in the Siamese cat.
FAU - Carroll, W M
AU  - Carroll WM
FAU - Jay, B S
AU  - Jay BS
FAU - McDonald, W I
AU  - McDonald WI
FAU - Halliday, A M
AU  - Halliday AM
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - Netherlands
TA  - J Neurol Sci
JT  - Journal of the neurological sciences
JID - 0375403
SB  - IM
MH  - Adolescent
MH  - Adult
MH  - Albinism/*genetics/physiopathology
MH  - Child
MH  - Evoked Potentials
MH  - Female
MH  - Genes, Recessive
MH  - Geniculate Bodies/physiopathology
MH  - Humans
MH  - Male
MH  - Reaction Time/physiology
MH  - Visual Cortex/physiopathology
MH  - Visual Fields
MH  - Visual Pathways/*physiopathology
MH  - Visual Perception/physiology
MH  - X Chromosome
EDAT- 1980/11/01 00:00
MHDA- 1980/11/01 00:01
CRDT- 1980/11/01 00:00
PHST- 1980/11/01 00:00 [pubmed]
PHST- 1980/11/01 00:01 [medline]
PHST- 1980/11/01 00:00 [entrez]
AID - 0022-510X(80)90206-3 [pii]
AID - 10.1016/0022-510x(80)90206-3 [doi]
PST - ppublish
SO  - J Neurol Sci. 1980 Nov;48(2):265-86. doi: 10.1016/0022-510x(80)90206-3.