When do asymmetrical full-field pattern reversal visual evoked potentials indicate visual pathway dysfunction in children?

Mellow, Tessa; Liasis, Alki; Lyons, Ruth J.; Thompson, Dorothy

doi:10.1007/s10633-010-9250-1

Cited by 14 publications

(16 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Pattern onset and pattern reversal VEPs in this infant showed trans-occipital amplitude differences of more than 50%, consistent with homonymous hemianopia [8]. The trans-occipital asymmetry of flash VEP amplitudes was not as large, but clearly exceeded the cited clinical decision minimum of 20% [26]. The overall pattern VEP distributions are similar to those reported in human albinism.…”

Section: Discussionsupporting

confidence: 75%

Case report: Unilateral optic nerve aplasia and developmental hemi-chiasmal dysplasia with VEP misrouting

et al. 2020

View full text Add to dashboard Cite

Purpose To describe the trans-occipital asymmetries of pattern and flash visual evoked potentials (VEPs), in an infant with MRI findings of unilateral optic nerve aplasia and hemi-chiasm dysplasia. Methods A child with suspected left cystic microphthalmia, left microcornea, left unilateral optic nerve aplasia, and hemi-chiasm underwent a multi-channel VEP assessment with pattern reversal, pattern onset, and flash stimulation at the age of 16 weeks. Results There was no VEP evidence of any postretinal visual pathway activation from left eye with optic nerve aplasia. The VEP trans-occipital distribution from the functional right eye was skewed markedly across the midline, in keeping with significant misrouting of optic nerve fibres at the chiasm. This was supported by the anatomical trajectory of the optic chiasm and tracts seen on MRI. Conclusion This infant has chiasmal misrouting in association with unilateral optic nerve aplasia and unilateral microphthalmos. Chiasmal misrouting has not been found in patients with microphthalmos or anophthalmos, but has been reported after early eye loss in animal models. Our findings contribute to our understanding of the discrepancy between the visual pathway physiology of human unilateral microphthalmia and animal models.

show abstract

Section: Discussionsupporting

confidence: 75%

Case report: Unilateral optic nerve aplasia and developmental hemi-chiasmal dysplasia with VEP misrouting

et al. 2020

View full text Add to dashboard Cite

show abstract

“…VEP asymmetries VEP asymmetries are relevant to define the chiasmal or post-chiasmal visual pathway dysfunction in children [50,51]. Children with achiasmia can show diverse clinical and MRI spectra, where this lack of the crossing of the fibres can be associated with additional visual pathway maldevelopment.…”

Section: Ocular Findings and Mri Characteristicsmentioning

confidence: 99%

VEP characteristics in children with achiasmia, in comparison to albino and healthy children

et al. 2012

View full text Add to dashboard Cite

Achiasmia is a rare disorder of visual pathway maldevelopment that can show diverse clinical and magnetic resonance imaging spectra. The aim of this study was to define the characteristics of visual evoked potentials (VEPs) that differentiate abnormal optic-nerve-fibre decussation in children with achiasmia versus children with albinism and healthy children. In four children with achiasmia, the following VEP characteristics were studied and compared to children with ocular albinism and with healthy control children: (a) flash and pattern onset VEP interhemispheric asymmetry; (b) flash N2, P2 and onset C1 amplitudes and latencies; (c) interocular polarity differences in interhemisphere potentials; and (d) chiasm coefficients (CCs). In the children with achiasmia, VEPs were related to an absence of or reduced optic-nerve-fibre decussation at the chiasm and showed: ipsilateral asymmetry, significantly higher VEP amplitudes over the ipsilateral hemisphere (p < 0.05), interocular inverse polarity and negative CC. Other VEP features (uncrossed asymmetry and positive CC) were also seen if additional visual pathway maldevelopment (such as severe optic nerve hypoplasia and/or absence of the optic tractus on one side) were associated with achiasmia. In the children with albinism, the VEPs were related to excess optic-nerve-fibre decussation at the chiasm and showed: contralateral asymmetry, significantly higher VEP amplitudes over the contralateral hemisphere (p < 0.001), interocular inverse polarity and negative CC. In achiasmia and albinism, the VEPs to flash stimulation were more robust and more clearly distinguished between the conditions compared with the VEPs to pattern onset stimulation. VEPs in achiasmia are associated with absent or reduced optic-nerve-fibre decussation, where ipsilateral interhemispheric asymmetry is associated with interocular inverse polarity and a negative CC.

show abstract

“…Visual evoked potentials (VEPs) are a validated technique for identifying chiasmal dysfunction or disproportional decussation in the clinical environment [8,9,10]. In order to detect chiasmal disproportion, monocular VEPs must be recorded employing a trans-occipital electrode array (clinically three to five electrodes are suggested) [11].…”

Section: Introductionmentioning

confidence: 99%

“…Monocular hemifield (HF) prVEP stimulation is a sensitive way to identify hemisphere and chiasmal dysfunction in patients with steady central fixation [24,25]. HF prVEPs are also invaluable for determining whether a full field VEP trans-occipital asymmetry is pathological or artifactual due to dipole orientation [10].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Occipital Petalia and Albinism: A Study of Interhemispheric VEP Asymmetries in Albinism with No Nystagmus

Liasis

Handley

Nischal

2019

JCM

View full text Add to dashboard Cite

The purpose of this study was to assess chiasmal misrouting in a cohort of children with albinism with no nystagmus using hemifield visual evoked potentials (VEP) measures. Methods: Monocular VEPs were recorded and analyzed from three electrodes (O1, Oz, and O2 referred to Fz) from 16 children with albinism without nystagmus. Pattern reversal (full field and hemifield stimulation), full field pattern appearance and flash stimuli were used to evoke VEPs for each eye. Results: The amplitude of the pattern reversal VEPs to stimulation of the hemifield corresponding to the crossing pathways were as expected significantly larger than those to the non-crossing in each eye ((right eye p = 0.000004), (left eye p = 0.001)). Pattern reversal VEPs recorded from the left hemisphere were also larger than those from the right and most evident when comparing the crossing pathways of each eye (p = 0.004). Conclusions: This study has demonstrated electrophysiological differences in visual pathway function of the left and right hemisphere in subjects with albinism like that previously described in controls. Nasal field stimulation activated crossing and non-crossing pathways in patients with albinism and as a result, nasal hemifield VEPs in albinism are less lateralized compared to what is found in normal subjects.

show abstract

When do asymmetrical full-field pattern reversal visual evoked potentials indicate visual pathway dysfunction in children?

Cited by 14 publications

References 24 publications

Case report: Unilateral optic nerve aplasia and developmental hemi-chiasmal dysplasia with VEP misrouting

Case report: Unilateral optic nerve aplasia and developmental hemi-chiasmal dysplasia with VEP misrouting

VEP characteristics in children with achiasmia, in comparison to albino and healthy children

Occipital Petalia and Albinism: A Study of Interhemispheric VEP Asymmetries in Albinism with No Nystagmus

Contact Info

Product

Resources

About