Titre du document / Document title

Visual-evoked potential evidence of chiasmal hypoplasia

Auteur(s) / Author(s)

THOMPSON D. A. ⁽¹⁾ ; KRISS A. ⁽¹⁾ ; CHONG K. ⁽²⁾ ; HARRIS C. ⁽¹⁾ ; RUSSELL-EGGITT I. ⁽¹⁾ ; SHAWKAT F. ⁽¹⁾ ; NEVILLE B. G. R. ⁽³⁾ ; ACLIMANDOS W. ⁽⁴⁾ ; TAYLOR D. S. I. ⁽¹⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Ophthalmology Department, Great Ormond Street Hospital NHS Trust, Great Ormond Street, London, ROYAUME-UNI
⁽²⁾ Radiology Department, Great Ormond Street Hospital NHS Trust, Great Ormond Street, London, ROYAUME-UNI
⁽³⁾ Neurology Department, Great Ormond Street Hospital NHS Trust, Great Ormond Street, London, ROYAUME-UNI
⁽⁴⁾ Department of Ophthalmology, Kings College Hospital, Denmark Hill, Hill, London, ROYAUME-UNI

Résumé / Abstract

Purpose: To show that chiasmal hypoplasia or aplasia need not be an isolated developmental anomaly and to examine the spectrum of associated clinical findings to explore the possibility that these patients may represent a phenotypic manifestation of a developmental gene anomaly. Design: An observational case series. Participants: Five infants, between several weeks and 7 months of age, in whom the electrophysiologic characteristic of chiasmal hypoplasia had been noted were included. Methods: Flash electroretinography and flash and pattern visual-evoked potentials (VEPs) were elicited from all patients. Clinical ophthalmologic examinations, including funduscopy, were performed, and all patients had magnetic resonance imaging (MRI) brain scans. Main Outcome Measures: The occipital distribution of monocular VEP response peaks was studied. The symmetry of lateral channel responses was compared for monocular stimulation. Results: All five patients had a crossed asymmetry in the monocular VEP occipital distribution, which is consistent with a paucity of fibers crossing at the chiasm. The MRI findings supported this electrophysiologic observation, illustrating degrees of chiasmal hypoplasia and variable coincidence of other midline abnormalities of the brain. Optic disc appearances varied from normal to hypoplastic and colobomatous. Conclusions: The ophthalmologic and MRI findings of five patients who showed a crossed asymmetry in monocular flash VEPs are consistent with a paucity of axons crossing at the chiasm. The similarities between achiasmia in humans and mice due to a Pax2 gene anomaly are discussed.

Revue / Journal Title

Ophthalmology   ISSN 0161-6420   CODEN OPHTDG 

Source / Source

1999, vol. 106, n^o12, pp. 2354-2361 (37 ref.)

Langue / Language

Anglais

Editeur / Publisher

Elsevier, New York, NY, ETATS-UNIS  (1976) (Revue)

Mots-clés anglais / English Keywords

Hypoplasia ; Optic chiasma ; Visual evoked potential ; Diagnosis ; Technique ; Human ; Case study ; Nervous system diseases ; Eye disease ; Malformation ; Congenital disease ; Electrodiagnosis ;

Mots-clés français / French Keywords

Hypoplasie ; Chiasma optique ; Potentiel évoqué visuel ; Diagnostic ; Technique ; Homme ; Etude cas ; Système nerveux pathologie ; Oeil pathologie ; Malformation ; Maladie congénitale ; Electrodiagnostic ;

Mots-clés espagnols / Spanish Keywords

Hipoplasia ; Quiasma óptico ; Potencial evocado visual ; Diagnóstico ; Técnica ; Hombre ; Estudio caso ; Sistema nervioso patología ; Ojo patología ; Malformación ; Enfermedad congénita ; Electrodiagnóstico ;

Localisation / Location

INIST-CNRS, Cote INIST : 18914, 35400008082316.0260