Visual evoked potentials with crossed asymmetry in incomplete congenital stationary night blindness

• Published in: Investigative ophthalmology & visual science Vol. 37; no. 9; pp. 1783 - 1792
• Main Authors: Tremblay, F, De Becker, I, Cheung, C, LaRoche, GR
• Format: Journal Article
• Language: English
• Published: Rockville, MD ARVO 01.08.1996; Association for Research in Vision and Ophtalmology
• Subjects: Adolescent; Adult; Albinism, Ocular - physiopathology; Biological and medical sciences; Child; Child, Preschool; Electroretinography; Evoked Potentials, Visual; Female; Humans; Infant; Male; Medical sciences; Night Blindness - physiopathology; Normal Distribution; Ophthalmology; Oscillometry; Reference Values; Vision disorders; Visual Acuity; Human; Skin disease; Pigmentation disorder; Congenital; Vision disorder; Oculocutaneous albinism; Visual evoked potential; Metabolic diseases; Night blindness; Uvea disease; Congenital disease; Melatonine; Genetic disease; Electrodiagnosis; Eye disease; Asymmetry; Comparative study; Aminoacid disorder
• ISSN: 0146-0404; 1552-5783

To investigate a proposed postretinal defect in patients with the incomplete form of congenital stationary night blindness (CSNB2) and to compare visual evoked potential (VEP) results with those found in various forms of albinism. Visual evoked potentials were performed in 10 patients with a diagnosis of CSNB2, 10 subjects with albinism, and 17 normal subjects. Visual evoked potentials were elicited monocularly with diffuse flash stimulation. Scalp electrodes were placed over each hemisphere and referred to the forehead. Interhemispheric bipolar recordings were derived, and the correlation coefficient (CC) was calculated for various segments of the interhemispheric responses. A crossed visual evoked potential asymmetry pattern could be demonstrated in 9 of 10 patients with CSNB2. All subjects with albinism and none of the normal subjects showed the crossed asymmetry pattern. Statistical comparison of the CC computed for various segments of the interhemispheric response shows that the pattern of inversion in CSNB2 is more prominent in the 25 to 100 msec range (median CC, -0.37) and in the 175 to 250 msec range (CC, -0.27). In subjects with albinism, all segments show a negative CC (range, -0.46 to -0.60). In normal subjects, all segments are positively correlated (range, 0.36 to 0.66). Crossed visual evoked potential asymmetry was found in patients with CSNB2; therefore, excessive decussation, as demonstrated by this testing procedure, should not be considered as pathognomonic for albinism.