Medical Journal of Babylon (Jan 2022)
Visual evoked potential findings and correlation between visual evoked potential and clinical severity in children with autism spectrum disorder
Abstract
Background: Autism spectrum disorder (ASD) is a heterogeneous behavioral disorder that is characterized by qualitative deficits in social communication and interaction and restricted, repetitive behavioral patterns, activities, and interests. For an optimum outcome in children with autism, early intervention (preferably before three years of age) is essential. Hence, there is a critical need to improve the awareness of ASD to enable earlier detection and intervention. The present study aims at achieving the following: (1) Investigating neural transmission within the visual system using visual evoked potentials (VEPs) as an index of the myelination process of the visual pathway. (2) Correlating the changes in the VEPs with the clinical severity of autism. (3) Investigating the possible gender differences in VEPs in autistic children. Materials and Methods: The study was conducted on 60 preschool children (11 females and 49 males) who were recruited from the autism center and the pediatric neurology ward and who met the DSM-V criteria for autism in the Pediatric Hospital for the period from 12 December 2019 to 1 June 2021. Their mean age was 4.5±1.17 years. Another 50 (40 males and 10 females) age- and gender-matched normally developed children served as the control group. Both groups were subjected to a detailed history, as well as complete physical and neurological examinations. The VEPs were assessed for all of them. The autistic children were excluded from the study if they had any motor, visual impairment, inborn errors of metabolism, epilepsy, other chronic medical or neurological disorders, or if they were taking medications during the period of study. Results: The P100 wave latency of the VEPs was significantly prolonged in both eyes of autistic children as compared with that of the control group. The N75-P100 amplitude was significantly lower in the left but not the right eye of patients when compared with those of normally developed children. Neither the P100 wave latency nor the N75-P100 amplitude of both eyes was associated with the gender or severity of illness. Conclusion: There are distinct changes in VEPs in autistic children, especially the abnormal prolongation of conduction time, suggesting that autistic children may have brainstem and visual pathway dysfunction. Gender and disease severity score have no impact on VEPs.
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