Exploratory Investigation of Brain MRI Lesions According to Whole Sample and Visual Function Subtyping in Children With Cerebral Visual Impairment

Abstract

Background: There is limited research on brain lesions in children with cerebral visual impairment (CVI) of heterogeneous etiologies and according to associated subtyping and vision dysfunctions. This study was part of a larger project establishing data-driven subtypes of childhood CVI according to visual dysfunctions. Currently there is no consensus in relation to assessment, diagnosis and classification of CVI and more information about brain lesions may be of potential diagnostic value.Aim: This study aimed to investigate overall patterns of brain lesions and associations with level of visual dysfunction and to compare the patterns between the classification subgroups in children with CVI.Methods: School-aged children with CVI received ophthalmological and neuro-psychological/developmental assessments to establish CVI-related subtyping. Other pediatric information was collected from medical records. MRI scans were coded according to a semi-quantitative template including brain regions (right hemisphere, left hemisphere, visual pathways) and summed for total scores. Non-parametric analyses were conducted.Results: 28 children had clinical brain MRI scans available [44% of total sample, Group A (lower severity of visual dysfunctions) n = 16, Group B (higher severity) n = 12]. Total brain scores ranged between 0 and 18 (Group A mdn = 7, IQR = 0.8–10.0, Group B mdn = 10, IQR = 6.5–11.8) and were widespread across regions. 71 per cent had post-geniculate visual pathway damage. The median total brain and hemisphere scores of Group B were higher than subgroup A but differences did not reach statistical significance. No statistically significant associations were found between brain scores and vision variables (acuity, contrast sensitivity).Conclusion: This study found a spread of lesions across all regions on the brain scans in children with congenital CVI. The majority had damage in the postgeniculate visual pathways and visual cortex region suggesting this is an area of interest and potentially informative for diagnosis. However the subtyping classification did not show differences in number or region of lesions though the trend was higher toward Group B. This study confirms the complex diffuse and variable nature of brain lesions in children with congenital CVI, many of whom have other neurological impairments.

Childhood cerebral visual impairment subtype classification based on an extensive versus a limited test battery

“…In this subtype we see reduced lower order visual defects with minimal or no VPDs probably as a result of retrograde degeneration of ganglion cells. In a follow up study Sakki et al (2022) compared their severity-based classification with MRI brain lesions and found no associations between visual function score and MRI lesions. However, another study showed a correlation between visual function score (without visual perception) and subcortical structures, corpus callosum, and cerebellum (Tinelli et al, 2020).…”

Reliability and validity of the Japanese version of the Visual Function Classification System for children with cerebral palsy

“…Spearman's correlation coefficient (ρ) was used to indicate the relationship between the VFCS and the GMFCS, MACS, CFCS and EDACS. As CVI is affected by damage in the post‐geniculate visual pathways and visual cortex region (Sakki et al, 2021), the brain injury sites that affect VFCS and ‘GMFCS, MACS and EDACS’ are expected to differ. Therefore, we did not expect any strong correlation between VFCS and GMFCS, MACS, or EDACS.…”

“…About 60%-70% of children with CP are reported to have CVI (Schenk-Rootlieb et al, 1994;Uggetti et al, 1996), although a recent systematic review reported the presence of some ambiguities in the definition of CVI (Philip et al, 2020). In a recent review and study (Sakki et al, 2018(Sakki et al, , 2021, attempts have been made to define CVI subtype classifications.…”