Global Motion Perception and Reported Features of Cerebral Visual Impairments in Children and Youths with Spastic Cerebral Palsy

This observational study aimed to investigate global motion perception and reported features of CVI in C&Y with spastic CP at different levels of motor functioning.

A structured history-taking questionnaire capturing features of CVI (CVIQ) was completed by parents of children with CP (n=67) and typically developing (TD) (n=40). High scores on the questionnaire indicate CVI (max score 156).  A computer-based visual motion coherence test (VMCT) was used to evaluate global motion perception at three velocities in C&Y with CP (n=37) and TD (n=36), aged 8-20. The maximum VMCT score 1.0 indicates excellent global motion perception. Raven’s coloured progressive matrices to evaluate general cognition and tests of visual acuity were also performed. The gross motor functioning classification system (GMFCS) ranging from level I, walking without limitations to level V, being transported in a wheelchair was used to describe motor functioning in the C&Y with CP.

Children with CP had more reported CVI features than the TD group; 58% had CVIQ scores above the TD group's 90th percentile (23.90). The children at GMFCS II-IV (n=30) had more reported CVI features than those at GMFCS I (n=37); CVIQ median [min, max] score: 45.5 [12, 132] vs. 24.0 [0, 102] (U=793.50,p=0.003). On the VMCT, the CP-group showed less accuracy in global motion perception than the TD-group as calculated with a generalized estimation equation, controlling for general cognition and age; mean (SE) score: 0.64 (0.1) vs 0.70 (0.2), (Wald=4.06, p=0.04). The C&Y at GMFCS II-III (n=9) showed a greater vulnerability in global motion perception than those at GMFCS I (n=28), more pronounced at high and low velocities. Corrected binocular visual acuity was normal/near normal (0.5 logMAR) in all C&Y performing the VMCT. CVIQ scores correlated negatively with VMCT global mean scores; Rho_s= -0.41; p=0.001 in the total group of C&Y, indicating congruent results.

C&Y with CP had more reported features of CVI and less accurate global motion perception than TD peers, especially those with more limited motor functioning. A velocity-dependent vulnerability in global motion perception was observed in C&Y with CP. A screening version of the CVIQ tailored for individuals with CP would be beneficial. 

Visual ability, including global motion perception, should be considered to understand motor functioning. Parents’ reports on vision-related everyday activities of their child with CP are valuable.