Motion matters: visual perception and motor functioning in children and youths with spastic cerebral palsy

Background Vision plays a crucial role in guiding and anticipating movements. In individuals with cerebral palsy (CP), a condition characterized by disorders of movement and posture attributed to disturbances of the developing brain, Cerebral Visual Impairments (CVI) are common. CVI involves difficulties with organizing and interpreting visual information. Gait alterations and activity limitations in children with CP such as reduced; walking speed, step length, and motor skill performance, may be over-attributed to the motor and musculoskeletal disorders. Knowledge of how visual perception influence motor functioning in individuals with CP is sparse. The aim of this study was to investigate global motion perception, the ability to interpret the coherent direction of visual motion, and reported features of CVI in children and youths (C&Y) with spastic CP at different levels of motor functioning. Methods C&Y aged 8–20 (mean age 14:4) years, CP; 37 (gross motor functioning classification system, GMFCS, I; 28, II-III; 9) and typically developing (TD); 36, performed a computer-based Visual Motion Coherence Test (VMCT) evaluating global motion perception at three velocities (score: 0.0–1.0, low scores indicate difficulties). Corrected visual acuity was normal/near normal in all C&Y. The Raven's CPM was used to evaluate fluid intelligence. Parents of C&Y with CP; 67 (GMFCS I; 37, II-IV; 30) and TD; 40, completed a questionnaire capturing features of CVI (CVIQ) (score: 0–156, high scores indicate CVI). Results Global mean (SE) VMCT score, controlled for age and fluid intelligence, was lower in the CP-group than the TD-group; 0.64 (0.03) vs. 0.70 (0.01), ( p = 0.04), and lower at high and low velocities vs. medium, most pronounced at GMFCS II-III. The median CVIQ score was higher in the CP-group than the TD-group; 28.0 vs. 4.5 ( p < 0.001), and in the GMFCS II-IV-group ( n = 30) compared to the GMFCS I-group ( n = 37); 45.5 vs. 24.0 ( p = 0.003). Conclusions A velocity-dependent vulnerability in global motion perception and many reported features of CVI were found in the C&Y with spastic CP, more so in the group with greater limitations in motor functioning. Visual perception should be considered when evaluating functioning and supporting perceptual and motor development in children with spastic CP.