Association between Sleep and Language Development in Children with Congenital Zika Syndrome

AIM: Congenital Zika Virus Syndrome (CZS) presents notable hurdles to neurodevelopment, with language development emerging as a crucial aspect. This study investigates sleep patterns and language skills in children with CZS, aiming to explore the potential synchronization of sleep development with their neurodevelopment. METHOD: We studied cross-sectionally 135 children with CZS aged 0 to 48 months, investigating sleep using the BISQ Questionnaire. Language development was assessed using the Early Language Milestone Scale, while motor development and cognitive and social ability were assessed using the Bayley Scales of Infant and Young Child Development 3rd edition. We also studied longitudinally a cohort of 16 children (initially aged 0 to 12 months) whom we followed for four years, assessing at one-year intervals. RESULTS: Sleep disturbances and language deficits were highly frequent in this population. In the 0–12 months group, a late bedtime and frequent nighttime awakenings were associated with poorer auditory expressive skills. At 13–24 months, nighttime awakenings were associated with poorer auditory expressive skills, while among 25–36-month-olds decreased auditory receptive skills were associated with longer sleep onset latency and reduced nighttime sleep duration. CONCLUSION: The brain alterations caused by Zika virus infection affect both sleep disturbances and delays in language development. It is possible that sleep disturbance may be a mediating factor in the pathway between CZS and delayed language development, as the three analyzed language skills showed a correlation with sleep parameters.