Impairments More Severe in Infants With CP Linked to Congenital Zika Syndrome, Study Finds

Motor, cognitive, and speech impairments are more severe in infants with cerebral palsy associated with congenital Zika syndrome (CZS), a study has found.

The study, “Cerebral Palsy in Children With Congenital Zika Syndrome: A 2-Year Neurodevelopmental Follow-up,” was published in the Journal of Child Neurology.

Cerebral palsy (CP) comprises a group of neurological disorders that affects posture and restricts movement. These disorders are caused by brain lesions that occur during fetal development or infancy.

According to previous studies, CP may be considered part of the CZS disease spectrum. CZS includes a series of birth defects — such as microcephaly (abnormally small head circumference), brain damage, hearing and vision loss, muscle stiffness, and motor impairments — which are caused by infection with the Zika virus during pregnancy.

Brazil was the most affected country by a Zika virus outbreak in 2015. By that time, investigators from the SARAH Network of Rehabilitation Hospitals and the Federal University of Bahia launched a rehabilitation program that enrolled more than 500 infants with microcephaly possibly associated with CZS.

“We have published the results of the 1-year follow-up of a sample of these children, but we did not expand a more detailed prognostic analysis then, considering the early age of the children. The additional follow-up of these children is relevant because it will allow a better understanding of the long-term prognosis,” the researchers wrote.

In this study, the team described how the disease evolved in a sub-group of these infants over a period of two years.

The study included data from 69 infants with CP associated with CZS who had been followed at a neurorehabilitation hospital in northeastern Brazil. All children completed a series of neurological and neurodevelopmental examinations when they reached the age of one and two years.

The Bayley III Scales of Infant and Toddler Development, the Hammersmith Infant Neurological Examination, and the Gross Motor Function Classification System (GMFCS) were used to evaluate neurological and motor development in these children.

From the 69 children analyzed, three (4.3%) had a normal head circumference. All children had spastic CP, and the majority (94.2%) had bilateral CP.

After two years of age, most infants (92.8%) showed severe motor impairments (GMFCS grade IV or V), epilepsy (73.1%), and poor performances on cognitive (94.2%), language (95.7%), and motor (95.7%) Bayley III test scores, which were consistent with those seen during their first year of life.

The median Hammersmith global score found in these children was 21.0, which was indicative of neurological impairments associated with CP.

Correlation analyses revealed that head circumference at birth was associated with cognitive, language, motor, and neurological impairments seen later in life.

Statistical analyses also found a correlation between low Hammersmith test scores — indicative of neurological impairments — and microcephaly, arthrogryposis (joint contracture), and epilepsy during the first year of life. This suggests that all of these features can be used as prognostic markers to predict the course of CP in children living with the disease.

“The present study demonstrated that on a 2-year follow-up, cerebral palsy related to congenital Zika evolve with a severe motor, cognitive, and language impairment, which corroborates the 1-year follow-up findings,” the researchers wrote.

“These findings are important for the neurorehabilitation program planning, parents’ guiding, and future prognostic studies,” they said.