Design and methods. The cross-sectional quantitiative study was undertaken in Kaunas County, Lithuania. The criteria for inclusion were the following: children born within the period of 1987−1998; children living in Kaunas County at the time of the study; and diagnosis of cerebral palsy mentioned in medical records at least once. An additional inclusion criterion for children living in orphanages was parents’ (or mother’s) living address in Kaunas County or unknown at the moment of the study. Refugees temporarily living in a refugees’ camp in Kaunas County were not included into the list. Additionally, all cases were included when any information about a neuroinfection at an early age, severe encephalopathy, severe unspecified developmental disorder or any other disorder that could have clinical signs similar to cerebral palsy was found in medical records (“suspected cases”). The study was performed in two stages. In the first stage, a list containing the study population was made. In the second stage, a child neurologist, using Survey Cerebral Palsy Europe Reference and Training Manual, examined every child and confirmed or refuted the diagnosis of cerebral palsy.

Results. There were 728 potential cerebral palsy cases. In 270 cases, diagnoses of cerebral palsy were confirmed. In 1987−1998, the population-based prevalence of cerebral palsy was 2−3.4 (mean 2.5, SD=0.398) per 1,000 children, and the birth rate-based prevalence was 1.9−3.3 (mean 2.3, SD=0.398) per 1,000 live births. In each study year, the population-based prevalence was higher than the birth rate-based prevalence. The difference was significant, Z=–2.842, P=0.004. There were no significant trends in the population-based prevalence of cerebral palsy (95% CI, 0.693−2.079), nor in the birth rate-based prevalence (95% CI, 0.693−2.079) over the study years.

Conclusion. The population-based prevalence of cerebral palsy over the period of 1987−1998 was 2−3.4 (mean 2.5, SD=0.398) per 1,000 children, and the birth rate-based prevalence was 1.9−3.3 (mean 2.3, SD=0.398) per 1,000 live births. Due to the low number of cerebral palsy cases in separate areas of Kaunas County or separately in each study year, the study data do not give a reliable view of trends of the prevalence of cerebral palsy. Further studies are needed to estimate trends in changes of the prevalence of cerebral palsy in Lithuania.