Neuropsychological outcome and the relation to neuroimaging findings are studied in a cohort of 9 children between 2.5 and 13 years of age with neonatal herpes encephalitis, examined at Karolinska University Hospital, Sweden. Diagnosis, established by CSF PCR analysis, was triggered by seizures that occurred in 7 patients. All exhibited EEG abnormalities; and all received acyclovir. CSF showed a high protein content, and CT performed in 7 infants and MRI in 1 revealed bilateral lesions, chiefly frontal and parietal. The extent of cerebral damage was not correlated with neurodevelopmental outcome. Eight children had cerebral palsy; 5 were mentally retarded, severe in 3; 7 exhibited deficits in attention; 8 had expressive language problems; and 3 attended special education classes. Relapse with reactivation of vesicles and leading to behavioral deterioration occurred in 1 child. 
COMMENT. Seizures with abnormalities in the EEG should alert to a possible diagnosis of neonatal herpes virus encephalitis. Neuropsychological investigation is recommended early as a measure of outcome and the detection of relapse.