Assessment of hippocampal volumes in infants with a history of bacterial meningitis

Purpose: To assess the hippocampal damage that occurs soon after a meningitic episode with a view to obtaining data that might contribute to an understanding of whether such changes were likely to be caused by the meningitis. Materials and Methods: Children under the age of 2 years were enrolled in the study. Hippocampal volumes and T2 relaxation times were measured. The results were compared with those of 12 control subjects undergoing magnetic resonance imaging of the brain for reasons other than epilepsy. Results: Ten of the 26 study infants had hippocampal reduction; six of them had bilateral and four had unilateral hippocampal reduction. Six of the study subjects that had experienced convulsions during the acute stage of meningitis had hippocampal reduction. Conclusion: There is a high prevalence of hippocampal damage in infants with a recent history of bacterial meningitis and this has a strong correlation with convulsions during meningitic episodes. Assessment of hippocampal atrophy in patients with a history of meningitis should warrant a volumetric analysis of the hippocampi with volume correction to identify possible bilateral volume loss.