Bilateral functional hippocampectomy following recurrent bacterial meningitis: a case report

The hippocampal formation is indispensable to convert short-term into long-term memories. It is a brain region particularly vulnerable to a variety of noxious stimuli. Severe hippocampal injury with complete inability to convert short-term into long-term memories is very rare in bacterial meningitis.

At the age of 62 years, a white German female teacher acquired Listeria monocytogenes meningitis after the consumption of goat cheese manufactured from raw milk. Malabsorptive hydrocephalus required placement of a ventriculoperitoneal shunt. The further course became complicated by two shunt infections. Severe bilateral hippocampal atrophy developed. In spite of restoration of CSF drainage via a replacement shunt, the patient lost the capacity to form new memories. Conversely, her personality and the ability to work with previously stored information remained intact for many years.

Protection of the hippocampal formation and preservation of the capacity to form new memories is a major goal in the treatment of bacterial meningitis. Further improvement of outcome in bacterial meningitis will depend on approaches that effectively protect the hippocampal formation.