Limbic encephalitis in a child: an atypical presentation

Background: Limbic encephalitis is a rare disorder with a generally subacute onset evolving over days to weeks. Patients present with a variable combination of memory loss, seizures, and psychiatric disturbance, and it is not rare for patients to be initially misdiagnosed.

Patient: We describe a previously healthy 12-year-old boy who developed his first seizures at 8 years of age. He had a total of eight prolonged focal seizures, each followed by a month of behavioral changes and short-term memory loss. There was no family history of seizures or other neurological disorders, and he had an otherwise unremarkable neonatal and medical history.

Results: Magnetic resonance imaging during each episode of seizures showed alternating unilateral brain hemispheric involvement consistent with limbic encephalitis that was followed by resolution for a total of six times. Despite a negative laboratory evaluation for a large panel of paraneoplastic antibodies, the clinical scenario and exclusion of other possible disorders made recurrent limbic encephalitis the most likely diagnosis.

Conclusion: Limbic encephalitis is a rare disorder that is diagnosed primarily on the basis of clinical criteria and is often associated with the presence of a paraneoplastic antibody. However, lack of a positive paraneoplastic antibody in a patient with a triad of seizure, behavioral changes, and short-term memory loss does not exclude the diagnosis. The unique presentation in a seronegative patient may indicate an unrecognized antibody.