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.

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.

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.

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.