Temporal Lobe Encephaloceles: A Potentially Curable Cause of Seizures

Temporal lobe encephaloceles are characterized by protrusion of brain parenchyma through a structural defect in the floor of the middle fossa. They have been reported to cause cerebrospinal fluid (CSF) leaks, conductive hearing loss, meningitis, and seizures. The association between temporal encephaloceles and epileptiform activity is particularly rare.

All patients who presented to a single tertiary referral center between 2011 and 2014 with intractable seizures and radiographic evidence of a middle cranial fossa encephalocele were evaluated. Five patients from this subset who underwent surgical repair of their encephalocele are presented.

Middle cranial fossa approach for encephalocele repair.

Postoperative epileptiform activity.

Five patients underwent a craniotomy for resection of a temporal lobe encephalocele with repair of a middle fossa floor defect. After surgery, CSF rhinorrhea resolved, when present, and all patients remained seizure-free through their last available follow-up. Range of follow-up time was 3.5 months to 4 years. Average follow-up time was 19.7 months.

Temporal lobe encephaloceles are an infrequent cause of seizures. Given that these lesions can be missed with standard imaging modalities, they are likely underdiagnosed upon initial medical evaluation. This diagnosis should be considered in patients with intractable seizures. If an encephalocele is found, focused resection of epileptogenic tissue associated with herniation and repair of the temporal floor defect can provide definitive treatment.