Temporal
encephaloceles (
TEs) are one of the cause of refractory
temporal lobe epilepsy (TLE). We reviewed the neuroimaging and video-electroencephalography (EEG) records of
epilepsy patients who underwent temporal lobectomy in our center to investigate frequency of
TEs. We retrospectively reevaluated 294 patients who underwent
epilepsy surgery in our tertiary
epilepsy centre between January 2010 and March 2019 and included 159 patients (78 females, 49 %; 81 males) who had temporal lobectomy. Preoperatively,
TEs were reported in 3 of 159 patients (1 female, 2 males). After reevaluation 4 more patients with
TEs (1 female, 3 males) were added. The ratio of TE in patients who underwent temporal lobectomy increased from 1.8 % (n=3) to 4,4 % (n=7). The median ages were 18 (range 16-22) versus 10 years (range 5-17) at habitual seizure onset and the median of
epilepsy duration was 5 (range 3-15) versus 175 (range 11-25) years between patients with and without TE. Habitual seizure onset age was significantly higher (p =, 007) in the patients with
encephalocele and
epilepsy duration was shorter (p =, 003) than patients without
encephalocele. The ictal EEG records of all patients TE rhythmic delta activity which is suggested neocortical temporal lobe onset
seizures. 4 of 7 patients' PET imaging showed temporal lobe hypometabolism compatible with ipsilateral to the
TEs. The three patients underwent
anterior temporal lobectomy without amygdalohippocampectomy and others had
anterior temporal lobectomy with amygdalohippocampectomy. We suggested that there might be some clues for temporal
encephalocele, an easily overlooked cause in patients with nonlesional
temporal lobe epilepsy.TLE patients with TE had relatively late onset of
epilepsy and rhythmic delta activity on ictal EEG. Also, temporal hypometabolism on PET may be a useful key to suspicion of TE.