Temporal encephaloceles in epilepsy patients and asymptomatic cases: Size may indicate epileptogenicity.

OBJECTIVE: This study was undertaken to identify temporal encephaloceles (TEs) and examine their characteristics in patients with temporal lobe epilepsy (TLE) and extratemporal lobe epilepsy (ETLE), as well as in asymptomatic cases. METHODS: Four hundred fifty-eight magnetic resonance imaging scans were examined retrospectively to identify TE in 157 patients with TLE, 150 patients with ETLE, and 151 healthy controls (HCs). RESULTS: At least one TE was identified in 9.6% of the TLE patients (n = 15, 95% confidence interval [CI] = 5.3%-15.3%), in 3.3% of patients with ETLE (n = 5, 95% CI = 1.1%-7.6%), and in 2.0% of the HCs (n = 3, 95% CI = .4%-5.7%), indicating a significantly higher frequency in patients with TLE compared to ETLE and HC subjects (p = .027, p = .005). Examining the characteristics of TEs in both asymptomatic and epilepsy patients, we found that TEs with a diameter of less than 6.25 mm were more likely to be asymptomatic, with a sensitivity of 91.7% and a specificity of 73.3% (area under the curve = .867, 95% CI = .723-1.00, p = .001). SIGNIFICANCE: Temporal encephaloceles may occur without presenting any clinical symptoms. Patients with TLE show a higher frequency of TEs compared to the ETLE and HC groups. According to our study, TE size could be used to suggest potential epileptogenicity.

Increased body mass index (BMI) associated with late epilepsy onset in patients with temporal encephaloceles: a systematic review and analysis of individual patient data.

OBJECTIVE: This study investigates the association of Body Mass Index (BMI) and age of epilepsy onset, in patients with epilepsy associated with temporal encephaloceles (TEs). METHODS: A comprehensive PubMed literature review was conducted using the keywords "temporal encephaloceles" and "epilepsy" for identifying articles for the analysis. Inclusion criteria encompassed all evidence levels reporting patients with TE-related epilepsy and documented BMI. Logistic regression analyses were performed to examine the effect of BMI on predicting epilepsy onset after the 25th year of age. Spearman's correlation assessed the relationship between BMI with epilepsy onset. Finally, the association between BMI and postsurgical outcomes, distinguishing between more favourable outcomes (Engel Class I and II) and less favourable outcomes (Engell Class III and IV) was explored. RESULTS: Of the initially identified 88 articles, nine were included in the analysis, involving 127 patients with TE-related epilepsy and reported BMI. The mean age of epilepsy onset was 24.9 years (SD = 14.8 years), with a mean BMI of 28.0 kg/m2 (SD = 7.4 kg/m2). A significant positive correlation was observed between BMI and age of epilepsy onset (rho = 0.448, p < 0.001). Female patients had higher BMI compared to male patients (30.1 kg/m2, SD = 8.7 kg/m2 and 26.5 kg/m2, SD = 5.3 kg/m2 respectively, p = 0.008). However, the epilepsy onset did not differ significantly between male and female patients (p = 0.26). The bivariate logistic regression showed that patients with increased BMI were more likely to have an epilepsy onset after the 25th year of age, adjusted for the confounder sex (OR = 1.133, 95%-CI [1.060, 1.211], p < 0.001). Finally, a potential trend indicated a higher average BMI among patients with more favourable postsurgical outcomes than less favourable postsurgical outcomes (27.3 kg/m2, SD = 7.7 kg/m2 and 24.8 kg/m2, SD = 2.2 kg/m2 respectively, p = 0.076).

Temporal encephaloceles and coexisting epileptogenic lesions.

OBJECTIVE: This study was performed to identify coexisting structural lesions in patients with epilepsy and known temporal encephaloceles (TEs). METHODS: Forty-seven structural magnetic resonance imaging (MRI) scans of patients with epilepsy and radiologically diagnosed TEs were retrospectively reviewed visually and using an automated postprocessing software, the Morphometric Analysis Program v2018 (MAP18), to depict additional subtle, potentially epileptogenic lesions in the 3D T1-weighted MRI data. All imaging findings were evaluated in the context of clinical and electroencephalographical findings. RESULTS: The study population consisted of 47 epilepsy patients (38.3% female, n = 18). The median age at the time of the scan was 40 years (range 12-81 years). Twenty-one out of 47 MRI scans (44.7%) showed coexisting lesions in the initial MRI evaluation; in 38.3% (n = 18) of patients, those lesions were considered probably epileptogenic. After postprocessing, probable epileptogenic lesions were identified in 53.2% (n = 25) of patients. Malformations of cortical development had initially been reported in 17.0% (n = 8) of patients with TEs, which increased to 38.3% (n = 18) after postprocessing. TEs and other epileptogenic lesions were considered equally epileptogenic in 21.3% (n = 10) of the cases in the initial MR reports and 25.5% (n = 12) of the cases after postprocessing. SIGNIFICANCE: Temporal encephaloceles are a potential cause of MRI-negative temporal lobe epilepsy. According to our data, TEs can occur with other lesions, suggesting that increased awareness is also required in patients with lesional epilepsy. TEs may not always be epileptogenic; hence, their occurrence with other structural pathologies may influence the presurgical evaluation and surgical approach. Finally, TEs can be associated with malformations of cortical development, which may indicate a common developmental etiology of those lesions.