Abstracts

Rationale:
Epilepsy is one in all the foremost common neurological disorders worldwide, affecting around 50 million people (WHO 2019). Thirty percent of these patients have drug-resistant epilepsy (Pérez-Pérez, 2019). Temporal lobe epilepsy (TLE) accounts for the majority of cases that are being referred for epilepsy surgery (Asadi-Pooya, 2017). However, after standard temporal lobectomy, around 40% of those patients will have recurrent seizures (René Andrade-Machado, 2016). The aim of this study is to assess the correlation between ictal semiology and its localization/lateralization value between temporal lobe (mesial / lateral) and temporal plus epilepsy using invasive EEG monitoring. In addition, to evaluate phase I pre-surgical assessment (including interictal/ictal scalp EEG, MRI, PET, neuropsychology) and surgical outcome in this group of patients
Method:
A retrospective cohort study among epilepsy patients who underwent resective surgery for temporal or temporal plus epilepsy from January 2008 till December 2018 at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. A 464 patients’ data was recruited for all surgical cases. One eighty-one patients had invasive electrode monitoring for drug resistant epilepsy; among them, 130 patients were extra-temporal and 51 were temporal/temporal plus epilepsy.  Of the fifty one patients, 48 subjects with initial diagnosis of drug-resistant temporal (TLE) or temporal plus (TPE) epilepsy who had undergone invasive monitoring for mesial, lateral temporal or temporal plus epilepsy cases and ended by resective surgery fulfilled the inclusion criteria
Results:
Forty-eight patients were included in our sample in which 66.7% were male. The mean age was 26.81 (SD 8.4). There was no statistical significant difference between TLE and TPE groups in age, age of epilepsy onset and seizure frequency per month. Temporal plus epilepsy cases were 15 patients. Auras were frequently presented in both groups; emotional aura in the form of fear is the most common presentation (35.4%). Localization value for auras include seeing familiar faces and visual hallucinations were statistically significant with (p-value: 0.03, 0.03) respectively for patients with temporal plus epilepsy. Early onset ictal manual automatism, oral automatism specifically lip smacking as well as late onset dystonic posture and late head turning were statistically significant for temporal lobe epilepsy without significant lateralization value. The progression to bilateral tonic-clonic seizures were statistically significant (p-value 0.04) to the mesial temporal lobe epilepsy. The most frequent inter-ictal patterns were spikes and sharp waves. The ictal onset zone localization was statistically significant between scalp and invasive EEG findings (p-value 0.023) in the mesial temporal lobe epilepsy patients. Surgical outcome in 2 years follow-up using Engle classification showed no statistical significant value (p-value: 0.800) between mesial, lateral temporal and temporal plus groups. The probability of seizure freedom (Engel classification Class I) was 58.3% at 2-years, 31.3% at 5-years and 12.5 % at 10-years follow-up
Conclusion:
Ictal symptomatology is a valuable step in evaluation patients with epilepsy. However, its localization and lateralization significance is variable. The completion of phase I pre-surgical work-up helpful to accurately localize the epileptogenic zone which will be confirmed by invasive EEG monitoring. Considering differentiating mesial from lateral temporal before surgical resection will result in better Engel outcome. However, involvement of temporal plus structures in coverage is required in other cases
Funding:
:No funding