Surgical outcome of patients with mesial temporal lobe epilepsy related to hippocampal sclerosis

Abstract

SUMMARYSeizure outcome in mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) that was evaluated according to a noninvasive protocol was assessed in 165 patients and reported using both Engel's and ILAE classifications. The mean postoperative follow-up was 5.0 ± 2.7 years. At the end of first year, 77.1% of patients were in Engel-I, and 52.7% were in ILAE-I. Antiepileptic drugs (AEDs) were discontinued in 41 patients (42.7%), all remained seizure-free for >2 years that could be accepted as "cure." Thirty-six patients had recurrences, 19 had running-down phenomena. Anterior temporal lobectomy (ATL) was performed in 27 patients with a better outcome when compared to patients operated by selective anterior hippocampectomy. Clinical risk factors for better and worse outcome, which show some similarity in different reports, seem to veil the main reason, which is the accurate delineation of epileptogenic zone considering the presence of different subgroups and underlying developmental pathologies. KEY WORDS: Hippocampal sclerosis, Temporal lobe epilepsy, Surgery.Mesial temporal lobe epilepsy (MTLE) is a form of focal seizure disorder that is refractory to antiepileptic drug (AED) therapy and known to be remediable by surgery, and hippocampal sclerosis (HS) is the most frequent substrate obtained from the surgical specimens in these patients. About 55-70% of patients undergoing temporal resection become completely seizure-free (Engel et al., 1993), where 20-30% of patients still experience seizures following surgery (Wyler et al., 1995;. Moreover, it is difficult to obtain the information solely on patients with MTLE-HS in the literature due to the format of published reports usually providing data on various etiologies, missing number of patients cured or with either recurrence or running-down phenomena.In this study, we present a large surgical cohort data, examining the year-by-year seizure outcome, during a longterm postsurgical follow-up in patients with MTLE-HS evaluated nonivasively according to a standard protocol METHODSOut of 183 patients with MTLE-HS who underwent surgery since 1995, 165 patients who were followed for at least 1 year were included. Patients with normal MRI or with structural lesions other than HS were excluded. Two patients were reoperated due to insufficient seizure control and excluded at the time of second surgery. All patients were evaluated according to a noninvasive protocol including clinical assessment, ictal video-EEG, MRI, neuropsychological, and psychiatric investigations. The intracarotid amobarbital procedure was performed in 65 patients with bilateral memory deficits, left-sided focus, or discordant findings. Patients were followed for 6 months after surgery and then yearly when possible. Seizure outcome was classified according to the Engel's (Engel et al., 1993) and ILAE classifications (Wieser et al., 2001). AEDs were discontinued in patients who remained seizure-free for at least 2 years. 696

Complications of epilepsy surgery in Sweden 1996–2010: a prospective, population-based study

“…38 In retrospective studies and in those in which the method for data collection is not stated, complication rates are presented in the range of 0%-7.5% major and 5.6%-15.2% minor complications for any procedure, 8,9,23,28,31,36 and for TLRs there were 0%-7% major complications and 0%-21.8% minor complications. 5,6,18,19,23,26,29,30,34,36,37 In pediatric cohorts, 0%-14.6% major and 5.2%-19% minor complications are presented for various kinds of procedures. 3,4,7,20,33 In a systematic review of 76 studies in which different methodologies were used, Hader et † This includes 1 patient with thalamic infarction due to perforating artery injury, 1 patient with air embolism, and 1 patient with permanent postoperative anosmia.…”

Clinical Spectrum, Seizure Outcomes, Correlation of Neuroradiology and Neuropathology, in Surgically Treated Epileptic Patients

“…Ayrıca tüm hastalar ele alındığında cerrahi sonrası ikinci yıl nöbet sonuçları, hastaların %80. [19] 2008 yılında yaptığı çalışmada 165 MTS nedeniyle ameliyat olmuş hastayı bir yıl takip etmişler ve %77'sinin nö-bet sonucunun Engel sınıf 1 olduğunu bildirmişlerdir. Engel ve ark.…”

“…1993 yılında yaptığı çalışmada, temporal rezeksiyon uygulanmış hastalarda nöbetsizlik oranlarını %55-70 arasın-da saptamışlardır. [19] Çalışmamızda PET, MRG, VEM incelemelerinin her üçünün uygulandığı 29 hasta mevcuttur. Bu hastalara uygulanan her üç incelemenin epileptojenik odağı lokalize ettiği hastalarda, cerrahi sonrası 24. ay nöbet durumu Engel sınıf 1 olan kişi oranı %85.7, bu testlerden ikisinin epileptojenik odağı lokalize edebildiği durumlarda cerrahi sonrası 24. ay nöbet durumu Engel sınıf 1 olan kişi oranı %72.7, incelemeden yalnız bir tanesinin lezyonu gösterebildiği durumlarda ise cerrahi sonrası 24. ay nöbet durumu Engel sınıf 1 olan kişi oranı %50'dir.…”

Surgery for intractable temporal lobe epilepsy: experience of a single institution

“…We prefer to use "corticoamygdalohippocampectomy", which describes the technique more accurately. However, studies comparing SAH and CAH by Ozkara et al (12,(14)(15)(16). There is also still no consensus on the extent of resection.…”