A Cochrane review [Abstract] 1 included 182 studies with a total of 16 855 participants. Nine studies were RCTs. Most of the remaining 173 non-randomised studies had a retrospective design; they were of variable size, recruited a wide demographic range of participants, used a wide range of surgical techniques and used different outcomes.In terms of freedom from seizures, two RCTs found surgery (n=97) to be superior to medical treatment (n=99), four RCTs found no statistically significant difference between anterior temporal lobectomy (ATL) with or without corpus callosotomy (n=60), between subtemporal or transsylvian approach to selective amygdalohippocampectomy (SAH) (n=47); between ATL, SAH and parahippocampectomy (n=43), or between 2.5 cm or 3.5 cm ATL resection (n=207), and one RCT found total hippocampectomy to be superior to partial hippocampectomy (n=70) and one found ATL to be superior to stereotactic radiosurgery (n=58); and another provided data to show that for Lennox-Gastaut syndrome, no significant differences in seizure outcomes were evident between those treated with resection of the epileptogenic zone and those treated with resection of the epileptogenic zone plus corpus callosotomy (n=43).Of the 16 756 participants included in this review, 10 696 (64%) achieved a good outcome from surgery; this ranged across studies from 13.5% to 92.5%.The following prognostic factors were associated with a better post-surgical seizure outcome: an abnormal pre-operative MRI, no use of intracranial monitoring, complete surgical resection, presence of mesial temporal sclerosis, concordance of pre-operative MRI and electroencephalography (EEG), history of febrile seizures, absence of focal cortical dysplasia/malformation of cortical development, presence of tumour, right-sided resection and presence of unilateral interictal spikes.
Comment: The quality of evidence is downgraded by inconsistency (heterogeneity in patients, interventions and outcomes).
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