From the Guidelines
Surgery for temporal lobe epilepsy with hippocampal sclerosis is highly successful, with approximately 65% of patients becoming seizure-free after the procedure. This is based on recent evidence from 1, which highlights the effectiveness of epilepsy surgery in patients with drug-resistant focal epilepsy.
Key Considerations
- The success of surgery depends on correctly detecting the source of epilepsy and its location outside of eloquent areas, making it overall safe, successful, and cost-effective 1.
- Patients with unilateral hippocampal sclerosis, concordant EEG findings, and failure to respond to at least two appropriate antiseizure medications are the best candidates for surgery.
- The procedure carries some risks, including memory and language deficits, visual field cuts, and the general risks associated with brain surgery.
Surgical Approach
- The most common surgical approaches are anterior temporal lobectomy or selective amygdalohippocampectomy, which involve removing the affected hippocampus and surrounding structures.
- These procedures aim to remove the epileptogenic focus in the sclerotic hippocampus, which is often the source of seizure activity in temporal lobe epilepsy.
Post-Surgical Care
- Recovery typically takes several weeks to months, and most patients continue antiseizure medications for at least 1-2 years after surgery, with potential for medication reduction or discontinuation if they remain seizure-free.
- The development of molecular neuroimaging with interictal [18 F]fluorodeoxyglucose ([18 F] FDG) positron emission tomography (PET), ictal perfusion SPECT, or ictal subtraction perfusion SPECT has influenced and impacted the presurgical management of epilepsy patients, allowing for more tailored resections and better preservation of motor, visual, language, or temporal lobe functions 1.
From the Research
Success Rates of Surgery for Temporal Lobe Epilepsy with Hippocampal Sclerosis
- The success rate of surgery for temporal lobe epilepsy with hippocampal sclerosis is relatively high, with studies showing that 60-80% of patients achieve significant reduction in seizures or become seizure-free 2, 3, 4, 5, 6.
- A study published in 2016 found that 90% of patients with hippocampal sclerosis achieved a favorable outcome at 1 year after surgery, with 80% being completely seizure-free 2.
- Another study published in 2022 found that 73.6% of patients with drug-resistant temporal lobe epilepsy associated with hippocampal sclerosis were free from disabling seizures after surgery, with 65% maintaining this outcome over a follow-up period of up to 23 years 3.
- A study published in 2004 found that 82% of patients with pathologically proven hippocampal sclerosis achieved complete postoperative seizure freedom at 12 months, with 64% maintaining this outcome at 63 months 4.
- A study published in 2024 found that patients over 50 years old with mesial temporal lobe epilepsy associated with hippocampal sclerosis had similar surgical outcomes to younger patients, with 80.3% achieving Engel I outcomes at the last follow-up 5.
Predictors of Successful Outcome
- Studies have identified several predictors of successful outcome after surgery for temporal lobe epilepsy with hippocampal sclerosis, including:
- Triple concordance of noninvasive tests (neuropsychological tests, video-electroencephalography monitoring, and magnetic resonance imaging) 2.
- Absence of dysmnesic and olfactory aura 3.
- History of febrile seizure 3.
- Surgical technique, with standard anteromesial temporal lobectomy leading to better outcomes than selective amygdalohippocampectomy via subtemporal approach 3.
- Early admittance for surgery 6.
Safety and Complications
- Surgery for temporal lobe epilepsy with hippocampal sclerosis is generally considered safe, with low rates of postoperative complications and morbidity 2, 3, 5, 6.
- A study published in 2024 found that major complication rates were comparable between older and younger patients, at 3.3% and 2.7%, respectively 5.
- Another study published in 2021 found that minor neurological complications were noted in 4.8% of patients, with permanent severe complications occurring in 0.4% of patients 6.