From the Guidelines
Reoperation can be a viable option for patients with failed temporal lobe epilepsy surgery, particularly when there is evidence of residual epileptogenic tissue or incomplete resection of the initial target, as supported by recent guidelines 1. The decision for reoperation should be based on a comprehensive reevaluation, including:
- Video-EEG monitoring to identify the source of ongoing seizures
- High-resolution MRI to assess the extent of resection and potential residual tissue
- Possibly PET or SPECT imaging, such as [18F]FDG PET, to localize the epileptogenic zone and guide reoperation 1 Candidates most likely to benefit from reoperation include those with:
- Clear evidence of residual hippocampal or mesial temporal structures
- Well-localized seizure onset
- Good concordance between imaging and electrophysiological findings The success rate of reoperation ranges from 30-60%, which is lower than initial surgeries but still meaningful 1. Timing of reoperation is typically at least 1-2 years after the initial surgery to allow for proper assessment of outcomes. Patients should be counseled about increased risks with reoperation, including higher rates of visual field defects, language or memory impairment, and infection. Alternative approaches like responsive neurostimulation (RNS), deep brain stimulation (DBS), or vagus nerve stimulation (VNS) may be considered for patients who are not good reoperation candidates. The decision requires multidisciplinary evaluation at a comprehensive epilepsy center with experience in reoperations to weigh individual risks and benefits, taking into account the latest guidelines and evidence 1.
From the Research
Role of Reoperation in Failed Epilepsy Surgery for Temporal Lobe Epilepsy
- Reoperation can be a viable option for patients with temporal lobe epilepsy who have failed initial surgery, with studies showing significant improvement in seizure outcomes 2, 3, 4, 5.
- The main reasons for seizure recurrence after initial surgery include incomplete resection of the putative epileptogenic lesion, presence of additional seizure foci, or progression of the underlying disease 2, 6.
- Reoperation has been shown to lead to approximately 70% long-term seizure freedom and reasonable neuropsychological outcomes, although it also carries an increased risk of permanent postoperative neurological deficits 2.
- Factors that may indicate a good chance of benefiting from reoperation include concordance of postsurgical imaging and electroclinical findings, absence of brain trauma and cerebral infection prior to epilepsy onset, and anterior temporal localization 4, 5.
Outcomes of Reoperation
- Studies have reported varying rates of seizure freedom after reoperation, ranging from 36.6% to 57% 3, 4, 5.
- Reoperation has also been shown to improve seizure outcomes in patients with temporal lobe epilepsy, with some studies reporting significant reductions in seizure frequency and severity 3, 4.
- However, reoperation also carries risks, including permanent neurological deficits, visual field defects, and hemiparesis 2, 4.
Predictors of Good Outcome After Reoperation
- Anterior temporal localization and abnormal imaging studies have been identified as predictors of a good outcome after reoperation 5.
- Absence of brain trauma and cerebral infection prior to epilepsy onset may also be associated with improved outcomes after reoperation 4.
- Concordance of postsurgical imaging and electroclinical findings is also an important factor in determining the success of reoperation 4.