Minimally invasive surgical approaches for temporal lobe epilepsy

Abstract

Surgery can be a highly effective treatment for medically refractory temporal lobe epilepsy (TLE). The emergence of minimally invasive resective and nonresective treatment options has led to interest in epilepsy surgery among patients and providers. Nevertheless, not all procedures are appropriate for all patients, and it is critical to consider seizure outcomes with each of these approaches, as seizure freedom is the greatest predictor of patient quality of life. Standard anterior temporal lobectomy (ATL) remains the gold standard in the treatment of TLE, with seizure freedom resulting in 60–80% of patients. It is currently the only resective epilepsy surgery supported by randomized controlled trials and offers the best protection against lateral temporal seizure onset. Selective amygdalohippocampectomy techniques preserve the lateral cortex and temporal stem to varying degrees and can result in favorable rates of seizure freedom but the risk of recurrent seizures appears slightly greater than with ATL, and it is not clear whether neuropsychological outcomes are improved with selective approaches. Stereotactic radiosurgery presents an opportunity to avoid surgery altogether, with seizure outcomes now under investigation. Stereotactic laser thermo-ablation allows destruction of the mesial temporal structures with low complication rates and minimal recovery time, and outcomes are also under study. Finally, while neuromodulatory devices such as responsive neurostimulation, vagus nerve stimulation, and deep brain stimulation have a role in the treatment of certain patients, these remain palliative procedures for those who are not candidates for resection or ablation, as complete seizure freedom rates are low. Further development and investigation of both established and novel strategies for the surgical treatment of TLE will be critical moving forward, given the significant burden of this disease.

Optic Radiation Tractography and Visual Field Deficits in Laser Interstitial Thermal Therapy for Amygdalohippocampectomy in Patients with Mesial Temporal Lobe Epilepsy

“…Anterior temporal lobectomy is a well-established treatment for patients with drug-resistant MTLE [24,25,26,27] and results in 60-80% seizure freedom in selected patients [5,28,29], but is associated with adverse effects, such as cognitive impairments and focal neurological deficits [30,31,32,33,34,35,36]. Therefore, the balance of effectiveness and possible complications of open resection needs to be taken into account for patients with MTLE.…”

“…However, patients are less likely to become seizure free with LITT when compared with open resection that resulted in 60-80% seizure freedom [5,6,7,8]. LITT has certain advantages over open surgery: LITT can be used to precisely target the epileptogenic focus and deeply located seizure foci that would not be amenable to open surgery with minimal disruption of healthy brain tissue [3,4], potentially decreases the risks and complications associated with open surgery [1,2], and reduces hospital stay and costs [2,3,4,5]. …”

Cortical gene expression correlates of temporal lobe epileptogenicity

“…Patients whose seizures are resistant to two tolerated, appropriately chosen and used antiepileptic drug schedules (whether as monotherapies or in combination) are referred to as having "intractable epilepsy" and become candidates for other treatments [5]. Amygdalohippocampectomy, with or without anterior temporal lobectomy (ATL), is the most commonly employed operation for those with TLE who fail to achieve good control of their seizures on two first-line AEDs [2,6,7]. Selective amygdalohippocampectomy has the benefit of preserving lateral cortical brain structures and results in positive outcomes for seizure freedom despite a possible small increased risk of recurrent seizures compared to ATL [7].…”

“…Amygdalohippocampectomy, with or without anterior temporal lobectomy (ATL), is the most commonly employed operation for those with TLE who fail to achieve good control of their seizures on two first-line AEDs [2,6,7]. Selective amygdalohippocampectomy has the benefit of preserving lateral cortical brain structures and results in positive outcomes for seizure freedom despite a possible small increased risk of recurrent seizures compared to ATL [7]. Seizure freedom can be achieved in approximately 65% of intractable TLE patients with temporal lobectomy with amygdalohippocampectomy (ATL/AH) [8].…”

Advancements in Stereotactic Epilepsy Surgery: Stereo-EEG, Laser Interstitial Thermotherapy, and Responsive Neurostimulation

“…Full discussion of the nuances of trajectory planning for interrogation of all relevant supratentorial structures with potential epileptogenic potential Stereotactic interventions form an increasingly significant portion of the minimally invasive approaches for surgical management of epilepsy. 1,2 This manuscript will review the application of three recent stereotactic techniques in the modern epilepsy surgery armamentarium, namely stereotactic electroencephalography (SEEG), responsive neural stimulation (RNS) and laser interstitial thermal therapy (LITT). While these interventions are a contemporary advancement, they are intellectually indebted to some of the most major developments and pioneers in the history of neurosurgery.…”