Minimally Invasive Surgical Epilepsy Trial for Temporal Lobe Epilepsy

Functional Anterior Temporal Lobectomy Via Minicraniotomy as a Novel Surgical Therapy for Temporal Lobe Epilepsy: a Randomized, Controlled Trial

Temporal lobe epilepsy (TLE) is a chronically neurological disease characterized by progressive seizures. TLE is the most frequent subtype of refractory focal epilepsy in adults. Epilepsy surgery has proven to be very efficient in TLE and superior to medical therapy in two randomized controlled trials. According to the previous experience, the investigators use functional anterior temporal lobectomy (FATL) via minicraniotomy for TLE. To date, this minimally invasive open surgery has been not reported. The investigators here present a protocol of a prospective trail which for the first time evaluates the outcomes of this new surgical therapy for TLE.

Temporal lobe epilepsy (TLE) is a chronically neurological disease characterized by progressive seizures, followed by a latency period of several years after various injuries including febrile seizures, infection, trauma, tumors, and vascular malformation. Hippocampal sclerosis is the most common histopathological finding. The macroscopic changes of TLE with hippocampal sclerosis include the diminished size, sclerosis, and reduced metabolism in mesial temporal structures (amygdala, hippocampus, and parahippocampal gyrus). The microscopic changes include neuronal loss, gliosis, and axonal reorganization. As TLE progresses, most of patients become resistant to current antiepileptic drugs. Therefore, TLE is the most frequent subtype of refractory focal epilepsy in adults.

Epilepsy surgery has proven to be very efficient for TLE and superior to medical therapy in two randomized controlled trials. Patients with surgical therapy have high seizure-free rate with the range of 60% to 80 % while less than 5% with medical treatment. Anterior temporal lobectomy (ATL) is the most frequently used approach for TLE. For patients with TLE, Engel suggested referral to ATL should be strongly considered. The decision analysis showed that ATL increased life expectancy and quality- adjusted life expectancy in patients with TLE compared with medical management. Nevertheless, ATL is performed by large frontotemporal craniotomy. Although complication rates after temporal lobectomy have decreased dramatically over time, ATL creates a large cavity with temporal lobe resected, causing potential complications such as bleeding, brain shifts and subdural collections. With the advances in minimally invasive surgery, surgical techniques of ATL for TLE need to be continuously improved.

For this reason, the investigators modify the surgical approach. Functional anterior temporal lobectomy (FATL) via minicraniotomy is established. Recently, 25 patients with TLE undergoing FATL obtained satisfactory outcomes in our center (unpublished data). To date, this new open surgery for TLE has been not reported. The safety and efficacy of FATL need to be verified. Therefore, the investigators here present a protocol of the minimally invasive surgical epilepsy trial for TLE (MISET-TLE) which for the first time evaluates the outcomes of FATL as a new surgical approach for TLE.

Inclusion Criteria:

1. male or female aged between 18 and 60 years;
2. drug- resistant temporal lobe epilepsy, remaining seizures after two or more tolerated and appropriately chosen antiepileptic drugs;
3. monthly or more seizures during the preceding year prior to trial;
4. the full- scale intelligence quotient (IQ) more than 70, understanding and completing the trial;
5. signing the informed consent;
6. good compliance, at least 12- month follow- up after surgery.

Exclusion Criteria:

1. tumor in temporal lobe;
2. extratemporal epilepsy and temporal plus epilepsy;
3. drug- responsive epilepsy, seizure freedom with current drugs in recent one year;
4. pseudoseizures;
5. seizures arising from bilateral temporal lobes;
6. significant comorbidities including progressive neurological disorders, active psychosis, and drug abuse;
7. a full- scale IQ lower than 70, unable to complete tests;
8. previous epilepsy surgery;
9. poor compliance and inadequate follow- up.