2019 Volume 28 Issue 6 Pages 326-333
Surgical treatment is indicated for patients with drug-resistant epilepsy, but it can take a long time to identify drug resistance, and the surgical referral is often delayed for years. However, early surgery is important for patients, especially children, with surgically accessible epileptogenic lesions, when removal of the lesion is expected to result in a high chance of freedom from seizures. Typical examples of such lesions include mesial temporal lobe epilepsy with hippocampal sclerosis and tumor-related epilepsy. Surgical intervention should always be considered for patients with a complex epilepsy syndrome, such as tuberous sclerosis complex, West syndrome, or Lennox-Gastaut syndrome. These syndromes are characterized by drug-resistant epilepsy and a diffuse or multi-focal epileptiform EEG. Adjunctive treatment options include palliative procedures, such as vagus nerve stimulation and corpus callosotomy. Patients with these conditions may also benefit from complex surgical interventions, such as multilobar resection or disconnection, after an intensive pre-surgical work-up.
The introduction of less invasive devices has broadened the surgical indication for epilepsy. For example, stereotactic robot systems can accurately position depth electrodes more quickly than is possible with frame-based or frameless stereoelectroencephalography (SEEG) systems. SEEG offers a safe and useful invasive option for monitoring patients whose epilepsy is difficult to localize, such as for the exploration of a deep-seated epileptogenic lesion or of the bilateral hemispheres or after failed epilepsy surgery. Magnetic resonance (MR)-guided laser interstitial thermocoagulation can be used to provide focal ablative therapy for relatively small epileptogenic lesions, such as for mesial temporal sclerosis, focal cortical dysplasia, and heterotopia. Another new ablative therapy for epilepsy is transcranial MR-guided focused ultrasound. Deep brain stimulation of the anterior nucleus of the thalamus has demonstrated an efficacy similar to that shown by vagus nerve stimulation in patients with drug-resistant epilepsy without an indication for resective surgery. Responsive neurostimulation has emerged as an important alternative option for the treatment of non-resectable epileptogenic lesions, such as those in the eloquent cortex. All these less invasive devices are yet to be introduced in Japan.
In this review, we discuss current and future perspectives of epilepsy surgery in Japan, focusing on the indication for surgical treatment, the timing of such treatment, and the potential roles of less invasive devices.
