2021 年 38 巻 4 号 p. 564-568
It has long been argued that epilepsy surgery is one of the most underutilized therapeutic intervention in medicine. Based on the health insurance claims, the annual number of epilepsy surgery performed in Japan is about half of that in the United States. It is important to consider surgical indication promptly when drug–resistant epilepsy (DRE) is suspected. When patients with DRE have surgically remediable etiology such as unilateral hippocampal sclerosis and low–grade epilepsy associated tumors, surgical indication should be considered at early stage of treatment. The chance of seizure control by the next drug becomes smaller as the number of previously–failed antiepileptic drugs increases. Surgical treatment should be considered when many antiepileptic drugs failed to control patient's seizures.
Less invasive approaches are increasingly utilized in epilepsy surgery. Stereotactic insertion of depth electrodes assisted by the robotic system was recently covered by insurance in Japan. This will accelerate the use of stereoelectroencephalogprahy (SEEG) for pre–surgical evaluation of epilepsy. SEEG enables the exploration of deep structures, including the hippocampus, insula, and cingulum, and may improve diagnostic accuracy and surgical outcome. Magnetic resonance–guided laser interstitial thermal therapy and brain–responsive neurostimulation have not been introduced in Japan. Deep brain stimulation (DBS) of the thalamus is known to be effective in reducing seizures in patients with DRE, although the use of DBS is not approved for epilepsy in Japan. All of these new approaches eliminate the need for craniotomy or the need for brain resection. The introduction of the less invasive procedures will reduce the burden on patients and may expand the indications for surgical treatment.
