First line therapy for epilepsy involves treatment with anticonvulsive drugs, also called antiepileptic drugs– most patients will respond to trials of one or two different medications.
[3][5][4] Epilepsy surgery has been performed for more than a century, but its use dramatically increased in the 1980s and 1990s, reflecting advancement in technique and improved efficacy in selected patients.
[10] The evaluation typically includes neurological physical examination, routine electroencephalography (EEG), Long-term video-EEG monitoring, neuropsychological evaluation, and neuroimaging such as MRI, functional magnetic resonance imaging (fMRI), single photon emission computed tomography (SPECT), positron emission tomography (PET), and magnetoencephalography (MEG).
[15][16][17] If noninvasive testing was inadequate in identifying the epileptic focus or in distinguishing the surgical target from normal brain tissue and function, then long-term video-EEG monitoring with the use of intracranial electrodes may be required for evaluation.
[24] Anatomic hemispherectomy involves the surgical removal of an entire cerebral hemisphere excluding deep structures such as the basal ganglia, thalamus, and brainstem to preserve vital functions.
WE Dandy recorded the first anatomic hemispherectomy in 1928 for glioma resection and the first surgery for epilepsy was performed by McKenzie ten years later.
[27] Depending on each patient case, alternate procedures such as hemidecortication or peri-insular hemispherectomies are available to disrupt the epilepsy signal but remain less invasive to minimize risks.
[30] Follow-up studies suggest that the procedure also has produced positive long-term effects that illustrate 63 percent of patients still remaining seizure-free.
[33] Important structures implicated in temporal lobectomies include the auditory cortex, hippocampus, Wernicke's area, and amygdala; the latter three broadly affecting memory, language, and emotion, respectively.
The hippocampus, amygdala, and parahippocampal gyrus are collectively termed the mesial temporal structures and are frequently targeted for resection in epilepsy.
[36] The ATL resection is the most common technique where the lateral and polar cortex are removed along with the aforementioned mesial temporal structures as well as the posterior part depending on which hemisphere the epileptogenic zone lies.
[37][38][39] ATL surgery resection encompasses the amygdala, hippocampus as well as surrounding tissue or neocortex whereas SAH is more targeted to the former two structures to be as minimally disruptive as possible.
One study of supratentorial brain tumors in children less observed a dramatic reduction in the severity and frequency of seizures at one and four year follow-up.
Ablative procedures are appropriate options for patients who otherwise would not be good surgical candidates due to other medical problems or specific anatomical reasons that would make targeting their epilepsy difficult with a traditional surgery.