Last updated on May 2019

Surgery as a Treatment for Medically Intractable Epilepsy

Brief description of study

  • Medically intractable epilepsy is the term used to describe epilepsy that cannot be controlled by medication. Many people whose seizures do not respond to medication will respond to surgical treatment, relieving seizures completely or almost completely in one-half to two-thirds of patients who qualify for surgery. The tests and surgery performed as part of this treatment are not experimental, but researchers are interested in training more neurologists and neurosurgeons in epilepsy surgery and care in order to better understand epilepsy and its treatment.
  • To use surgery as a treatment for medically intractable epilepsy in children and adults.
  • Children and adults at least 8 years of age who have simple or complex partial seizures (seizures that come from one area of the brain) that have not responded to medication, and who are willing to have brain surgery to treat their medically intractable epilepsy.
  • Participants will be screened with a medical history, physical examination, and neurological examination. Imaging studies, including magnetic resonance imaging and computer-assisted tomography (CT), may also be conducted as part of the screening. Participants who do not need surgery or whose epilepsy cannot be treated surgically will follow up with a primary care physician or neurologist and will not need to return to the National Institutes of Health for this study.
  • Prior to the surgery, participants will have the following procedures to provide information on the correct surgical approach.
  • Video electroencephalography monitoring to measure brain activity during normal activities within a 24-hour period. Three to four 15-minute breaks are allowed within this period.
  • Wada test to evaluate speech, comprehension, and memory centers of the brain, using a contrast dye to study the blood vessels of the brain and a short-term anesthetic administration procedure to test the effects on areas of speech and memory.
  • Depth electrodes and/or brain surface electrodes to measure brain activities and determine the part of the brain that is responsible for the seizures (seizure focus).
  • Participants will have a surgical procedure at the site of their seizure focus. Brain lesions, abnormal blood vessels, tumors, infections, or other areas of brain abnormality will be either removed or treated in a way that will stop or help prevent the spread of seizures without affecting irreplaceable brain functions, such as the ability to speak, understand, move, feel, or see.
  • Participants will return for outpatient visits and brain imaging studies 2 months, 1 year, and 2 years after surgery.

Detailed Study Description


This protocol is being performed provide standard care therapy for patients with drug resistant epilepsy and to follow the therapeutic course of patients from pre-operative evaluation, through surgery, and post-operatively, and to collect prospective data on seizure outcomes following surgery to add to the body of knowledge in this field. Primary outcome measures will be used to assess efficacy of

surgery for clinical care purposes. Any treatment under this protocol will be based on the current standard of care for epilepsy surgery. The secondary goals of this protocol will be to investigate neurophysiological correlates of human cognitive function and to provide invasive monitoring for patients with tumor related epilepsy.

Study Population

Patients 8 years and older whose seizures are uncontrollable with medication may participate in this study as well as patients with tumor related epilepsy in whom invasive monitoring is indicated.

Study Design

Patients will be screened by study neurologists to confirm their diagnosis of drug resistant epilepsy. Patients that do not have a confirmed diagnosis of drug resistant epilepsy will be offered further evaluation in protocol 18-N-0066, Investigating Epilepsy: Screening,Evaluation and Treatment. Patients confirmed to have drug resistant epilepsy will be offered standard invasive and non-invasive diagnostic and surgical procedures. Diagnostic invasive monitoring with intracranial electrodes for further localization of their seizure focus may be required. The ultimate goal is to surgically remove or modify the epileptic focus. Standard procedures to be performed are 1) anterior temporal lobectomy or 2) amygdalohippocampectomy for temporal lobe epilepsy, 3) focal cortical resection for epilepsy that arises outside the temporal lobe, 4) removal of brain lesions causing epilepsy, and 5) multiple subpial transection.

In patients in whom invasive monitoring is medically necessary, neurophysiologic activity during cognitive tasks will be captured from intracranial surface and depth electrodes. Analysis will focus on the role of neuronal firing and aggregate neural activity 1) during cognitive function, 2) in other states such as wakefulness and sleep, and 3) during periods of time surrounding seizure activity.

Drug Resistant Epilepsy

Patients with drug resistant epilepsy will be followed for two years after the surgical procedure and will receive standard neurological examinations and MRI evaluation of the brain. Patients who do not have surgical resection of epileptogenic tissue will complete participation after the three-month post-op visit. Participants in this protocol will be evaluated for potential eligibility for other NINDS clinical trials.

Tumor Related epilepsy

Patients with tumor related epilepsy will be enrolled in this protocol because of clinical indications arising from participation in a seperate protocol, 16-N-0041 Tumor Related Epilepsy. Patients will complete participation after the three-month post-op visit.

Outcome Measures

The primary goal of this protocol is to provide standard care therapy for patients with drug resistant epilepsy, and to determine the efficacy of surgery for treatment while collecting physiology, tissue, and behavioral data for research.The primary outcome measure for patients with drug resistant epilepsy is the change in seizure frequency, as measured by the Engel scale before and 1 year after treatment. Secondary outcome measures include 1) percentage of patients who are able to be completely withdrawn from anti-epileptic medication; 2) percentage of patients who are seizure-free (Engel Class I); 3) mean Engel Class one year after surgery stratified by the type of surgical procedure; 4) percentage of patients with permanent neurological side-effects from surgical treatment; and 5) neurophysiological correlates of cognitive function. Outcomes for patients with tumor related epilepsy will be assessed under a seperate protocol, 16-N-0041, Tumor Related Epilepsy.

Clinical Study Identifier: NCT01273129

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