The decision to undergo epilepsy surgery is not simple for the patient or the doctor even with the convincing evidence that surgical treatment is often effective when medications have failed. One particularly challenging aspect of the decision is its timing. Neurologists most often conceptualize the timing based on the number of antiepileptic medications that have been tried without successful seizure control. This measure has been studied as a means to understand epilepsy prognosis, and an International League Against Epilepsy commission recently proposed to define drug resistant epilepsy as the failure of two tolerated, appropriately chosen anti-epileptic drugs. However, the overwhelming majority of patients try more than two medications before considering surgery while some patients seek care at epilepsy surgery centers because the first medication has failed. This suggests that a diagnosis of medication resistant epilepsy does not determine the timing of the decision, and another factor may be more important.

Epilepsy surgery is elective surgery as it is not urgently needed to correct an acute condition and non-surgical treatment is an alternative. Therefore, there is time to consider the options carefully and make the best possible decision. However, the fear and complexity of the situation, especially considering that the treatment is brain surgery and irreversible, can produce indecision or a decision to wait. Even the recognition that the seizures are disabling, injurious, or life threatening does not necessarily lead to consideration of surgery because it may instead lead to the decision to try another medication. Often, epilepsy surgery is seen as a "last resort" without a sense of when to actually consider it. As such, the "last resort" perpetually remains at the bottom of a list that continually grows longer.

This difficulty in determining when to consider surgical treatment may be related to the nature of epilepsy as an unpredictable condition. A major factor in the disability and risks of epilepsy is the unpredictable timing of seizures, and the unpredictable timing also impacts that determination of a treatment's effectiveness. If seizures occurred once daily without exception, then even one day of seizure control would be clear evidence of success. However, establishing whether treatment has been successful is complicated by the lack of a stable pattern to seizure occurrence. Months can be spent without certainty about the treatment's benefit, and then additional months without certainty follow an adjustment to that treatment. Hope alternates with frustration throughout the treatment, and this is partly experienced as confusion, which leads to postponing a decision about surgical treatment.

Overall, the impact of seizure unpredictability on the decision to consider surgery may be understood through operant conditioning, that is, the learning of voluntary behavior. In this framework, learning is hampered by the consequence's lack of immediacy and contingency. For medication resistant epilepsy, the recognition that medications are not sufficiently effective is hampered by each seizure's delayed occurrence after the medication change and inconsistent responses to the medication changes. This results in an irony with the unpredictable nature of seizures producing both disability and a cause for continued disability.

Thinking of the issue of timing from the perspective of treating unpredictable episodes may explain why the joint publishing of an evidence-based practice parameter for epilepsy surgery by the American Academy of Neurology, American Epilepsy Society, and the American Association of Neurological Surgeons has not impacted the timing of epilepsy surgery. Haneef and colleagues' recent report documents no change in the duration of epilepsy before considering epilepsy surgery following the release of the parameters. Evidence for benefit from surgery does not affect the process by which the decision is made to choose surgery. Perhaps earlier consideration of surgery would result by approaching the problem of "last resort" mindful of the influence of the unpredictability.

Stagnation in the treatment of epilepsy may be due to natural inclinations in unpredictable situations, so focusing on predictability may be a useful approach to the consideration of surgery. Obviously, true predictability is not possible for individual patients despite the desire each patient has for guarantees. Predictability has to be through consideration of patient groups, which is what clinical research results provide. Therefore, predictability can enter the discussion with an individual patient as likelihoods for the specific occurrences, which are known with accuracy from groups of patients. Being specific and grounded in this way can help reduce confusion and make the overall situation more certain. Talking about likelihoods addresses straightforwardly that guarantees do not exist in life, and we commonly make decisions based on the likelihood of events. This approach is reorienting and may break the cycle of recurring treatment failures due to impaired recognition that pharmacologic treatment has failed.

Discussion of likelihood is not new to clinical practice. Surgeons routinely discuss likelihoods when obtaining consents. However, the twist here is to bring the discussion to a time before determining candidacy for surgery as a way to help in the consideration of the evaluation. The decision of to consider epilepsy surgery should be faced with the facts that epilepsy surgery results cannot be guaranteed, but having epilepsy surgery is safer for the average patient than not having it because, in general, the risks of continued seizures are greater than the risks of the operation. To a person with an unpredictable condition, the status quo can seem safer than it trulyis. Getting beyond the status quo may depend on recognizing the particular challenges of living with an unpredictable condition.

John Stern, M.D.
Last Reviewed: 1/15/11