A randomized study of the effectiveness of epilepsy surgery

In the past, epilepsy surgery was often been regarded as an unsafe, expensive "last resort" for patients who continued to have uncontrolled seizures after being treated with medication for many years. A problem of most studies of epilepsy surgery was that they just reported on the outcomes of patients who underwent operations, a carefully selected group, without measuring how a comparable group of patients would fare if continued on medication alone. This kind of non-randomized study is likely to overestimate benefits and underestimate harm.

An important study was reported at the annual meeting of the American Academy of Neurology in May 2001, Dr. Samuel Wiebe of the University of Western Ontario presented the results of a randomized study comparing surgery to treatment with medication in 80 patients with difficult-to-control temporal lobe epilepsy. The randomized structure of this study was possible because patients at the hospital where Dr. Wiebe and his colleagues practice are routinely placed on a 1-year waiting list before undergoing surgery. For the purposes of the study, half of the study group (40 patients) received this standard treatment. During the year they spent on the waiting list, these 40 patients took medications prescribed by skilled epileptologists. The other 40 patients underwent immediate presurgical evaluation and surgery.

After 1 year, 58% of the patients who had undergone surgery had not experienced a complex partial seizure (a seizure that impairs consciousness), and 38% had not experienced any seizures, including auras. In contrast, only 8% of the patients treated with medication were free of complex partial seizures, and 3% had no seizures. For the patients treated with surgery who continued to have some seizures, they were less frequent than in the other group, but the severity was similar.

The quality of life of the patients treated with surgery was judged to be significantly better than for the other patients. Of the patients who had surgery, 55% were working or studying, versus 36% in the other group. Negative effects of surgery included a decline in memory in a small number of patients and a defect in a small part of their visual field in 55%.

Although standard statistical analysis of the results of this study showed surgery to be significantly better with regard to seizure control and quality of life, some caution about the interpretation of the results was advised by Dr. Wiebe and by Dr. Susan Spencer of Yale University, who was the "Discussant" for this presentation. Both of them noted that a longer follow-up period would be valuable, especially with regard to measuring quality of life. Some other studies of epilepsy surgery that have followed patients for longer periods have found that some patients who are initially seizure-free may experience seizures later, and their quality-of-life scores may worsen somewhat, especially if they continue to experience seizures.

Nevertheless, Dr. Wiebe concluded that surgery is an effective treatment for mesial temporal lobe epilepsy when medication fails to control seizures. Although care is certainly necessary in choosing which patients are likely to benefit from surgery, physicians and insurers should not persist with unsuccessful medical treatment for many years or decades before recommending surgery, as has often been the practice.

The same study was subsequently published in the New England Journal of Medicine: Wiebe S, Blume WT, Girvin JP, Eliasziw M; Effectiveness and Efficiency of Surgery for Temporal Lobe Epilepsy Study Group. A randomized, controlled trial of surgery for temporal-lobe epilepsy. N Engl J Med 2001 345:311-8.

Topic Editor: Howard L. Weiner, M.D.
Last Reviewed:3/8/04