Epilepsy surgery: When it’s not good to wait

epilepsy surgery life expectancyAbout a third of children with epilepsy do not get better with drug treatment. Many physicians are inclined to try additional drugs to control the seizures—and there are many to choose from. However, analysis of data from tens of thousands of patients suggests that if two or more well-chosen drugs have failed, and surgery is a safe option, there’s no benefit in holding off.

The decision analysis, published in the February issue of Epilepsia, found that average life expectancy was more than five years greater when eligible children had surgery rather than prolonged drug treatment. And children spent more of their lives seizure-free.

Although clinical guidelines currently do call for earlier surgery, physicians tend to use it as a last resort—even when brain-mapping studies indicate that it’s unlikely to endanger vital brain structures.

“People tend to avoid short-term risk and overlook the cumulative long-term risks,” says Boston Children’s Hospital neurologist Iván Sánchez Fernández, MD, lead researcher on the study. “There is a bias toward thinking, ‘maybe if I had another drug, that might work.’ That certainly happens in some patients, but the majority do not sustain prolonged remissions once two appropriately chosen and dosed medications have failed.”

epilepsy surgery life expectancy

Drugs vs. surgery

In all, the decision analysis drew on 19 studies—the best available data in the literature—including three reviews of multiple studies. From these, Sánchez Fernández and colleagues calculated:

  • mortality in the general population
  • excess mortality in patients with epilepsy
  • mortality and complications with epilepsy surgery
  • year-by-year probabilities of attaining seizure freedom (or, conversely, relapsing) with drugs versus surgery

The analysis found that epilepsy surgery increased life expectancy in children of all ages. For a cohort of 10-year olds, for example, life expectancy increased by 5.9 years in children with temporal lobe epilepsy and 5.6 years in children with extratemporal epilepsy (affecting other lobes of the brain).

The study could not analyze quality of life or cognitive outcomes for children whose development has been disrupted by frequent seizures. But it could estimate the amount of time children spent seizure-free.

For 10-year-olds with temporal lobe epilepsy, children who had surgery were seizure-free for an estimated 49 percent of their life-expectancy years—nearly half their projected lifetime—versus 14 percent for children who continued with medications only. For extratemporal epilepsy, these percentages were 43 and 14 percent, respectively.

Second-order Monte Carlo simulations, which model risk based on probability distributions in the literature, indicated that 93 percent of 10-year-olds with temporal lobe epilepsy and 88 percent of those with extratemporal epilepsy would gain more life expectancy from surgery than from continued drug treatment.

In general, the mortality risk in epilepsy surgery is less than 1 percent, says Tobias Loddenkemper, MD, of Boston Children’s, senior investigator on the study. However, the researchers note that medications might still be preferable for individual children, as when surgery carries an unusually high risk of complications.

But the findings build on a 2001 study published in The New England Journal of Medicine that found that once a patient with epilepsy fails to respond to a second drug, properly chosen and dosed, the probability of another medication working is very low.

“Studies recommend early surgery in refractory epilepsy, but delays are still the norm,” says Sánchez Fernández. “By quantifying life expectancy, we hope to change practice.”