Conference Coverage
Surgical Candidates?
Various common misconceptions about contraindications for surgery also may prevent patients from being referred to specialized centers. For instance, bilateral interictal spikes are not a contraindication for surgery because in most patients with this finding, all seizures originate from one side. A normal MRI is not a contraindication for surgery because techniques such as PET-MRI fusion and magnetoencephalography can identify epileptogenic regions that do not appear on MRI. If a patient has multiple or diffuse lesions, only one of the lesions might be epileptogenic, or if a patient has a large lesion, only part of the lesion might be epileptogenic. When an abnormality is in a primary cortex, there are ways to identify cortex that cannot be removed and still obtain good results with surgery, Dr. Engel said.
In patients with existing memory deficits, surgery typically does not worsen memory and can improve it. In patients who do not have memory deficits, however, surgery of the language-dominant temporal lobe may worsen memory, and this complication may be a concern.
Chronic psychosis is not a contraindication for surgery. “If it’s postictal psychosis, it will go away after seizures stop. If it’s interictal psychosis, a patient with schizophrenia is better off without epilepsy than with epilepsy, even if they’ll still have schizophrenia,” Dr. Engel said. An IQ less than 70 was once considered a contraindication for surgery, but that is no longer necessarily the case.
Another issue that may be increasingly common is the removal of lesions at hospitals that perform few epilepsy surgeries (ie, low-volume hospitals). “The outcomes are not as good. There’s more morbidity, and there’s mortality, which we don’t see very much in the epilepsy centers,” Dr. Engel said. In addition, many lesions are incidental findings. “You really need to demonstrate when you see a lesion that that lesion is the source of the habitual seizures,” Dr. Engel said.
In an analysis of 6,200 epilepsy surgery procedures published in the August issue of Epilepsy Research, Rolston et al observed higher rates of adverse events when low- and high-volume centers were examined together, compared with high-volume centers alone.
ERSET Outcomes
Some 100,000 to 500,000 patients with epilepsy in the US are potential surgical candidates, and about 2,000 epilepsy surgeries are performed per year. Surgical outcomes have improved over the last few decades, and new surgical techniques have been developed, including laser thermal ablation, which can be performed through a small drill hole, Dr. Engel said.
To determine whether surgery soon after failure of two antiepileptic drug trials is superior to continued medical management, Dr. Engel and colleagues conducted the Early Randomized Surgical Epilepsy Trial (ERSET), which was published in JAMA in 2012. The multicenter trial was stopped early due to slow study recruitment. It included 38 participants (ages 12 and older, 18 men) who had mesial temporal lobe epilepsy and disabling seizures for no more than two consecutive years after their two failed drug trials. Only surgical candidates were randomized. In an intent-to-treat analysis, all of the patients in the medical arm continued to have seizures, while 11 patients in the surgical arm (73%) were seizure-free during year two of follow-up. In an analysis that included only patients for whom researchers had complete data, 85% of patients in the surgical group were seizure-free. Compared with the medical treatment group, patients in the surgical group had improved quality of life. Adverse events included three episodes of status epilepticus in the medical group and a transient stroke in the surgical group. Memory decline occurred in four participants after surgery, but the sample was too small to assess the effect of treatment on cognitive function.
“All people with refractory epilepsy deserve a timely consultation at an epilepsy center,” Dr. Engel said. “Many are not refractory. Many are surgical candidates. And the remainder of them deserve psychosocial support.”
—Jake Remaly
