Literature Review

Modeling Favors Immediate AED Treatment After an Unprovoked First Seizure

Factoring in quality of life, seizure risk, and side effects, a model prefers immediate over delayed treatment.


 

Immediate treatment of a first unprovoked seizure may be preferable to delayed treatment over a wide range of patients, including those who are at low risk of recurrent seizures, results of a decision analysis suggest.

Taking into account quality of life, seizure risk, and antiepileptic drug (AED) side effects, a model favored treatment of a patient with a single unprovoked seizure who did not meet the International League Against Epilepsy (ILAE) definition of epilepsy, investigators reported.

The model also favored treatment of patients who did meet ILAE criteria, namely, a 10-year recurrence risk greater than 60% in a patient with a single unprovoked seizure, according to the analysis, which was published in the October 9 issue of Neurology.

Together, these findings suggest that the current ILAE epilepsy definition is “too simplistic” for deciding whether to start or withhold AED treatment after a first unprovoked seizure, said M. Brandon Westover, MD, PhD, Associate Professor of Neurology at Massachusetts General Hospital in Boston, and his coauthors.

“A more precise and patient-personalized definition of epilepsy should encompass not only seizure recurrence probability but also a multitude of other risks and benefits associated with AED treatment,” they said.

Weighing Risks and Benefits

To determine which patients with a first unprovoked seizure might benefit from immediate AED treatment, Dr. Westover and his colleagues used a decision model with measures constructed from retrospective clinical trial data.

The goal of the simulation was to determine which treatment strategy—immediate or delayed AED treatment—would maximize the patient’s expected quality-adjusted life years (QALYs). Toward that end, Dr. Westover and his coinvestigators considered three base cases, which represented various degrees of seizure-recurrence risk.

The first case was a 30-year-old man with no risk factors for recurrent seizure other than having had a first seizure. In that case, immediate and deferred AED treatment resulted in 19.04 and 18.65 QALYs, respectively.

“In dollar values, using the conservative approximation of $50,000/QALY gained, this difference in treatment outcomes would amount to $19,500 gained per individual,” Dr. Westover and his coauthors wrote in their report.

The second case was a 30-year-old woman who presented with a first unprovoked seizure and had positive MRI results that establish a high risk of recurrence. As expected, because of the high recurrence risk, this scenario also favored immediate treatment, with 15.23 and 14.75 QALYs, respectively, for the immediate and deferred strategies.

The final case was a wheelchair-bound 60-year-old woman with a first unprovoked seizure and high risk of recurrence, but also a high risk of AED adverse effects and a smaller expected quality of life reduction from further seizures. In this scenario, in which treatment might be “intuitively discouraged” because of the AED side-effect risk, the cohort simulation favored deferred AED treatment by a small margin, the investigators said.

“A high baseline risk for recurrent seizures does not by itself always favor immediate AED treatment,” they said.

Findings May Shift Discussions About Therapy

The conclusion of this decision analysis by Dr. Westover and colleagues is “likely correct” that early treatment of a first unprovoked seizure could be favorable in a wide range of clinical scenarios, according to the authors of an accompanying editorial.

Next Article: