Managing Seizure Risk After Stroke: Who Needs Antiseizure Meds, and for How Long?

Following a stroke, when a first-time convulsive seizure is witnessed or an electrographic one is detected by continuous EEG monitoring, many patients are appropriately started on antiseizure medications (ASMs). Sometimes, however, patients without evidence of seizure may be prescribed ASMs. Most are discharged from the hospital on ASMs. While 65% to 80% of these patients never have another seizure, many remain on ASMs for months or even years. This unduly exposes patients to unnecessary medication use and possible harmful effects and leaves them unjustifiably labeled with an epilepsy diagnosis.

Such concerns, along with guidance on initiating and discontinuing ASMs in patients following a stroke, were discussed in a presentation at the 2023 American Epilepsy Society (AES) annual meeting by Vineet Punia, MD, MS, an epileptologist with Cleveland Clinic’s Epilepsy Center.

“Assessing seizure risk — and patient preference — is critical for optimal management of potential seizures from acute brain injury,” says Dr. Punia. “Clinicians may be uncertain about seizure risk and therefore are reluctant to stop medications.”

Acute symptomatic seizures defined

So-called acute symptomatic seizures occur within seven days of a systemic infection, stroke or head trauma. Termed “symptomatic” for being a symptom of the brain insult, the seizures may be apparent (convulsive) or identified only by EEG. With the increasingly common practice of continuous EEG monitoring in intensive care units, detecting electrographic seizures has become more frequent. According to published reports, up to 15% of stroke patients develop an acute symptomatic seizure.

Starting ASMs

Dr. Punia recommends that identified post-stroke seizures be aggressively treated, as the risk of mortality increases if they continue. “Most patients with convulsive or electrographic seizures during hospitalization should be discharged on an ASM,” he says, noting that the risk of seizure recurrence is high in the immediate period.

In the absence of a documented seizure, he provides the following guidance for determining which patients are at high risk and should start ASMs at discharge:

• Conduct continuous EEG monitoring on high-risk patients. This includes stroke patients whose mental status is not improving as expected following the event. A study led by Dr. Punia of patients who underwent continuous EEG within seven days of a stroke found that epileptiform abnormalities were the main predictors of future seizures, increasing risk twelvefold (Ann Clin Transl Neurol. 2022;9[4]558-563).
• Use the SeLECT score for predicting late seizures after acute ischemic stroke. A higher score, favoring the need for ASMs, includes severe stroke, occurrence of a clinical seizure within seven days of the stroke, presence of large-artery atherosclerosis, cortical involvement and stroke location in the territory of the middle cerebral artery.
• Use the CAVE score for predicting late seizures after an acute hemorrhagic stroke. Higher risk is associated with cortical involvement, age greater than 65 years, blood volume greater than 10 mL and seizure occurrence within seven days of the stroke.

Managing ASMs

Dr. Punia leads research in the use of ASMs in patients following post-stroke seizures. Data from Cleveland Clinic showed that two-thirds of patients who are started on ASMs during hospitalization are discharged on them, with more than 90% continuing on the drugs after their first follow-up visit to the stroke clinic (Ann Clin Transl Neurol. 2021;8[9]:1857-1866). In another study, 90% of patients still on ASMs at six-month follow-up had not had a seizure since hospital discharge, and many patients stayed on ASMs for three years or more. (Neurol Clin Pract. 2022:12[6]e154-e161).

Global practices are similar, according to data from a soon-to-be-published international survey Dr. Punia presented at the AES meeting: about two-thirds of providers continue ASMs at the first 12-week follow-up visit, and just one-third perform testing at that time. Patient preference is considered by only 10%.

“Any patient without a history of epilepsy who is taking ASMs following a stroke needs follow-up with a physician who feels comfortable assessing the need for long-term ASM treatment,” says Dr. Punia, who directs the Post-Acute Symptomatic Seizure (PASS) Clinic at Cleveland Clinic, the lead site of a multicenter network of clinics known as PASSION (PASS Investigation and Outcomes Network). “In our experience, most patients do not need to continue medications for a long time.”

Eight to 12 weeks following hospital discharge with ASMs, Cleveland Clinic patients are seen at the PASS Clinic. Each undergoes one-hour EEG monitoring before seeing a provider. Patients with epileptiform discharges should likely stay on ASMs, Dr. Punia states.

In addition to the patient’s clinical picture and information from EEGs and imaging, he takes the following factors into account:

• Etiology of brain insult. If seizures arose from a temporary problem, such as infection or electrolyte imbalance, the patient can likely discontinue ASMs. Stroke injury, being a more enduring problem, needs further risk assessment using inpatient and outpatient EEG data as well as CAVE and SeLECT scores.
• Patient and family preference. Most patients have a good sense of how much they fear having a future seizure, Dr. Punia notes. He provides them with an estimate of the likelihood of a future seizure — most fall in the range of 10% to 30% — and takes their feelings and risk aversion into account.

“Chronic use of ASMs following stroke is widespread and based on little evidence,” Dr. Punia concludes. “More studies are needed to guide management of this consequential issue.”