Prevention of Post-Stroke Seizures and Subsequent Dementia Still Under Evaluation

By Daniel K. Brantley
Tuesday, April 12, 2022

Researchers at Penn State Health Milton S. Hershey Medical Center confirm the correlation between stroke, epilepsy and dementia and seek to improve patient outcomes through appropriate treatment and monitoring.

Of nearly 800,000 Americans who experience stroke annually, at least 4% will develop a seizure within a year of their stroke — and 32,000 individuals will be diagnosed with epilepsy due to post-stroke seizure (PSS).

“Seizure is a frequent and often overlooked and underdiagnosed complication of stroke. In fact, it is the main etiology of diagnosed epilepsy after 65 years [of age],” says Alain Lekoubou Looti, MD, MS, assistant professor of neurology and public health sciences at Penn State College of Medicine and physician at Penn State Health Milton S. Hershey Medical Center. “We need to identify those who are at highest risk of developing seizures and take actions to counsel them appropriately or allocate adequate follow-up and therapeutic resources.”

Dr. Lekoubou led multiple research projects to better understand who is at highest risk and what steps may protect against PSS and subsequent dementia.

Various Therapies, Equal Risk

In 2020, the American Heart Association determined that PSS could be linked to increased risk of death or disability among adults who experience severe ischemic stroke. Curious to know whether specific reperfusion therapies affected the risk for PSS, Dr. Lekoubou and his team performed a meta-analysis of scientific articles published from 1995 to 2019.

They identified 13,753 stroke patients, of whom 592 experienced PSS, a pooled incidence rate of 5.9%. Incidence of PSS varied only slightly based on treatment method:

  • Intravenous therapy (IVT) (6.1%)
  • Mechanical thrombectomy (5.9%)
  • A combination of both (5.8%)

Late PSS, which occurs at more than seven days or later after the stroke, was twice as common as early PSS (6.7% vs. 3.14%).

Dr. Lekoubou says the findings are not particularly novel or unexpected. The results match previously published research on the prevalence of PSS and confirm that the rate of PSS is independent of the type of reperfusion therapy used. Nonetheless, his research provides a framework for subsequent studies on dementia among stroke survivors.

“The current work provides a more definitive answer to a contentious question,” Dr. Lekoubou explains. “Some studies have found a positive association between IV thrombolysis … or mechanical thrombectomy and seizures in stroke patients. On the other hand, several other studies failed to find such an association.”

The team’s rigorous summary of studies that focused on the relationship between PSS and acute reperfusion therapies yielded the following insights:

  • These therapies should not be withheld on the grounds of perceived risk of seizures.
  • Patients with large infarct sizes and severe National Institutes of Health Stroke Scale scores are at risk of PSS and should be closely monitored post-treatment.
  • Those who experienced hemorrhagic transformation are also at high risk of PSS.
  • More scrutiny should be exerted when a patient presents a clinical change not explained by morphological changes or an infarct fails to improve after treatment.
  • Within high-risk populations, continuous electroencephalography monitoring can allow for immediate diagnostic and therapeutic measures.

Determining and Reducing Dementia Risk

The Milton S. Hershey Medical Center team also completed two investigations into how post-stroke seizures interact with dementia risk. Each study relied upon large nationwide administrative databases in the United States.

In the first prospective study, researchers identified young stroke survivors in the commercial database MarketScan. Among this population, those who developed seizures after stroke were 2.5 times more likely to develop dementia than those who did not.

The second study included data on more than 128,000 hospitalized stroke patients taken from the National Inpatient Sample. Information culled from these individuals showed a positive association between seizures, all stroke types and all types of dementia — vascular and Alzheimer’s disease.

“We are continuing our efforts to highlight the contribution of seizures and their biomarkers and define the framework for identifying those biomarkers and preventing dementia by intervening on them,” Dr. Lekoubou says.

He further explains that nearly half of stroke survivors go on to experience dementia after 25 years. However, he adds, careful evaluation and monitoring of patients may reduce this statistic.

At this time, early use of prophylactic antiseizure therapies is not recommended. Additional studies are needed to better grasp PSS risk factors and ensure the therapies do not unnecessarily increase the risk of complications.

Optimal Outcomes Achieved Through Focus

Application of these findings is not relegated to individual providers. According to Dr. Lekoubou, comprehensive stroke centers are impacted as well. The need is such that updated metrics for measuring the quality of care within comprehensive stroke centers have been proposed by the American Heart Association and the American Stroke Association.

Though the updated metrics do not specifically include seizure management, Dr. Lekoubou says centers that have a neuro-ICU and administer IVT and mechanical thrombectomy provide best results, noting that “patients who develop post-treatment complications, such as seizures, are more likely to receive optimal care.”

At Hershey Medical Center’s neuro-ICU, medical intensivists, neurosurgeons and neurologists are working to improve outcomes for stroke patients. These medical professionals will join Dr. Lekoubou and his team as they continue pressing forward with a new study. Once funding is secured, this large collaborative effort will rely upon the assistance of providers within the immediate area and beyond to help identify and recruit patients. Dr. Lekoubou says he hopes these efforts encourage providers to recognize the threat that PSS poses and work to improve outcomes for their own stroke patients.

“Studies have demonstrated that both early- and late-onset seizures accelerate cognitive impairment in stroke survivors,” he adds. “Identifying and treating seizures in stroke survivors should be on the mind of providers at every stage of the disease.”

Visit or call 717-531-3828 to refer a patient or learn more.