What are the characteristics of stroke patients at risk for seizures and how are they managed with antiepileptic drugs (AEDs)?

Characteristics of Stroke Patients at Risk for Seizures

Routine prophylactic anticonvulsant therapy is not recommended for stroke patients, as it may harm neurological recovery, and treatment should be reserved for patients who actually experience seizures. 1

High-Risk Patient Characteristics

Stroke-Related Risk Factors

• Cortical involvement significantly increases seizure risk compared to deep hemispheric or infratentorial lesions 1, 2
• Hemorrhagic stroke (ICH) carries higher seizure risk than ischemic stroke 1, 2, 3
• Hemorrhagic transformation of ischemic stroke increases the likelihood of seizures 2
• Larger stroke size and greater stroke severity are associated with increased seizure risk 4

Patient-Specific Risk Factors

• Pre-existing dementia substantially increases the risk of late seizures (occurring >7 days post-stroke) 1, 2
• Elderly patients have higher rates of post-stroke epilepsy, with stroke accounting for 30-40% of epilepsy cases in this population 5, 6

Temporal Classification

• Early seizures (within 24 hours to 7 days) occur in 2-6% of stroke patients, are typically due to acute metabolic disturbances, and are often self-limiting 1, 2, 3
• Late seizures (>7 days post-stroke) occur in 10-12% of patients, indicate development of an epileptogenic focus, and carry >50% recurrence risk 2, 3

Management Approach

Acute Seizure Management

• New-onset seizures during acute stroke should be treated with short-acting medications (e.g., IV lorazepam) if not self-limiting 1, 7
• A single self-limiting seizure within 24 hours should NOT receive long-term anticonvulsant treatment, as recurrence risk within the first week is only 10-20% 1, 7, 3
• All patients with seizures require evaluation for reversible causes (metabolic disturbances, electrolyte abnormalities) in addition to potential AED use 1, 7

When to Initiate Long-Term AED Therapy

• A single late seizure (>7 days post-stroke) carries 71.5% recurrence risk at 10 years and is diagnostic of post-stroke epilepsy, warranting AED treatment 3, 4
• Recurrent seizures should be treated according to standard epilepsy management protocols 1, 7

Critical Contraindication

• Prophylactic AEDs are NOT recommended for stroke patients without seizures, as evidence suggests they may worsen outcomes and impair neural plasticity mechanisms essential for stroke recovery 1, 7, 8
• Traditional AEDs (phenytoin, benzodiazepines) may dampen neural plasticity that contributes to behavioral recovery after stroke 1

Optimal AED Selection

Preferred Agents

• Lamotrigine and gabapentin provide level A evidence for use in elderly patients with epilepsy and are preferred first-line options 5
• Gabapentin is the only AED specifically evaluated in stroke patients, demonstrating high rates of long-term seizure freedom 5
• Levetiracetam is a reasonable alternative given its favorable side effect profile and lack of drug interactions 6

Agents to Avoid

• Phenytoin should be avoided due to harmful impact on functional recovery, bone health concerns, interactions with anticoagulants/antiplatelet agents, and poor tolerability 5, 6
• Carbamazepine requires caution due to interactions with anticoagulants and potential for hyponatremia (particularly problematic in elderly stroke patients) 9, 5
• Valproate is contraindicated in women of childbearing potential due to high teratogenic risk and should be used cautiously in elderly patients due to hepatotoxicity risk 10

Monitoring Recommendations

• Patients with early post-stroke seizures require close monitoring for recurrence during routine vital sign checks 1, 7
• Consider EEG monitoring in high-risk populations: neonates, children with stroke, and adults with unexplained reduced consciousness 1, 2
• Seizure assessment should be part of initial acute stroke evaluation, including monitoring for seizure activity during vital sign checks 1

Key Clinical Pitfalls

• Do not confuse early versus late seizures – this distinction is critical as early seizures have low recurrence risk (10-20%) while late seizures have high recurrence risk (>70%) 2, 3, 4
• Avoid reflexive long-term AED initiation after a single early seizure, as this exposes patients to unnecessary medication risks without clear benefit 1, 7
• Remember that AED side effects may be mistaken for stroke progression (confusion, weakness, unsteadiness), particularly with agents causing hyponatremia 9
• Start AEDs at low doses and titrate slowly in elderly stroke patients to minimize adverse effects 5, 6