A stroke occurs when the blood supply to a part of the brain is interrupted or reduced, leading to brain cell death. This happens when a blood vessel is blocked by a clot (ischemic stroke) or bursts (hemorrhagic stroke). Stroke damage can lead to various neurological complications, including difficulties with thinking, memory, communication, and movement. Seizures are among these potential neurological events.
How Often Seizures Occur After Stroke
Approximately 5% of stroke survivors experience at least one seizure. These seizures are categorized into acute symptomatic and delayed, often leading to post-stroke epilepsy.
Acute symptomatic seizures typically manifest within the first week after a stroke, resulting from acute brain injury and inflammation. Their incidence is higher in hemorrhagic strokes and those affecting the cerebral cortex.
Delayed seizures occur more than seven days after the stroke, potentially developing months or years later. When two or more unprovoked seizures occur more than 24 hours apart after a stroke, it is classified as post-stroke epilepsy. The overall risk of developing post-stroke epilepsy is around 3-5%, with the highest risk in the first year.
Why Seizures Develop
Seizures develop after a stroke due to brain tissue damage and subsequent changes during healing. When a stroke deprives brain cells of oxygen, they can become damaged or die, creating an area of altered brain activity. This injured tissue can become hyperexcitable, meaning it is more prone to abnormal electrical discharges that characterize a seizure.
The formation of a glial scar, a type of scar tissue that develops as the brain attempts to repair itself after injury, plays a role in this process. This scar tissue can disrupt normal neural pathways, causing electrical signals to misfire. Brain inflammation following a stroke can also contribute to neuronal instability and increase the likelihood of seizures.
Hemorrhagic strokes, where bleeding occurs in the brain, carry a higher risk compared to ischemic strokes, which are caused by a clot. Strokes that affect the cerebral cortex are also more strongly associated with seizures. The severity of the stroke and the extent of brain tissue damage further impact the risk of developing seizures.
Identifying and Treating Seizures
Seizures can manifest in various ways, from subtle changes in awareness to more dramatic physical symptoms. Focal seizures, originating in a specific brain area, might cause twitching in one limb, sensory disturbances, or brief confusion. Generalized seizures, involving wider brain networks, can lead to loss of consciousness, body stiffening, and rhythmic jerking movements.
Healthcare providers diagnose seizures using clinical observation, patient history, and diagnostic tests. An electroencephalogram (EEG) measures brain electrical activity, helping to identify abnormal patterns associated with seizures. Brain imaging, such as MRI or CT scans, assesses the extent and location of stroke-related damage contributing to seizure activity.
Treatment for post-stroke seizures typically involves anti-seizure medications, also known as anti-epileptic drugs (AEDs). These medications stabilize brain electrical activity to prevent or reduce seizure frequency. The choice of medication depends on the individual’s seizure type, other medical conditions, and potential side effects. Medical consultation is important to determine the appropriate treatment plan and monitor its effectiveness.
Life with Post-Stroke Seizures
Living with seizures after a stroke involves ongoing medical management to maintain seizure control and promote quality of life. While some individuals experience only isolated seizures, others develop recurrent seizures, leading to a diagnosis of post-stroke epilepsy. This condition means a tendency for ongoing unprovoked seizures due to the lasting effects of the stroke on the brain.
The prognosis for individuals with post-stroke epilepsy varies, but many can achieve seizure control with consistent medication adherence. Regular follow-up appointments with a neurologist are important to monitor seizure activity, adjust medication dosages, and address any side effects. Lifestyle adjustments, such as maintaining a regular sleep schedule and avoiding seizure triggers, can also contribute to better management.