Seizures Caused by a Stroke

What is a seizure?

Seizures are episodes of erratic brain activity that result in abnormal body movements or loss of consciousness or both. Seizures can happen spontaneously (primary seizures) or as a result of brain damage (due to stroke). Sometimes, your doctor may discuss seizure prevention with you after you have had a stroke because seizures are not uncommon after a stroke. Strokes and seizures both involve the brain.

Find out about the differences and similarities between strokes and seizures here.

What Does a Seizure Look Like?

There are different types of seizures. Typically people think of seizures as episodes of loss of consciousness, shaking of the legs and arms, tongue biting and bowel or bladder incontinence. This type of seizure, commonly called a "generalized tonic-clonic seizure," is one of several seizure types. Other types are much more subtle and can be extremely difficult to identify by an observer. For instance petit mal seizures make people stare quietly into space, while gelastic seizures simply make people laugh.

What is epilepsy?

Epilepsy is the chronic condition in which people have repeated seizures over time.  People who have experienced two or more seizures in their life are said to suffer from epilepsy. Not everyone who experiences a seizure is aware of it. Why? Some seizure types are just too subtle to be recognized.

If you observe (or experience) intermittent abnormal behaviors or movements, talk to your doctor about it. What you have been observing (or experiencing) may be a recurrent seizure.

How Common Are Seizures After a Stroke?

One large study reported that approximately 10% of all ischemic stroke survivors experience at least one seizure by the 5th year after their stroke.

Stroke survivors who experience a stroke that injures the cerebral cortex are the most likely to experience a seizure after the stroke. The risk of a seizure after a hemorrhagic stroke is higher. Approximately 27% of patients with intracerebral hemorrhage and 34% of patients with subarachnoid hemorrhage, suffered at least one seizure during the same time period.

How Common is Epilepsy After a Stroke?

The incidence of new onset epilepsy after a stroke is much lower than the incidence of seizures. Epilepsy after stroke is reported to occur in only 2 to 4% of stroke survivors. Yet, as whole, stroke is the most commonly identified cause of epilepsy in adults older than 35 and accounts for more than 50% of all new cases of epilepsy of known cause in the elderly population.

What Medications Are Used to Treat Stroke-Related Epilepsy?

Stroke-related epilepsy can typically be well controlled with antiseizure medicines. The oldest and most commonly used medicines for this purpose are phenytoin (dilantin) and carbamazepine (tegretol). The high efficacy and low side effect profile of some of the newer anti-epileptic drugs has slowly driven doctors to try new medication regimens. Two of these new medications are levetiracetam (Keppra) and lamotrigine (Lamictal).

I Take my Medicines. Why am I Still Having Seizures?

Some of the most common reasons why people continue to have seizures in spite of taking their medications include:

  • Inadvertently missing doses: Some people just forget to take their medicines. This is especially problematic when someone develops memory problems from a stroke and inadvertently, but frequently, skips doses. In these cases, the help of a caregiver is essential not only to ensure appropriate treatment with antiseizure medications but also with other medicines.
  • Knowingly missing a dose: Some people experience unwanted side effects from their anti-epileptic medicines and decide to skip doses to avoid them. If you develop side effects from your medicines, it is very important that you talk to your doctor about it before you decide to skip a dose.
  • Lack of sleep: For reasons that are not completely understood, people who suffer from epilepsy are more likely to have a seizure when they are sleep-deprived. Some stroke survivors have abnormal sleep patterns due to brain damage, depression or both. If you are sleep-deprived from depression or from any other cause and you are also having seizures in spite of taking your medications, talk to your doctor about it. Sometimes a simple suggestion, such as good sleep hygiene, can help you feel better and stop the seizing.
  • Alcohol: Similar to sleep deprivation, alcohol increases the likelihood that someone will have a seizure. If you have epilepsy and you drink, do so in moderation.
  • Insufficient dose of antiseizure medicine: Antiseizure medicines are broken down in the body by a set of proteins called "enzymes," whose action can be affected by things such as the amount of medication in your bloodstream, your overall health and your nutritional status. These enzymes can also interact with other medications in your bloodstream and cause your daily dose of medicine to build up very high or low blood levels. Both of these situations are dangerous, as they can result in toxicity to your body or in a new bout of seizures, respectively. Because of this, epilepsy doctors routinely rely on blood tests to carefully monitor the medication levels in your bloodstream. One thing you can do to assist your doctor in this difficult task is to bring all your pill bottles, including vitamins and herbal supplements, with you every time you are scheduled to see your doctor.
  • Worsening epilepsy: Epilepsy can get worse over time, regardless of whether or not you take your medicines. In such cases, it is extremely important to change medicines, increase doses of existing medicines or add a second or third medicine to your regimen. It may even be appropriate to ask your doctor whether you should be evaluated for surgery. To assist your doctor, keep a seizure diary and bring it with you to each doctor's visit. This simple tool can be of great value in evaluating whether or not you need changes in your medication regimen.

How can I find a doctor who can treat my seizures?

The best doctors to treat recurrent seizures are called "epileptologists," neurologists who specialize in the diagnosis and treatment of seizures. Ask your primary care physician about an epileptologist in your area.

Edited by Heidi Moawad MD

Development of epilepsy after ischaemic stroke, Pitkänen A, Roivainen R, Lukasiuk K, Lancet Neurology, November 2015

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