Causes and Prevention of Seizures

Coloured composite image of a magnetic resonance imaging (MRI) scan of the brain and 2D and 3D computed tomography (CT) scans of the head and neck of a 35 year old patient
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Seizures are episodes characterized by involuntary movements, changes in consciousness or both. They are more likely to occur when a person has a seizure disorder, which is often called epilepsy. Sometimes, people who do not have epilepsy can also experience an unexpected seizure, usually due to different medical conditions of the brain listed below.

Causes of Seizures

Head trauma and brain injury - Severe head trauma may produce sudden seizures at the time of trauma and may also cause brain injuries that result in long lasting epilepsy.

 The reason that some brain injuries cause seizures is that bleeding and scars inside the brain may interfere with the normal electrical activity in the brain, producing cerebral (brain) hyperactivity or erratic nerve stimulation that generates a seizure.

Medical illnesses - Several medical conditions can also interfere with the brain's function, resulting in seizures. These conditions may cause seizures that occur until the illness resolves, but they may also cause of development of a lasting seizure disorder that continues even after the illness resolves.

Illnesses that cause seizures include:

  • Brain tumors - Cancer that starts in the brain itself or cancer that metastasizes (spreads) to the brain from elsewhere in the body can cause swelling and pressure in the brain, disrupting the brain's normal activity, and causing seizures. Seizures may be the first sign that a person has cancer in or near the brain. Often, once the cancer is removed, the seizures no longer continue to occur.
  • Stroke - Strokes cause small or large areas of brain infarct (tissue damage) that may produce seizures by preventing areas of the brain from functioning normally. Strokes in certain regions of the brain, such as the temporal lobe, are more likely to cause a seizure disorder than are strokes in other parts of the brain, such as the brainstem.
  • Hemorrhage - Brain hemorrhage (bleeding in or around the brain) can cause irritation of the brain tissue, which results in seizures. In general, hemorrhagic strokes are more often associated with seizures than are ischemic (lack of blood flow) strokes.
  • Encephalitis/Brain abscess - Brain infections and inflammation are relatively serious, and may produce immediate seizures, as well as lasting epilepsy. Encephalitis is inflammation or infection of the brain tissue. A brain abscess is an enclosed infection in the brain. These are both relatively uncommon types of infection.
  • Meningitis - An infection of the meninges (protective layers that surround the brain) may disrupt brain activity, resulting in a seizure. Most of the time, seizures that are associated with meningitis resolve once the meningitis infection is treated.
  • Metabolic problems - Extreme electrolyte imbalances and liver and kidney failure can disrupt the activity of the neurons in the brain, causing overactivity of the neurons, which manifests as seizures. The seizures that result from electrolyte abnormalities and organ failure often do not continue once the medical problem is resolved.
  • Fevers - Very high fevers can cause seizures, particularly in young children and babies. These types of seizures are called febrile seizures. If your child has a febrile seizure, you need to get medical attention for your child promptly.

    Seizures can also be caused by issues relating to substance use:

    • Alcohol withdrawal - Often, alcohol withdrawal, which is the abrupt discontinuation of alcohol after heavy use, can cause seizures. This reaction can be dangerous, and if you or someone you know experiences alcohol withdrawal seizures, it is essential to get medical attention right away.
    • Use of illicit drugs - Many recreational drugs are associated with seizures. This response is somewhat unpredictable and can happen even if you have used a particular drug without having had associated seizures in the past. If you or someone you know experiences seizures in association with illegal recreational drugs, you should seek medical attention promptly, and be sure to inform the medical team of the drug use so that you can get the right emergency treatment in a timely manner.
    • Drug withdrawal - Withdrawal from certain recreational drugs, which is abrupt discontinuation of drugs after heavy use, can also cause seizures. This is, like alcohol withdrawal, a dangerous reaction that requires emergency medical attention.

    Causes of Epilepsy

    Epilepsy has many causes including including hereditary, congenital, and structural abnormalities, such as brain trauma, strokes, vascular malformations, brain infections, and tumors as described above. However,  for many people with epilepsy a cause cannot be identified, even after an extensive medical evaluation.

    Hereditary epilepsy runs in the family, and people with hereditary epilepsy often develop their first seizure within the first two decades of life.

    In congenital epilepsy, the child is born with the predisposition to have epilepsy, and that may or may not be hereditary. The seizures characteristic of congenital epilepsy generally begin early in life.

    The medical evaluation of patients with seizures usually includes a brain MRI (a detailed picture of the brain) that may show if there are any areas of damage that can predispose to seizures, and an electroencephalogram (EEG), which is a brain wave test that evaluates the function of the brain and may show the presence of abnormal electrical activity typical of seizure disorders. Yet, for some people with epilepsy, these tests can be completely normal.

    Seizure Triggers

    Seizure triggers are events or circumstances that are known to provoke seizures and can be particularly problematic for people with epilepsy. If you have epilepsy, knowing and avoiding these triggers is important to reduce your seizure risk.

    Common seizure triggers include:

    • Alcohol intake - Many people who have epilepsy experience seizures whenever they consume alcohol. This can occur even if the epilepsy is well controlled with anticonvulsants. Alcohol can alter the electrical activity brain in a manner that triggers seizures, and it can also interfere with anticonvulsant metabolism, preventing the medicine from working properly.
    • Lack of sleep – Fatigue that results from lack of sleep or from inadequate sleep is also a well-known trigger of seizures. In fact, a sleep deprived EEG is one of the tests used to evaluate seizure disorders. A sleep deprived EEG is an EEG that is obtained after a period of deliberate lack of sleep. For a person who has epilepsy, a seizure is most likely to occur during the sleep-deprived state, and this makes the EEG confirmation of seizure activity more likely, which assists in diagnosis and treatment. However, sleep deprived EEGs are always done under close medical supervision so that the seizure can be safely controlled.
    • Flashing lights - Photo convulsive seizures are seizures triggered by rapidly flashing lights. While this type of seizure is not common, and is more often a problem for people who have epilepsy, the resulting seizures can be quite severe.
    • Stress, weather changes, certain smells - Most people who have epilepsy also notice specific triggers, such as stress, exposure to certain odors, and even weather changes. The evidence about these factors as a cause of seizures is not consistent, and the triggers differ for each individual.

    An important way for people who have epilepsy to manage the disorder is to learn to identify and recognize personal triggers, and to avoid them as much as possible.

    Seizure Prevention

    Seizures can result in socially awkward situations, physical injury, car accidents, and dangerous falls. Whenever possible, it is best to prevent seizures. There are two main approaches to seizure prevention. The first is with medication:

    • Anticonvulsants are the most effective way for a person with epilepsy to avoid having seizures. There are many anticonvulsant medications that effectively control seizures. If you have epilepsy, your doctor will be able to decide which anticonvulsant or combination of anticonvulsants is most suitable for control of your seizure disorder.
    • Taking anti-seizure medications with regularity is also an important part of seizure control. If you are taking anticonvulsants to prevent seizures, you should take them as directed, and at approximately the same time every day. In general, anti-seizure medication effects can last between 8 and 48 hours, depending on the medication. And maintaining a regular schedule is the best way to maintain an even level of anticonvulsant levels in your body.
    • If you experience side effects from taking anticonvulsants, or if you are dissatisfied with the anticonvulsant that you are taking, it is important to communicate this with your doctor as soon as you can. Anticonvulsants are generally prescribed for seizure control, but are also prescribed for some other medical problems as well. You should not stop taking an anticonvulsant without discussing the matter with a doctor. Suddenly discontinuing your anticonvulsant medications can provoke seizures, and your doctor may advise you to slowly taper off of the anticonvulsant or replace it with another one so that you will not experience a seizure triggered by medication withdrawal.

    The second approach is to avoid seizure triggers. If you have been diagnosed with epilepsy, it is important to maintain lifestyle habits that avoid the known seizure triggers. This means getting enough sleep, not drinking alcohol and being extra cautious about flashing bright lights or any other trigger that you have personally noticed.

    A Word From Verywell

    Epilepsy is a medical condition that impacts your lifestyle. There are a number of known causes that can incite seizures even among people who do not have epilepsy. Many of these are not easy for you to predict or prevent, such as encephalitis or electrolyte imbalance, while some, such as drug withdrawal, are preventable.

    If you have been diagnosed with epilepsy, you can significantly reduce your chances of having a seizure by regularly taking your anticonvulsant medication as prescribed, communicating your concerns about any anticonvulsant medication side effects with your doctor, and learning about seizure triggers so that you can avoid the known seizure triggers. It is also important to pay attention to whether or not you have noticed any particular triggers that occur prior to your seizures, so that you can avoid these situations as well.

    Most people with epilepsy are able to attain good seizure control by taking anti-seizure medication as prescribed and by adopting lifestyle approaches for seizure prevention.

    Source:

    Provoked and reflex seizures: surprising or common? Kasteleijn-Nolst Trenité DG, Epilepsia. 2012 Sep;53 Suppl 4:105-13. doi: 10.1111/j.1528-1167.2012.03620.x.

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