Seizure (patient information)
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Seizure On the Web
Editor-In-Chief: C. Michael Gibson, M.S., M.D. ; Assistant Editor-in-Chief: Ethan Leeman
An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement (tonic-clonic seizure) or as mild as a brief loss of awareness. It can manifest as an alteration in mental state, tonic or clonic movements, convulsions, and various other psychic symptoms (such as déjà vu or jamais vu). The medical syndrome of recurrent, unprovoked seizures is termed epilepsy, but seizures can occur in people who do not have epilepsy.
About 4% of people will have an unprovoked seizure by the age of 80 and yet the chance of experiencing a second seizure is between 30% and 50%. Treatment may reduce the chance of a second one by as much as half. Most single episode seizures are managed by primary care physicians (emergency or general practitioners), whereas investigation and management of ongoing epilepsy is usually by neurologists. Difficult-to-manage epilepsy may require consultation with an epileptologist, a neurologist with an interest in epilepsy.
Non-epileptic seizures are paroxysmal events that mimic an epileptic seizure but do not involve abnormal, rhythmic discharges of cortical neurons. They are caused by either physiological or psychological conditions. The latter is discussed more fully in psychogenic non-epileptic seizures.
Medically, when used on its own, the term seizure implies an epileptic seizure. The lay use of this word can also include sudden attacks of illness, loss of control, spasm or stroke. Where the physician is uncertain as to the diagnosis, the medical term paroxysmal event and the lay terms spells, funny turns or attacks may be used.
Types of seizure
There are many types of seizures. These can be classified into two broad groups:
- Primary generalized seizures—seizures begin with widespread involvement of both sides of the brain. Generalized seizures are divided according to the effect on the body, but all involve loss of consciousness. These include absence, myoclonic, clonic, tonic, tonic–clonic, and atonic seizures.
- Absence: In absence seizures, the person may appear to be staring into space with or without jerking or twitching movements of the eye muscles. These periods last for seconds, or even tens of seconds. Those experiencing absence seizures sometimes move from one location to another without any purpose.
- Myoclonic: Myoclonus is brief, involuntary twitching of a muscle or a group of muscles. The most common time for people to encounter them is while falling asleep (hypnic jerk), but myoclonic jerks are also a sign of a number of neurological disorders. Hiccups are also a kind of myoclonic jerk specifically affecting the diaphragm. Also when a spasm is caused by another person it is known as a "provoked spasm". Shuddering attacks with babies also fall in this category. In almost all instances in which myoclonus is caused by Central Nervous System (CNS) disease it is preceded by other symptoms.
- Clonus is a series of involuntary muscular contractions due to sudden stretching of the muscle. Clonus is a sign of certain neurological conditions, and is particularly associated with upper motor neuron lesions such as in stroke, multiple sclerosis, spinal cord damage and hepatic encephalopathy. Unlike the small, spontaneous twitching known as fasciculations (usually caused by lower motor neuron pathology), clonus causes large motions that are usually initiated by a reflex.
- Tonic-clonic: Tonic–clonic seizures (formerly known as grand mal seizures or gran mal seizures) are a type of generalized seizure that affects the entire brain. Tonic–clonic seizures are the seizure type most commonly associated with epilepsy and seizures in general. There are two phases of a seizure, tonic and clonic, and is often preceded by an aura: The person may feel a sense of strong déjà vu, lightheadedness and/or dizziness, unusual (and possibly inappropriate) emotions, intense feelings of discomfort or foreboding, altered vision and hearing (which may or may not include hallucinations), and sometimes other symptoms. In the tonic phase, the person will quickly lose consciousness, and the skeletal muscles will suddenly tense, often causing the extremities to be pulled towards the body or rigidly pushed away from it, which will cause the person to fall if standing. The tonic phase is usually the shortest part of the seizure, usually lasting only a few seconds. Lastly, the clonic part of the seizure is the part most people are familiar with: The person's muscles will start to contract and relax rapidly, causing convulsions. These may range from exaggerated twitches of the limbs to violent shaking or vibrating of the stiffened extremities. The person may roll and stretch as the seizure spreads. The eyes typically roll back or close and the tongue often suffers bruising sustained by strong jaw contractions. Incontinence is seen in some cases.
- Tonic seizures (also called drop seizures, akinetic seizures or drop attacks), are a minor type of seizure. They consist of a brief lapse in muscle tone that are caused by temporary alterations in brain function. The seizures are brief - usually less than fifteen seconds.
- Partial seizures—seizures begin with involvement of a smaller, localized area of the brain. With some partial seizures, the disturbance can still spread within seconds or minutes to involve widespread areas of the brain (secondary generalized seizure). Partial seizures are further divided on the extent to which consciousness is affected (simple partial seizures means consciousness unaffected, and complex partial seizures means consciousness is affected).
What are the symptoms of Seizure?
It may be hard to tell if someone is having a seizure. Some seizures only cause a person to have staring spells, which may go unnoticed. Specific symptoms of a seizure depend on what part of the brain is involved. They occur suddenly and may include:
- Change in alertness; the person cannot remember a period of time
- Mood changes, such as unexplainable fear, panic, joy, or laughter
- Change in sensation of the skin, usually spreading over the arm, leg, or trunk
- Vision changes, including seeing flashing lights
- Rarely, hallucinations (seeing things that aren't there)
- Falling, loss of muscle control, occurs very suddenly
- Muscle twitching that may spread up or down an arm or leg
- Muscle tension or tightening that causes twisting of the body, head, arms, or legs
- Shaking of the entire body
- Tasting a bitter or metallic flavor
Symptoms may stop after a few minutes, or continue for 15 minutes. They rarely continue longer.
What causes Seizure?
Unprovoked seizures are often associated with epilepsy and related seizure disorders.
Causes of provoked seizures include:
- Sleep deprivation
- Cavernoma or cavernous malformation is a treatable medical condition that can cause seizures, headaches, and brain hemorrhages. An MRI can quickly confirm or reject this as a cause.
- Arteriovenous malformation (AVM) is a treatable medical condition that can cause seizures, headaches, and brain hemorrhages. An MRI can quickly confirm or reject this as a cause.
- Head injury may cause non-epileptic post-traumatic seizures or post-traumatic epilepsy, in which the seizures chronically recur.
- Intoxication with drugs
- Drug toxicity, for example aminophylline or local anaesthetics
- Normal doses of certain drugs that lower the seizure threshold, such as tricyclic antidepressants
- Infection, such as encephalitis or meningitis
- Fever leading to febrile convulsions (but see above)
- Metabolic disturbances, such as hypoglycaemia, hyponatremia or hypoxia
- Withdrawal from drugs (anticonvulsants, antidepressants, and sedatives such as alcohol, barbiturates, and benzodiazepines,)
- Space-occupying lesions in the brain (abscesses, tumors)
- Seizures during (or shortly after) pregnancy can be a sign of eclampsia.
- Seizures in a person with hydrocephalus may indicate severe shunt failure.
- Binaural beat brainwave entrainment may trigger seizures in both epileptics and non-epileptics
- Haemorrhagic stroke can occasionally present with seizures, embolic strokes generally do not (though epilepsy is a common later complication); cerebral venous sinus thrombosis, a rare type of stroke, is more likely to be accompanied by seizures than other types of stroke
- Multiple sclerosis sufferers may rarely experience seizures
Some medications produce an increased risk of seizures and electroconvulsive therapy (ECT) deliberately sets out to induce a seizure for the treatment of major depression. Many seizures have unknown causes.
Seizures which are provoked are not associated with epilepsy, and people who experience such seizures are normally not diagnosed with epilepsy. However, the seizures described above resemble those of epilepsy both outwardly, and on EEG testing.
Seizures can occur after a subject witnesses a traumatic event. This type of seizure is known as a psychogenic non-epileptic seizure and is related to posttraumatic stress disorder.
Mild seizures can be induced through a combination of quickly standing, hyperventilation and applying pressure to the sternum.
When to seek urgent medical care?
Call 911 or your local emergency number if:
- A seizure occurs in a person who has never had one before
- It is an unusually long seizure in someone who has a seizure disorder
Report all seizures to the person's health care provider. The doctor may need to adjust or change the person's medications.
A person who has had a new or severe seizure is usually seen in a hospital emergency room. The health care provider will try to diagnose the type of seizure based on the symptoms.
Tests will be done to rule out other medical conditions that cause seizures or similar symptoms. This may include fainting, transient ischemic attack (TIA) or stroke, panic attacks, migraine headaches, sleep disturbances, and others.
Tests may include:
- Blood tests
- CT scan of the head or MRI of the head
- EEG (usually not in the emergency room)
- Lumbar puncture (spinal tap)
Further testing is needed if you have:
- A new seizure without an obvious cause
- Epilepsy (to make sure the person is taking the right amount of medicine)
A single seizure due to an obvious trigger (such as use of a certain drug) is treated by eliminating or avoiding that trigger.
The first aid for a seizure depends on the type of seizure occurring. Generalized seizures will cause the person to fall, which may result in injury. A tonic–clonic seizure results in violent movements that cannot and should not be suppressed. The person should never be restrained, nor should there be any attempt to put something in the mouth. Potentially sharp or dangerous objects should also be moved from the vicinity, so that the individual is not hurt. After the seizure if the person is not fully conscious and alert, they should be placed in the recovery position. Bystanders should remain calm and avoid crowding the person.
It is not necessary to call an ambulance if the person is known to have epilepsy, if the seizure is shorter than five minutes and is typical for them, if it is not immediately followed by another seizure, and if the person is uninjured. Otherwise, or if in any doubt, medical assistance should be sought.
A seizure longer than five minutes is a medical emergency. Relatives and other caregivers of those known to have epilepsy often carry medicine such as rectal diazepam or buccal midazolam in order to rapidly end the seizure.
A sudden fall can lead to broken bones and other injuries. Children who are affected by frequent drop seizures may wear helmets to protect the head during a fall.
The unusual behavior resulting from the chaotic brain activity of a seizure can be misinterpreted as an aggressive act. This may invoke a hostile response or police involvement, where there was no intention to cause harm or trouble.
A seizure response dog can be trained to summon help or ensure personal safety when a seizure occurs. These are not suitable for everybody. Rarely, a dog may develop the ability to sense a seizure before it occurs.
Where to find medical care for a Seizure?
Directions to Hospitals Treating seizure
Prevention of Seizure
There is no specific way to prevent all seizures. However, the following tips may help control some of them:
- Always take your medications as your doctor instructed. Family members should observe and record any seizure information to make sure the person gets proper treatment.
- Get plenty of quality sleep, reduce stress, exercise, and eat a healthy diet. Poor health habits can make you more likely to have more seizures.
You might help lower your risk of seizures if you:
- Use helmets to prevent head injury. This will lessen the likelihood of a brain injury that leads to seizures.
- Avoid illegal street drugs.
You should not drive if you have uncontrolled seizures. Every U.S. state has a different law detailing which people with a history of seizures are allowed to drive. If you have uncontrolled seizures, you should avoid activities where loss of awareness would cause great danger, such as climbing to high places, biking, and swimming alone.