What are seizures?
Seizures are recurrent, sudden, abnormal, uncontrolled and excessive periods of electrical activity in the brain that usually only last a few seconds to minutes. They usually cause changes in awareness and consciousness, behavior, and movements.
People who have recurrent seizures are said to have epilepsy.
What causes seizures?
Seizures are caused by a disruption in the nerve cell pathways in the brain. These are the pathways in the brain that create, send and receive electrical impulses. Most seizures are caused by epilepsy, which is a brain condition that intermittently causes episodes of abnormal electrical activity. Some children are born with epilepsy, or it can develop after any type of brain injury, such as a brain infection, stroke, brain tumor, head injury or trauma. Sometimes there is no known cause.
Seizures may also occur following alcohol withdrawal, low blood sugar or other metabolic disturbance, or brought on by certain medications, such as certain pain relievers, antidepressants or smoking cessation therapies, that lower the seizure threshold. These are called provoked seizures and once the problem is corrected, they do not usually occur again.
Some other conditions may resemble symptoms of seizures, but they are not seizures. Examples include fainting, psychological conditions, or muscle disorders. These are called nonepileptic seizures
What are the symptoms of a seizure?
Symptoms of a seizure vary depending on where and how they begin in the brain. Most seizures last from 30 seconds to two minutes. Any seizure that lasts longer than five minutes is considered a medical emergency and urgent medical attention should be sought. Symptoms depend on the type of seizure.
These result from abnormal activity in just one area of the brain.
Symptoms may include:
- Loss of consciousness or impaired awareness
- Apparent daydreaming, staring into space, or lack of response to normal environmental cues
- Repetitive movements, such as chewing, hand rubbing, swallowing or walking in circles
Some focal seizures occur without a loss of consciousness and these may cause symptoms such as a change in the way things look, smell, feel, taste or sound; spontaneous sensory symptoms such as tingling, dizziness and flashing lights; a change in emotions or mood; or involuntary jerking of a body part, such as an arm or leg.
Some focal seizures may be confused with other conditions, such as migraine, narcolepsy or mental illness.
Abnormal electrical activity seems to involve most areas of the brain.
There are several different types of generalized seizure, such as:
- Absence seizures: Typically occur in children and are characterized by staring into space and subtle body movements such as eye blinking or lip-smacking. May occur in clusters and cause a brief loss of awareness.
- Tonic seizures: These cause stiffening of the muscles and may cause you to fall to the ground. Muscles in the back, arms, and legs are usually affected
- Atonic seizures: these cause a sudden loss of muscle control, causing a sudden collapse
- Clonic seizures: These are associated with repeated or rhythmic, jerking muscle movements. Muscles in the neck, face, and arms are usually affected
- Myoclonic seizures: These appear as sudden brief jerks or twitches of the arms and legs
- Tonic-clonic seizures: These can an abrupt loss of consciousness, body stiffening and shaking, loss of bladder control or tongue biting.
How are seizures diagnosed?
See your doctor if experience a seizure for the first time.
Seek emergency help if:
- The seizure lasts more than five minutes
- Breathing is difficult once the seizure has stopped
- Confusion persists once the seizure has stopped
- A second seizure follows soon after the first
- Signs of an infection (eg, fever) are present
- You are pregnant or have diabetes
- If an injury has occurred following the seizure.
Your doctor will order some blood tests, conduct a neurological exam and take a recording of your brain activity, called EEG (electroencephalogram). Imaging scans and other tests may also be ordered.
How are Seizures Treated?
For people with recurrent seizures, treatments may include:
- Antiseizure medications
- Vagus nerve stimulation
- Deep brain stimulation
- Surgery and other therapies
- Dietary therapy (eg, a ketogenic diet).