Because epilepsy is caused by abnormal activity in the brain, seizures can affect any process your brain coordinates.
Seizure signs and symptoms may include:
- Contraction and jerking of muscles: When people think of seizures, they usually think of the type in which multiple muscles in the body contract and jerk. However, involuntary muscle contractions can also occur in isolated areas of your body.
- Loss of consciousness: Some seizures may cause a loss of consciousness or awareness that occurs suddenly and can last for a few seconds to hours. With some seizure types, this may be the only sign of a seizure that's visible to others. This may be associated with automatisms-purposeless and repetitive movements done without thought.
- Weakness: Weakness can occur in any area of your body. For instance, you may have weakness in one arm, one leg, or both. Usually, you will have weakness in the same part of the body with recurrent seizures. Weakness in one part of the body may look very much like a stroke, but it resolves when the seizure is over. However, strokes can sometimes cause seizures, so it's not always possible to know the cause of this symptom right away.
- Anxiety: Before a seizure, often a focal seizure, some people feel anxious. This can be its own symptom and/or a signal that a seizure is about to occur (i.e., aura). Some people experience intense anxiety, fear, or a sense of impending doom.
- Staring: Staring into space is a symptom when you have absence seizures. You may appear to be briefly daydreaming or lost in thought when, in fact, you're actually experiencing a seizure.
Symptoms vary depending on the type of seizure.
In most cases, a person with epilepsy will tend to have the same type of seizure each time, so the symptoms will be similar from episode to episode.
Doctors generally classify seizures as either focal or generalized, based on how the abnormal brain activity begins.
When seizures appear to result from abnormal activity in just one area of your brain, they're called focal (partial) seizures.
These seizures fall into two categories:
- Focal seizures without loss of consciousness.
Once called simple partial seizures, these seizures don't cause a loss of consciousness.
They may alter emotions or change the way things look, smell, feel, taste or sound.
They may also result in involuntary jerking of a body part, such as an arm or leg, and spontaneous sensory symptoms such as tingling, dizziness and flashing lights.
- Focal seizures with impaired awareness. Once called complex partial seizures, these seizures involve a change or loss of consciousness or awareness.
During a complex partial seizure, you may stare into space and not respond normally to your environment or perform repetitive movements, such as hand rubbing, chewing, swallowing or walking in circles.
Symptoms of focal seizures may be confused with other neurological disorders, such as migraine, narcolepsy or mental illness.
A thorough examination and testing are needed to distinguish epilepsy from other disorders.
Seizures that appear to involve all areas of the brain are called generalized seizures.
Six types of generalized seizures exist:
- Absence seizures. Absence seizures, previously known as petit mal seizures, often occur in children and are characterized by staring into space or subtle body movements such as eye blinking or lip smacking.
These seizures may occur in clusters and cause a brief loss of awareness.
- Tonic seizures. Tonic seizures cause stiffening of your muscles. These seizures usually affect muscles in your back, arms and legs and may cause you to fall to the ground.
- Atonic seizures. Atonic seizures, also known as drop seizures, cause a loss of muscle control, which may cause you to suddenly collapse or fall down.
- Clonic seizures. Clonic seizures are associated with repeated or rhythmic, jerking muscle movements. These seizures usually affect the neck, face and arms.
- Myoclonic seizures. Myoclonic seizures usually appear as sudden brief jerks or twitches of your arms and legs.
- Tonic-clonic seizures. Tonic-clonic seizures, previously known as grand mal seizures, are the most dramatic type of epileptic seizure and can cause an abrupt loss of consciousness, body stiffening and shaking, and sometimes loss of bladder control or biting your tongue.