Types of Seizures

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Common Types

A seizure is a brief disruption of electrical activity in the brain. Seizures may be convulsions, short periods of unconsciousness, distortion of the senses, or loss of control over movement. The kind of seizure a person has depends on where in their brain the abnormal activity starts and where it spreads. There are two primary types of seizures: generalized and partial.

Generalized seizures affect both cerebral hemispheres (sides of the brain) from the beginning of the seizure. They produce loss of consciousness, either briefly or for a longer period of time, and are sub-categorized into two major types:

  1. Tonic clonic, previously known as grand mal seizures, involve loss of consciousness. The person will fall down if standing and then a rhythmic jerking of the head, arms and legs begin. This type of seizure usually ends after one to three minutes and the person may be confused and want to sleep. A headache sometimes occurs and full recovery takes minutes to hours, depending on the individual.
  2. Absence, previously known as petit mal seizures, are lapses of awareness, sometimes with staring, that begin and end abruptly, lasting only a few seconds. There is no warning and no after-effect.

Partial seizures are the most common type of seizure and they originate from a specific area of the brain. Partial seizures are divided into two groups:

  1. Simple partial seizures are generally brief and do not involve loss of consciousness. The person remains aware of the environment, remembers the experience, but may be limited in how he or she can interact while it is in progress. The character of the seizure is affected by the area of the brain. For example, a seizure that begins in a motor area may cause movement of the hand or face. A simple partial seizure can also be a tingling in the hand or face, visual distortions, a sudden feeling of fear, or a peculiar smell, depending on the location of the seizure activity in the brain.
  2. Complex partial seizures affect consciousness. A person having this type of seizure will be unaware of his surroundings during the seizure. They may wander aimlessly, run, do a series of repetitive movements, pick at clothes, chew, mumble and, to a casual onlooker, appear to be drunk, on drugs or even mentally ill. After the seizure ends, the person will have little or no memory of the actual seizure or what happened during it.

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Infantile Spasms

Infantile spasms may begin up to age 2, but most commonly begin between the 4 and 6 months, with about 90 percent beginning in the first year. The causes are widely variable and in some cases are unknown. However, the most common causes are tuberous sclerosis and perinatal asphyxia (lack of oxygen).

Parents sometimes attribute the cause to pertussis vaccination, a connection that has yet to be proven. Since the peak in onset of spasms occurs at the same age range that the vaccination is given, it is likely that the concurrent timing is the only link.


The characteristic symptoms of infantile spasms are, usually, rapid, though generally not violent , muscular contractions or extensions of limbs or other parts of the body. The spasms last one to two seconds and occur in clusters ranging from a few to more than 100 at a time. Infants may experience up to 60 clusters a day. The episodes rarely occur during sleep but are common in the early morning and just after naps.

The following are behaviors or symptoms that might occur in what is classified as infantile spasms or West syndrome:

  • Repetitive forward head nodding or bobbing
  • Bowing from the waist when sitting
  • Drawing up of knees when lying down
  • Extending/stiffening the neck, trunk, arms and legs
  • Crossing arms across body as if self-hugging
  • Thrusting arms to the side, elbows bent

Infants may cry and show irritability during or after a flurry of spasms.

Spasms are easily missed, especially if they occur singly or in small or infrequent clusters. Other potential symptoms that parents might notice are a loss of muscle tone, loss of head control or reaching ability, loss of eye contact, inattention to sounds, lack of responsiveness, poor smiling, or decrease in alertness.


Almost any condition that can cause brain damage is a potential cause of infantile spasms. Brain abnormalities are seen in about three-fourths of infants with this syndrome. In tracking down the specific cause, the doctor will likely order a variety of laboratory tests and EEGs, plus a CT or MRI brain imaging scan.

The initial step is a detailed medical history and physical examination. Among the signs the doctor will look for are neurological abnormalities that might have been present before the onset of seizures. Since tuberous sclerosis is often associated with infantile spasms, an examination of the skin for possible lesions (hypopigmentation) typical of tuberous sclerosis may be conducted.

Brain-wave patterns are especially informative in diagnosing infantile spasms. EEG tracings taken during and between seizures, and during both sleep and wakefulness are useful in confirming the diagnosis. A chaotic pattern (hypsarrythmia) between seizures is characteristic of those with infantile spasms. The pattern during sleep is markedly different and, in some infants, the disordered waves may be seen to lessen or disappear.

Neuroimaging by CT or MRI is conducted for possible signs of tuberous sclerosis, brain infection, or structural abnormality. If the cause still remains unknown, the initial battery of laboratory tests ordered by the doctor will likely be expanded to rule out metabolic and other potential causes.


Spasms in some infants may stop spontaneously without any treatment. But most will require some form of therapy, the primary drugs for which are adrenocorticotropic hormone (ACTH) or synthetic corticosteroid drug such as prednisone. These therapies can have a dramatic effect in arresting or slowing seizure activity and the treatment period may be relatively short. The side effects can be significant, however, and long-term use of these drugs requires careful monitoring.

Some infants may respond to conventional anticonvulsant drugs such as felbamate, lamotrigine, topiramate and valproic acid. Infantile spasms associated with tuberous sclerosis responds especially well to vigabatrin. However, vigabatrin, which is available in the United States, is toxic to the eye and can cause loss of peripheral vision.

A medically controlled ketogenic diet, may control or reduce seizures in some infants when medications fail. Brain surgery is another option when the seizures are identified with a lesion or structural abnormality that can be removed without damage to vital tissue. For example, new innovations in surgical procedures have begun to increase the success rate for surgery in infants with tuberous sclerosis.


The prognosis for children with infantile spasms is directly related to the cause. Infants with an known cause for their spasms have a better prognosis than those with an unknown cause for their spasms. Infants with no signs of neurological abnormality or developmental delay before the onset of spasms also have better outcomes. Those whose seizures come under control quickly or cease early tend to fair better as well.

Infantile spasms rarely continue beyond age 5, but are sometimes replaced by other seizure types. A significant number of infants with this syndrome have long-term cognitive and learning impairment. Some may have a behavior disorder accompanied by autistic symptoms. These impairments are likely due to the same brain injury that causes the seizures.

The presence of other seizures types with the spasms may also suggest a poor outcome. In the most severe cases, seizures will continue and the condition may evolve to the Lennox-Gastaut syndrome.

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SUDEP stands for Sudden Unexpected Death in Epilepsy

May be the cause of death when:

  • A healthy person with epilepsy dies suddenly without drowning or trauma
  • The person may or may not have had a seizure before death
  • No other reason for death is found upon exam after death
    • Person was not using illegal drugs (example: cocaine)
    • Person did not have a heart attack

The exact cause is not yet known. Some common theories causing SUDEP include:

  • Heart arrythmias (abnormal heart rhythms)
  • Breathing trouble
  • Brain shutdown


  • 1 out of 1,000 patients with epilepsy die unexpectedly each year
  • In those with uncontrolled epilepsy, risk increases to 1 out of every 150 people
  • Risk of SUDEP increases when:
    • Seizures are not well controlled (treatment resistant epilepsy)*
      • Treatment resistant epilepsy = failure of 2 rounds of appropriate and tolerated seizure medication
      • Treatment resistant epilepsy is common in patients with autism
    • A patient suffers from generalized tonic-clonic seizures
    • Seizures happen at night when the person is sleeping

Bereavement Resources

If you have lost a loved one from SUDEP and are looking for more information for support groups in your area, call the Epilepsy Foundation of New Jersey at 800.336.5843.

If you are from another state and would like to find the closest Epilepsy Foundation to you, please visit: www.epilepsyfoundation.org. The main Foundation site will let you find the closest Foundation to your home by entering your zip code.

Oftentimes local hospital systems offer face-to-face bereavement groups for families that have lost a loved one. While these groups may not be SUDEP specific, people do find it helpful to speak with others going through a similar loss.

Other bereavement groups may be offered through local organizations, like community religious centers as well. Should you find that you need to speak to a healthcare professional in private, please do not hesitate to call your physician to obtain the name of someone local that you can speak with.

The following websites listed have a lot of good information about SUDEP. Should you want to learn more about SUDEP, please feel free to visit the sites listed below for more information. These sites, especially the Epilepsy Foundation’s and sudepaware.com are constantly being updated as research becomes more current.

Here is a list of websites with more information on SUDEP:

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