Petit mal seizure

Alternative names
Seizure - petit mal; Absence seizure; Seizure - absence

Definition
A petit mal seizure is a temporary disturbance of brain function caused by abnormal electrical activity in the brain and characterized by abrupt, short-term lack of conscious activity (“absence”) or other abnormal change in behavior.

Causes, incidence, and risk factors

Petit mal seizures occur most commonly in people under age 20, usually in children ages 6 to 12. They may occur in combination with other types of seizures.

Typical petit mal seizures last only a few seconds, with full recovery occurring rapidly and no lingering confusion. Such seizures usually manifest themselves as staring episodes or “absence spells” during which the child’s activity or speech ceases.

The child may stop talking in mid-sentence or cease walking. One to several seconds later, speech or activity resume. If standing or walking, a child seldom falls during one of these episodes.

“Spells” can be infrequent or very frequent, occurring many times per hour. Up to hundreds of seizures can occur in a single day. They may occur for weeks to months before they are noticed. They can interfere with school function and learning. Teachers may interpret these seizures as lack of attention or other misbehavior.

Atypical petit mal seizures begin slower, last longer, and may have more noticeable muscle activity than typical petit mal seizures. There is usually no memory of the seizure.

No cause can usually be found for typical petit mal seizures. No neurologic or other disorders are usually discovered. Atypical seizures may or may not be associated with other neurologic disorders.

Causes may be unidentifiable, or identified as congenital brain abnormalities, complications of kidney or liver disease, or brain injuries from trauma or birth complications. Sometimes, a family history of seizures indicates a hereditary type of seizures.

Symptoms
TYPICAL

     
  • Muscle activity changes
    • No movement    
    • Hand fumbling    
    • Fluttering eyelids    
    • Lip smacking    
    • Chewing

     

  • Consciousness changes
       

    • Staring episodes (unintentional)    
    • Lack of awareness of surroundings    
    • Sudden halt in conscious activity (movement, talking, etc.)    
    • May be provoked by hyperventilation or flashing lights, in some cases    
    • Abrupt beginning of seizure    
    • Each seizure lasts no more than a few seconds    
    • Full recovery of consciousness, no confusion

     

  • No memory of seizure

ATYPICAL

     
  • Atonic seizure
    • No muscle movement    
    • Slumping, loss of posture    
    • Loss of muscle tone    
    • Falling down

     

  • Consciousness changes
       

    • Unintentional staring    
    • Lack of awareness of surroundings    
    • Sudden stop of conscious activity (movement, talking, etc.)    
    • Hand fumbling    
    • Fluttering eyelids    
    • May be provoked by hyperventilation, in some cases    
    • May have slower, gradual beginning of seizure    
    • Each lasts only seconds to minutes    
    • Recovery may be slower    
    • May have short period of confusion or bizarre behavior

     

  • No memory of seizure

Note: Unexplained difficulties in school and learning difficulties may be the first indication of petit mal seizures.

Signs and tests

The physical examination is usually normal, although some neurologic abnormalities may be present in some patients.

Transmission of information from nerve cell to nerve cell occurs by an electrochemical process that can be detected as electrical activity by an electroencephalograph (EEG). A single or multiple EEG exams may be necessary to show changes typical of petit mal seizures. Occasionally, a patient may need to have EEG monitoring from 1 to several days to detect these EEG changes.

Various laboratory tests, a head CT scan, or a head MRI may be used to rule out specific causes of the seizures.

Treatment

As seizures can interfere with learning or result in injury, the goal of treatment is to prevent or minimize the number of seizures and to minimize any side effects of the treatments. In some cases, treatment of identifiable causes may reduce or eliminate seizures.

Anticonvulsant (antiseizure) medications may prevent or minimize the number of seizures. Petit mal seizures usually respond to valproic acid, ethosuximide, clonazepam, and certain other drugs. Response to medications varies and the medication and dosage may have to be adjusted repeatedly. For some drugs, monitoring of plasma drug levels is important for continued control of seizures and reduction of medication side effects.

Absence status epilepticus (multiple, frequently-repeated seizures) may be treated with intravenous medications and other treatments.

Support Groups

A resource you may find helpful is the American Epilepsy Society.

Expectations (prognosis)

Almost all children with petit mal seizures have significantly fewer (or no) seizures with the use of medications. Petit mal seizures may stop spontaneously after the child reaches adulthood, they may continue indefinitely, or the person may progress to a grand mal seizure.

Long-term prognosis depends on whether there are any underlying neurological problems or other seizure types in addition to the petit mal seizures.

Most people with petit mal seizures live a fairly normal life, with few restrictions on school activities or social life. As adulthood approaches, restrictions may be placed on driving or operating dangerous machinery if seizures continue.

Complications

     
  • Learning disabilities  
  • Absence status epilepticus  
  • Injury from falls  
  • Injury caused by seizure during driving/operating machinery  
  • Side effects of medications (with or without symptoms)  
  • Progression to generalized tonic-clonic seizure

Calling your health care provider

Go to the emergency room or call the local emergency number (such as 911) if a seizure lasts longer than 2 to 3 minutes or if there is no history of previous seizures. This is an emergency situation.

Go to the emergency room or call the local emergency number (such as 911) if symptoms of absence status epilepticus occur:

     
  • Prolonged changes in mental status such as confusion or poor responsiveness  
  • Prolonged seizure activity/unconscious activity and automatic behaviors (people may eat or move without being aware of where they are or what they are doing)

This may be an emergency situation.

Call your health care provider if this is the first time the person has had seizures.

Call your health care provider if this is a new type of seizure for the person or if other types of seizures begin occurring.

Call your health care provider if any new symptoms occur, including possible side effects of medications such as changes in mental status (drowsiness, restlessness, confusion, sedation or others), nausea and vomiting, rash, loss of hair, tremors or abnormal movements, rash, fevers, or problems with coordination.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.