The Absence crisis Are an episode in which the child loses consciousness, stays with the gaze, as if looking at the horizon and does not respond to any stimulus. These episodes last about 10 seconds and start and end abruptly.
This type of crisis is not very common, suffering between 2% and 8% of people with epilepsy, especially in children but can also occur in adults. The cause of this type of crisis is not yet known, although it seems that the genetic component plays an important role in the development of this condition.
The prognosis is quite favorable, in 65% of cases, the seizures respond well to treatment and disappear during adolescence without neuropsychological sequelae.
Characteristics of absence crises
The crisis of absence, previously known as little evil (petit mal), are episodes in which the child loses consciousness, does not respond to the stimuli and leaves the gaze lost, as if he could not see.
For example, they do not realize that someone is talking to them and they do not answer, it can even happen to them while they are talking and they stop talking suddenly. When the crisis ends the person usually does not remember that anything has happened and continues to do the same thing he was doing before.
The episodes usually last about 10 seconds and end abruptly, when the child"wakes up." The seizures are quite frequent and can occur between 1 and 50 times a day, especially if the child is doing some exercise.
People who have absence crisis usually do not have crises with Tonic-clonic seizures (Commonly known as epileptic seizures), although they may have suffered prior or subsequently suffered from developing the epilepsy With absence crisis.
Classification
There are two types of absence crisis:
Simple absence crisis
These crises are characterized by the person sits still without responding to any stimulus for about 10 seconds. These crises are so rapid that, often, the person does not even realize that they have happened, being able to be confused with a lack of temporary attention.
Complex Absence Crisis
Complex absence crises differ from previous ones in that they are longer, last for about 20 seconds, and the person does not sit still, can perform movements or gestures such as flashing repeatedly, moving the mouth as if chewing or moving hands.
The symptoms may be so mild that the person may have the disease for years without realizing it. In children it is often confused with a attention deficit And the first sign that something is wrong is usually that they are late at school.
Between 2% and 8% of the population with epilepsy suffer this type of crisis. Absence seizures usually begin between 4 and 8 years of age in children who do not have any neurological condition and who have normal levels of intelligence . It can also occur in adolescents and young adults, but is much less frequent.
All epilepsies occur because there is abnormal activity in the patient's brain.
Although the exact cause of this abnormal activity is not known, it is known that the genetic component is quite important, since 1/3 of the relatives of children with absence crisis have also suffered this type of absence and it has been found that a 10% of the siblings of these children also develop the disease.
Patients show abnormal activity in the EEG With a peak-wave discharge of 1.5 to 4 Hz (cycles per second) in both brain hemispheres . With other neuroimaging techniques such as Computed tomography wave magnetic resonance , No brain abnormality is observed.
Treatment for absence crises
Currently there is no treatment to cure crises, but to control them. Patients are usually prescribed Ethosuximide (Trade name: Zarontin), valproic acid (Trade name: Depakote) or Lamotrigine (Trade name: Lamictal).
Valproic acid has the advantage that it also serves to treat seizures with tonic-clonic seizures, so they are especially indicated in patients who have these two types of seizures.
If absence seizures are severe and can not be controlled with a single medication, administration of two drugs, usually ethosuximide and valproic acid, is usually combined.
Clinical trials are currently underway to check the efficacy of other drugs in the treatment of absence seizures. The drugs under study are levitaracetam (trade name: Keppra), Topiramate (Trade name: Topamax) and the Zonisamide (Trade name: Zonegram), among others.
Forecast
Absence crises do not have to leave Cognitive sequelae , Although children with this type of epilepsy are often behind in school and have social problems arising from crises.
The prognosis of children with absence crisis is quite favorable, 65% of patients with this type of epilepsy respond well to treatment and seizures usually disappear in adolescence. Although in some cases the crises may continue into adulthood.
Diagnosis of absence crises
Absence crises are difficult to identify, especially simple ones, so people often have the disease for years before it is diagnosed.
In children, the delay in school with respect to their peers is usually the first indicator, although it is necessary to rule out other problems since this sign can occur in multiple diseases and disorders.
In adults it is very difficult to realize, the person himself usually thinks that he has had an attentive lapse or that he was daydreaming. It is easier to identify complex absence crises because some of the following signs are present:
- Repeated blinks.
- Moistening of lips.
- Move your mouth as if you were chewing.
- Finger snapping.
- Move the hands.
Once the person, or their parents (in the case of children), realizes that a problem is occurring it is important that the doctor see. It is normal for the doctor to suspect several neurological disorders and to perform a Electroencephalography (EEG) to observe brain activity.
The EEG is a painless test consisting of the placement of electrodes on the scalp that record the electrical activity of neurons. People with epilepsy have a typical activation pattern, called peak-wave, which can be seen with this test.
Another test, a little more rudimentary, to test if the person has epilepsy with absence crisis is to cause a crisis. This is usually done by asking him to breathe fast, as if he were exercising, since the crisis is more likely to occur under those conditions. This test would not be enough to rule out epilepsy, since the crisis may not occur at that time but the person does suffer from epilepsy.
If you notice in these signs or in someone close these signs it is very important that you go to the doctor to diagnose this or other disorders.
How to differentiate an epilepsy with crisis from absence of daydreaming
If you have noticed the signs mentioned above in you or someone close to you, but do not know if it is an absence crisis or is simply dreaming awake, I recommend that you read the following table, which shows the main differences between these two types Of episodes.
References
- Holmes, G. L., & Fisher, R. S. (September 2013). Childhood Absence Epilepsy. Obtained from Epilepsy Foundation.
- Sirven, J. I., & Shafer, P. O. (March 2014). Absence Seizures. Obtained from Epilepsy Foundation.