UNDERSTANDING EPILEPSY
What Is Epilepsy ?
The English word epilepsy has Greek origin - epilepsia, meaning 'taking hold of' or 'seizing'. It is a disorder of the brain.
While we are awake or asleep, walking or talking, reading or watching TV, all our actions are controlled by our brain. Our brain is an extremely sensitive and complex organ. It consists of millions of tiny cells called neurons. These neurons generate 'electric current' and all the activity of the brain is in the form of these 'electric charges'.
As long as the brain functions normally, all is well and all our actions are well synchronised. But there are times when suddenly, a group of nerve cells become hyperactive and produce excessive 'electric charge'. Such a sudden excess of electrical discharge by the neurons results in brief moments of confusion or minor spasm. People use different words to describe this spasm. Some refer to it as a 'fit', others call it a 'convulsion' still others call it a 'seizure'.
The tendency to have repeated seizures or fits or convulsions is called EPILEPSY.
TYPES OF EPILEPSY
Epilepsy is not a single disorder. It covers a wide spectrum of problems. Though most seizures are broadly classified under the following two main categories :
- Partial (or Focal) Seizures, and
- Generalised Seizures.
(there are some seizures that cannot be classified under these two categories, hence they appear as Other Seizures).
Partial Or Focal Seizures
Under this category there are further 2 sub-categories :
- Simple Partial Seizure : (also called Jacksonian epilepsy) : is the result of the neurons in only a certain part of the brain ( as compared to the full brain) becoming hyperactive. Such a seizure is characterised by the person experiencing confusion, jerky movements, a tingling feeling, odd mental/emotional events, mild hallucinations, or extreme response to smell and taste.
The seizure lasts for a brief while and after the seizure the patient usually has temporary weakness.
- Complex Partial Seizures : About 80% of this type of seizure originates in the temporal lobe of the brain. Which means the part of the brain that is located close to the ear. Disturbance in this part of the brain results in loss of judgement, involuntary or uncontrolled behaviour or even loss of consciousness.
Whereas in the balance 20% of cases, the disturbance originates in the frontal lobes of the brain. In this type of epilepsy the person sometimes experiences a warning sign before the onset of the seizure. Such a warning is called an 'aura'. Aura can take the form of odd 'smell' or 'visual' or 'sound' related hallucination. Under such a seizure a person may become unconscious for a brief while, appear (to others) as motionless with a vacant stare. Then after a few seconds, the epileptic starts performing repetitive movements like chewing, smacking of lips, licking of the tongue, jerking the head etc. This kind of a seizure generally lasts for 2 -3 minutes.
Generalised Seizures
- Absence (Petit Mal) Seizures : A person experiencing this kind of a seizure, becomes (physically) motionless and loses attention. During this kind of seizure, if the person does not lose consciousness then the seizure may even go unnoticed by others. These are brief seizures, each lasting for 3 - 30 seconds. However, there may be as many as 50 -100 such seizures in a day.
About 25% of patients with Absence Seizure develop Tonic-Clonic seizure (described below).
- Tonic-Clonic Seizures : There are 2 phases in this type of seizure. The Ist phase is called Tonic Phase. (The word Tonic in this case should not be confused with its more common usage, meaning a group of products that stimulate growth/appetite etc.) During Tonic Phase, the muscles suddenly contract, causing the patient to fall and lie rigidly. Most people under this kind of seizure lose consciousness. In some cases (of affected larynx - sound box) there may be a high-pitched musical sound when the patient inhales. Typically such a seizure would last for 10 -30 seconds.
After which, the patient enters the next phase. The Clonic Phase. In this phase the muscles begin to alternate between relaxation and rigidity. The patient tends to lose some control and may pass urine or stools.
The Tonic-Clonic Seizure lasts for about 2 - 3 minutes. The patient however, generally remains unconscious for much longer and awakens to confusion and extreme fatigue.
Other Seizures
Apart from the ones described above, there are other kinds of epilepsies like :
- Myoclonic Epilepsy : This is a rare genetic seizure that can be either mild or severe in nature. In its milder form, the patient experiences brief periods of jerkiness in limited parts of the body (typically restricted to the face or the trunk). In more severe cases, it can take the form of Tonic-Clonic seizure. Severe form of seizures can cause loss of hearing or can result in damage to the brain or heart.
- Atonic (or Akinetic) Epilepsy : This is also called drop attack because during this seizure, a person loses control on the muscle tone. Sometimes the seizure affects only one part of the body (jaws slackens or head drops) and at other times the seizure may affect the whole body. In which case the person suddenly falls.
|
