Epilepsy
What is Epilepsy?
Epilepsy is a disorder of the nervous system in which seizures (also called fits) or convulsions occur repeatedly in a person. These seizures are caused due to the abnormal release of an electric charge in the brain. Information between the nerve cells are transmitted in the form of electric impulses. Sometimes when these charges become too large, a seizure occurs.
What are the causes?
Most cases of epilepsy are said to be idiopathic i.e. doctors cannot find a clear cause. Thus, 60% of grand mal is "idiopathic" and nearly 100% of classic absence is idiopathic. Partial seizures are always due to focal brain disease.The ones where doctors find a cause are called symptomatic i.e. the fit is a symptom of some brain damage. Among such cases are brain tumour, strokes, head injury, cerebral infection and errors of development that are present since birth. Biochemical cause like low sugar, low calcium, very high sugar and high blood pressure, and less circulation of blood to brain may cause seizures.Idiopathic only means that the doctors are unable to locate the exact cause. However, the cause may be genetic or development abnormalities which are at microscope levels and cannot be seen by the MRI Scan.
What are the symptoms?
Seizures of any of the above type are the main symptoms of epilepsy. Epilepsy in most cases is also associated with some intellectual impairment, though it is not always present. During the seizure, there may also be frothing at the mouth and rolling back of the eyes.
What are the types?
Epileptic seizures are of several types. People with epilepsy may have predominantly one type of seizure, but the degree of the attack may vary and some may have more than one type.Grand mal seizures (generalised tonic clonic seizures) – they are violent seizures that cause whole body convulsions. All major portions of the body are affected and the patient may lose consciousness for sometime. Breathing may stop for some time and the face may become pale. The patient may bite her cheek or tongue during the attack and may lose control over her urinary bladder. Such attacks are often preceded by a loud cry due to spasm of vocal cord.Petit mal (absence) seizures – these are milder seizures and are characterised by a temporary loss of consciousness. Thus, the patient may just stare, stop what he/she is doing and not be aware of what others are saying. There may be repeated blinking of the eye accompanied by a sudden loss of awareness. The attack lasts 10-25 seconds and may occur several times a day. Characteristic of this absence is that the patient is not aware that she is going to get an attack and after the attack is quite normal immediately. There is another form of absence where the patient feels some warning, then is absent for some while and then would like to sleep for 5-10 minutes. This is called Atypical absence. Absence seizures were called Petit mal earlier.Simple focal seizures – these seizures affect a particular part of the body. There are recurrent muscle contractions in that part of the body. This is usually associated with nausea, vomiting and sweating. There is no loss of consciousness. At times an attack can start focally at one part of the body and get generalised and so look like grand mal seizure. When it gets generalised the patient loses consciousness.Complex partial seizures – these seizures are characterised by confusion and an inability to remember the last few minutes. The patient may also get a prior indication of the fit. Warnings are of different types. There may be a smell, or a sound or seeing objects, which are not there. There may be a warning like a sense of fear or confusion or giddiness or a funny feeling in the stomach. The warning is followed by the fit. The fit may be like a usual grand mal or it may be unusual. The child might turn round and round, or run in some direction, or become violent. The person may not be aware of what is happening during the attack, she may not remember what happened after the attack and the attack is brief usually less than 10 minutes.Myoclonic fit. Here there is a sudden involuntary shock like contraction of the limbs. If it affects the hands, objects appear to be thrown out and if it affects the legs the patient may fall and then get up by herself. In children it may affect the trunk and cause falling.
How is the diagnosis made?
Epilepsy is essentially diagnosed by taking a careful history of what happens during an attack. This is best taken from one who has observed the attack. It is only rarely that a doctor can see an attack but if he does he should be able to diagnose. The two conditions, which are most likely to be confused are faints (which are brief losses of consciousness with no jerking and which are known to come under certain circumstances) and a patient who is faking a fit to try and gain sympathy, attention etc. The EEG is a record of the electrical activity of the brain and is often helpful but as the record lasts only 15-30 minutes, it may be normal in a patient whose fits are uncommon (1 EEG is normal in 30-40% of epileptics).Once a diagnosis of epilepsy is made one tries to find a cause either by history or by tests. A CT Scan or MRI is very useful to look for a structural lesion. Blood tests may find biochemical causes low sugar, low calcium etc. Examination of the cerebro-spinal fluid is done if infection is thought to be the cause. In India, one infection particularly known to cause epilepsy is cysticercosis. It often shows a small ring like lesion on the CT Scan or MRI.
What is the treatment?
Epilepsy may be treated with the help of anti-convulsant drugs like phenytoin, sodium valporate, phenobarbitone, carbamazepine, lamotrigine, gabapentin and topiramate. The patient may be able to identify certain materials (which might be some food products) that aggravate the symptoms of the condition. The use of such materials called triggers, must be avoided. The seizures may also be minimized or stopped by treating the underlying cause such as removal of a brain tumour. With the use of one drug, given in proper dose and gradually increased, 65% of all epileptics can be controlled. By adding a second drug and sometimes a third, upto 80% of cases can be fully controlled. For the remaining there are now newer drugs e.g. clobazam, tamotrigene, Vigabatrine.For myoclonic epilepsy, absence and idiopathic grand mal Sodium Valproate is the most commonly used drug. For focal epilepsy phenytoin and carbamezapine is the first choice drug. Phenobarbitone is a cheap and very effective drug and is the mainstay at our Public Health Centers.Surgery may be useful in some partial epilepsies. The important thing in treatment is that drug be continued for 3 years after the last fit and then slowly tapered. Stopping after 6 months - 2 years is a cause of relapse and leads the patient to believe there is no effective treatment and then he seeks other medicines and faith healers. The drugs are very useful if well used.
What are the first aid to be given?
In case a patient is having an epileptic seizure, the following should be done to provide relief: The patient should be made to lie down in a comfortable position on her side, so that the saliva can flow out of the side of the mouth and the person does not gag. All the clothing of the patient must be loosened so that she is able to breathe easily. No hard object like a spoon should be inserted in the mouth of the patient. To prevent her from biting her tongue, she can be made to clamp her teeth on a piece of cloth or a handkerchief. The person should not be made to drink water or any other liquid during the seizure as she may choke. If the patient falls asleep immediately after the seizure, she should be allowed to rest and not be made to move or walk. In simple terms a fit will subside by itself in 1-10 minutes and the attendant only needs to see that the patient does not hurt himself. After the attack is over she should see a doctor or if she is already a known epileptic she should take an extra dose of his usual medicine as the occurrence of a fit implies the dose is inadequate.