Types of Epilepsy
Seizures are broadly classified into Generalized Seizures and Focal Seizures.
Generalised Seizures affect both sides of the brain at once and can happen without warning and afterwards they will not remember what happened during the seizure. The common types of generalised seizures are as follows-
1. Generalised tonic clonic seizures - This is the most common type of seizure. It is characterized by sudden loss of consciousness with tightening of the body and generalised jerking as the body relaxes and can last for seconds to a few minutes (usually less than 2 minutes). There can be tongue biting and urinary incontinence during this seizure.
2. Absence Seizure - Absence seizures are more common in children than adults and can happen very frequently. During an absence seizure a person becomes unconscious for a short period and will have a blank stare or a few eye blinks. It is very brief and sometimes mistaken to be day dreaming.
3. Myoclonic seizure - Myoclonic means 'muscle jerk'. Myoclonic seizures are brief but can happen in clusters (many happening close together in time) and often happen shortly after waking.
Focal or partial seizures occur when one part or lobe of the brain generates abnormal electrical activity causing dysfunction of that region of the brain and clinical manifestation depends on the region affected. Patients can have motor or sensory symptoms or both. Sometimes, patients just report visual or unusual feelings like déjá vu.
When consciousness is preserved during an attack, it is a Simple Partial Seizure and when consciousness is impaired then it is Complex Partial Seizure. The commonest type of complex partial seizure is temporal lobe seizures manifested as sudden confusion, patient may be seen fiddling his or her clothes or holding one hand in an abnormal posture lasting for a few seconds to minutes. There can be a warning before the seizure such as a rising feeling in the abdomen and a metallic taste in the mouth.
In many cases, a particular cause for epilepsy, it is called idiopathic epilepsy. Genetic predisposition can be found in patients sometimes.
Epilepsy can also be secondary to various brain insults such as birth trauma caused by lack of oxygen, genetic syndromes, and malformations in the brain during development. Epilepsy can also be acquired later in life due to brain infections, head trauma following accidents, strokes, neuro-degenerative disorders and brain tumors.
Epilepsy is a clinical diagnosis aided by tools like imaging, (eg: CT scan, MRI brain scan) EEG ( Electroencephalogram- recording brain waves using electrodes on the surface head), blood tests. It is thus very important that a person reports to a doctor if he has suffered with single or multiple seizures. It is important to confirm the diagnosis and also look for a cause to see if we can eradicate it.
Epilepsy can be controlled with appropriate medications once diagnosis is confirmed. It is important to classify the epilepsy as generalised or focal when the diagnosis is made so that the correct medications can be administrated. In most people, epilepsy is well controlled with drugs.
In some people, epilepsy is very severe and refractory to treatment with medications alone. In those people, epilepsy surgery option is considered, especially if it is a focal seizure and if we establish with imaging and EEG that the seizures are arising from one focus. The abnormal focus can be surgically removed and it is a good treatment option for established temporal lobe seizures with scarring in the temporal lobe.
Surgery cannot be done for generalised seizures and it is only considered in select patients with focal seizures after a lot of investigations to prove that the patient will benefit from the surgery.
There is also a special diet called ketogenic diet, high in fat, low in protein and almost carbohydrate-free is effective in the treatment of difficult-to-control seizures in children.
Thus epilepsy is a neurological condition which can be treated successfully when recognized early and when you seek medical treatment as early as possible.