What is epilepsy? Different types of seizures in epilepsy
What is epilepsy?
Epilepsy word is originated from the Greek word epilambanein which means to seize. Epilepsy is the disorder of central nervous system which is characterized by recurrent paroxysmal aberrations of brain functions usually self-limited and brief. There are mainly two possible mechanisms for
1. Loss of the inhibitory control mechanism of central nervous system.
2. Chemical super sensitivity, which increases excitability of neurons.
Each single episode of epilepsy is termed as seizure. A seizure can either lasts for few minutes or can go for hours.
Types of seizures in Epilepsy-
Broadly speaking, we can divide types of seizures in following three parts.
1. Partial seizures-
As the name suggests, this type of seizures are limited to a certain part of the brain. The temporal lobes are the most common originating area for partial seizures. Partial seizures are further classified into the following types.
a) Simple partial seizures-
In this type of partial seizure, there is an initial discharge from a specific, limited neuronal cortical area, which is termed as focus.
b) Complex partial seizure-
This is type of partial seizure in which consciousness is impaired of the patient.
c) Partial evolving to secondary generalised seizures-
The origin of this type of seizure is partial but slowly slowly it evolves as generalised seizure spreading to the whole brain.
2. Generalised seizures-
The name of the seizure is self-explanatory, in this type of seizure; there is simultaneous involvement of both cerebral hemispheres and loss of consciousness. The initial neuronal discharge spreads quickly into the entire gray matter of body. Generalised seizures are further classified into the following types-
a) Absence seizures-
Absence seizures are either of typical type or atypical type. In typical absence seizure, there is rapid onset and cessation of loss of consciousness. In atypical absence seizure, there is slower onset and cessation of loss of consciousness.
b) Myoclonic seizures-
It consist of sudden, very brief, jerking contractions that may involve the entire body or be confined to limited areas.
c) Tonic seizures-
This type of seizures occur mostly in the children and characterized by increased tone in extensor muscles, which results in falling to the ground.
d) Atonic seizures-
In this type of seizure, very sudden decrease in muscle tone occur, which leads to head drop and drooping of limbs. There can be loss of all muscle tone also resulting in falling of patient.
e) Clonic seizure-
This type of seizure almost occurs only in babies or young children. A loss or impairment of consciousness occurs simultaneously with a decrease in muscle tone or with a generalised tonic contraction.
f) Tonic-Clonic (Grand mal) Seizures-
It represents a maximal epileptic response of the brain. Grand mal seizure is characterised by tonic stiffening of all muscle groups, causing the patient to fall.
3) Status epilepticus-
Status epilepticus is another type of seizure. It is defined as condition in which there is a single prolonged seizure lasting more than five minutes or in which there is insufficient time between multiple seizures to permit recovery.
Note- This article is written for the purpose of providing the basic knowledge of epilepsy and should not be considered for medical prescription