Various Classifications of Epilepsy / Seizure

Classification

There are various classification of epilepsy these confuse the issue. Seizure are classified by clinical pattern

(1) Generalized implies abnormal electrical activity that is bilateral n the brain with bilateral motor describes a localized seizure without loss of awareness.

(2) Simple- manifestations. Consciousness is impaired.

(3) A partial seizure without loss of consciousness.

(4) Complex-with loss of awareness.

(5) Unclassifiable seizure.

Generalized seizure types

Tonic-clonic seizures (grand mal seizures, generalized major convulsions)Following a vague warning, the tonic phase commences. The body becomes rigid, for up to a minute.

The patient utters a cry and falls, sometimes suffering serious injury. The tongue is usually bitten. There may be incontinence of urine or faeces.

The clonic phase then begins, a generalized convulsion, with frothing at the mouth and rhythmic jerking of muscles. This lasts from a few seconds to several minutes. Seizures are usually self-limiting, followed by drowsiness, confusion or coma for several hours.

Typical absences (petit mal)

This generalized epilepsy almost invariably begins in childhood. Each attack is accompanied by 3Hz spike-and-wav EEG activity. Activity ceases, the patient stares and pales slightly for a few seconds.

The eyelids twitch; a few muscle jerks may occur. After an attack, normal activity is resumed. Typical absence attacks are never due to acquired lesions such as tumours.

They are a developmental abnormality of neuronal control. Children with typical absences attacks tend to develop generalized tonic-clonic seizure in adult life(known as primary generalized epilepsy).

Petit mal describes only these 3 Hz absences seizures. Clinically similar absence attacks are also caused by partial seizures of temporal lobe origin, a source of some confusion.

Other generalized seizure types

Myoclonic seizure describes isolated muscle jerking. Tonic seizures describe intense stiffening of the body not followed by convulsive jerking. Atonic seizures cause sudden loss of tone, with falling and loss of consciousness.

Partial Seizure types

A partial seizures implies that an area brain (e.g. temporal lobe) has generated abnormal electrical activity that may spread. The seizure frequently has clinical features that provide evidence of its site.

An aura describes effects of initial focal electrical events, such as an unusual smell, tingling in a limb or a strange inner feeling often recognized by the patient as a warning of an impending seizure.

Focal motor Seizures

These simple partial seizures originate in the motor cortex. Jerking movement typically begin at the angle of the mouth or in the thumb and index finger, spreading to involve the limbs on the side opposite the epileptic focus.

The clinical evidence of this spread of activity is called the march of the seizure. With a frontal lesion, conjugate gaze deviates away from the irritative epileptic focus .This is called an adversive seizure. Weakness of the convulsing limbs for several hours sometimes follows a seizure .

Temporal lobe seizures

These partial seizures, either simple or complex, describe feelings of unreality or undue family with the surroundings. Absence attacks, vertigo.

Visual hallucinations are other examples of temporal lobe seizures . Many other type of partial seizure occur, such as autonomic disturbances with piloerection, flushing and over breathing , strange smells, sensory disturbances crude visual shapes or strange sounds .