The International League Against Epilepsy has developed a classification system that combines clinical description with EEG findings. Over 90% of seizure patients may be classified using this system. Using the international classification scheme, seizures may be divided into partial, generalized, or unclassified.

Table 2. Classification of epileptic seizures

Traditional classification	New nomenclature
Focal motor; Jancksonian seizure	1. Partial seizures (seizures begin locally) 1) Simple (without impairement of consciousness) With motor symptoms With special sensory or somatosensory symptoms With autonomic symptoms With psychic symptoms
Temporal lobe or psychomotor seizures	2)Complex (with impairment of consciousness) Simple partial onset followed by impairment of consciousness - with or without automatisms Impaired consciousness at onset-with or without automatisms 3) Secondarily generalized (partial onset evolving to generalized tonic-clonic seizures)
Petit mal	2. Generalized seizures (bilaterally symmetrical and without local onset) 1) Absence
Minor motor	2) Myoclonic
Limited grand mal	3) Clonic 4) Tonic
Grand mal	5) Tonic-clonic
Drop attacks	6) Atonic 7) Infantile spasms
-	3. Unclassified seizures 4. Status epilepticus (prolonged partial or generalized seizures without recovery between attacks)

1) Partial epileptic seizures

Partial seizures begin in one hemisphere of the brain and, unless they become secondarily generalized, result in an asymmetric seizure. Partial seizures may be described as focal or unilateral seizures and may be subdivided into simple and complex. Partial seizure manifest as alterations in motor functions, sensory or somatosensory symptoms, or autonomic symptoms. If there is no impairment of consciousness, the seizures are classified as simple partial. If there is impairment of consciousness, the seizures are described as complex partial. With complex partial seizures, aberration of behavior (automatisms) may occur. Patients may exhibit inappropriate behavior like lip smacking, tearing of clothing and aimless wandering. Often there is postictal period. Complex partial seizures are more likely to progress to a secondarily generalized seizure.

Table 3. Partial epileptic seizures

	Simple partial seizures (focal)	Complex partial seizures
Consciousness	Unaffected	Impaired
Age group	Any age	Any age
Duration	Seconds-minutes	Minutes
Symptoms	Depends upon focus localization ; no postictal confusion	Depends upon focus localization ; postictal confusion
Ictal EEG	Contralateral epileptiform discharges ; in many instances no ictal abnormalities (in scalp recording)	Unilateral or bilateral epileptiform discharges, diffuse or focal
Special features	An aura is simple partial seizure !	-

Table 4. Secondarily generalized seizures

Initial symptoms	Depends seizure type (simple/complex partial) localization of epileptic focus
Subsequent symptoms	Generalized tonic-clonic convulsion

2) Generalized epileptic seizures

Generalized tonic-clonic seizures are the most common form of epilepsy. It is characterized by the patients losing consciousness and falling at the onset of the seizure. Tonic muscle spasms (rigid posturing of the limbs or torso) occur and may be accompanied by a cry which results from air being moved out of the larynx. Following the tonic phase, there is a period of generalized clonic movements. After the clonic phase, the patients returns to consciousness, but may remain lethargic and confused for varying periods of time.

¨ç Absence seizure
Absence seizure consists of episodes of brief loss of consciousness. Eyelid fluttering, small chewing movements or mild shaking of the hands may be exhibited. The EEG during the seizure has a characteristic 2 to 4 cycles spike and slow wave complex. The patient regain awareness quickly and there is no postictal state. Complex absence seizure may be accompanied by muscle twitching, myoclonic jerking or autonomic manifestations. The patients do not fall as with tonic-clonic seizures.

¨è Tonic-clonic seizures
Tonic-clonic seizures are what many people think as epilepsy. Although they may be preceded by premonitory symptoms known as aura, the majority of patients lose consciousness without warning. The seizure results in a sudden sharp tonic contraction of muscles followed by a period of rigidity. During this period the patient may fall and be injured. During the seizure the patient may cry or moan, lose sphincter control, bite his or her tongue, or develop cyanosis. After the seizure the patient may be unconscious for a variable time, and frequently goes into a deep sleep. Tonic and clonic seizures may occur separately.

¨é Myoclonic
Brief shock-like muscular contractions of the face, trunk, and extremities are known as myoclonic jerks. They may be isolated events or rapidly receptive.

¨ê Atonic
A sudden loss of muscle tone is known as an atonic seizure. This may be described as a head drop, the dropping of a limb, or a slumping to ground.

3) Unclassified seizures

Unclassified seizures include all seizures that cannot be classified because of inadequate or incomplete data.

Table 5. Generalized epileptic seizures

	Absences	Myoclonic seizures	Atonic seizures	Genenalized tonic-clonic seizure
Age group	Children and juveniles	Children and juveniles	Infants and children	Any age
Duration	Few-30 seconds	1-5 seconds	Few seconds	1-3 minutes
Symptoms	Sudden loss of consciousness accompanied by staring and blinking; immediate regain of consciousness	Brief jerks in arms or legs	Sudden loss of muscle tone causing severe head injuries (fall)	Initial cry (sometimes); loss of muscle tone; respiratory arrest; cyanosis; tonic convulsions; clonic convulsions; relaxation followed by deep sleep
Ictal EEG	Bilateral regular 3 (2-4) Hz spike-waves	Polyspike-waves, spike-waves, or sharp and slow waves	Polyspike-waves, flattening, or low-voltage fast activity	Often obscured by muscle artifacts
Special features	Long absence with automatism, lip smacking, chewing, fiddling, fumbling	Often occur in series	-	Possible tongue biting and urinary incontinence