The pathogenesis of the epilepsy is very complicated, can be divided into 3 categories, whilst there are many influence factors of the disease:

1.Idiopathic epilepsy
The pathogenesis is suspicious genetic predisposition and no other obvious causes, the disease onset is often at a particular age, the diagnosis is clear with clinical feature and EEG.

2.Symptomatic epilepsy
The central nervous system disorder affect the structure or function etc., such as chromosome abnormality, focal or diffuse disorder of the brain, and some systemic diseases caused by.

A.Localized or diffuse brain disease

(1) Congenital anomaly
The porencephaly deformity, microcephaly, congenital hydrocephalus and cortical dysplasia, corpus callosum absent, fetal brain damage during the perinatal period and so on caused by various pathogenesis during the embryonic development period;
(2) Acquired brain injury
Such as, after the brain injury or brain surgery or stroke or intracranial infection, or acute alcohol intoxication;
(3) Birth injury
The incidence of neonatal seizures is about 1%; during the childbirth period, the birth injury occurs with cerebral hemorrhage or anoxic lesion; during the neonatal period, congenital malformations or birth injury occurs, which will lead to the incidence of epilepsy, 25%;
(4) Inflammation
It includes the infection of bacteria, viruses, fungi, parasites, helix and AIDS and central nervous system complications etc.;
(5) Cerebrovascular diseases
Such as, cerebral arteriovenous malformations, cerebral infarction and cerebral hemorrhage, etc.;
(6) Intracranial tumor
Primary tumor such as glioma, meningioma, etc;
(7) Inherited metabolic diseases
Such as tuberous sclerosis, brain-face angiomatosis, phenylketonuria etc.;
(8) Nervous system degenerative diseases
Such as Alzheimer’s disease, Pick’s disease for about a third of the patients with combined seizures.

B. Systemic disease

(1) Anoxic encephalopathy
Such as cardiac arrest, asphyxia of CO poison, anesthetic accident and respiratory failure, which can cause myoclonic seizures or systemic attack;
(2) Metabolic encephalopathy
Such as hypoglycemia, which most often leads to epilepsy, other metabolic and endocrine disorders, such as hyperglycemia, hypocalcemia, hyponatremia, and uremia, hepatic encephalopathy, and thyroid toxaemia, etc, all of those can cause seizures;
(3) Cardiovascular diseases
Such as cardiac arrest, hypertensive encephalopathy, etc;
(4) Febrile convulsion
Febrile seizure causes hippocampal sclerosis, which is the important pathogenesis of temporal lobe epilepsy secondary to systemic attack and of the refractory epilepsy;
(5) Eclampsia;
(6) Poisoning
Such as alcohol, isoniazid, kappa azole drugs and heavy metal poisoning such as lead, thallium.

3.The cryptogenic epilepsy
It is often occurred among the patient group, the clinical characteristic indicates the diagnosis of symptomatic epilepsy, but did not find a clear etiology, onset in special age, no certification from the special clinical features and EEG.