Epilepsy
Alternate Names : Seizure Disorder
Epilepsy is a disorder of the brain in which seizures occur repeatedly. Seizures are caused by sudden, large discharges of electrical impulses from brain cells.
What is going on in the body?
Neurons are the nerve cells within the brain. They coordinate movement, thinking, personality, and sensory activities. Neurons communicate with each other through electrical discharges. A seizure occurs when excitable neurons give off abnormal electrical discharges. There are different types of seizures, depending on where the excitable neurons are located. Epilepsy is diagnosed when an individual has a repeating pattern of seizures.
Epilepsy is divided into two main types: generalized and partial. Generalized epilepsy affects the entire brain. The person loses consciousness or awareness of the environment. Partial epilepsy affects only one part of the brain. The individual usually doesn't lose consciousness.
Generalized epilepsy may cause the following types of seizures:
absence seizures
atonic seizures
clonic seizures
myoclonic seizures
tonic seizures
tonic-clonic seizures
Partial epilepsy may cause the following types of seizures:
complex partial seizures
secondary generalized seizures
simple partial seizuresWhat are the causes and risks of the condition?
Epilepsy may be caused by many diseases and conditions. Some of the diseases that can cause epilepsy are as follows:
advanced liver disease
Alzheimer's disease and other types of dementia
atherosclerosis, or hardening of the arteries
bleeding into the brain, such as a subarachnoid hemorrhage
infections involving the brain, including encephalitis and bacterial meningitis
brain tumors
congenital diseases or conditions
hereditary diseases
stroke
transient ischemic attack, which is also called a small stroke
Certain conditions that can cause epilepsy include the following:
abnormalities in the blood vessels of the brain
chromosomal abnormalities
craniotomy, which is brain surgery
head injury
illegal drugs, such as cocaine
injury during birth or in the uterus
lead poisoning
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