What Causes Epilepsy?

Seizures are symptoms of abnormal brain function. With the exception of very young children and the elderly, the cause of the abnormal brain function is usually not identifiable.

However, when seizures start, the physician will try to identify an underlying etiology (cause). This is because the most specific diagnosis as to why seizures are occurring depends on finding a cause, and proper therapy, and prognosis (or long term outcome) will depend on the cause.

If a specific diagnosis of cause cannot be made, then the epilepsy will be described according to seizure type or epilepsy syndrome.

Symptomatic seizures are called that when they can be linked to identifiable diseases or brain abnormalities.

Cryptogenic seizures are diagnosed when no cause for the seizures can be found. Idiopathic or primary seizures are diagnosed when a genetic (or family) cause for the seizures is suspected. When it is necessary to classify epilepsy according to cause, similar terms are used.

Causes of seizures (and sometimes epilepsy) are further divided into acute and remote causes. This sub-classification depends on whether there is active brain disease (an acute cause) or whether the brain abnormality is the result of an injury caused by a previous event (in which case it would be called remote). For example, if a child with meningitis experiences seizures during the illness, they would be termed acute symptomatic seizures. If that same child developed seizures 2 years afterwards, she would be diagnosed as having remote symptomatic epilepsy.

Many acute symptomatic causes of seizures may, if severe enough, continue to produce recurring seizures (chronic epilepsy) later on.

Potential causes of epilepsy in:
Newborns

  • Brain malformations
  • Lack of oxygen during, or before delivery, or at birth.
  • Low levels of blood sugar, blood calcium, blood magnesium or other electrolyte disturbances
  • Inborn errors of metabolism (chemical disorders)
  • Intracranial hemorrhage (bleeding in the brain)
  • Maternal drug use

Infection

  • Infants and Children
  • Fever (febrile seizures)
  • Brain tumor (rarely)
  • Infections
  • Brain Malformation

Children and Adults

  • Congenital conditions (Down syndrome; Angelman’s syndrome; tuberous sclerosis and neurofibromatosis)
  • Genetic factors (Primary seizure disorders)
  • Progressive brain disease (rare)
  • Head trauma

Elderly

  • Stroke
  • Alzheimer’s disease
  • Head trauma

Information from: Epilepsy Foundation of America.