Epilepsy - Causes

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Head Injuries in Infants and Children. Infants are at high risk for head trauma. In fact, one study suggested that any infant who had a scalp fracture with a hematoma may be at risk for brain injury. A hematoma is a swelling caused by a broken blood vessel, which creates a large purplish hue like a bruise. Hematoma is quite common after childbirth, but typically causes no problems.

Childhood Viral Infections. A small 2001 study of children with status epilepticus (sustained periods of convulsions) indicated the presence of several pediatric viruses. Human herpesvirus 6 was particularly associated with severe seizures. Herpesvirus 6 is common in children and causes roseola infantum, an acute, but usually benign, illness that can lead to high fever and skin rash.

Hydrocephalus and Shunts. Hydrocephalus occurs when cerebrospinal fluid (CSF) accumulates in the brain, leading to excessive swelling of the brain ventricles. The resulting pressure can damage the brain's tissue. Hydrocephalus itself is not commonly known to cause seizures, but its treatment, which involves insertion of a shunt, may. The shunt is a device that drains the excess fluid from the brain. A 2001 study noted that up to half of children who receive shunts may experience epileptic seizures, particularly if the shunt is placed before 2 years of age. More research on its relationship to epileptic seizures is needed.

Focal Cortical Dysplasia. This is an abnormality in fetal development in which the normal migration of nerve cells is altered. It can cause very severe epilepsy that is difficult to treat.

Other Causes of Seizures in Children. Seizures in infants and children may be due to birth defects, difficulties during delivery, or poisoning.

Causes of Adult-Onset Seizures

Alcohol Abuse. Alcohol abuse is one of the most common causes of adolescent- and adult-onset seizures. Seizures, nearly always generalized tonic-clonic, occur in about 10% of adults during withdrawal. Multiple seizures happen in about 60% of these patients. The first seizure occurs 7 hours to 2 days after the last drink, and the time between the first and last seizure is usually 6 hours or less. [For more information, see In-Depth Report #56: Alcoholism.]

Head Injuries in Adults. Head injuries to adults can cause seizures, with the risk highest in severe head trauma. A first seizure related to the injury can occur years later. People with mild head injuries, which involve loss of consciousness for less than 30 minutes, have only a slight risk that lasts up to 5 years after the injury.