Seizure - Causes

Causes

Unprovoked seizures are often associated with epilepsy and related seizure disorders.

Causes of provoked seizures include:

• dehydration
• sleep deprivation
• cavernoma or cavernous malformation is a treatable medical condition that can cause seizures, headaches, and brain hemorrhages. An MRI can quickly confirm or reject this as a cause.
• arteriovenous malformation (AVM) is a treatable medical condition that can cause seizures, headaches, and brain hemorrhages.
• head injury may cause non-epileptic post-traumatic seizures or post-traumatic epilepsy, in which the seizures chronically recur.
• drug overdose or toxicity, for example aminophylline or local anaesthetics
• normal doses of certain drugs that lower the seizure threshold, such as tricyclic antidepressants
• infection, such as encephalitis or meningitis
• fever leading to febrile convulsions (but see above)
• metabolic disturbances, such as hypoglycaemia, hyponatremia or hypoxia
• withdrawal from drugs (anticonvulsants, antidepressants, and sedatives such as alcohol, barbiturates, and benzodiazepines,)
• space-occupying lesions in the brain (abscesses, tumours). In people with brain tumours, the frequency of epilepsy depends on the location of the tumor in the cortical region.
• seizures during (or shortly after) pregnancy can be a sign of eclampsia.
• seizures in a person with hydrocephalus may indicate severe shunt failure.
• haemorrhagic stroke can occasionally present with seizures, embolic strokes generally do not (though epilepsy is a common later complication); cerebral venous sinus thrombosis, a rare type of stroke, is more likely to be accompanied by seizures than other types of stroke
• multiple sclerosis sufferers may rarely experience seizures
• parasitic infections such as cerebral malaria

Some medications produce an increased risk of seizures and electroconvulsive therapy (ECT) deliberately sets out to induce a seizure for the treatment of major depression. Many seizures have unknown causes.

Seizures which are provoked are not associated with epilepsy, and people who experience such seizures are normally not diagnosed with epilepsy. However, the seizures described above resemble those of epilepsy both outwardly, and on EEG testing.

Seizures can occur after a subject witnesses a traumatic event. This type of seizure is known as a psychogenic non-epileptic seizure and is related to posttraumatic stress disorder.