Cause |
Examples |
High fever |
Infections |
Viral encephalitis |
|
Metabolic disorders |
High blood levels of sugar (hyperglycemia) or sodium Low blood levels of sugar (hypoglycemia), calcium, magnesium, or sodium |
Other disorders |
Kidney failure or liver failure, which can lead to dysfunction of the brain (encephalopathy) Vitamin B6 deficiency (in newborns) |
Inadequate oxygen supply to the brain |
Near suffocation |
Structural damage to the brain |
Brain tumor (noncancerous or cancerous) Intracranial hemorrhage (bleeding within the skull) Stroke |
Abnormalities present or occurring at birth, including genetic disorders |
Hereditary metabolic disorders, such as Tay-Sachs disease or phenylketonuria |
Fluid accumulation in the brain (cerebral edema) |
|
Prescription drugs* |
Buspirone (used to treat anxiety disorders) Camphor *Chlorpromazine (used to treat schizophrenia) Ciprofloxacin (an antibiotic) Chloroquine (used to treat malaria) Clozapine (usually used to treat schizophrenia) Cyclosporine (used to prevent and treat rejection of organ transplants) Imipenem (an antibiotic) *Indomethacin (used to relieve pain and reduce inflammation) *Meperidine (used to relieve pain) *Phenytoin† Theophylline (used to treat asthma and other airway disorders) Tricyclic antidepressants |
Recreational drugs |
Cocaine (overdose) |
Withdrawal of a drug after heavy use |
General anesthetics (used during surgery) Sedatives, including sleep aids |
Exposure to toxins |
Strychnine |
* Various drugs can cause seizures if too much is taken. In some people, certain drugs can make seizures more likely to occur by making nerve cells in the brain easier to stimulate. These drugs are said to lower the seizure threshold. |
|
† Phenytoin, used to treat seizure disorders, can cause seizures if too much is taken. |