Grand mal seizures occur when the electrical activity over the whole surface of the brain becomes abnormally synchronized. The brain's nerve cells normally communicate with each other by sending electrical and chemical signals across the synapses that connect the cells.
In people who have seizures, the brain's usual electrical activity is altered. Exactly what causes the changes to occur remains unknown in about half the cases.
However, grand mal seizures are sometimes caused by underlying health problems, such as:
Injury or infection
- Traumatic head injuries
- Infections, such as encephalitis or meningitis, or history of such infections
- Injury due to a previous lack of oxygen
Congenital or developmental abnormalities
- Blood vessel malformations in the brain
- Genetic syndromes
- Brain tumors
- Very low blood levels of glucose, sodium, calcium or magnesium
June 10, 2014
- Using or withdrawing from drugs, including alcohol
- Seizures and epilepsy: Hope through research. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/epilepsy/detail_epilepsy.htm. Accessed March 11, 2014.
- Tonic-clonic seizures. Epilepsy Foundation. http://www.epilepsyfoundation.org/aboutepilepsy/seizures/genconvulsive/tonicseizures.cfm. Accessed March 11, 2014.
- Schachter SC. Evaluation of the first seizure in adults. http://www.uptodate.com/home. Accessed March 11, 2014.
- Seizure disorders. The Merck Manuals: The Merck Manual for Health Care Professionals. http://www.merckmanuals.com/professional/neurologic_disorders/seizure_disorders/seizure_disorders.html. Accessed March 11, 2014.
- Schmidt D, et al. Drug treatment of epilepsy in adults. British Medical Journal. 2014;348:g254.
- FDA Drug safety communication: Aseptic meningitis risk with use of seizure drug Lamictal. U.S. Food and Drug Administration. http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm221847.htm. Accessed March 12, 2014.
- Ahmed R, et al. Epilepsy in pregnancy. Australian Family Physician. 2014;43:112.
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