Epilepsy

Abstract

Epilepsy is a chronic neurologic disorder characterized by recent epileptic seizures. It occurs in 0.7% of the population. There are many underlying causes. These include essentially anything that can injure the cerebral cortex and include head trauma, tumors, stroke and infection. However, the most common cause is crytogenic (meaning unknown). Medications are the mainstay of treatment. Surgical treatments are also done. These include ablative procedures, implanted devices and split brain procedures (Dudek's part not included).

Keywords: seizure; epilepsy; convulsion; epileptogenic; antiepileptic drugs

Figure 1.

The three cortical areas contributing to seizure onset. (a) The epileptogenic lesion, a structural abnormality that leads to the development of epileptic foci (b). Each focus consists of a group of excessively discharging neurons (blue) surrounded by a zone of inhibited neurons (shaded area) which keeps each focus from spreading to neighbouring neurons (pink). (c) The epileptogenic zone, a large group of excessively discharging neurons (blue) created by the breakdown of the foci and responsible for seizure onset.

Figure 2.

Simulated electroencephalogram (EEG) of a generalized seizure characterized by a tonic–clonic convulsion. Each line tracing (channel) is from electrodes positioned on the scalp as shown in the inset EEG montage. Adapted from Gastaut H and Broughton R (1972) Epileptic Seizures. Springfield, IL: Charles C. Thomas.

Figure 3.

Simulated electroencephalogram of generalized 3‐Hz spike‐and‐wave complexes during an absence seizure. Note the abrupt onset and sudden cessation of the bilaterally synchronous activity. Adapted from Lothman EW and Collins RC (1990) In: Pearlman AL and Collins RC (eds) Neurobiology of Disease. New York: Oxford University Press.

Figure 4.

Coronal section, at the level shown in the inset, illustrating the spread of the seizure discharge. The discharge spreads from the epileptogenic zone in one cerebral hemisphere to the supplementary motor (SM) cortex, into the same areas of the opposite hemisphere across the corpus callosum, and subcortically into the basal ganglia (BG) and thalamus (T). Spreading into descending motor pathways activates muscles resulting in a convulsion.

close

Further Reading

Bazil CW (1994) Living Well with Epilepsy and Other Seizure Disorders: An Expert Explains What You Really Need to Know. New York: Harper Resource.

Cohen‐Gadol AA, Wilhelmi BG, Collignon F et al. (2006) Long‐term outcome of epilepsy surgery among 399 patients with nonlesional seizure foci including mesial temporal lobe sclerosis. Neurosurgery 104(4): 513–524.

Delgado‐Escueta AV and Bourgeois BF (2008) Debate: Does genetic information in humans help us treat patients? PRO‐genetic information in humans helps us treat patients. CON‐genetic information does not help at all. Epilepsia 49(suppl. 9): 13–24.

Engel J, Pedley TA and Arcardi J (eds) (2007) Epilepsia: A Comprehensive Textbook. Philadelphia: Lipincott, Williams and Williams.

Glauser T, Ben‐Menachem E and Bourgeois B (2006) ILAE treatment guidelines: evidence‐based analysis of antiepileptic seizures and syndromes. Epilepsia 47(7): 1094–1120.

Hauser WA and Hesdorffer DC (1990) Epilepsy: Frequency, Causes, and Consequences. New York: Demos.

Hauser WA, Annengus JF and Kernland LT (1994) Incidence of epilepsy and unprovoked seizures. Rochester, Minnesota 1935–1984. Epilepsia 34: 453–460.

Levy RH, Mattson RH and Meldrum BS (eds) (2002) Antiepileptic Drugs, 5th edn. New York: Raven Press.

Lothman EW and Collins RC (1990) Seizures and Epilepsy. In: Pearlman AL and Collins RC (eds) Neurobiology of Disease. New York: Oxford University Press.

Luders HO (2008) Epilepsy Surgery. New York: Raven Press.

Privitera MD, Cavitt J and Ficker DM (2006) Clinicians Guide to Antiepileptic Drug Use. Philadelphia: Lipincott, Williams and Williams.

Schwartzkroin PA (ed.) (1993) Epilepsy: Models, Mechanisms, and Concepts. New York: Cambridge University Press.

Seino M (2006) Classification criteria of epileptic seizures and syndromes. Epilepsy Research 70(suppl. 1): S27–S33. Epub 7 July.

Tellez‐Zenteno JF, Dhar R and Wiebe S (2005) Long‐term seizure outcomes following epilepsy surgery: a systemic review and meta‐analysis. Brain 128(Pt 5) . Epub March.

Wyllie E, Gupta A and Lachhwani K (eds) (2005) The Treatment of Epilepsy: Principles and Practice, 3rd edn. Philadelphia: Williams and Wilkins.

Zucca C, Redaelli F, Epifanio R et al. (2008) Cryptogenic epileptic syndromes related to SCN1A: twelve novel mutations identified. Archives of Neurology 65(4): 489–494.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Spitz, Mark C, and Dudek, F Edward(Dec 2009) Epilepsy. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0000100.pub2]