Wednesday, March 30, 2011

Epileptic Seizures

Almost every part of the brain connects either directly or indirectly with every other part, and this creates a serious problem.  If the first part excites the second, the second the third, the third the fourth, and so on until finally the signal re-excites the first part, it is clear that an excitatory signal entering any part of the brain would set off a continuous cycle of re-excitation of all parts.  If this should occur, the brain would be inundated by a mass of uncontrolled reverberating signals - signals that would be transmitting no information but, nevertheless, would be consuming the circuits of the brain so that none of the informational signals could be transmitted.  Such an effect occurs in widespread areas of teh brain during epileptic seizures.

- Fatigue is probably the most important means by which the excess excitability of the brain during epileptic seizures is finally subdued so that the seizure ceases.  Thus, the development of fatigue is a protective mechanism against excess neuronal activity.

- Electroencephalograms (EEG's) provide diagnostic information about the location of abnormal activity in the brain.  They are capable of showing patients undergoing epileptic seizure.

- Epilepsy is a common, neurological disease occurring in at least 40 different (mild, intermediate, and severe) forms.  It is associated with abnormal synchronized discharges of cerebral neurons.

References:
1.  Guyton, Arthur C., & Hall, John E. Textbook of Medical Physiology 11th Edition. 2006.

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