EPILEPSY Made Easy - Types,Classification, and Diagnosis

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Epilepsy is a group of neurological disorders characterized by epileptic seizures.[10][11] Epileptic seizures are episodes that can vary from brief and nearly undetectable to long periods of vigorous shaking.[1] These episodes can result in physical injuries including occasionally broken bones.[1] In epilepsy, seizures tend to recur and as a rule, have no immediate underlying cause.[10] Isolated seizures that are provoked by a specific cause such as poisoning are not deemed to represent epilepsy.[12] People with epilepsy in some areas of the world experience stigma due to the condition.[1]

The cause of most cases of epilepsy is unknown.[1] Some cases occur as the result of brain injury, stroke, brain tumors, infections of the brain, and birth defects, through a process known as epileptogenesis.[1][2][3] Known genetic mutations are directly linked to a small proportion of cases.[4][13] Epileptic seizures are the result of excessive and abnormal nerve cell activity in the cortex of the brain.[12] The diagnosis involves ruling out other conditions that might cause similar symptoms such as fainting and determining if another cause of seizures is present such as alcohol withdrawal or electrolyte problems. This may be partly done by imaging the brain and performing blood tests. Epilepsy can often be confirmed with an electroencephalogram (EEG), but a normal test does not rule out the condition.

Epilepsy that occurs as a result of other issues may be preventable. Seizures are controllable with medication in about 70% of cases. Inexpensive options are often available.[1] In those whose seizures do not respond to medication, then surgery, neurostimulation, or dietary changes may be considered Not all cases of epilepsy are lifelong, and many people improve to the point that treatment is no longer needed.

Normally brain electrical activity is non-synchronous.[2] Its activity is regulated by various factors both within the neuron and the cellular environment. Factors within the neuron include the type, number and distribution of ion channels, changes to receptors and changes of gene expression.[55] Factors around the neuron include ion concentrations, synaptic plasticity and regulation of transmitter breakdown by glial cells.[55][56]

Epilepsy[edit]
The exact mechanism of epilepsy is unknown,[57] but a little is known about its cellular and network mechanisms. However, it is unknown under which circumstances the brain shifts into the activity of a seizure with its excessive synchronization.

In epilepsy, the resistance of excitatory neurons to fire during this period is decreased.This may occur due to changes in ion channels or inhibitory neurons not functioning properly. This then results in a specific area from which seizures may develop, known as a "seizure focus".Another mechanism of epilepsy may be the up-regulation of excitatory circuits or down-regulation of inhibitory circuits following an injury to the brain. These secondary epilepsies occur through processes known as epileptogenesis. Failure of the blood–brain barrier may also be a causal mechanism as it would allow substances in the blood to enter the brain.

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