Epilepsy
Epilepsy is a group of neurological disorders characterized by epileptic seizures. Epileptic seizures are episodes that can vary from brief and nearly undetectable to long periods of vigorous shaking. These episodes can result in physical injuries including occasionally broken bones. In epilepsy, seizures tend to recur and as a rule, have no immediate underlying cause. Isolated seizures that are provoked by a specific cause such as poisoning are not deemed to represent epilepsy. People with epilepsy in some areas of the world experience stigma due to the condition.
The cause of most cases of epilepsy is unknown. 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. Known genetic mutations are directly linked to a small proportion of cases. Epileptic seizures are the result of excessive and abnormal nerve cell activity in the cortex of the brain.
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.
Signs and Symptoms of Seizures
Generalized Seizures
Generalized seizures are caused by abnormal electrical impulses in the brain and typically occur with no warning. There are six types of generalized seizures.
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Tonic-Clonic (Grand-Mal) Seizure — This seizure causes you to lose consciousness and often collapse. Your body becomes stiff during what's called the "tonic" phase. During the "clonic" phase, muscle contractions cause your body to jerk. Your jaws clamp shut and you may bite your tongue. Your bladder may contract and cause you to urinate. After one to two minutes, you fall into a deep sleep.
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Absence (Petit Mal) Seizure — During these brief episodes, you lose awareness and stare blankly. Usually, there are no other symptoms. They tend to begin and end suddenly and last for about five to 10 seconds, although they can last longer. These seizures may occur several times a day.
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Myoclonic Seizure — These very brief seizures cause your body to jerk, as if shocked by electricity, for a second or two. The jerks can range from a single muscle jerking to involvement of the entire body.
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Clonic Seizure — This seizure causes rhythmic jerking motions of the arms and legs, sometimes on both sides of your body.
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Tonic Seizure — Tonic seizures cause your muscles to suddenly stiffen, sometimes for as long as 20 seconds. If you're standing, you'll typically fall.
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Akinetic or Atonic Seizure — This seizure causes your muscles to relax or lose stength, particularly in the arms and legs. Although you usually remain conscious, it can cause you to suddenly fall and lead to injuries. These seizures also are called "drop attacks."
Focal Seizures
