Seizure threshold

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The term seizure threshold is used to describe the balance between excitatory (glutaminergic) and inhibitory (GABA-ergic) forces in the brain which affect how susceptible a person is to seizures. Those diagnosed with epilepsy or certain other neurological conditions are more vulnerable to seizures if the threshold is reduced, and should be compliant with their anticonvulsant drug regimen.

Medications that lower seizure threshold include the antidepressant and nicotinic antagonist bupropion, the atypical opioid analgesics tramadol and tapentadol, reserpine, [1] theophylline, [2] , antibiotics (Fluoroquinolones, imipenem, penicillins, cephalosporins, metronidazole, isoniazid) and volatile anesthetics. So can other factors, including:

Cancer and certain disorders of the nervous, cardiovascular and gastrointestinal systems can also influence the severity and frequency of seizures. [5]

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Epilepsy Human neurological disease causing seizures

Epilepsy is a group of neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures are episodes that can vary from brief and nearly undetectable periods to long periods of vigorous shaking. These episodes can result in physical injuries, including occasionally broken bones. In epilepsy, seizures have a tendency 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 may be treated differently in various areas of the world and experience varying degrees of social stigma due to their condition.

Epileptic seizure Period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain

A seizure, formally known as an epileptic seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with loss of consciousness, to shaking movements involving only part of the body with variable levels of consciousness, to a subtle momentary loss of awareness. Most of the time these episodes last less than 2 minutes and it takes some time to return to normal. Loss of bladder control may occur.

Phenytoin chemical compound

Phenytoin (PHT), sold under the brand name Dilantin among others, is an anti-seizure medication. It is useful for the prevention of tonic-clonic seizures and focal seizures, but not absence seizures. The intravenous form is used for status epilepticus that does not improve with benzodiazepines. It may also be used for certain heart arrhythmias or neuropathic pain. It can be taken intravenously or by mouth. The intravenous form generally begins working within 30 minutes and is effective for 24 hours. Blood levels can be measured to determine the proper dose.

Topiramate an anticonvulsant (antiepilepsy) drug

Topiramate, sold under the brand name Topamax among others, is a medication used to treat epilepsy and prevent migraines. It has also been used in alcohol dependence. For epilepsy this includes treatment for generalized or focal seizures. It is taken by mouth.

Photosensitive epilepsy epilepsy characterized by seizures triggered by visual stimuli that form patterns in space or time, such as flashing lights

Photosensitive epilepsy (PSE) is a form of epilepsy in which seizures are triggered by visual stimuli that form patterns in time or space, such as flashing lights; bold, regular patterns; or regular moving patterns.

Myoclonus medical sign

Myoclonus is a brief, involuntary, irregular twitching of a muscle or a group of muscles. It describes a medical sign and, generally, is not a diagnosis of a disease. These myoclonic twitches, jerks, or seizures are usually caused by sudden muscle contractions or brief lapses of contraction. The most common circumstance under which they occur is while falling asleep. Myoclonic jerks occur in healthy people and are experienced occasionally by everyone. However, when they appear with more persistence and become more widespread they can be a sign of various neurological disorders. Hiccups are a kind of myoclonic jerk specifically affecting the diaphragm. When a spasm is caused by another person it is known as a provoked spasm. Shuddering attacks in babies fall in this category.

Clonazepam Benzodiazepine sedative

Clonazepam, sold under the brand Klonopin among others, is a medication used to prevent and treat seizures, panic disorder, and the movement disorder known as akathisia. It is a tranquilizer of the benzodiazepine class. It is taken by mouth. Effects begin within one hour and last between six and twelve hours.

Ketogenic diet High-fat, adequate-protein, low-carbohydrate diet

The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet that in medicine is used mainly to treat hard-to-control (refractory) epilepsy in children. The diet forces the body to burn fats rather than carbohydrates.

Phenobarbital chemical compound

Phenobarbital, also known as phenobarbitone or phenobarb, is a medication of the barbiturate type. It is recommended by the World Health Organization (WHO) for the treatment of certain types of epilepsy in developing countries. In the developed world, it is commonly used to treat seizures in young children, while other medications are generally used in older children and adults. It may be used intravenously, injected into a muscle, or taken by mouth. The injectable form may be used to treat status epilepticus. Phenobarbital is occasionally used to treat trouble sleeping, anxiety, and drug withdrawal and to help with surgery. It usually begins working within five minutes when used intravenously and half an hour when administered by mouth. Its effects last for between four hours and two days.

Tiagabine chemical compound

Tiagabine is an anticonvulsant medication produced by Cephalon that is used in the treatment of epilepsy. The drug is also used off-label in the treatment of anxiety disorders and panic disorder.

Ethosuximide A medication used to treat absence seizures

Ethosuximide, sold under the brand name Zarontin among others, is a medication used to treat absence seizures. It may be used by itself or with other antiseizure medications such as valproic acid. Ethosuximide is taken by mouth.

Reflex seizures are epileptic seizures that are consistently induced by a specific stimulus or trigger making them distinct from other epileptic seizures, which are usually unprovoked. Reflex seizures are otherwise similar to unprovoked seizures and may be focal, generalized, myoclonic, or absence seizures. Epilepsy syndromes characterized by repeated reflex seizures are known as reflex epilepsies. Photosensitive seizures are often myoclonic, absence, or focal seizures in the occipital lobe, while musicogenic seizures are associated with focal seizures in the temporal lobe.

Epilepsy in animals is a group of neurological disorders characterized by seizures, caused by abnormal bursts of electrical activity in the brain. They can start and stop very abruptly and last any amount of time from a few seconds to a few minutes. Canine epilepsy is often genetic but epilepsy in cats and other pets is rarer, likely because there is no hereditary component to epilepsy in these animals.

Myoclonic epilepsy refers to a family of epilepsies that present with myoclonus. When myoclonic jerks are occasionally associated with abnormal brain wave activity, it can be categorized as myoclonic seizure. If the abnormal brain wave activity is persistent and results from ongoing seizures, then a diagnosis of myoclonic epilepsy may be considered.

A generalized tonic–clonic seizure, commonly known as a grand mal seizure or GTCS, is a type of generalized seizure that produces bilateral, convulsive tonic and clonic muscle contractions. Tonic–clonic seizures are the seizure type most commonly associated with epilepsy and seizures in general and the most common seizure associated with metabolic imbalances. It is a misconception that they are the sole type of seizure, as they are the main seizure type in approximately 10% of those with epilepsy.

Post-traumatic seizures (PTS) are seizures that result from traumatic brain injury (TBI), brain damage caused by physical trauma. PTS may be a risk factor for post-traumatic epilepsy (PTE), but a person who has a seizure or seizures due to traumatic brain injury does not necessarily have PTE, which is a form of epilepsy, a chronic condition in which seizures occur repeatedly. However, "PTS" and "PTE" may be used interchangeably in medical literature.

There are many causes of seizures. The factors that lead to a seizure are often complex and it may not be possible to determine what causes a particular seizure, what causes it to happen at a particular time, or how often seizures occur.

A neonatal seizure is a seizure in a baby younger than 4 weeks old. Seizures are abnormally excessive or synchronous neuronal activity in the brain. They are the most frequent neurological problem in the nursery, and often require evaluation and treatment in a neonatal intensive care unit. Seizures in the neonatal population can be categorized into acute symptomatic seizures and genetic or structural causes. Diagnosis relies on identification of the cause of the seizure, and verification of an actual seizure activity by measuring of electrical activity with electroencephalography (EEG). Treatment depends on the cause of the seizure, but often includes pharmacologic treatment with anti-epileptic drugs.

Imepitoin Anti-convulsant medicine used to treat seizures in dogs.

Imepitoin (INN), sold under the brand name Pexion, is an anticonvulsant which is used in veterinary medicine in Europe to treat epilepsy in dogs. It was recently approved in the United States. The drug also has anxiolytic effects. It was originally developed to treat epilepsy in humans, but clinical trials were terminated upon findings of unfavorable metabolic differences in smokers and non-smokers.

Combined hormonal contraception Form of hormonal contraception combining both an estrogen and a progestogen

Combined hormonal contraception (CHC), or combined birth control, is a form of hormonal contraception which combines both an estrogen and a progestogen in varying formulations.

References

  1. Laboratory Tests and Diagnostic Procedures (6 ed.). Elsevier. 2008. pp.  953-993.
  2. Conn's Current Therapy 2018. Elsevier. pp. 1248–1300.
  3. Meyler's Side Effects of Drugs (16 ed.). pp. 492–542.
  4. Goldman-Cecil Medicine (25 ed.). Elsevier. 2012. pp.  762-774.
  5. "Seizure Mechanisms and Threshold". Epilepsy Foundation. Retrieved 2008-03-19.