Slimedins.comWhich of the following is not true of antiseizure medications?

Epileptic seizure

7.19.2018 | Kennedy

In a complex partial seizure a person may appear confused or dazed and can not respond to questions or direction. Focal seizure may become generalized.

Benzodiazepines given by a non-intravenous route appear to be better than those given by intravenous as the intravenous takes time to start. If there is no effect after two doses, barbiturates or propofol may be used. This may be repeated if there is no effect after 10 minutes. The first line treatment of choice for someone who is actively seizing is a benzodiazepine, most guidelines recommend lorazepam.

Different causes of seizures are common in certain age groups.

They may show signs of other injuries. Most people are in a postictal state (drowsy or confused) following a seizure. A bite mark on the side of the tongue helps confirm a seizure when present, but only a third of people who have had a seizure have such a bite.

In children additional tests may be required. A lumbar puncture may be useful to diagnose a central nervous system infection but is not routinely needed. In adults, testing electrolytes, blood glucose and calcium levels is important to rule these out as causes, as is an electrocardiogram. Routine antiseizure medical levels in the blood are not required in adults or children.

Focal seizures (previously called partial seizures ) are divided into simple partial or complex partial seizure. Current practice no longer recommends this, and instead prefers to describe what occurs during a seizure.

Which of the following is not true of antiseizure medications?
Epileptic seizure

Of those with seizure about 25% have epilepsy. A number of conditions are associated with seizures but are not epilepsy including: most febrile seizures and those that occur around an acute infection, stroke, or toxicity. In many the cause is unknown. Seizures have a number of causes. These seizures are known as "acute symptomatic" or "provoked" seizures and are part of the seizure-related disorders.

Difficulties with withdrawal seizures commonly occurs after prolonged alcohol or sedative use, a condition known as delirium tremens. Both medication and drug overdoses can result in seizures, as may certain medication and drug withdrawal. Common drugs involved include: antidepressants, antipsychotics, cocaine, insulin, and the local anaesthetic lidocaine.

Two-thirds of these begin as focal seizures and become generalized while one third begin as generalized seizures. The remaining 40% of seizures are non-convulsive, an example of which is absence seizure. The most common type of seizure is convulsive (60%). The signs and symptoms of seizures vary depending on the type.

Contrary to a common misconception, bystanders should not attempt to force objects into the mouth of the person suffering a seizure, as doing so may cause injury to the teeth and gums. A seizure longer than five minutes is a medical emergency known as status epilepticus. After the seizure if the person is not fully conscious and alert, they should be placed in the recovery position. Potentially sharp or dangerous objects should be moved from the area around a person experiencing a seizure, so that the individual is not hurt.

Several techniques and methods have been proposed, but evidence regarding their usefulness is still lacking. Scientific work into the prediction of epileptic seizures began in the 1970s.

They all involve a loss of consciousness and typically happen without warning. There are six main types of generalized seizures: tonic-clonic, tonic, clonic, myoclonic, absence, and atonic seizures.

Those who have a seizure that is provoked (occurring close in time to an acute brain event or toxic exposure) have a low risk of re-occurrence, but have a higher risk of death compared to those with epilepsy. In adults, after 6 months of being seizure-free after a first seizure, the risk of a subsequent seizure in the next year is less than 20% regardless of treatment. In those with a status epilepticus, mortality is between 10% and 40%. Up to 7% of seizures that present to the emergency department (ER) are in status epilepticus. The greatest predictors of more seizures are problems either on the electroencephalogram or on imaging of the brain. Following a first seizure, the risk of more seizures in the next two years is 40%–50%.

An electroencephalogram and brain imaging with CT scan or MRI scan is recommended in the work-up of seizures not associated with a fever. Hypoglycemia may cause seizures and should be ruled out. It is important to distinguish primary seizures from secondary causes. Depending on the presumed cause blood tests and/or lumbar puncture may be useful.

Additionally, there are a number of conditions that look like epileptic seizures but are not. Seizures can also occur in people who do not have epilepsy for various reasons including brain trauma, drug use, elevated body temperature, low blood sugar and low levels of oxygen.

Severity, duration, and time at which stress occurs during development all contribute to frequency and susceptibility to developing epilepsy. Stress can induce seizures in people with epilepsy, and is a risk factor for developing epilepsy. It is one of the most frequently self-reported triggers in patients with epilepsy.

Epilepsy results in economic costs in Europe of around 15.5 billion Euros in 2004. They make up about 1% of emergency department visits (2% for emergency departments for children) in the United States. In India, epilepsy is estimated to result in costs of 1.7 billion USD or 0.5% of the GDP. Seizures result in direct economic costs of about one billion dollars in the United States.

These may include: sensory, visual, psychic, autonomic, olfactory or motor phenomena. Focal seizures are often preceded by certain experiences, known as an aura.

In those with a history of febrile seizures, medications (both antipyretics and anticonvulsants) have not been found effective for prevention. Some, in fact, may cause harm.

Jerking activity may start in a specific muscle group and spread to surrounding muscle groups—known as a Jacksonian march. Unusual activities that are not consciously created may occur. These are known as automatisms and include simple activities like smacking of the lips or more complex activities such as attempts to pick something up.

As may hepatic encephalopathy and the genetic disorder porphyria. A number of disorders including: low blood sugar, low blood sodium, hyperosmolar nonketotic hyperglycemia, high blood sodium, low blood calcium and high blood urea levels may cause seizures. Dehydration can trigger epileptic seizures if it is severe enough.

There is a lack of evidence for preventative anti-epileptic medications in the management of seizures related to intracranial venous thrombosis.

If it is normal an epileptic seizure is still possible and a serum prolactin does not separate epileptic seizures from syncope. Serum prolactin level is less useful for detecting partial seizures. A high blood prolactin level within the first 20 minutes following a seizure may be useful to confirm an epileptic seizure as opposed to psychogenic non-epileptic seizure. It is not recommended as a routine part of diagnosis epilepsy.

If this is not effective pyridoxine is recommended. In seizures related to toxins, up to two doses of benzodiazepines should be used. Phenytoin should generally not be used.

Some seizures such as epileptic spasms are of an unknown type. Generalized seizures are divided according to the effect on the body and include tonic-clonic (grand mal), absence (petit mal), myoclonic, clonic, tonic, and atonic seizures. Seizure types are organized by whether the source of the seizure is localized ( focal seizures ) or distributed ( generalized seizures ) within the brain.

At present there is not enough evidence to support the use of cannabis for the management of seizures, although this is an ongoing area of research. There is tentative evidence that a ketogenic diet may help in those who have epilepsy and is reasonable in those who do not improve following typical treatments. Evidence for this, however, is poor. Some claim that seizure response dogs, a form of service dog, can predict seizures. Helmets may be used to provide protection to the head during a seizure.

Gliosis, neuronal loss, and atrophy of specific areas of the brain are linked to epilepsy but it is unclear if epilepsy causes these changes or if these changes result in epilepsy. Focal seizures begin in one hemisphere of the brain while generalized seizures begin in both hemispheres. Some types of seizures may change brain structure, while others appear to have little effect.

In the mid 1800s the first anti seizure medication, bromide, was introduced.

Seizures may occur as a result of high blood pressure, known as hypertensive encephalopathy, or in pregnancy as eclampsia when accompanied by either seizures or a decreased level of consciousness. Typically this requires a temperature greater than 42 °C (107.6 °F). Very high body temperatures may also be a cause.

A number of measures have been attempted to prevent seizures in those at risk. Following traumatic brain injury anticonvulsants decrease the risk of early seizures but not late seizures.

Seizure activity may be propagated through the brain's endogenous electrical fields.

If a person has a previous diagnosis of epilepsy with previous imaging repeat imaging is not usually needed with subsequent seizures. MRI is generally a better imaging test except when intracranial bleeding is suspected. Imaging may be done at a later point in time in those who return to their normal selves while in the emergency room. Diagnostic imaging by CT scan and MRI is recommended after a first non-febrile seizure to detect structural problems inside the brain.

There is no clear evidence that antiepileptic drugs are effective or not effective at preventing seizures following a craniotomy, following subdural hematoma, after a stroke, or after subarachnoid haemorrhage, for both people who have had a previous seizure, and those who have not.

Many areas of the world require a minimum of six months from the last seizure before people can drive a vehicle.

Diseases of the brain characterized by an enduring predisposition to generate epileptic seizures are collectively called epilepsy. An epileptic seizure, also known as an epileptic fit, seizure or fit, is a brief episode of signs or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. The outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness (absence seizure).

Non-epileptic seizures may also occur due to a number of other reasons. Other possible conditions that can mimic a seizure include: decerebrate posturing, psychogenic seizures, tetanus, dystonia, migraine headaches, and strychnine poisoning. In addition, 5% of people with a positive tilt table test may have seizure-like activity that seems to be due to cerebral hypoxia. Differentiating an epileptic seizure from other conditions such as syncope can be difficult. Convulsions may occur due to psychological reasons and this is known as a psychogenic non-epileptic seizure.

This usually lasts 3 to 15 minutes but may last for hours. Psychosis after a seizure is relatively common, occurring in between 6 and 10% of people. Other common symptoms include: feeling tired, headache, difficulty speaking, and abnormal behavior. After the active portion of a seizure, there is typically a period of confusion called the postictal period before a normal level of consciousness returns. Often people do not remember what occurred during this time.

5–10% of people who live to 80 years old have at least one epileptic seizure and the chance of experiencing a second seizure is between 40% and 50%. Epilepsy affects about 1% of the population currently and affected about 4% of the population at some point in time. Most of those affected—nearly 80%—live in developing countries. About 50% of patients with an unprovoked apparent "first seizure" have had other minor seizures, so their diagnosis is epilepsy.

This results in a wave of depolarization known as a paroxysmal depolarizing shift. In epileptic seizures, due to problems within the brain, a group of neurons begin firing in an abnormal, excessive, and synchronized manner. Normally brain electrical activity is non synchronous.

Following an injury to the brain, another mechanism of epilepsy may be the up regulation of excitatory circuits or down regulation of inhibitory circuits. Normally after an excitatory neuron fires it becomes more resistant to firing for a period of time. This is due in part from the effect of inhibitory neurons, electrical changes within the excitatory neuron, and the negative effects of adenosine. These secondary epilepsies occur through processes known as epileptogenesis. In epilepsy the resistance of excitatory neurons to fire during this period is decreased. Failure of the blood–brain barrier may also be a causal mechanism. 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".

Typically one type of anticonvulsant is preferred. They are generally recommended after a second one has occurred. Ongoing anti-epileptic medications are not typically recommended after a first seizure except in those with structural lesions in the brain. Following a first seizure, while immediate treatment with an anti-seizure drug lowers the probability of seizure recurrence up to five years it does not change the risk of death and there are potential side effects. Approximay 70% of people can obtain full control with continuous use of medication.

A first seizure generally does not require long term treatment with anti-seizure medications unless there is a specific problem on either electroencephalogram or brain imaging.

Electroconvulsive therapy (ECT) deliberay sets out to induce a seizure for the treatment of major depression.

A seizure can last from a few seconds to more than five minutes, at which point it is known as status epilepticus. Absence seizures are usually around 10 seconds in duration. Most tonic-clonic seizures last less than two or three minutes.

Known epilepsy though is an uncommon cause of seizures in the emergency department, accounting for a minority of seizure-related visits. 5–10% of people who live to 80 years old have at least one epileptic seizure and the chance of experiencing a second seizure is between 40% and 50%. About 50% of patients with an unprovoked apparent "first seizure" have had other minor seizures, so their diagnosis is epilepsy. About 0.7% in the general population of the United States go to an emergency department after a seizure in a given year, 7% of them with status epilepticus.

This is where mediators of stress interact with their target receptors to produce effects. These hormones act on both excitatory and inhibitory neural synapses, resulting in hyper-excitability of neurons in the brain. The hippocampus is known to be a region that is highly sensitive to stress and prone to seizures. Stress exposure results in hormone release that mediates its effects in the brain.

In certain situations it may be useful to prefer the EEG while sleeping or sleep deprived. It cannot be used to rule out the diagnosis and may be falsely positive in those without the disease. In children it is typically only needed after a second seizure. An electroencephalography is only recommended in those who likely had an epileptic seizure and may help determine the type of seizure or syndrome present.

The word epilepsy derives from the Greek word for "attack". Seizures were long viewed as an otherworldly condition and this view was seen by Hippocrates (400 BC) as treating it as a sacred disease which he wrote about and concluded that it had natural causes just as other diseases did.

Following standardization proposals devised by Henri Gastaut and published in 1970, terms such as "petit mal", "grand mal", "Jacksonian", "psychomotor", and "temporal-lobe seizure" have fallen into disuse.

Which of the following is not true of antiseizure medications?