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Seizures in cats are caused by various onsets. Cats can have reactive, primary (idiopathic) or secondary seizures. Idiopathic seizures are not as common in cats as in dogs however a recent study conducted showed that of 91 feline seizures, 25% were suspected to have idiopathic epilepsy. In the same group of 91 cats, 50% were secondary seizures and 20% reactive.
The mainstay treatment of epilepsy is anticonvulsant medications, possibly for the person's entire life. The choice of anticonvulsant is based on seizure type, epilepsy syndrome, other medications used, other health problems, and the person's age and lifestyle. A single medication is recommended initially; if this is not effective, switching to a single other medication is recommended. Two medications at once is recommended only if a single medication does not work. In about half, the first agent is effective; a second single agent helps in about 13% and a third or two agents at the same time may help an additional 4%. About 30% of people continue to have seizures despite anticonvulsant treatment.
There are a number of medications available including phenytoin, carbamazepine and valproate. Low-quality evidence suggests that phenytoin, carbamazepine, and valproate may be equally effective in both focal and generalized seizures. Controlled release carbamazepine appears to work as well as immediate release carbamazepine, and may have fewer side effects. In the United Kingdom, carbamazepine or lamotrigine are recommended as first-line treatment for focal seizures, with levetiracetam and valproate as second-line due to issues of cost and side effects. Valproate is recommended first-line for generalized seizures with lamotrigine being second-line. In those with absence seizures, ethosuximide or valproate are recommended; valproate is particularly effective in myoclonic seizures and tonic or atonic seizures. If seizures are well-controlled on a particular treatment, it is not usually necessary to routinely check the medication levels in the blood.
The least expensive anticonvulsant is phenobarbital at around $5 USD a year. The World Health Organization gives it a first-line recommendation in the developing world and it is commonly used there. Access however may be difficult as some countries label it as a controlled drug.
Adverse effects from medications are reported in 10 to 90% of people, depending on how and from whom the data is collected. Most adverse effects are dose-related and mild. Some examples include mood changes, sleepiness, or an unsteadiness in gait. Certain medications have side effects that are not related to dose such as rashes, liver toxicity, or suppression of the bone marrow. Up to a quarter of people stop treatment due to adverse effects. Some medications are associated with birth defects when used in pregnancy. Many of the common used medications, such as valproate, phenytoin, carbamazepine, phenobarbitol, and gabapentin have been reported to cause increased risk of birth defects, especially when used during the first trimester. Despite this, treatment is often continued once effective, because the risk of untreated epilepsy is believed to be greater than the risk of the medications. Among the antiepileptic medications, levetiracetam and lamotrigine seem to carry the lowest risk of causing birth defects.
Slowly stopping medications may be reasonable in some people who do not have a seizure for two to four years; however, around a third of people have a recurrence, most often during the first six months. Stopping is possible in about 70% of children and 60% of adults.
Epilepsy is usually treated with daily medication once a second seizure has occurred, while in those at high risk, medication may be started after the first seizure. Supporting people's self management of their condition may be useful. In drug-resistant cases different management options may be looked at including a special diet, the implantation of a neurostimulator, or neurosurgery.
Many antiepileptic drugs are used for the management of canine epilepsy. Oral phenobarbital, in particular, and imepitoin are considered to be the most effective antiepileptic drugs and usually used as ‘first line’ treatment. Other anti-epileptics such as zonisamide, primidone, gabapentin, pregabalin, sodium valproate, felbamate and topiramate may also be effective and used in various combinations. A crucial part of the treatment of pets with epilepsy is owner education to ensure compliance and successful management.
Like other forms of epilepsy, nocturnal epilepsy can be treated with anti-convulsants.
Despite the effectiveness of anti-convulsants in people who suffer from nocturnal epilepsy, the drugs are shown to disrupt a person's sleeping structure. This may cause concern in people who suffer specifically from nocturnal epilepsy because undisrupted sleep is important for these people, as it lowers the likeliness of epileptic symptoms to arise.
One particular study by V. Bradley and D. O'Neill analysed the different forms of epilepsy, including nocturnal epilepsy and its relationship with sleep. They found that some patients only experienced epileptic symptoms while they are asleep (nocturnal epilepsy), and that maintaining good sleep helped in reducing epileptic symptoms. Another study determined that anti-convulsant medications can minimize epilepsy not just in people who are awake, but also in people who are asleep. However, some of these anti-convulsant medications did also have adverse effects on subjects' sleeping structures, which can exacerbate epileptic symptoms in people who suffer from nocturnal epilepsy.
To minimize epileptic seizures in these people, it is important to find an anti-convulsant medication that does not disrupt a person's sleeping structure. The anti-convulsant medications that were tested to meet this criteria are: phenobarbital, phenytoin, carbamazepine, valproate, ethosuximide, felbamate, gabapentin, lamotrigine, topiramate, vigabatrin, tiagabine, levetiracetam, zonisamide, and oxcarbazepine. Oxcarbazepine is shown to have the least amount of adverse effects on sleep. Another study shows that it enhances slow wave-sleep and sleep continuity in patients with epilepsy.
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.
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.
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.
The trigger needs to be identified before prescribing anti-epileptics. The most commonly prescribed drugs for reflex epilepsy are valproate, carbamazepine and clonazepam, though lamotrigine, levetiracetam are promising.
Seven anti-epileptic drugs are approved for use in cases of suspected primary generalized epilepsy:
- Felbamate
- Levetiracetam
- Zonisamide
- Topiramate
- Valproate
- Lamotrigine
- Perampanel
Valproate, a relatively old drug, is often considered the first-line treatment. It is highly effective, but its association with fetal malformations when taken in pregnancy limits its use in young women.
All anti-epileptic drugs (including the above) can be used in cases of partial seizures.
The lack of generally recognized clinical recommendations available are a reflection of the dearth of data on the effectiveness of any particular clinical strategy, but on the basis of present evidence, the following may be relevant:
- Epileptic seizure control with the appropriate use of medication and lifestyle counseling is the focus of prevention.
- Reduction of stress, participation in physical exercises, and night supervision might minimize the risk of SUDEP.
- Knowledge of how to perform the appropriate first-aid responses to seizure by persons who live with epileptic people may prevent death.
- People associated with arrhythmias during seizures should be submitted to extensive cardiac investigation with a view to determining the indication for on-demand cardiac pacing.
- Successful epilepsy surgery may reduce the risk of SUDEP, but this depends on the outcome in terms of seizure control.
- The use of anti suffocation pillows have been advocated by some practitioners to improve respiration while sleeping, but their effectiveness remain unproven because experimental studies are lacking.
- Providing information to individuals and relatives about SUDEP is beneficial.
Though there is limited evidence, outcomes appear to be relatively poor with a review of outcome studies finding that two thirds of PNES patients continue to experience episodes and more than half are dependent on social security at three-year followup. This outcome data was obtained in a referral-based academic epilepsy center and loss to follow-up was considerable; the authors point out ways in which this may have biased their outcome data. Outcome was shown to be better in patients with higher IQ, social status, greater educational attainments, younger age of onset and diagnosis, attacks with less dramatic features, and fewer additional somatoform complaints.
In 1999, Sachdeo and colleagues at the University of Medicine and Dentistry of New Jersey and the Robert Wood Johnson Medical School in New Brunswick reported that 33% of the patients in a group of patients taking topiramate experienced a minimum 50% reduction in seizures (specifically drop attacks and tonic–clonics), compared with 8% in the placebo group. It was also found to be effective as an adjunctive therapy in a review published by Drs. Edith Alva Moncayo and Antonio Ruiz Ruiz in March 2003.
Motte reported in 1997 that lamotrigine was effective in the treatment of LGS, with the most common side effect in the treatment group relative to placebo being colds or viral illnesses. Two years later, it was approved by Health Canada for adjunctive therapy in Lennox Gastaut in adults and children. The United States Food and Drug Administration approved it for that in August 1998.
Felbamate is indicated in the use of LGS in the event that everything else fails, and was found to be superior to placebo in controlling treatment resistant partial seizures and atonic seizures. However, it has been known to cause aplastic anemia and liver toxicity.
The ketogenic diet mimics some of the effects of starvation, in which the body first uses up glucose and glycogen before burning stored body fat. In the absence of glucose, the body produces ketones, a chemical by-product of fat metabolism that has been known to inhibit seizures.
A modified version of a popular low-carbohydrate, high-fat diet which is less restrictive than the ketogenic diet.
The low glycemic index treatment (LGIT) is a new dietary therapy currently being studied to treat epilepsy. LGIT attempts to reproduce the positive effects of the ketogenic diet. The treatment allows a more generous intake of carbohydrates than the ketogenic diet, but is restricted to foods that have a low glycemic index, meaning foods that have a relatively low impact on blood-glucose levels.
These foods include meats, cheeses, and most vegetables because these foods have a relatively low glycemic index. Foods do not have to be weighed, but instead careful attention must be paid to portion size and balancing the intake of carbohydrates throughout the day with adequate amounts of fats and proteins.
Deep brain stimulation of the anterior nuclei of the thalamus is approved for DRE in some countries in Europe, but has been and continues to only be used in a very few patients. After 5 years of DBS a seizure reduction of 69% and a 50%-responder rate of 68% was reported in a randomized-double blinded trial. The rate of serious device related events was 34% in this study.
Responsive neurostimulation (RNS) is approved for DRE in the USA and involves stimulation directly to 1 or 2 seizure foci when abnormal electrocorticographic activity is detected by the devices software. After 2 years of RNS a seizure reduction of 53% was reported in a randomized-double blinded trial as well as a rate of serious device related events of 2.5%.
Transcutaneous vagus nerve stimulation (tVNS) is approved for DRE in some European countries and involves externally stimulating the auricular branch of the vagus nerve in the ear. tVNS failed to demonstrate efficacy in a first randomized-double blinded trial: responder rates did not differ between active and control groups potentially indicating a placebo effect behind the 34% seizure reduction seen in the patients who completed the full follow-up period.
A modified Atkins diet describes the long term practice of the first phase of the popular Atkins diet the so-called induction phase to reduce seizures through ketosis. In this diet the fat content of the nutrition is slightly lower than in the ketogenic diet at around 60%, the protein content is around 30% and the carbohydrate content is around 10% rendering the diet less restrictive and more compatible with the daily life compared to the ketogenic diet. Several studies show that the modified Atkins diet produces a similar or slightly lower seizure reduction to the ketogenic diet. Some physicians, especially in the USA, recommend the modified Atkins diet because they assume that patients will adhere to it on the long-term because it is more compatible with daily life and the meals are more enjoyable. It has also been concluded in another study that the diet is well tolerated and effective in hard to treat childhood epilepsy.
Potentially sharp or dangerous objects should be moved from the area around a person experiencing a seizure, so that the individual is not hurt. After the seizure if the person is not fully conscious and alert, they should be placed in the recovery position. A seizure longer than five minutes is a medical emergency known as status epilepticus. 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.
The treatment for seizures may include antiepileptic medications, diet, and vagus nerve stimulator.
No high quality evidence has shown any drug very useful as of 2013. Rufinamide, lamotrigine, topiramate and felbamate may be useful.
Like other forms of epilepsy, abdominal epilepsy is treated with anticonvulsant drugs, such as phenytoin. Since no controlled studies exist, however, other drugs may be equally effective.
Most generalized epilepsy starts during childhood. While some patients outgrow their epilepsy during adolescence and no longer need medication, in others, the condition remains for life, thereby requiring lifelong medication and monitoring.
Most children who develop epilepsy are treated conventionally with anticonvulsants. In about 70% of cases of childhood epilepsy, medication can completely control seizures. Unfortunately, medications come with an extensive list of side effects that range from mild discomfort to major cognitive impairment. Usually, the adverse cognitive effects are ablated following dose reduction or cessation of the drug.
Medicating a child is not always easy. Many pills are made only to be swallowed, which can be difficult for a child. For some medications, chewable versions do exist.
The ketogenic diet is used to treat children who have not responded successfully to other treatments. This diet is low in carbohydrates, adequate in protein and high in fat. It has proven successful in two thirds of epilepsy cases.
In some cases, severe epilepsy is treated with the hemispherectomy, a drastic surgical procedure in which part or all of one of the hemispheres of the brain is removed.
The prognosis of ICOE-G is unclear, although available data indicate that remission occurs in 50–60% of patients within 2–4 years of onset. Seizures show a dramatically good response to carbamazepine in more than 90% of patients. However, 40–50% of patients may continue to have visual seizures and infrequent secondarily generalized convulsions, particularly if they have not been appropriately treated with antiepileptic drugs.
Patients with ICOE-G need prophylactic treatment mainly with carbamazepine or other antiepileptic drugs licensed for focal seizures. A slow reduction in the dose of medication 2 or 3 years after the last visual or other minor or major seizure should be advised, but if visual seizures reappear, treatment should be restored.
No cure is available for PSE, although the sensitivity of some patients may diminish over time. Medical treatment is available to reduce sensitivity, with sodium valproate being commonly prescribed. Patients can also learn to avoid situations in which they might be exposed to stimuli that trigger seizures and/or take steps to diminish their sensitivity (as by covering one eye) if they are unavoidably exposed. These actions together can reduce the risk of seizures to almost zero for many PSE patients.
Some PSE patients have trigger stimuli that are so specific that they are never likely to encounter them in real life. Their PSE may only be discovered by accident in an unusual situation or during examination for other complaints.
Given the benign nature of the condition and the low seizure frequency, treatment is often unnecessary. If treatment is warranted or preferred by the child and his or her family, antiepileptic drugs can usually control the seizures easily. Carbamazepine is the most frequently used first-line drug, but many other antiepileptic drugs, including valproate, phenytoin, gabapentin, levetiracetam and sultiame have been found effective as well. Bedtime dosing is advised by some. Treatment can be short and drugs can almost certainly be discontinued after two years without seizures and with normal EEG findings, perhaps even earlier.
Parental education about Rolandic epilepsy is the cornerstone of correct management. The traumatizing, sometimes long-lasting effect on parents is significant.
It is unclear if there are any benefits to clobazam over other seizure medications.
There are several different ways to treat frontal lobe epileptic seizures, however, the most common form of treatment is through the use of anticonvulsant medications that help to prevent seizures from occurring. In some cases, however, when medications are ineffective, a neurologist may choose to operate on the patient in order to remove the focal area of the brain in which the seizures are occurring. Other treatments that can be administered to aid in reducing the occurrence of seizures include the implementation of a specific, regimented diet and/or the implantation of a vagus nerve stimulator.