8 condition characterized by recurrent seizures.
Epilepsy is the tendency to have recurrent nonprovoked seizures.
The diagnosis of epilepsy requires the occurrence of at least one unprovoked seizure in the likelihood of greater than 60% that the patient will have another unprovoked seizure.
Illicit and prescription drugs, alcohol withdrawal, glucose and electrolyte abnormalities or common reasons for provoked seizures.
Some forms of epilepsy can be classified as an epilepsy syndrome, which are types of epilepsy in which clear demographic seizure type, EEG pattern, and prognosis or known.
Means recurrent seizures and effects approximately 1-1.5% of the population
One of the most prevalent neurological diseases, and the estimated 3.4 million individuals in the US. affected.
70 million people worldwide have epilepsy.
Lifetime likelihood of having a diagnosis of epilepsy is almost 3%.
In the US approximately one and 26 will develop epilepsy at some pointin their lifetime.
Epilepsy is a paroxysmal event that manifests with phenomena that include motor phenomena, and sensory phenomena:patients may experience visual, auditory, and psychological symptoms.
Patients with epilepsy have an increased risk for injury in accidents, drowning, burns, poisoning, adverse effects of medication, and traumatic brain injury.
The risk of sudden death epilepsy is approximately one per 1000 adults a year and one per 4500 children a year.
Annual cost of epilepsy management in the US is over $12.5 billion.
Epilepsy is associated with increased risk of depression, accidents, and death.
Patients with major depressive disorder have a 4 to 7 fold increase risk of unprovoked seizures.
A seizure is a brief excessive discharge of electrical activity in the brain that transiently alters behavior.
A disorder of the brain characterized by predisposition to generate epileptic seizures and by neurobiological, cognitive, psychological and social consequences of this process.
Epileptic seizures are paroxysmal episodes with transient motor, sensory, psychiatric, or anomic, and visual signs and symptoms is the result of abnormal synchronous neuronal electrical activity propagated through one or more brain circuits involving cortical and subcortical structures.
The definition requires the occurrence of at least one epileptic seizure.
Epilepsy can be diagnosed after a single seizure if it was unprovoked, that is unrelated to drugs, alcohol, hyponatremia or a glucose abnormality and that the patient has greater than 60% chance of having another one.
Current definition of epilepsy is the presence of one of the following: at least two unprovoked seizures occurring more than 24 hours port, one unprovoked seizure and the probability of further unprovoked (60%) seizures similar to the recurrence risk after two unprovoked seizures occurring over the next 10 years, or a diagnosis of an epilepsy syndrome.
Factors associated with recurrent seizures after a first unprovoked seizures include: epileptiform discharges on EEG, a previous brain injury and occurrence during sleep.
A normal EEG does not exclude the diagnosis of epilepsy: Up to 45 to 50% a routine EEGs, of up to one hour can be normal and patients with epilepsy.
The sensitivity EEGs is approximately 85% within 24 hour ambulatory EEG‘s.
Over forty types of epilepsy are recognized and these are divided into two main groups: focal seizures and generalized seizures.
Seizures are classified based on the appearance of the seizure and parts of the cerebral cortex involved in the seizure.
Seizures have been classified as focal, generalized, and unknown, based on clinical and EEG criteria.
Generalized seizures consist of ictal activity that originates synchronously in both hemispheres.
In an unknown seizure type is when the clinical and EEG data cannot establish whether it is focal or generalized.
There is a frequent occurrence of psychiatric or cognitive disturbances and psychosocial problems with epilepsy.
Mood and anxiety disorders occur in approximately 35% of patients with epilepsy.
Problems with attention and memory can affect up to 25% of patients with epilepsy.
Classification of seizures has important consequences for determining the etiology , treatment, and overall prognosis.
Focal seizures account for approximately sixty percent of all adult cases.
Temporal lobe epilepsy (TLE) is the single most common form of focal seizure.
Extremely heterogenous disease can affect otherwise healthy adults with two or three seizures in their lifetime or an individual with static encephalopathy and many seizures per day or seizures that begin only after an acute neurological injury, such as acute ischemic stroke or meningitis.
Between 16 and 51 new cases per 100,000 people every year.
Affects approximate 65 million people worldwide in about one percent of the US population.
Incidence rates are higher among individuals younger than one year and older than 85 years.
Epilepsy is more common in low income countries.
Refers to an acute onset of a transient alteration in behavior caused by excessive neuronal discharge in the cerebral cortex.
All individuals have a seizure threshold and could potentially experience a seizure.
Risk factors from multiple: post stroke epilepsy reported in 12% of patients with stroke over 10 year follow-up, up to 3% of patients with severe traumatic brain injury followed for 12 month period, up to 80% of patients with rain tumors, and 70 to 95% of patients with symptomatic neurocysticercosis.
Over time recurrent convulsive seizures can impair cognition and behavior and alter brain structure (Hermann B et al).
A spectrum disorder some leading productive lives, while others may be completely dependent on others.
Affects people of every age, but most commonly starts before the age of one and increases again after the age of 50 with the highest incidence after age 75.
Many children outgrow the the problem, while in others it may lead to premature death, including unexplained sudden death.
Sudden death in the epilepsy refers to death unrelated to trauma, drowning, status epilepticus or other such causes, and autopsy findings find no evidence for alternative causes of death such as stroke, myocardial infarction, drug intoxication.
Higher seizure free rate is observed among elderly men than among younger people.
People with epilepsy have lower crash rates than do healthy teenage male drivers.
Alcohol causes greater than 150 times more driver deaths than do seizures.
Lifelong prevalence of experiencing a single seizure is approximately 10%, but approximately 30% can have recurrent seizures and experience epilepsy.
Epilepsy has also been linked with polymorphisms in BDNF.
Poststroke epilepsy occurs in 2 to 4% of patients with stroke.
The major risk factors for post-stroke epilepsy are stroke severity and hemorrhagic stroke, and other possible factors include younger age at stroke onset and the cortical involvement of stroke.
Catamenial epilepsy refers to seizures that increase in relation to the menstrual cycle.
Catamenial epilepsy is most common for the focal epilepsies.
Catamenial epilepsy occurs in approximately 1/3 of all women with focal seizures and seizure frequency doubles in a particular portion of the menstrual cycle.
Catamenial epilepsy is driven by an increase in estradiol compared with progesterone.
Some medications prescribed for patients with stroke that include antibiotics , antipsychotics, analgesics, and anti-depressants may also precipitate seizures.
In a study of 245 children with a diagnosis of epilepsy in 1964 and followed prospectively for 40 years and the cumulative risk of sudden, unexplained death was 7% at 40 years overall and 12% in subjects who were not in long-term remission and not receiving medication (Sillanpaa M, Shinnar S).
Affects neonates to elderly.
2.5 million Americans have epilepsy and 150,000 diagnosed each year.
1% of U.S. population have epilepsy.
Accounts for 1% of global burden of disease based on disability-adjusted life-years, indicating productive years lost to disability or premature death.
20-40% of patients who have medically intractable epilepsy account for 80% of the cost.
Only 44% of American adults with epilepsy report their seizures are controlled.
Approximately 70% of patients may become seizure free with appropriate therapy, and the remaining 30% have drug resistant epilepsy.
30-35% of patients with seizures have drug resistant epilepsy, defined as failure of two antiepileptic medications given at appropriate dosage.
Approximately 750,000 persons in the US have drug resistant epilepsy.
0.5-1% of the world’s population have active epilepsy.
Prevalence is around 50 per 100,000 in developed countries.
Prevalence is equal between the sexes until old age when and increased incidence in elderly men occurs that is related to cerebrovascular disease.
Incidence higher in older than younger individuals.
Risk factors for the development of epilepsy include: prolonged childhood febrile seizures, status epilepticus, CNS infections, head trauma, neoplasms, temporal sclerosis, perinatal/vascular insults, and family history.
Risk factors are thought to be the result of brain injury at the molecular level, leading to morphological and biologic changes over years and ultimately resulting in the development of epileptic activity.
Molecular level changes may include apoptosis, necrosis, synaptogenesis, gene expression changes and axonal sprouting (Herman ST).
Cleveland Clinic study revealed 40% of children with chronic epilepsy have mood disorders, 31% have ADHD, 25% have anxiety disorders and almost 15% autistic spectrum processes.
Children with this disorder have an increased risk of learning and behavior problems compared to children with other chronic illnesses.
The poor have a higher incidence.
Incidence above 100 per 100,000 population in resource poor countries.
Incidence in childhood has fallen over the past three decades probably associated a result of improved sanitation and perinatal care, and immunizations.
Increasing incidence in elderly reflects increased survival in patients with cerebral vascular disease and cerebral degeneration.
Cumulative lifetime incidence approaches 3%.
Incidence highest in the first year of life and in the elderly.
The risk of epilepsy later in life may be reduced in men who exercise vigorously as young adults.
Epilepsy is 79% and 36% less likely to develop in men who have a high level of fitness than in those with low and medium fitness levels, respectively.
Primary physicians see about 83% of new-onset patients and provide about 40% of ongoing seizure care.
Long-term follow-up of patients with epilepsy reveals a 2-3 fold increased mortality risk compared to the general population.
2-6 fold increase in risk for patients to have skeletal fractures primarily due to falls and secondarily related to antiepileptic drugs related to ataxia or impaired equilibrium.
Children with symptomatic epilepsy have a 20-fold increased risk of mortality risk.
A study reported intrinsic religiosity and religiosity outside of organized religion were higher in patients with epilepsy than in controls.
There are, at least, 15 antiepileptic drugs approved by the FDA(1/06).
Initiation of antiepileptic treatment for a patient with a single seizure, negative history and normal neurologic examination cancer wait until evaluation is complete.
Initiation of antiepileptic therapy where alcohol withdrawal or hypoglycemia is present can be delayed until neurological evaluation is completed.
Immediate antiepileptic therapy should be initiated in patients with multiple seizures, have neurological findings, have a eleptiform electroencephalogram (EEG) or have a history of conditions predisposing to seizures.
Vagus nerve stimulation for epilepsy was associated with a greater than 50% seizure reduction in 55% of 470 children who had partial or generalized epilepsy and a greater than 50% seizure reduction in 55% of 113 patients with Lennox-Gastaut syndrome.
Approximately 70% of patients will become seizure free with the use of a single antiepileptic drug.
About 20-40% of patients have controlled disease.
Approximately 30% of patients with epilepsy continue to experience seizures despite anti epileptic drugs.
Patients with refractory epilepsy have a risk of sudden unexpected death from epilepsy or premature death from other causes.
In temporal lobe disease surgery is superior to long term medication.
Drug resistant epilepsy associated with increased risks of premature death, injury, psychosocial dysfunction, and reduced quality of life.
Drug resistant epilepsy decreases approximately 4% per year among adults and a higher rate among children.
Drug-resistant epilepsy associated with the early phase of the disorder and with structural causes particularly hippocampal sclerosis.
Temporal lobe epilepsy most common cause of anticonvulsant drug therapy resistance.
Temporal lobe epilepsy treated with surgery results in 60-90% effectiveness, with control of temporal lobe seizures postoperatively.
Surgery is the treatment of choice for medically intractable temporal lobe epilepsy.
Mesial temporal lobe epilepsy (MTLE) that is refractory and disabling can be treated with receptive surgery plus anti epileptic drug therapy results in a lower probability of seizures during year 2 of follow-up then continued anti epileptic drug treatment alone (Engel JJ et al).
If seizures are not controlled with 3 anticonvulsant drugs seizures are considered intractable.
80% of cost of epilepsy is attributable to intractable disease in the U.S.
Most patients with epilepsy have focal onset seizures or partial epilepsy.
Status epilepticus is a life-threatening neurological emergency, defined as a stage of continuous seizures without interval recovery.
Status epilepticus is recognized at two points in time – for convulsive seizures the first time point is five minutes at which the patient should be clinically diagnosed and treated for status epilepticus, and the second time point at 30 minutes is when neural damage is likely to occur.
Mesial temporal role epilepsy (MTLE) has premonitory symptoms including dejavu, epigastric distress, hallucinations, altered mental status, and automatisms, hippocapal atrophy, sclerosis, or both.
Surgery is considered if seizures are intractable and is most successful for people who have a specific area of the brain identified as their focus of disease.
Only 1500 of the 750,000 persons in the US with drug-resistant epilepsy undergo epilepsy surgery per year.
When seizures no longer respond to medical therapy and there is a clear identification of a seizure-onset zone resection of the involved area of the brain may benefit such patients.
Operations for epilepsy may involve resections of the medial structures of the temporal lobe, including the amygdala, hippocampus, and entorhinal cortex and the temporal neocortex.
The Early Randomized Surgical Epilepsy Trial (ERSET) evaluated the efficacy of surgical treatment for patients with refractory MTLE by a prospective study of patients 12 years or older comparing medical therapy alone or antimesial temporal resection combined with medical therapy : none of the 23 patients in the medical group was seizure free during the 2nd year of follow-up, where as 11 of 15 patients (73%) in the surgical group was seizure free.
In the above ERSET study the surgical group had more impaired memory, worst scores on immediate and delayed recall class, but no difference in terms of employment status.
Patients treated with temporal lobe surgery and resectable lesions visualize with MRI have the greatest likely of becoming seizure free.
The morbididity of mortality from epilepsy surgery are low.
Advances in neuroimaging, electroencephalography, functional MRIs, cortical mapping have improved the success of identifying the ictal onset zone and surgical management of refractory focal epilepsy result in freedom from seizures in 60 to 70% after one to two years follow-up.
Vagus nerve stimulation is associated with a greater than 50% seizure reduction in 55% of 470 children who had partial or generalized epilepsy and a greater than 50% seizure reduction in 55% of 113 patients with Lennox-Gastaut syndrome.
Late follow-up for surgically managed medically refractory focal epilepsy reports seizure freedom rates of 40-50% at 10 years.
Surgical treatment for epilepsy is the most underused treatment modality.
More than 100,000 patients in the U.S. with temporal lobe epilepsy may be candidates for surgery.
In a large and long prospective study of epilepsy surgical management outcomes of more than 5200 person-years of follow-up the percentage of patients remaining free of partial seizures was 63% at two years, 52% at five years, and 47% after 10 years (de Tisi J et al).
Control of temporal lobe seizures with surgical treatment more likely than pharmocotherapy (Weibe).
The treatment of choice for intractable temporal lobe epilepsy is surgery.
Pseudoresistant epilepsy refers to the presence of seizures that process because the underlying disorder has not been adequately or appropriately treated.
Pseudoresistant epilepsy is most commonly due to misdiagnosis and may be mimicked by vasovagal syncope, cardiac arrhythmias, metabolic abnormalities, and other episodic neurologic disorders such as migraine or TIAs.
Drug-resistant seizures may be due to psychogenic, nonepileptic, causes and may account for as many as 25% of adult cases.
Treatment resistant epilepsy associated with anxiety, depression, cognitive and memory disturbances.
The ketogenic diet is the most established diet for the treatment of epilepsy.
The diet is high and fat low in carbohydrates and can be successful in the prevention of seizures.