Seizures, Partial and Generalized
Seizures arise from abnormal electrical discharges in the cerebral cortex that lead to alterations of consciousness, behavior, motor activity, sensation, or autonomic function. Epilepsy is a disease defined as (i) two or more seizures without acute provocation, (ii) one seizure and >60% further risk of additional seizures, or (iii) diagnosis of an epilepsy syndrome. Seizures are classified as focal, generalized, unknown, and focal to bilateral based on where the seizure starts.
- Focal seizure types
- Awareness should be described as focal aware, focal impaired awareness, or awareness unknown.
- Motor and other symptoms should be described as focal motor seizure and focal nonmotor seizure.
- Aura is not in the updated classification but can still be used to describe a feeling at the beginning of a seizure.
- Generalized seizure types
- Tonic–clonic, absence, myoclonic, clonic, tonic, atonic
- Unknown onset seizure types: epileptic spasms, behavior arrest
- Focal to bilateral seizure is used to describe a seizure that is focal in onset and evolves into a generalized seizure.
Epilepsy affects 0.5–1% of all children (birth through 16 years). 120,000 children seek care annually in the United States for a seizure. Between 20,000 and 45,000 children per year are diagnosed with epilepsy; highest risk is in the 1st year of life.
4 to 10 per 1,000 children in developed countries have epilepsy.
- Brain tumor
- Malformations of cortical development
- Prior stroke
- Cerebral malaria
- Pyridoxine-dependent epilepsy
- N-methyl D-aspartate (NMDA) receptor encephalitis
- Unknown cause
- Epilepsy is both polygenic and multifactorial.
- There are currently >400 single genes known to be associated with epilepsy in childhood.
- Copy number variations encompassing deletions and duplications of various sizes have also been implicated in the genetics of epilepsy.
- The risk of epilepsy with an affected primary relative increases from the population risk (1–2%) to 4–8%.
- Epilepsy may also be a feature of other genetic disorders such as trisomy 21 and Angelman syndrome or be part of a larger neurodevelopmental presentation.
Commonly Associated Conditions
- The incidence of childhood-onset epilepsy associated with intellectual disability and cerebral palsy is 15–38%.
- Epilepsy occurs in 8–28% of children with autism.
- Attention deficit hyperactivity disorder (ADHD), depression, and anxiety are more common in children with epilepsy than in the general population.
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