Epilepsy is a neurological condition of recurrent episodes of unprovoked epileptic seizures. A seizure is an abnormal neuronal brain activity that can cause intellectual, emotional, and social consequences. Epilepsy affects children and adults of all ages and races, and is one of the most common neurological disorders of the nervous system. Epilepsy is more common among children than adults, affecting about 6 out of 1000 US children that are between the age of 0 to 5 years old. The epileptic seizures can be of different types depending on the part of the brain that was affected, seizures are classified in 2 main types partial seizure or generalized seizure.
Once a child has their first seizure or suspect seizure, they should be referred to specialized paediatrician in epilepsy and seizures to assess the seizure and conclude a diagnosis. The specialist doctor will take a detailed history of the child, perform physical examinations, clinical laboratory tests such as blood and genetic test, and neuroimaging. If the child is suspected of epileptic seizures, then additional investigations are to be performed such as, an electroencephalogram (EEG) which can give more information of the brain electrical activity and the seizure type.
The epileptic seizure in the vast majority of pediatric epilepsy patients is ephemeral, and symptoms typically subside on their own after the seizure comes to an end, but some children experience what is known as a "seizure cluster," in which the first seizure is followed by a second episode approximately six hours later. These recurrent seizure episodes pose a higher risk of death for children.
Children should be treated with proper and effective therapy to prevent irreversible neural damage. Treatment options for epilepsy include medications, diet, and surgery. PMID 36270899 Diet and surgery are considered for children who have medication resistant epilepsy.
Epilepsy is classified according to seizure types, epilepsy types, and epilepsy syndromes. The seizure types include focal onset, generalized onset, and unknown onset, while the epilepsy types include focal, generalized, combination focal and generalized, and unknown. Accurate classification of epilepsy will help in providing an appropriate treatment and management therapy.
Diagnosis Assessment for epilepsy is conducted and diagnosed by a neurologist. The International League Against Epilepsy (ILAE) propose that before treating epilepsy it should be properly classified and diagnosed. Epilepsy is confirmed when at least one of the following conditions is present in the patient:
After at least two unprovoked (or reflex) seizures occurring greater than 24 hours apart. Or after one unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years. Or when epilepsy syndrome is identified. As for the first condition, the time of the seizures occurring greater than 24 hours apart is necessary in the diagnosis parameters, but there is not a specific time frame that can be utilized to reset the clock. For example, a person who has their first unprovoked seizure at the age of 5 and another seizure 20 years later, would have the diagnosis of epilepsy. When seizures are temporary, short-lived, or spontaneously occurring as a result of acute brain trauma, fever, alcohol withdrawal, low or high blood sugar, then that would not be diagnosed as epilepsy and, because seizures that occur due to a known cause are considered provoked.
In terms of the second condition, high recurrence risk, it is when a patient who already had developed one unprovoked seizure and is then labeled to have a greater than or equal to 60% risk of having another seizure within the next 10 years. Two criteria must be met to predict greater than or equal to 60% risk of having a second seizure in the next 10 years. The first one is brain imaging should indicate there is a potential for the brain to generate spontaneous and recurrent seizures. As for the second criteria, an EEG test must show abnormal electrical brain patterns that indicate a high risk of recurrence of another seizure. If the neuroimaging and the EEG tests show abnormal findings that does not have an epileptiform potential, meaning there are certain brain waves or activity that imply or are associated with epilepsy and the patient experienced one unprovoked seizure, then the patient would not be diagnosed with epilepsy. The consensus to set the percentage at greater than or equal to 60% is because it represents the minimum level of confidence for someone who already experienced two unprovoked seizures to likely have a third one.
As for the third condition that is a diagnosed epilepsy syndrome. Epilepsy syndromes are notably different than epilepsy types, they are identified by a combination of specific findings that come from clinical features, EEG, neuroimaging, genetic testing, and age dependent features. If there is evidence from the findings suggesting a specific epilepsy syndrome, then the patient is assumed to have epilepsy.
Testing Multiple types of tests may be conducted in order have the most accurate diagnosis, as well as to create a personalized treatment regimen for the patient.
Brain imaging tests record brain wave patterns and detect any abnormalities. The most common brain imaging test is electroencephalogram (EEG). Electrodes are attached to the scalp with a paste-like substance and a cap and record the electrical activity of the brain. A high-density EEG may be used, where more electrodes are attached in order to produce a more precise, localized result of seizure activity. Other brain imaging tests include CT scans, MRI scans, PET scans, and single-photon emission computerized tomography.
There is a tendency for misdiagnosing epilepsy in children, posing a challenge in establishing precise diagnosis at this life stage. Nevertheless, miRNA profiling is considered a reliable test for diagnosing and prognosticating epilepsy. This approach is effective in preventing misdiagnosis, reducing diagnostic costs, and providing a prompt diagnosis.
Statistical parametric mapping (SPM), electrical source imaging (ESI), and magnetoencephalography (MEG) are additional analysis techniques that may be conducted to further locate the origin of the seizures.
Accurate diagnosis of seizure type and where seizures begin is critical for finding the most effective treatment. Epilepsy diagnosis can be resolved in patients who did not have a seizure for the last 10 years or are off antiseizure therapy or are who had an age dependent epilepsy syndrome and now they are past the applicable age.
Classification An accurate way of classifying seizures and epilepsy types comes from obtaining a detailed patient history and performing appropriate tests and using supporting data. As mentioned above, seizure types include focal, generalized, or unknown. The seizure classification initially starts with whether the seizures are focal or generalized. Focal seizures are ones that occur in one hemisphere, they can be either localized in one area or distributed over the cerebral hemisphere. As for generalized seizures, they originate in one area of the brain and rapidly are distributed bilaterally over the two hemispheres. If the onset of the seizure is unclear due to insufficient data from the patient's history as well as from the tests performed to classify it as focal or generalized, then the seizure is classified as of unknown onset.
Epileptic seizures has been classified into two categories based on the region of the brain they occur: Focal seizures and Generalized seizures.
Generalized seizures: These types of seizures occur simultaneously in both right and left cerebral hemispheres and then spread to other brain neurons. It is further classified as: Tonic-clonic seizures: Indicated by stiffness of muscles which are then followed by twitching movements of the muscle. It occurs most often in children as compared to adults with the chances of recurrence even after treatment. Absence seizures: These episodes are generalized and are instantly followed by constant staring at one place or looking at one spot over a long period of time. It occurs most commonly in children rather than in adults. Febrile seizures: These episodes are generalized and can occur in any region of the brain but stays for a longer period of time, sometimes followed by high body temperature. This can be treated by addressing the underlying cause of the fever which can be caused by infections, any nutritional imbalances like hypoglycemia, moreover it is controlled through symptom management.
Focal seizures: These types of seizures can occur in only one hemisphere which causes twitching or stiffness of the muscles or sudden involuntary movements and can also spread out to other parts of the body. It is often managed through vagal nerve stimulation. Focal seizures are associated with auras which are sensations that precede the seizure such as, strange taste or smell, lip smacking and hand rubbing. This type is further divided in three subtypes that are: Retained or impaired awareness: When the patient is fully aware of the events during the seizure it is called retained awareness. When the patient loses some events it is called as impaired awareness seizure. Some seizures are associated with memory loss of the events during the seizure. Motor or non-motor onset: In motor seizure there is movement of muscles and can be subdivided in types such as, focal tonic seizure, focal clonic seizure, focal atonic seizure. Non-motor seizure are not accompanied with muscle movement, as well they are subdivided into more specific types like focal non-motor cognitive seizures and focal non-motor emotional seizures. Focal to bilateral tonic-clonic.
After classifying seizure types, the second part is the classification of the epilepsy type. Classification of the epilepsy types assumes that the patient has epilepsy as defined by one of the three condition as detailed above in the diagnosis section. Epilepsy types just as seizure types include focal, generalized, unknown, and another category called combined focal and generalized. To determine which of the four categories the patient belongs to, the patient's seizure type be defined. If a patient is classified to have focal with cognitive awareness to bilateral tonic-clonic seizures that originate from both hemispheres, they will be classified to have focal epilepsy. If the patient has both focal and generalized seizures, they will be classified as having the combined focal and generalized epilepsy.
Causes and symptoms The causes of epilepsy in childhood vary. In about of cases, it is unknown. CauseFrequency (%)Unknown67.6Congenital20Trauma4.7Infection4Stroke1.5Tumor1.5Degenerative0.7Causes of seizures include an imbalance of neurotransmitters (nerve-signaling brain chemicals), brain tumors, stroke, and brain damage from illness or injury, or even a combination of several causes. However, for the majority of seizures, the cause is unable to be determined. Factors that may contribute to a seizure episode include head injuries, recent fever or infection, concurrent health conditions, and medication.
There are many different symptoms to look for in epilepsy in children, of which can vary based on the seizure type. Common signs of a seizure include: Movement: Jerking movements of arms and legs, stiffening of the body, rhythmic head nodding, rapid eye blink and staring, sudden falling (typically as a result of loss of consciousness) Loss of consciousness Blue tinted lips Loss of bladder or bowel control Abnormal breathing Not responding to noise or words, appearing in a haze
The child may appear confused or sleep following the seizure episode.