Epilepsy is one of the most common neurologic conditions characterized by recurrent, unprovoked seizures. A person with epilepsy has an overactive brain or parts of the brain which will send too many signals. According to the Epilepsy Foundation, epilepsy affects 2.5 million people in the United States and 50 million worldwide. It is the most common chronic neurological condition of childhood, affecting 0.5%–1% of children worldwide. The effect of seizures can differ from person to person in epilepsy. The signs and symptoms can differentiate between focal seizures and generalized seizures, depending on which part of the brain is affected. Seventy percent of epilepsy patients have no idea what causes their seizures, which may be linked to brain injuries or genetics. Seizures are sometimes caused only by small muscle twitches, but can also result in convulsions (uncontrollable shaking) and loss of consciousness, also known as epileptic fits.
The main symptom of epilepsy is repeated seizures. Epileptic seizures can vary greatly from person to person. Some only last a few seconds and even go unnoticed, some only affect one arm or one leg, whereas others affect the whole body. Seizures can occur when the patient is awake or asleep. Sometimes they can be triggered by something, such as stress, sleep deprivation or fatigue, insufficient food intake, alcohol use or drug abuse, or failure to take prescribed anticonvulsant medications. There are several common symptoms of epilepsy including temporary confusion, a staring spell, stiff muscles, uncontrollable movements of the arms and legs, loss of consciousness and awareness, and psychological symptoms like anxiety and fear. Other possible causes of seizures are brain tumors, neurological problems, drug withdrawal, and medications.
The cornerstones of epilepsy diagnosis are symptoms, physical signs, history, and neurological examination, while laboratory investigations are helpful to assess the progression and severity of the disease. These tests include electroencephalograms (EEGs), CT scans, MRIs,
The electroencephalogram (EEG) is the primary investigation required in epileptic patients. . It is used to confirm the diagnosis and to get additional information about seizures. During this painless procedure, electrodes are attached to the scalp with a paste-like substance or cap. The electrodes record the electrical activity of the brain in the form of wavy lines.
Computerized tomography (CT) scan
CT scans are used to obtain cross-sectional images of the brain using X-rays. The CT scan can reveal abnormalities in the brain structure, such as tumors, bleeding, and cysts, which might be causing seizures. CT scans are not as detailed as MRI scans, but they are performed quickly and can be helpful during emergencies.
Magnetic Resonance Imaging (MRI)
An MRI uses powerful magnets and radio waves to create computerized two- or three-dimensional images of the brain, necessary for evaluating partial complex epilepsy. The scans may detect damaged tissue, lesions, or structural abnormalities that could be the cause of epilepsy (lesional epilepsy) or may be normal (non-lesional epilepsy such as cortical dysplasia, hamartomas, etc). MR imaging is essential in the presurgical evaluation of patients with medically refractory epilepsy.
Positron emission tomography (PET)
The PET with fluorodeoxyglucose (FDG) scan measures brain metabolic activity (a measure of glucose uptake). Interictal (between episodes) FDG-PET is sensitive (84%) to temporal lobe epilepsy (TLE) and 33% sensitive and 95% specific to extratemporal epilepsy.
Single-photon emission computed tomography (SPECT)
A person's blood flow increases in the brain region where a seizure begins when they have a seizure. The SPECT scan can identify the brain regions where blood flow increases during seizures, thereby indicating their origin. It is performed when a patient is admitted to the hospital to undergo video-EEG monitoring.
Neuropsychological evaluation and functional MRI:
Functional MRI (fMRI) is used to evaluate cognitive abilities, particularly language and memory function, to determine if there is any memory loss or changes in its function in the epileptic region. This enables the prediction of cognitive deficits following surgery.
Intracarotid amobarbital/methohexital (Wada test)
In selected cases, this test involves the injection of a medication such as sodium amobarbital or methohexital into one carotid artery at a time. The medication temporarily paralyzes one half of the brain for 1- 5 minutes, allowing independent testing of language and memory function in the other half. This test is also used to predict post-operative language and memory deficits.
Epilepsies can be caused by primary genetic abnormalities (more than half of epilepsies are thought to be linked to genetic markers) or by structural or metabolic disorders, some of which even have genetic causes. Genetics are mostly used to evaluate epilepsy in children. The genetic test includes chromosomal microarray (CMA), epilepsy gene panels, and whole-exome sequencing (WES).
Anti-epileptic drugs (AEDs)
Epilepsy is most commonly treated with AEDs. More than 20 drugs are available to treat epilepsy successfully in 70 percent of newly diagnosed patients. The drugs used to treat epilepsy work by reducing the electrical activity of the brain, either by blocking calcium or sodium channels, enhancing potassium channel function, inhibiting glutamate-mediated excitation, or promoting GABA-mediated inhibition.
Epilepsy surgery is an option when AEDs are not controlling seizures or tests show seizures are caused by a problem in a small part of the brain. The part can be removed without serious side effects. Seizures can likely be eliminated after surgery.
Vagus nerve stimulation (VNS)
In vagus nerve stimulation (VNS), an electrical device similar to a pacemaker is placed underneath the patient chest skin to treat epilepsy. It is connected to the vagus nerve by a wire that goes under the skin. An electric current is sent along the wire to the nerve. It can reduce seizures by changing electrical signals in the brain. Seizures cannot usually be stopped completely by VNS, but they can be used to optimize seizure control by changing the intensity, duration, and frequency of stimulation. In 40 to 50 percent of patients, VNS decreases seizure frequency by at least half, but it does not eliminate all seizures. It can be used by those who do not qualify for other surgical procedures.
Responsive neurostimulation (RNS)
The RNS device can be used to treat adults suffering from partial-onset seizures that are not controlled by two or more antiepileptic drugs. Stimulators or devices are implanted in the bone covering the brain. There is no pain or unusual sensation associated with it. It isn't permanent. The device can be turned off or removed if it doesn't work or if the person no longer wants to use it.
The ketogenic diet is high in fat and low in carbohydrates and protein. Before the advent of AEDs, the ketogenic diet was a primary treatment for epilepsy. It is now recommended mostly for children with seizures that aren't controlled by AEDs. Seizures can be reduced in children by lowering levels of chemicals in the brain as a result of a healthy diet. Due to the link between high-fat diets and serious health conditions, such as diabetes and cardiovascular disease, it is no longer widely used in adults. Dehydration, constipation, weight gain, kidney stones, and broken bones are some of the side effects seen in children as well.