The brain communicates with itself and the rest of the body through electrical impulses sent between neurons. In seizure disorders, the electrical impulses in the brain are temporarily disrupted, resulting in a wide variety of symptoms due to brain dysfunction. According to the Merck Manual Home Edition, approximately 2 percent of American adults will have a seizure at some point in time, with the majority never having another one again.
Types
There are many types and sub-categories of seizure disorders, but classification is important in determining a course of treatment. According to the Epilepsy Foundation, seizures are classified into four broad categories that include generalized, partial, nonepileptic and status epilepticus seizures, based upon the area and size of the brain affected. Generalized seizures are further divided into absence, atonic, tonic-clonic and myoclonic. Partial seizures can either be simple or complex. Individuals with seizure disorders may experience one or several types of seizures.
Causes
Seizure disorders most often begin in early childhood or late adulthood. Seizures before the age of 2 are most commonly caused by damage to the brain due to high fever, injury or metabolic abnormalities, such as imbalances in vital body minerals like calcium or magnesium. Genetic defects or injuries during the birthing process may also lead to seizure disorders. Often, however, especially when diagnosed between the ages of 2 and 14, the cause of the seizures is unknown. If seizures begin in adulthood, the most common cause is a head injury, stroke, tumor or alcohol withdrawal, according to the Merck Manual Home Edition.
Symptoms
Seizure disorder symptoms vary widely based upon the individual and type of seizure. Generally, seizures are brief, lasting several seconds, but can occur for several minutes. Many individuals report an aura or sensation such as abnormal smells and tastes, deja vu and butterflies in the stomach before a seizure is about to begin. Convulsions and muscle spasms are common during seizures, but other symptoms include visual hallucinations, speech impairment and unresponsiveness. When a seizure has subsided, individuals often feel fatigued, sore and confused, often not remembering what happened during the seizure.
Diagnosis
A diagnosis of a seizure disorder can only occur if an individual has had at least two unprovoked seizures at separate times. The diagnosis is based upon symptoms and the description of the seizure event by an eyewitness, because often an individual is unaware of the episode. Key diagnosis aspects include how fast the seizure started, the presence of abnormal movement and the length of seizure and recovery time. An electroencephalography, or EEG, which measures electrical activity, is often used to confirm diagnosis. Further testing, such as blood and urine tests, along with CT and MRI scans, is done to determine the cause.
Treatment
The first step in treating seizure disorders is to identify and remove triggers that might initiate a seizure. Prescription anticonvulsant medications are effective in decreasing the risk of recurring seizures. They function by suppressing the rapid and excessive impulse firing of neurons. If medications prove ineffective, brain surgery may be required. Removal of the brain defect causing seizures or severing the corpus callosum, a structure that connects the two sides of the brain, are two surgical options for seizure disorders. If surgery is not an option, vagus nerve stimulation may be recommended, according to the Epilepsy Foundation. It involves implanting a small device near the vagus nerve in the neck that can be activated by patients to stimulate the vagus nerve when they sense a seizure coming on. The vagus nerve is believed to have connections to areas in the brain involved in seizures.
