There are many categories of epilepsy. Since the treatment of each type is highly specific, it is critical to properly diagnose and characterize seizures. We make a diagnosis of epilepsy based on the description of the events that children who have seizures and their family members or their caregivers give us.
A child--especially an older child--may remember and be able to describe what happens to her physically and mentally before and aftera seizure. A family member or other caregiver may be able to recount what happens during a seizure as well as how the child appeared or acted just before or after an episode. The majority of the time, this information is adequate enough to make an accurate diagnosis. On occasion, however, this information may simply not provide enough insight for an accurate diagnosis. Under these circumstances, further testing is required.
Epilepsy may show itself in many different ways. Since the brain is involved in a myriad of functions, a seizure may express itself in extremely diverse ways. Depending on which region of the brain is involved in the seizure, a variety of clinical events may be observed. Motor movements, which can range from a single jerk of a small muscle to rhythmic jerks involving the entire body, are the most easily recognized. Occasionally there may be loss of all muscle tone resulting in a fall or drop attack. Other types of seizures involve regions of the brain that govern sensation. During these seizures the person will experience an alteration of normal sensation such as episodes of strange smells and tastes, hallucinations involving what he sees or hears, and tactile changes such as numbness or a pins-and-needles sensation.
The brain is also involved in higher level functions such as thought processing, emotion and memory. These functions can also be affected by seizures, producing confusion and unusual behavior.
But not all seizures are from epilepsy. Many neurologic and psychiatric conditions, as well as normal behaviors, in infants and children can mimic a epileptic event. These episodes are referred to as "non-epileptic events" and represent a broad spectrum of behaviors, movement disorders, and psychologic disturbances that can mimic a true epileptic seizure. Among the most common are syncope, breathholding spells, parasomnias (disorders related to sleep), gastrointestinal reflux, and movement disorders such as paroxysmal choreoathetosis (see glossary for definition). Unusual behavioral responses are often confused with true epilepsy, especially in infants. Common conditions such as gastrointestinal reflux in the infant may result in spasm-like movements as they respond to the unpleasant sensation produced by the reflux of gastric acids. Since the management of these conditions is completely different from that of epileptic seizures, the correct diagnosis is of paramount importance.
When we need to characterize a type of epilepsy or differentiate true epilepsy from the non-epileptic variety, we perform an electroencephalogram (EEG). This is a test that analyzes the electrical activity of the brain (brain waves) and prints them out as wavy lines.
In children with epilepsy, we often find abnormalities in an EEG that can assist in the diagnosis. To prepare for an EEG, electrodes are placed over a child's scalp to detect the brain's electricial signals. It is a painless test, but if a child is fearful of it, a mild sedative may be given.
In children with epilepsy, abnormalities in EEG printouts can often help us with a diagnosis. The most common and characteristic abnormality is that of a "spike discharge." This discharge is aptly named; it resembles a spike in the line of brain waves. The point on the tape where the spike occurs helps us determine the location of the part of the brain involved with the seizures (the "seizure's focus").
The most definitive information by far is obtained if a seizure is actually witnessed during the EEG test. …