What Is Epilepsy? The Science of Seizures
Most people have heard the term epilepsy before and know that it involves seizures. But you may not understand the deeper mechanics of what causes these seizures.
What Are Seizures?
Seizures are a brain malfunction in which cortical nerve cells, or cells in the cerebral cortex, fire abnormally for a period. During normal brain function, nerve cells are sending electrical messages at different times. When a seizure occurs, a lot of cells begin firing at the same time. This creates synchronous waves of electrical current in the brain that cause abnormal mental and bodily reactions.
Epileptic seizures can occur in very localized parts of the brain, or they can be neurons misfiring all over the place all at once.
Seizures can manifest themselves in several ways. The most serious cause the patient to shake uncontrollably and even stop breathing. These seizures are often preceded by certain sensory stimulants, such as seeing strange lights and smelling unpleasant smells. But often seizures are just a momentary lapse in mental awareness. Such small seizures may pass undetected by observers, and even the patient.
Seizures and Epilepsy
The defining feature of epilepsy is that these seizures recur, and they don’t seem to have any obvious underlying cause. This means that the seizures occur again and again, and there doesn’t seem to be a reason that the brain cells begin to misfire the way they do. There are many neurological disorders that include seizures as one of their symptoms. But these are not considered epileptic seizures as they have a defined cause.
For example, lissencephaly, a rare brain disorder, includes seizures as one of its symptoms. A patient with this condition lacks the ridges in the cerebral cortex that facilitate neural activity, and this malformation leads to neurons frequently misfiring. Since these seizures have a known root cause, they are not considered epileptic.