Epilepsy is a neurological disorder in which the brain activity becomes abnormal and results in seizures or periods of unusual behavior, sensations, and sometimes leads to loss of awareness. Epileptic seizures occur when electrical impulses in the brain escape their normal limits and spread to neighboring areas. This creates an uncontrolled storm of electrical activity. This results in twitches or convulsions. Epileptic seizures are of two types i.e. focal seizures (or partial seizure) and generalized seizures. Seizures may occur after a stroke, a closed head injury, infection such as meningitis or another illness, etc.
The image shows a representation of EEG or electroencephalogram. It is a test to record the electrical signals of the brain. Doctors generally use it to help diagnose epilepsy and sleep problems. Other tests such as CT scan, MRI scan, MRS scan, blood test, etc can also help in the diagnosis of epilepsy. EEG is the most common test to record electrical activity in the brain and is the most commonly used method for epilepsy. High-density EEG helps in determining areas of the brain which are affected by seizures.
The brain is made up of millions of nerve cells called neurons. These cells generate electrical impulses to produce thoughts, feelings, movement and control body functions. Sometimes, these cells do not function the right way causing changes in behavior, sensation, or motor function. These dusturbances cause what we call as seizures. A person who has experienced two or more seizures is said to have the condition called epilepsy. It is important to develop an understanding of the basic structure of the brain and how it functions normally to demystify epilepsy. The cerebrum is the largest and most recognizable of the three structures and is perhaps the most involved structure of brain in epilepsy. Mesial or middle part of the temporal lobe is also of interest to understand epilepsy in adults but not so in kids. This region is comprised of structures which control emotion and which are responsible for processing smells. As a result, seizures that arise in these areas commonly produce strong emotions or the sensation of typical odors.
One of the most important neurotransmitters that plays a role in epilepsy is GABA (gamma-aminobutyric acid), which is an inhibitory neurotransmitter. Researchers have identified drugs which alter the amount of GABA in the brain or change how the brain responds to its activity.
There are different types of seizures. Most seizures are categorized as focal or generalized. Focal seizures occur when seizure activity is limited to a part of a brain hemisphere. Generalized seizures occur when there is widespread seizure activity in the left and right hemispheres of the brain.