Focal seizures affect a small area of the brain, while generalized seizures affect the entire brain. Also called partial seizures, focal seizures are classified as simple or complex, depending on whether or not a person is conscious during the episode. A seizure can happen unexpectedly to anyone, although it is more common in people suffering from congenital epilepsy, recent head trauma, or stroke. Some symptoms of focal seizures include uncontrollable facial movements, abnormal tingling or numb sensations, or muscle twitching.
A simple focal seizure is one during which the person remains aware of what is happening. Mixed electrical signals in a limited area of the brain cause muscle spasms on one or both sides of the body, unusual facial movements or tics, numbness, and blurred vision. An individual may begin to feel nauseated, dizzy, and confused. Episodes can cause hallucinations, increased heart rate, changes in smell or hearing, and difficulty speaking.
Complex focal seizures involve a lapse in consciousness and memory during or after an episode. An individual may pass out during a seizure and cannot remember exactly what happened. In most cases, a complex focal seizure follows a simple seizure. An episode can occur while you are asleep or while you are awake, and many people report that their attacks trigger feelings of déjà vu. Simple and complex seizures can last from a few seconds to about five minutes.
People may experience only one simple or complex focal seizure in their lives, without any warning or understood medical reason. People who have congenital epilepsy, head injuries, strokes, or brain tumors experience multiple focal seizures over time. Bacterial and viral infections can also cause seizures, and people with meningitis and encephalitis are at especially high risk for epileptic seizures. Short-term or long-term drug and alcohol abuse affect chemicals and electrical signals in the brain, which can sometimes cause focal seizures.
Medical evaluation and treatment are very important after a person experiences a focal seizure. A doctor usually performs an electroencephalogram (EEG) test to check for abnormal electrical activity in the brain. During the EEG test, specialists place several small electrodes on the scalp to record electrical signals and display accurate readings on a computer screen. The results of the EEG, along with other medical imaging scans and blood tests, can help doctors determine the cause of the seizures along with the best ways to prevent future episodes.
Many people are prescribed medication to help control and prevent their epilepsy. Infections are usually treated with antibiotics, and brain tumors may need to be surgically removed. In addition, anyone can help preserve brain health and reduce seizure risk by not taking drugs, getting enough sleep, exercising regularly, and eating a good diet.