Observing a seizure-event is a good way for doctors to diagnosis, identify, and determine proper treatment for a epilepsy. They may use the following tests to observe the electrical activity of the brain to help with their diagnosis:
Electroencephalograph (EEG)
The electroencephalograph (EEG) is a machine that translates the electrical activity of the brain into series of wavy lines. Normal electrical activity makes a recognizable pattern. Seizure-causing changes or irregularities produce different patterns. It's like a polygraph test, except thin wires, called electrodes are pasted on the scalp of the person being tested. Doctors can often identify the patterns likely to be present when someone has epilepsy. The recording may also show which part of the brain is affected. Having an EEG is a painless, safe procedure. The machine cannot read your mind or give you an electric shock. It doesn't measure intelligence or reveal mental or emotional illness. It is not used to treat or to cure - just to find out.
They may also decide to observe your seizures through a sleep-deprived EEG. Many seizures often occur when the individual is under stress. Sleep-deprivation is one of the easiest ways for doctors to observe the person under stressful conditions.
CAT Scanning
Computerized Tomography (CAT or CT) scanning, a procedure introduced in the early 1970s, has revolutionized the ability to 'see' the brain. Low-dose X-rays are detected and interpreted by a computer, which then generates a picture "just as if we had cut a slice of the brain."
The principal reason for a CT scan is to see whether the seizure had a cause that can be treated surgically. The CT can also reveal other causes for which there may be specific treatments.
Magnetic Resonance Imaging (MRI)
While CT scanning has revolutionized our ability to 'see' the brain by taking pictures of the inside of the brain, magnetic resonance imaging (MRI), which is even newer, has increased our ability to look inside the brain, as it were, even more clearly. Unlike CT scanning, MRI does not employ X-rays but rather uses a huge magnet to create an image, which is then analyzed by computer in a fashion similar to the CT. It produces pictures of even greater detail.
It is ideal for observing the structures of the brain. MRI scans may show tumours, abnormal blood vessels, cysts, and areas of brain cell loss or other brain damage. These tests apply to both adults and children.
The only disadvantages of the MRI are that, with current equipment, a scan takes about 15-30 minutes, during which the person must lie perfectly still in the tunnel-like machine and thus may require sedation; also, the test is more expensive than a CT. When, however, detail of the brain is important, or when subtle changes must be seen, the MRI is a very important diagnostic tool. An abnormal structure observed on a scan is not necessarily the cause of the seizures. Based on the evidence from observation of the seizure as well as the information gathered from EEG and CT data, if the MRI data indicates a brain abnormality in the area believed to be the origin of the seizures then we can presume cause and effect.
PET Scan
Positron emission tomography (PET) is different from the MRI and CT scans because it demonstrates brain metabolism while the others show structure. The doctors will look for the metabolism in the brain region of the suspected origin of the seizure.
This procedure not used as often as the CT or MRI scans because they are often more accurate.