A proper diagnosis is based on a person's medical history and observations of a witness during the seizure.
Seizures can be suspected if you have symptoms such as loss of consciousness, muscle spasms, loss of bladder control, sudden confusion, and an inability to pay attention.
True seizures are actually less common than most people think; most episodes of brief unconsciousness are more likely to be fainting.
Being able to describe exactly what happened can be helpful to a doctor in diagnosing what happened.
If there is an eyewitness, an accurate description is best- include length of the episode; any abnormal muscle movements, tongue biting; loss of bladder control; and how quickly the person recovered. It is also helpful if you can include if the person had any warning that something unusual was going to happen- flashing lights or a certain sound.
To help diagnose a seizure disorder, doctors will use electroencephalography, which is a painless, safe procedure that records electrical activity in the brain. By examining the recording, doctors can cehck for evidence of any abnormal electrical discharges in the brain.
Usually doctors examine the patients after depricing them of sleep becuase abnormal electircal discharges are more likely to occur after little sleep. Usually, the EEG will be scheduled after 18 to 24 hours of deprived sleep. Even if a a seizure does not occur, there may still be abnormalities becasue EEG's have a limited recording time and may miss the abnormality.
Brain Activity During a Seizure
An electroencephalogram (EEG) is a recording of the brain's electrical activity. The procedure is simple and painless. About 20 small adhesive electrodes are placed on the scalp, and the brain's activity is recorded under normal conditions. Then the person is exposed to various stimuli, such as bright or flashing lights, to try to provoke a seizure. During a seizure, electrical activity in the brain accelerates, producing a jagged wave pattern. Such recordings of brain waves help identify a seizure disorder. Different types of seizures have different wave patterns.
Once a seizure disorder is diagnosed, more tests are usually needed to identify the cause. Routine blood tests are performed to measure the levels of sugar, calcium, and sodium in the blood and to determine whether the liver and kidneys are functioning properly. A complete blood count is performed to determine how many white and red blood cells are present. A high white blood cell count may indicate an infection. A low red blood cell count (anemia) may indicate an inadequate supply of oxygen to the brain. Often, electrocardiography (ECG) (see Symptoms and Diagnosis of Heart and Blood Vessel Disorders: Electrocardiography) is performed to rule out an abnormal heart rhythm as a possible cause of symptoms. Because an abnormal heart rhythm can reduce blood flow (and therefore the oxygen supply) to the brain, it can trigger seizures and cause loss of consciousness.
Computed tomography (CT) or magnetic resonance imaging (MRI) of the head is usually performed to check for structural damage to brain tissue (for example, by a stroke). Sometimes a spinal tap (lumbar puncture (see How a Spinal Tap Is Performed) is needed to determine whether the person has an infection of the layers of tissue covering the brain (meningitis) or of the brain (encephalitis).
I am not a doctor, physician, or specialist. The information that I have provided is from personal research. For more information, always ask your neurologist form more information.