By Lisa Marinelli Smith
EEGs give doctors information about how our brain communicates and sends messages to the rest of our body. If brain waves look irregular, they may indicate a physical or psychological condition.
EEGs, short for electroencephalograms, are painless, non-invasive tests that track electrical activity produced when neurons in the brain transmit messages to each other. The info then gets relayed to other nerves, muscle or gland cells throughout the body.
When thousands of neurons fire simultaneously, they create an electrical field strong enough to measure through the skull. Electrodes attached to the forehead, temples and scalp track this electrical activity, and a neurologist can interpret it. The neurologist will look at various brain wave patterns to see if they look normal or have irregularities.
What is an EEG used to diagnose?
Your primary care provider or specialist can order an EEG to gather more information or make a diagnosis of a number of conditions, including epilepsy and PTSD.
The length of time an EEG takes varies from a half-hour to several days, so a neurologist can gather a wealth of data while you’re awake and sleeping. Often EEGs are coupled with video monitoring for even more data.
If my EEG results come back abnormal, then what?
The EEG is one piece of the puzzle that neurologists, psychiatrists or other members of your health care team will use to evaluate your symptoms.
An abnormal EEG may occur because of:
EEGs and seizures
Seizures are one of the most common reasons for an EEG. Sometimes the results confirm epilepsy. Other times when EEGs look normal, providers will need to look for other reasons to explain why seizures are occurring.
Only seizures caused by epilepsy change the brain’s electrical activity. Nonepileptic seizures, which don’t alter the brain’s electrical activity, won’t show up on an EEG. These seizures are known as “provoked seizures.”
A psychological event can also cause nonepileptic seizures. This type of seizure is called a “psychogenic nonepileptic seizure” (PNES). In this case, an EEG result would look normal and rule out epilepsy. Your health care team would start to look for other causes of seizures.
Chronic traumatic encephalopathy, or CTE, was previously known as dementia pugilistica or “punch-drunk syndrome” for its association with former boxers demonstrating declining ability, memory loss, and lack of coordination. The hallmark risk factor that separates the syndrome from other tauopathies and dementias is repeated trauma to the head, otherwise known as traumatic brain injuries, or TBIs. It’s this repeated trauma where things become an issue for contact sports.