Healthy Impulses: Measuring Brain Activity Can Help Diagnose Brain Disorders

measure brain waves eegEven while sleeping, your brain is hard at work. About 100 billion specialized cells in the brain called neurons act like tiny messengers. Neurons send and receive messages using electrical impulses that create brain waves, which indicate what’s happening inside your brain.

A simple, noninvasive test called an electro encephalogram (EEG) measures and records the brain waves. Conditions known for disrupting normal brain activity, such as epilepsy, stroke, brain injury or dementia, are diagnosed and monitored with this test. EEGs also measure the effectiveness of certain medications.

What to Expect

“It’s the easiest test in the world,” said Alendia Hartshorn, MD, a neurologist with Mission Neurology. “You just come in and take a nap.”

But first, electrodes are placed on the scalp. Patients are made comfortable in a quiet room and rest lying down, hopefully dosing off to sleep. If so, doctors get two readings — brain activity while sleeping and awake.

“That’s ideal. It’s almost two tests in one,” said Dr. Hartshorn.

How to Prepare

Almost no prep is needed aside from getting less sleep than normal to help patients relax and doze during the test. Follow normal eating and medication routines, but avoid excessive caffeinated drinks prior to the test. Also avoid conditioner or slick hair products within 24 hours of testing, because they affect how electrodes stick to the scalp.


The noninvasive test is simple and an option for babies through seniors. Some patients have a mild allergic reaction to the glue used on electrodes, resulting in an itchy scalp. Seizures may also occur during the short test, and staff stands ready to minimize seizure activity.

“These simple tests provide invaluable insight into the brain’s activity and function,” said Dr. Hartshorn.

Electroencephalograms (EEGs) measure and record brain activity and are used to monitor, treat or diagnose:

Alendia Hartshorn, MD, is a neurologist with Mission Neurology.

Mission Neurology provides a wide spectrum of inpatient and outpatient neurology services. To learn more, visit [1].