A Detailed Look at Long-Term EEG Monitoring

An electroencephalogram (EEG) is a diagnostic test that measures the electrical activity of the brain. Most EEGs are recorded for 20–30 minutes, depending on the reason for the study or diagnosis. However, there are cases where a longer recording provides more valuable insights.

Long-Term EEG monitoring involves recording brainwave activity continuously over several hours to multiple days. This extended monitoring includes a video component that captures physical movements and clinical correlates during events. Recording EEG for longer periods increases the chances of capturing abnormalities and events that wouldn’t be possible during a routine EEG, aiding in the treatment of seizures and epilepsy and reducing the misdiagnosis of seizures.

Where Is Long-Term EEG Monitoring Performed?

Long-term EEGs are conducted in a variety of clinical settings, including:

• Inpatient hospital units, such as Epilepsy Monitoring Units (EMUs), where medications may be safely reduced or paused to provoke an event under close observation.
• ICU settings, where critically ill patients are monitored for subclinical seizures or general brain function.
• sEEG (stereo EEG) procedures, in which electrodes are surgically implanted to precisely identify seizure foci as part of a presurgical workup.
• Ambulatory EEGs, performed in outpatient or at-home environments, allowing patients to maintain their daily routines in a more natural and comfortable setting. These may or may not include video and can be set up either in a clinic or at the patient’s home.

What to Expect During Long-Term EEG Monitoring

For most long-term EEGs (excluding sEEG), electrodes are placed non-invasively on the scalp to monitor electrical activity. EEG technologists either live-monitor the data or review it frequently to detect abnormalities and expedite reporting to the clinical care team.

If undergoing long-term EEG monitoring in a hospital, the patient will likely need to remain in their room, but they can still engage in everyday activities like watching TV, reading, or playing video games. In contrast, ambulatory EEG allows for more freedom and normalcy, though some movement restrictions still apply depending on the equipment used.

Why Long-Term EEG Matters

Long-term EEG Monitoring is a great diagnostic tool looking at the brain’s electrical activity to aid in the diagnosis and treatment of seizures, epilepsy, and other neurological conditions. Whether conducted in a hospital or at home, long-term EEG gives clinicians the insights needed to provide more effective and personalized care.

Written by: Alexis Gerber, R.EEG.T, CLTM