Trending at Lifelines This Month, #BurstSuppressionTrends
EEG recording of burst suppression pattern, courtesy of Lifelines iEEG Trends Guide (2018)
By Melissa Burke, R.EEG/EP T., CNIM
Recording continuous EEG (cEEG) in conjunction with burst suppression trend analysis is a helpful way to observe gradual changes in the EEG activity over several hours and even days. These changes may be progressive or regressive, which assists in the ongoing evaluation of the patient’s prognosis. This overview will present the benefits and use of burst suppression trends.
Lifelines’ Acquire Pro Trend package offers three burst suppression trends, which are displayed in the overview window above the continuous, raw EEG recording. Depending on the patient population, one, or a combination of these trends, along with the EEG, can greatly assist during interpretation.
- Burst Suppression Ratio (BSR) is the ratio of time spent in cerebral suppression as a percentage of the total time of each segment. BSR shows that ratio as a percentage, updating every second.
- Bursts per Minute (BPM) counts each burst per minute, updating every second.
- Interburst Interval (IBI) counts the seconds in between bursts, updating every second.
In the adult and pediatric population, a progressive change could mean a patient is coming out of a coma. The brainwaves progress from a burst suppression pattern into a slow wave pattern, and finally to a normalized EEG. A regressive change may be a burst suppression pattern that changes to an isoelectric EEG or brain death pattern (Niedermeyer, 2009).
In the neonatal population, burst suppression trends can assist in evaluation of prognosis in preterm babies and neonates. EEG patterns may contain some discontinuity, and knowledge of the neonate’s postmenstrual age is critical in determining whether discontinuity is normal or excessive for age (LaRoche, 2013, p. 185).
Discontinuity refers to “on” periods called bursts and “off” periods, called interburst intervals.
Abnormal burst suppression pattern refers to a pattern with interburst intervals of low amplitude (often defined as less than 5µV ) alternating with higher amplitude bursts. It is nonreactive and invariant (LaRoche, 2013).
At a quick glance, the combination of cEEG with burst suppression trends helps clinicians determine how sick or healthy the state of the monitored brain has been over the course of a recording. Burst suppression trends also assist the medical team in providing vital treatment to the patient over several days by providing critical information regarding the brain’s improvement or regression as recorded in his or her EEG.
A complete Lifelines iEEG Trends Guide will be released soon to Lifelines customers.
LaRoche, S. M. (2013). Handbook of ICU EEG Monitoring. New York: Demos Medical Publishing, LLC.
Niedermeyer, E. (2009). The Burst Suppression Electroencephalogram. Am J Electroneurodiagnostic Technol, 333-341.