Product
C-Trend in Bittium’s BrainStatus monitor
Cerenion’s C-Trend analysis is available in EU as an option in Bittium’s BrainStatus™ monitor that brings continuous long term EEG monitoring to the bedside of acutely ill patients. BrainStatus records the EEG signal, using a single-use sub-hairline electrode that can be attached within minutes.
Cerenion C-Trend Software Library consists of four qEEG parameters and their trends
These waveforms are a representation of the raw EEG signal, detected by Bittium’s single-use, subhairline EEG Electrode. The displayed channels are user-configurable. Their amplitude is scalable, and the raw EEG can be browsed back in time, either at the bedside or remotely.
C-Trend Index analyses low frequencies (<1Hz) of EEG that are typical in the healthy brain during propofol sedation and sleep. The index describes slow-wave activity as a single number between 0-100, where a high value indicates high slow-wave activity. A low value indicates abnormal or absent slow-wave activity. A higher C-Trend Index within 12 hours of ROSC (Return of Spontaneous Circulation) in resuscitated, sedated cardiac arrest survivors has been shown to be a prognostic sign of a good outcome.
Burst-Suppression Ratio (BSR) helps detect suppressed periods in the EEG signal. BSR is calculated from a 60-second time window by dividing the duration of the suppression periods by the total time window duration. The result is expressed on a scale of 0-100, where 0% corresponds to continuous EEG (no suppression periods) and 100% to suppressed EEG (time window contains only suppression). Common causes of high BSR and suppression periods in EEG are deep anesthesia and various brain disorders, e.g. hypoxic ischemic encephalopathy (HIE), epileptic seizures or infection.
aEEG (Amplitude-integrated EEG) is conventionally applied in the neonatal intensive care units (NICU’s), where it is used to detect epileptic seizures. We apply it to the adult patients, where it has similar value. aEEG describes the filtered and time-compressed amplitude of the signal and helps you detect changes in amplitude. Such changes may occur e.g. during an epileptic seizure. Lower, upper, and median parameters indicate the thresholds below which 5%, 95%, and 50% of the raw aEEG values are. In addition to these three parameters, raw EEG values are presented in the trend view (gray trend). aEEG provides three parameters calculated from a 5-minute time window.
ADR (Alpha-Delta Ratio) is known to react to reduced oxygen supply, for instance in the case of stroke and vasospasm. It displays the ratio between signal power in alpha (8-13 Hz) and delta (1-4 Hz) ranges. The parameter is calculated separately for both hemispheres (the left and right hemisphere) from the five channels on that side using a 2-minute time window. An increase in the ADR indicates relative shift of power from delta frequencies to alpha frequencies. Decreasing values of ADR on the other hand indicate relative shift of power from alpha frequencies to delta frequencies. These kind of changes in the power spectrum of the signal may occur in several different conditions such as during anesthesia or lack of oxygen in brain tissue. The lack of oxygen in a specific area of the brain, for example, typically shifts the activity from higher frequencies to lower frequencies and thus decreases ADR.
ADR is a sensitive but not necessarily specific indication of delayed cerebral ischemia (DCI) after subarachnoid hemorrhage. There is no exact reference value for ADR, as the underlying phenomenon may be local or global. Therefore, the interpretation is based on the comparison of the difference between the right and left ADR and the observation of possible sudden changes in the values.
