Predicting clinical outcome in Neurosurgical ICU using quantitative uninterrupted real-time wireless EEG analysis

Monitoring in the Neuro Intensive Care Unit (NICU) is mainly performed through the neurological examination. However, this may not be feasible in patients who are sedated and/or

mechanically ventilated(1). The ability to assess patient prognosis early in the course of hospital treatment facilitates clinical decision-making and permits accurate family counseling to impart realistic expectations for recovery. Several clinical and radiographic measures, Glasgow Coma Scale [GCS] score, pupil reactivity, age, lesions on early computed tomography [CT] scans) have significant predictive value when studied alone or in combination. All these are indirect parameters and occur at delayed intervals following the insult. Electroencephalogram is one modality similar to the Electrocardiogram (ECG) which can provide direct information about the electrical activity of the brain. EEG has been used to detect delayed neurological deterioration in subarachnoid hemorrhage but hasn’t been evaluated in traumatic brain injury and ICH.

Continuous electroencephalography (cEEG) is a non- invasive tool that can provide real-time measurement of electrical brain activity (5). EEG abnormalities arise when the normal cerebral blood flow (CBF) of 50 to 70 ml/100 g/min decreases to 25 to 30 ml/100 g/min. cEEG, therefore, provides a potential window of opportunity to therapeutically intervene

by detecting changes in cerebral perfusion prior to the point of irreversible damage (5-7).

transformation (compressed spectral array). In three studies that used this technique, various features were shown to correlate with DCI such as the trending of the total EEG power, relative alpha variability, and alpha–delta ratios (1) (8) (9). Changes on qCEEG were observed prior to Transcranial Doppler (TCD) abnormalities and preceded clinical deterioration up to 2 days (8) (9). Other selected characteristics of raw EEG, such as the back-ground rhythm and Synek scale, spontaneous variability and responsiveness stimulation, have been used to assist in estimating prognosis (2). The lack of P-Alpha variability over time during the initial three days after severe TBI was associated with clinical outcome at 1 month and 6 months (10,11). EEG power spectrum analysis has also been used to determine Intracranial pressure (12).

Muse- the brain sensing headband, is an electroencephalography (EEG) technology. Muse is used in hospitals, clinics, and universities worldwide as a research tool. The research domains extend from cognitive neuroscience, to brain health, psychotherapy, music cognition, and more. It provides an open platform where anyone can record raw data with Muse and anyone can build their own Muse application. EEG data can be recorded with MuseLab, MusePlayer, or via the third-party mobile application MuseMonitor (for Android and iOS). It is wireless (Bluetooth), lightweight, flexible, adjustable, and easily worn with less than one minute of set-up. Muse uses two channels on the left and two on the right, so it is ideal for exploring hemispheric asymmetries.