Abstracts

Rationale: Standard equipment EEG utilization is difficult and cumbersome in the setting of an emergency department (ED). However, EEG evaluation should be prioritized in patients with altered mental status (AMS) due to a high proportion of EEG abnormalities including non-convulsive status epilepticus (NCSE). Mobile EEG (miniature, portable, battery-powered, and wireless EEG device devices) is a modality that is utilized to an increasing extent among biomedical researchers. Although mobile EEG systems sometimes have lower system specifications compared to their static counterparts, their success has been promoted by maneuverability. In this open study, we evaluated mobile EEG in patients with AMS and assessed its relevance to clinical and radiological data. Methods: Patients older than 18 years of age with AMS of unknown cause who presented to a tertiary care academic medical center adult ED (Clinical Center of Serbia) were included in the study in two consecutive months (September 1st, 2018 - October 31st, 2018). EEG data acquisition was performed using the SMARTING (mBrainTrain, Serbia) wireless EEG system, using a sampling frequency of 250Hz and 24-bit data resolution. The small and lightweight EEG amplifier (85 x 51 x 12 mm, 60gr) is tightly connected to a 24- channel electrode cap in the occipital site of the patients' head, using an elastic band. Briefly trained research assistant recorded 30 minutes EEG and data were reported by an off-site epileptologist within two hours. Results: EEG was recorded in 25 consecutive patients (61.9+-17.9 years old) with AMS (24% in confusion; 32% in somnolence;12% in stupor; and 32% in coma) admitted in the ED in Clinical Center of Serbia. EEG was normal in one patient. Two patients with NCSE were detected and treated immediately with a good response. Majority of patients had positive brain CT findings (N=14; 56%): ischemic leucoencephalopathy (N=4; 28.6%), cerebral multi infarcts (N=2; 14.3%), significant brain atrophy (N=1; 7.1%), mass-lesion (N=1; 7.1%), and acute cerebral infarction (N=6; 42.9%). Eight patients died in the course of the disease (32%), 6 patients recovered to premorbid level (24%), 3 patients recovered with sequelae (12%), and the outcome was unknown in 8 patients (32%). Background alpha was registered in 24%. Predominant background frequency was theta band in 80%, and alpha band in 20%, which was continuous in 76%, nearly discontinuous in 12%, discontinuous in 8%, and burst-suppression in 4% of patients. The anterior-posterior gradient was registered in 8% of patients. More deteriorating level of consciousness was associated with the absence of anterior-posterior gradient, and not to other EEG variables. Rhythmic or periodic patterns were registered in 28% of patients. Artifacts obscured EEG occasionally in 3 patients (12%), and frequently in 6 patients (24%). Conclusions: With minimal training, ED personnel could use this small, mobile EEG device t(SMARTING) to obtain an EEG recording. EEG signal acquired from the mobile EEG system SMARTING is providing meaningful and robust data which are relevant in the clinical management of AMS patients. Funding: No funding