Objective Previous work has shown that it is possible to build an EEG-based binary brain-computer interface system (BCI) driven purely by shifts of attention to auditory stimuli. However, previous studies used abrupt, abstract stimuli that are often perceived as harsh and unpleasant, and whose lack of inherent meaning may make the interface unintuitive and difficult for beginners. We aimed to establish whether we could transition to a system based on more natural, intuitive stimuli (spoken words “yes” and “no”) without loss of performance, and whether the system could be used by people in the locked-in state. Methodology We performed a counterbalanced, interleaved within-subject comparison between an auditory streaming BCI that used beep stimuli, and one that used word stimuli. Fourteen healthy volunteers performed two sessions each, on separate days. We also collected preliminary data from two subjects with advanced ALS, who used the word-based system to answer a set of simple yes-no questions. Main Results The N1, N2 and P3 event-related potentials elicited by words varied more between subjects than those elicited by beeps. However, the difference between responses to attended and unattended stimuli was more consistent with words than beeps. Healthy subjects’ performance with word stimuli (mean 77% ± 3.3 s.e.) was slightly but not significantly better than their performance with beep stimuli (mean 73% ± 2.8 s.e.). The two subjects with ALS used the word-based BCI to answer questions with a level of accuracy similar to that of the healthy subjects. Significance Since performance using word stimuli was at least as good as performance using beeps, we recommend that auditory streaming BCI systems be built with word stimuli to make the system more pleasant and intuitive. Our preliminary data show that word-based streaming BCI is a promising tool for communication by people who are locked in.

BACKGROUND Preoperative hemoglobin A1c (HbA1c) is a useful screening tool since a significant portion of diabetic patients in the United States are undiagnosed and the prevalence of diabetes continues to increase. However, there is a paucity of literature analyzing comprehensive association between HbA1c and postoperative outcome in lumbar spine surgery. Objective To assess the prognostic value of preoperative HbA1c > 8% in patients undergoing elective lumbar spine surgery. MethodS The Michigan Spine Surgery Improvement Collaborative (MSSIC) database was queried to track all elective lumbar spine surgeries between January 2018 and December 2019. Cases were divided into 2 cohorts based on preoperative HbA1c level (≤8% and >8%). Measured outcomes include any complication, surgical site infection (SSI), readmission (RA) within 30 d (30RA) and 90 d (90RA) of index operation, patient satisfaction, and the percentage of patients who achieved minimum clinically important difference (MCID) using Patient-Reported Outcomes Measurement Information System. Results We captured 4778 patients in this study. Our multivariate analysis demonstrated that patients with HbA1c > 8% were more likely to experience postoperative complication (odds ratio [OR] 1.81, 95% CI 1.20-2.73; P = .005) and be readmitted within 90 d of index surgery (OR 1.66, 95% CI 1.08-2.54; P = .021). They also had longer hospital stay (OR 1.12, 95% CI 1.03-1.23; P = .009) and were less likely to achieve functional improvement after surgery (OR 0.64, 95% CI 0.44-0.92; P = .016). Conclusion HbA1c > 8% is a reliable predictor of poor outcome in elective lumbar spine surgery. Clinicians should consider specialty consultation to optimize patients’ glycemic control prior to surgery.