The goals of our study: (1) the utility of orexin as a marker of coma recovery, (2) the correlation between orexin and recovery at 7 and 14 days, (3) correlation of orexin and Glasgow Coma Score (GCS) over time, and (4) the correlation between CSF and serum orexin.

A prospective, IRB approved study with a target n= 20 with a diagnosis of coma due to stroke, including hemorrhagic, and TBI, treated in the Neuro Critical Care Unit at Stony Brook University Hospital. CSF was collected from an external ventricular drain (EVD) and corresponding blood serum samples on Days 0, 7, and 14. There was no modification to the clinical treatment of individual patients.

Day 0 CSF orexin concentration was highly predictive of whether patients recovered consciousness vs. deteriorated. Logistic regression showed the relative risk of recovery vs. deterioration:  (95%CI -299.8 ±44.4, 72.3 ±10.2, respective p-values=0.4954e-39, 0.001e-39). Baseline CSF orexin was less predictive of initial coma severity (GCS), with a correlation coefficient, R=0.338. Correlation between CSF and Serum Orexin was low (R=0.2325, 0.2343, -0.964, -0.2881)