Prognostic Value of Muscle Mass Measured via Brain Computed Tomography in Neurocritically Ill Patients

Background: To investigate whether skeletal muscle mass estimated via brain computed tomography (CT) can be used to predict neurological outcomes in neurocritically ill patients. Methods: This is a retrospective, observational study. Adult patients who were admitted to the neurosurgical intensive care unit (ICU) in tertiary hospital from January 2010 to September 2019 were eligible. We included patients who were hospitalized in the neurosurgical ICU for more than 7 days. Cross-sectional areas of paravertebral muscle at the first cervical vertebra level (C1-CSA) and temporalis muscle thickness (TMT) on brain CT were measured to evaluate skeletal muscle mass. Primary outcome was Glasgow Outcome Scale score at 3 months. Results: Among 189 patients, 167 (88.4%) survived until discharge from the hospital. Of these survivors, 81 (42.9%) patients had favorable neurologic outcomes. Initial TMT values and follow-up TMT values were higher in patients with favorable neurologic outcome compared to those with poor neurological outcome (p = 0.003 and p = 0.001, respectively). Initial the C1-CSA/body surface area was greater in patients with poor neurological outcome than in those with favorable outcome (p = 0.029). In multivariable analysis, age (adjusted odds ratio [OR]: 2.05, 95% confidence interval [CI]: 1.543–2.724), BMI (adjusted OR: 0.74, 95% CI: 0.638–0.849), use of mannitol (adjusted OR: 27.45, 95% CI: 4.833–155.860), change of C1-CSA (adjusted OR: 1.36, 95% CI: 1.054–1.761), and change of TMT (adjusted OR: 1.27, 95% CI: 1.028–1.576) were significantly associated with poor neurological outcome (Hosmer–Lemeshow test, Chi-square = 11.4, df = 8, p = 0.178) with the areas under curve of 0.803 (95% CI 0.740–0.866) using 10-fold cross validation method. Especially, the risk of poor neurologic outcome was proportional to changes of C1-CSA and TMT. Conclusions: In this study, the follow-up skeletal muscle mass at first week from ICU admission, based on changes in C1-CSA and TMT, was associated with neurological prognosis in neurocritically ill patients. Eventually, brain CT-measured sarcopenia may be helpful in predicting poor neurological outcomes in these patients.