Fig. 1

Dark-light phase fluctuations in patient ICP, blood pressure, and CSF dynamics . A Average ICP measured in patients during the light phase (6 AM to 6 PM) and the dark phase (6 PM to 6 AM), left panel, with the intra-patient ∆ICP illustrated in the right panel, n = 24. Statistical significance evaluated with paired Wilcoxon t-test (left) and Wilcoxon signed-rank test (right). B MAP measured in the same patient group obtained in the light phase (6 AM to 6 PM) and the dark phase (6 PM to 6 AM), left panel, with the intra-patient ∆MAP illustrated in the right panel, n = 21. Statistical significance evaluated with paired two-way t-test (left) and one sample t-test (right panel). C CSF volume collected from the extraventricular drain in the patient group during the light phase (6 AM to 6 PM) and the dark phase (6 PM to 6 AM), left, with the intra-patient ∆CSF volume illustrated in the right panel, n = 24. Statistical significance evaluated with paired two-way t-test (left panel) and one sample t-test (right panel). ICP  intracranial pressure, MAP mean arterial pressure, CSF cerebrospinal fluid. Data are shown as mean ± SD. **P < 0.01, ***P < 0.001