Age‐Dependence of Cerebrospinal Fluid Pressure Metrics During Queckenstedt’s Test

Introduction Quantification of craniospinal compliance is a known practice in neurological diagnostics. It is regularly done through external volume application during infusion testing and takes 30–60 min. We previously described a reliable method to obtain cerebrospinal fluid pressure (CSFP) pulsatility curve using a 10‐s auto‐infusion test, also known as Queckenstedt’s test (QT). Metrics such as relative pulse pressure coefficient (RPPC‐Q) and pressure at infinite compliance (P 0 ‐Q) obtained by QT may contain information on cerebrospinal compliance. As compliance changes with age, it would be of value to quantify potential age‐dependent changes in these QT‐derived metrics. Materials and Methods Lumbar puncture was performed in lateral recumbent position in 14 adults < 50 years (38.7 ± 7.8 years, 7F) with no suspicion of spinal canal stenosis. Results were compared to 14 older patients (59.7 ± 9.3 years, 6F) (NCT02170155). CSFP was recorded during resting state and QT, and was repeated during head reclination. RPPC‐Q and P 0 ‐Q were computed from repeated QTs. Results Between the two groups, there was no difference in mean CSFP ( p = 0.65), cardiac‐driven CSFP peak‐to‐valley amplitude (CSFPp) ( p = 0.75), or in mean CSFP rise during QT (△CSFP) ( p = 0.10). However, CSFPp at peak QT was lower in the young cohort (3.1 {1.7} mmHg vs. 3.7 {1.7}, p = 0.002), as were median RPPC‐Q (0.09 {0.09} vs. 0.18 {0.06}, p = 0.009), and P 0 ‐Q (3.1 {5.4} vs. 7.1 {3.5}, p = 0.004). Regression analysis showed a positive correlation between age and both RPPC‐Q (0.003, p = 0.02) and P 0 ‐Q (0.2, p = 0.02). Conclusions The differences in RPPC‐Q and P 0 ‐Q between the two age groups suggest that information on craniospinal compliance can be derived from this simple bedside test. A study comparing these QT‐derived metrics to their corresponding metrics obtained by infusion testing is warranted. Trial Registration: ClinicalTrials.gov Registry NCT02170155