Variability of Consecutive Lumbar Puncture Opening Pressures.

Area of Science:

• Neurology
• Clinical Measurement
• Intracranial Pressure Monitoring

Background:

• Lumbar puncture (LP) opening pressures (OPs) are vital for diagnosing elevated intracranial pressures (ICPs).
• OPs are known to fluctuate due to various factors, yet single measurements are often relied upon.
• Understanding OP variability is crucial for accurate clinical interpretation.

Purpose of the Study:

• To assess the variability of consecutive lumbar puncture opening pressures.
• To determine the range of variability for a given lumbar puncture opening pressure measurement.
• To identify factors influencing opening pressure fluctuations.

Main Methods:

• Retrospective cohort study of patients with at least two LPs within 30 days.
• Exclusion of patients with known ICP-influencing pathologic conditions.
• Analysis of OP data from a large referral center (Mayo Clinic, 2001-2016).

Main Results:

• Mean OP showed minimal difference between consecutive LPs (1 mm H2O), but a coefficient of repeatability (CR) of 86.4 was observed.
• Higher initial OP (>200 mm H2O) correlated with greater variability (CR 111.4 vs. 74.6).
• Conditions like headache and anxiety, along with higher initial OP and BMI, were associated with increased OP variability.

Conclusions:

• Variability in lumbar puncture opening pressures is influenced by initial pressure, headache, and anxiety.
• Opening pressures inconsistent with clinical presentation warrant cautious interpretation.
• The study highlights the dynamic nature of OPs and the need for careful consideration of individual patient factors.