# Patients with chronic post‐dural puncture headache do not have typical imaging features of intracranial hypotension: An MRI study using the Bern score

## TL;DR

This study finds that MRI scans of patients with chronic post-dural puncture headache rarely show typical signs of intracranial hypotension, suggesting current imaging methods are not reliable for diagnosing this condition.

## Contribution

The study introduces the use of the Bern score to evaluate MRI findings in chronic post-dural puncture headache, revealing that typical intracranial hypotension features are uncommon in this patient group.

## Key findings

- Chronic post-dural puncture headache patients typically have low Bern scores and rarely show spinal epidural fluid.
- Current MRI diagnostics are unreliable for detecting chronic post-dural puncture headache.
- Spinal epidural fluid, when present, is associated with higher Bern scores.

## Abstract

This study evaluated cranial magnetic resonance imaging (MRI) signs in patients with post‐dural puncture headache (PDPH) using an established assessment score developed for spontaneous intracranial hypotension (Bern score). We hypothesize that patients with chronic PDPH do not have typical imaging features of intracranial hypotension.

PDPH is a well‐known complication following an intentional or unintentional lumbar dural puncture with positional headache, neck stiffness, and hearing disturbances usually resolving within 14 days. However, the chronic course of PDPH is poorly represented in the third version of the International Classification of Headache Disorders (ICHD‐3). Moreover, data on the role of cranial MRI in this cohort are lacking, but could facilitate care and management of chronic PDPH.

In this post hoc retrospective case series based on a chart review, we identified 86 consecutive patients from a tertiary medical care center in Freiburg, Germany between 01/2018 and 10/2024 with chronic PDPH, defined as persisting symptoms for >14 days post puncture and/or persisting after one or more epidural blood patches (EBP). Inclusion criteria were history of lumbar puncture (LP) or unintended dural puncture (UDP) and contrast enhanced cranial MRI for assessment of Bern score in all patients. Presence of epidural lumbar fluid was evaluated using heavily T2‐weighted MRI or computed tomography (CT) myelography, whenever available (83/86 patients). Data were reviewed independently and blinded by two radiologists.

Eighty‐six patients with chronic PDPH (66 females; mean age of 38.8 ± 11.2 SD years) were included with LP as primary cause in 72% (n=62) and UDP while peridural (synonymous epidural) anesthesia (PDA) in 28% (n = 24). Median symptom duration was 220.0 (interquartile range [IQR] 94.0‐474.0) days. Overall median Bern score was 2.0 (IQR 1.0‐3.0) with no significant differences between LP versus PDA (p = 0.379). Local epidural fluid was present in 9/83 (11%) cases with adequate imaging and accompanied by higher median Bern scores (5.0 vs. 2.0; p = 0.026). Prior EBP was linked to lower median Bern scores (1.0 vs. 3.5; p < 0.001).

Patients with chronic PDPH predominantly present a low Bern score and rarely exhibit spinal epidural fluid. If present, spinal epidural fluid is accompanied by higher Bern score. Our findings highlight the unreliability of current MRI diagnostics to detect patients with chronic PDPH, which must not lead to a mitigation of the diagnosis or a refusal of treatment. Further research on MRI markers is needed here.

Post‐dural puncture headache (PDPH) is a common complication after lumbar puncture or unintended dural puncture and may become chronic. In this study, we used cranial MRI to evaluate the Bern score in a group of patients with chronic PDPH. Our results suggest that current MRI workups are not helpful in detecting this type of headache disorder and further research on diagnostic imaging markers in this cohort is needed; additionally, clinicians should be aware that a normal MRI does not rule out the diagnosis of chronic PDPH.