Relationship of Bern Score, Spinal Elastance, and Opening Pressure in Patients With Spontaneous Intracranial Hypotension

Andrew L Callen; Jack Pattee; Ashesh A Thaker; Vincent M Timpone; David A Zander; Ryan Turner; Marius Birlea; Danielle Wilhour; Chantal O'Brien; Jennifer Evan; Fabio Grassia; Ian R Carroll

doi:10.1212/WNL.0000000000207267

Relationship of Bern Score, Spinal Elastance, and Opening Pressure in Patients With Spontaneous Intracranial Hypotension

Neurology. 2023 May 30;100(22):e2237-e2246. doi: 10.1212/WNL.0000000000207267. Epub 2023 Apr 4.

Affiliations

¹ From the Neuroradiology Section (A.C., A.A.T., V.M.T., D.Z., R.T.), Department of Radiology, Headache Section (M.B., D.W., C.O.B., J.E.), Department of Neurology, and Neurosurgery (F.G.), University of Colorado Anschutz Medical Campus, Aurora; Department of Biostatistics & Informatics (J.P.), Colorado School of Public Health, University of Colorado-Denver Anschutz Medical Campus, Aurora and Department of Anesthesiology (I.C.), Perioperative and Pain Medicine, Stanford University, CA. andrew.callen@cuanschutz.edu.
² From the Neuroradiology Section (A.C., A.A.T., V.M.T., D.Z., R.T.), Department of Radiology, Headache Section (M.B., D.W., C.O.B., J.E.), Department of Neurology, and Neurosurgery (F.G.), University of Colorado Anschutz Medical Campus, Aurora; Department of Biostatistics & Informatics (J.P.), Colorado School of Public Health, University of Colorado-Denver Anschutz Medical Campus, Aurora and Department of Anesthesiology (I.C.), Perioperative and Pain Medicine, Stanford University, CA.

Abstract

Background and objectives: Existing tools to diagnose spontaneous intracranial hypotension (SIH), namely spinal opening pressure (OP) and brain MRI, have limited sensitivity. We investigated whether evaluation of brain MRI using the Bern score, combined with calculated craniospinal elastance, would aid in diagnosing SIH and provide insight into its pathophysiology.

Methods: A retrospective chart review was performed of patients who underwent brain MRI and pressure-augmented dynamic CT myelography (dCTM) for suspicion of SIH. Two blinded neuroradiologists assigned Bern scores for each brain MRI. OP and incremental pressure changes after intrathecal saline infusion were recorded to calculate craniospinal elastance. The relationship between Bern score, OP, and elastance and whether a leak was found were analyzed.

Results: Seventy-two consecutive dCTMs were performed in 53 patients. Twelve CSF-venous fistulae, 2 ruptured meningeal diverticula, 2 dural defects, and 1 dural bleb were found (17/53, 32%). Among patients with imaging-proven CSF leak/fistula, OP was normal in all but 1 patient and was not significantly different in those with a leak compared with those without (15.1 vs 13.6 cm H₂O, p = 0.24, A = 0.40). The average Bern score in individuals with a leak was significantly higher than that in those without (5.35 vs 1.85, p < 0.001, A = 0.85), even when excluding pachymeningeal enhancement from the score (3.77 vs 1.57, p = 0.001, A = 0.78). The average elastance in those with a leak was higher than that in those without, but this difference was not statistically significant (2.05 vs 1.20 mL/cm H₂O, p = 0.19, A = 0.40). Increased elastance was significantly associated with an increased Bern score (95% CI -0.55 to 0.12, p < 0.01) and was significantly associated with venous distention, pachymeningeal enhancement, prepontine narrowing, and subdural collections, but not a narrowed mamillopontine or suprasellar distance.

Discussion: OP is not an effective predictor for diagnosing CSF leak and if used in isolation would result in misdiagnosis of 94% of patients in our cohort. The Bern score was associated with a higher diagnostic yield of dCTM. Elastance was significantly associated with certain components of the Bern score.

MeSH terms

Cerebrospinal Fluid Leak / diagnosis
Humans
Intracranial Hypotension* / complications
Intracranial Hypotension* / diagnostic imaging
Magnetic Resonance Imaging
Myelography
Retrospective Studies
Spine