The following is a summary of “Relationship of Bern Score, Spinal Elastance, and Opening Pressure in Patients With Spontaneous Intracranial Hypotension,” published in the May 2023 issue of Neurology by Callen, et al.
Diagnosing spontaneous intracranial hypotension (SIH) can be challenging due to the limited sensitivity of current diagnostic tools such as spinal opening pressure (OP) and brain MRI. For a study, researchers sought to investigate the potential of using the Bern score, in combination with calculated craniospinal elastance, to aid in the diagnosis of SIH and provide insights into its underlying pathophysiology.
A retrospective review of patient charts was conducted to identify individuals who underwent brain MRI and pressure-augmented dynamic CT myelography (dCTM) for suspected SIH. Two neuroradiologists, blinded to clinical information, assigned Bern scores to each brain MRI. OP measurements and incremental pressure changes following intrathecal saline infusion were recorded to calculate craniospinal elastance. The relationship between the Bern score, OP, elastance, and the presence of a cerebrospinal fluid (CSF) leak was analyzed.
A total of 72 consecutive dCTMs were performed in 53 patients. Among these patients, CSF-venous fistulae, ruptured meningeal diverticula, dural defects, and dural bleb were found in 17 patients (32%). Interestingly, among patients with imaging-proven CSF leak/fistula, OP measurements were within the normal range in all but one patient. There was no significant difference in OP between patients with a leak and those without (15.1 vs. 13.6 cm H2O, P = 0.24, A = 0.40). On the other hand, the average Bern score was significantly higher in individuals with a CSF leak compared to 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). Although the average elastance was higher in patients with a leak than those without, 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 a higher Bern score (95% CI -0.55 to 0.12, P < 0.01) and correlated with venous distention, pachymeningeal enhancement, prepontine narrowing, and subdural collections but not narrowed mamillopontine or suprasellar distance.
The study’s findings suggested that OP alone is not an effective predictor for diagnosing CSF leaks in patients with suspected SIH, as it would result in misdiagnosis in most cases in this cohort. In contrast, the Bern score demonstrated a higher diagnostic yield when combined with dCTM.
Elastance was significantly associated with specific components of the Bern score, indicating its potential relevance in the pathophysiology of SIH.