There is a lack of reliable spontaneous intracranial hypotension (SIH) diagnosing tools. The commonly used Bern Score, which integrates six established imaging signs, has proven reliable in discriminating spinal cerebrospinal fluid (CSF) leaks. However, this score does not include several commonly observed imaging features, and new signs have been reported recently. This study aimed to identify additional reliable imaging signs in order to develop a new scoring system for the diagnosis of SIH. In this case-control study, brain MR images from consecutive SIH patients and control participants at our institution were retrospectively and independently reviewed by 3 blinded readers. 3 qualitative and 9 quantitative imaging signs were evaluated. Firth’s regression was performed and a diagnostic scoring system composed of reliable imaging signs was developed. The performance of this new scoring system was validated in an external retrospective patient cohort and compared with that of the Bern Score. Our derivation cohort comprised 20 SIH patients and 20 age- and gender- matched control participants, while the validation cohort included 55 SIH patients and 55 controls. We identified pituitary height (ICC=0.873) and the clivus-mesencephalic angle (ICC=0.897) as two additional reliable and practicable imaging features. All six imaging signs in the original Bern Score showed good inter-observer and inter-study agreement (except for prepontine cistern size, which was smaller in the present study). We then developed a new scoring system, the PS-Bern score (PS denoting pituitary and skull base). It incorporates pituitary height (2 points), clivus-mesencephalic angle (1 point) and the full Bern Score (prepontine cistern size ≤4 mm). In the validation cohort, the PS-Bern score outperformed the Bern score. For ruling in SIH (cutoff ≥5 vs Bern ≥4), the PS-Bern score had a sensitivity of 89.1% and specificity of 98.2%, compared to 85.5% and 94.6% for the Bern score. For ruling out SIH (cutoff ≤3 vs Bern ≤2), its sensitivity and specificity were 89.1% and 92.7%, respectively, superior to the Bern score's values of 65.5% and 90.9%. Pituitary height and clivus-mesencephalic angle are useful imaging biomarkers and the PS-Bern score including these two signs may aid in the timely and accurate diagnosis of SIH. The small sample size requires that the results be validated in larger cohorts. • The Bern Score exhibits best performance for diagnosing SIH at a threshold of ≥ 4 points. • Pituitary height ≥ 7 mm in males or ≥ 7.5 mm in females is indication of SIH. • Clivus-mesencephalic angle can be a substitute for pontomesencephalic angle • PS-Bern score incorporates pituitary height, clivus-mesencephalic angle and the original Bern Score will aid the diagnosis of SIH.
Zhou et al. (Sun,) studied this question.