Aim: Spontaneous intracranial hypotension (SIH) is a heterogeneous syndrome arising from spinal CSF leakage. This study aimed to assess the relationship between the Bern SIH score, morphometric MRI measurements, and aetiological subtype, and to propose a stepwise management algorithm.

Methods: Nine patients with confirmed SIH admitted between March 2020 and February 2026 were retrospectively evaluated. Bern score (0–9), pontomesencephalic angle (PMA), mammillopontine distance (MPM), and clivo-axial angle (CXA) were systematically measured. Patients were classified into four subtypes per Schievink criteria; clinical response was assessed using an NRS-based three-tier grading system, and complications were graded with the Clavien-Dindo classification.

Results: All nine patients were female (median age 49.5 years). Subtype distribution was as follows: Type 1 (n=3), Type 2 (n=1), Type 3 CVF (n=2; both admissions from the same patient), and cryptogenic (n=3). PMA ranged from 27.4° to 37.5°, MPM from 3.3 to 4.6 mm, and CXA from 141.5° to 167.3°; all values were below normal reference ranges. The venous distension sign was positive in eight patients (88.9%). Complete clinical response was achieved in eight patients (88.9%; 95% CI 52.0%–99.7%); no Clavien-Dindo Grade IV–V complications occurred.

Conclusion: The Bern score, PMA, and CXA consistently correlate with SIH aetiological subtype and treatment complexity. Type 1 osteophytic leaks with significant cord compression require direct surgical repair; Type 3 CVFs are refractory to EBP and mandate endovascular embolisation as first-line invasive treatment. Post-embolisation rebound intracranial hypertension necessitates active MRI surveillance.

Keywords: spontaneous intracranial hypotension, Bern SIH score, pontomesencephalic angle, clivo-axial angle; epidural blood patch, CSF-venous fistula, treatment algorithm, case series