Predicting Spinal CSF Leaks in Intracranial Hypotension: A Scoring System Based on Brain MRI Findings

Abstract

Background: Various signs may be observed on brain magnetic resonance imaging (MRI) in patients with spontaneous intracranial hypotension (SIH). However, the lack of a classification system integrating these findings limits decision making in clinical practice. The objective was to assess the likelihood of an underlying spinal CSF leak based on a probability score taking into account the most relevant brain MRI findings. Methods: Three blinded readers retrospectively reviewed the brain MRI of 56 SIH patients with a proven spinal CSF leak and 60 healthy controls, evaluating seven quantitative and nine qualitative signs. We then derived a predictive diagnostic score based on multivariable backward logistic regression analysis. Its performance was further validated internally in a prospective cohort of 20 patients presenting with clinical signs of SIH. Findings: Six imaging findings were included in the final scoring system. Three were weighted as major (2 points): pachymeningeal enhancement, engorgement of venous sinus, effacement of the suprasellar cistern 5, respectively. The discriminatory ability of the proposed score could be demonstrated in the validation cohort. Interpretation: The three-tier predictive scoring system we propose is based on the six most relevant brain MRI findings and allows to assess the likelihood (low, intermediate or high probability) of finding a spinal CSF leak in SIH patients. It may be useful in triaging patients who may or may not benefit from further invasive myelographic examinations before considering targeted therapy. Funding Statement: The authors declare: This study was not funded, as all examinations were part of our routine clinical protocol. Declaration of Interests: PJM receives Swiss National Science Foundation (SNSF) grants for research on brain aneurysms. JG is a global PI of STAR, CEC member of the PROMISE study (Penumbra) PI for the SWIFT DIRECT study (Medtronic), Consultancy; and receives Swiss National Science Foundation (SNSF) grants for magnetic resonance imaging in stroke. JB is global PI of SWITCH and TOSCAN studies. He received SNSF grant for ultrasound perfusion imaging. All other authors declare no competing interests. Ethics Approval Statement: Institutional review board approval was obtained for this single-center study (Kantonale Ethikkommission Bern, Switzerland, number: 2017–00861).