The CSF-Inventory: A Self-Reported Assessment Tool for Spinal Cerebrospinal Fluid (CSF) Leak Symptoms and Functional Impact

Patients with spontaneous intracranial hypotension (SIH) or post-dural puncture headaches (PDPH) frequently experience a variety of symptoms such as orthostatic headaches, cognitive decline, vestibulocochlear and visual disturbances, that may lead to physical, mental, and social burden. Despite increasing awareness, standardized tools for symptom assessment are lacking. This study aims to provide a framework for reporting the heterogeneous symptoms and to quantify the burden associated with spinal CSF leaks.

The conceptual development and structure of the CSF-Inventory, a patient-reported outcome measure (PROM) were designed via a modified Delphi consensus through a bicentric panel including experts from neurology, neurosurgery, neuroradiology, and dedicated nursing, all with extensive experience in spinal CSF leaks. Patient feedback guided the item generation and revision. Short-interval response agreement was explored in 20 patients via intraclass correlation coefficient (ICC) and Cohen's kappa as appropriate.

The CSF-inventory instrument comprises 18 items clustered into three domains: (1) functional limitations, (2) symptom profile, and (3) symptom severity. The resulting tool captures key features such as working capacity, daily upright tolerance, headache frequency and severity, as well as the presence and severity of other specified symptoms. Repeated testing yielded almost identical results (ICC/Kappa > 0.98), underscoring basic clarity and feasibility.

The CSF-Inventory provides a standardized framework for assessing CSF leak-related symptoms by bridging expert and patient experiences. As such, it may provide metrics for longitudinal monitoring and the definition of patient-centered study endpoints.