Radiological signs supporting idiopathic intracranial hypertension in symptomatic patients with lumbar puncture opening pressure < 250 mm.

Objective Lumbar puncture opening pressure (LPOP) exceeding 250mmH2O stands as a pivotal criterion in diagnosing idiopathic intracranial hypertension (IIH), according to the revised Friedman’s criteria. However, many studies discuss the variability of LPOP, while others highlight the accuracy of radiological findings as a credible diagnostic tool for IIH. We have encountered many symptomatic patients who did not meet the LPOP criteria (with or without papilledema), despite having IIH-related symptoms and neuroimaging findings. This study aimed to investigate the radiological findings and clinical symptoms in patients suspected of having IIH without meeting the LPOP criteria. Methods We retrospectively evaluated cerebral venous sinus stenosis using the conduit Farb score (CFS) as well as other radiological findings suggestive of IIH by computed tomography venography and magnetic resonance venography in female patients ≥18 years of age with chronic headaches and suspected IIH with an LPOP <250mm. Results Our cohort comprised eighty-eight women (56 with LPOP < 200 mm H2O and 32 with LPOP ranging between 200-250 mmH2O). Among patients with LPOP in the 200-250 mmH2O range, 40% (12 patients) exhibited three or more radiological findings supporting IIH, compared to 17% (8 patients) in the LPOP < 200 mmH2O group (p=0.048). Furthermore, cerebral venous stenosis, as measured by a Conduit Farb Score (CFS) of 5 or lower, was observed in 80% (24 patients) of the LPOP 200-250 mmH2O group, contrasting with 40% (19 patients) in the LPOP < 200 mmH2O group (p<0.001). Conclusion Cerebral venous stenosis, as well as other supportive radiological findings, were significantly more common in patients with LPOP 200-250 mmH2O than LPOP<200 mmH2O. These findings suggest that given supportive clinical and radiological evidence, patients with LPOP between 200-250 mmH2O, with or without papilledema, may benefit from treatment for IIH. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The author(s) received no specific funding for this work. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: the Soroka University Medical Center IRB committee (18.12.2016, protocol code 0350-16). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All relevant data are within the manuscript and its Supporting Information files.