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

ObjectiveLumbar puncture opening pressure (LPOP) exceeding 250mmH2O stands as a pivotal criterion in diagnosing idiopathic intracranial hypertension (IIH), according to the revised Friedmans 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. MethodsWe 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. ResultsOur 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). ConclusionCerebral 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.