Updated Results on Cerebrospinal Fluid (CSF) Volume Removal for Idiopathic Intracranial Hypertension (IIH): Removing Less CSF May Be Best (P3.101)

Objective: To assess the effect of low-volume CSF removal in patients with IIH-related headache and evaluate subsequent incidence of post-lumbar puncture (LP) headaches. Background: LPs can be used both for diagnostic evaluation and head pain relief in patients with IIH. However, LPs can also lead to unintended, low-pressure headaches. We hypothesized that low-volume CSF removal to a “high-normal” closing pressure (CP), approximately 18–20 cm H20, may result in relief of IIH-associated headache with a low incidence of post-LP headache. Design/Methods: We conducted a single-center retrospective analysis of 211 patients who underwent fluoroscopic LPs aiming for high-normal CPs from 2011–2016. One week post-LP follow-up calls or clinic visits documented whether headache was worse, unchanged, or better. Inclusion criteria were: 1) preexisting diagnosis of IIH, or opening pressure (OP) and clinical context diagnostic for IIH, 2) height and weight recorded within 1 year, 3) OP, CP, and removed CSF volume were recorded. 146 patients were included in the analysis. Results: Mean age was 34.9 years and mean BMI was 39.2 kg/m2. Mean volume removed was 9.7 ml +/− 4.6 ml. The mean CP was 17.9 cm H20. The mean pressure change (OP-CP) per volume removed was 1.50 ± 0.6 cm H20/mL. Headache symptoms at follow-up were improved in 64% of patients, worse in 26%, and unchanged in 10%. Eleven patients were headache-free and 11 patients required emergency or hospital care for post-LP headache. Conclusions: Low-volume CSF removal to approximately 18 cm H20 resulted in relief of IIH-associated headache in most patients, and a low incidence of post-LP headache after 1 week. In our cohort, for every 1 ml of CSF removed, the CP decreased approximately 1.5 cm H2O, although with large clinical variability. Disclosure: Dr. Parikh has nothing to disclose. Dr. Fiorito Torres has nothing to disclose. Dr. Rayhill has nothing to disclose. Dr. McAdams has nothing to disclose. Dr. Perloff has nothing to disclose.