Chronic orthostatic headache after dural puncture is a serious condition lacking defined diagnostic criteria and pathophysiologic understanding. Prevailing opinion suggests CSF outflow through an unsealed dural hole after a lumbar puncture. We aimed to systematically search for a leak with MRI and perform dynamic CSF infusion testing in patients with chronic orthostatic headache after a lumbar puncture. In a retrospective, single-center cohort study at the Medical Center-University Hospital Freiburg, patients with chronic postdural puncture headache (cPDPH), defined by a history of dural puncture and new orthostatic headache either persisting >14 days after puncture and/or persisting after 1 or more epidural blood patches (EBPs), were included between April 2018 and July 2022. We excluded patients with proven spontaneous CSF leakage and those with previous interventions other than EBPs. Our workup included clinical data such as demographics, symptoms, prior treatment, and imaging data. We analyzed opening pressure and CSF dynamics by lumbar infusion test (LIT) including resistance to CSF outflow (RCSF), pressure at baseline and plateau, pulse amplitude at baseline and plateau, elastance, and pressure-volume index (PVI). We included 21 consecutive patients with cPDPH in our final cohort. Complete data sets were available in 21 patients, of whom 19 were female and 2 were male. The median age was 39 years (interquartile range IQR 30-49 years). Spinal imaging showed pathologic extrathecal fluid in 2 patients (10%). After lumbar puncture, the median opening pressure was 12 cmH2O (IQR 9-17). LIT yielded a median RCSF of 10.77 mm Hg/(mL/min) (IQR 6.79-13.78), a median lumbar pressure baseline of 9.84 mm Hg (IQR 7.24-14.05), and a median PVI of 13.47 mL (IQR 9.62-18.47). There was no correlation between LIT parameters and symptom duration. Our results do not support the hypothesis that all patients with cPDPH have a leaking dural defect or are in a state of CSF depletion. We conclude that symptoms may not be related to CSF dynamics as measured by opening pressure or with LIT and that further investigation into the pathomechanism of persisting orthostatic symptoms is warranted.
Fung et al. (Tue,) studied this question.