gms | German Medical Science

Objective: Spinal cerebrospinal fluid (CSF) leakage causes spontaneous intracranial hypotension (SIH) with the leading symptom being orthostatic headache amongst others. The clinical spectrum and radiological manifestations are broad requiring multiple imaging procedures and this makes SIH a challenging diagnosis. Up to now only opening pressure during lumbar puncture is included as a diagnostic criterion leaving other CSF dynamics aside. The aim of the study was to assess CSF outflow resistance by lumbar infusion testing in patients with and without a spinal CSF leak.

Method: We included consecutive patients with suspected SIH treated between January 2012 to February 2015. A CSF leak was defined as contrast media passage from the intra- to extrathecal space by either spinal MRI, myelography or post-myelography-CT. Computerized lumbar infusion testing with a constant rate of 2ml/min was performed to analyze CSF outflow resistance (RCSF), lumbar pressure and pulse amplitude (AMP) at baseline and plateau, elastance coefficient (e) and pressure volume index (PVI).

Results: Thirty-one patients were included in this study. 14 patients had a proven CSF leakage. In patients with and without a leak RCSF (1.97mmHg/ml/min vs. 11.78mmHg/ml/min), lumbar pressure at baseline (5.26mmHg vs. 11.77mmHg) and plateau (16.11mmHg vs. 32.06mmHg), AMP at plateau (1.03mmHg vs. 2.80mmHg), and PVI (26.43ml vs. 20.93ml) were associated with the existence of a spinal CSF leakage. Median opening pressure in patients with a CSF leakage was 5.26mmHg compared to 11.77mmHg in patients without a leak (p<0.001). Eight patients (57.1%) with a proven leak had an opening pressure higher than 4.4mmHg (current threshold of the ICHD society for SIH).

Conclusions: The computerized lumbar infusion tests showed a strong association with the existence of a spinal CSF leakage. RCSF had the highest diagnostic yield, higher than lumbar opening pressure. RCSF can easily be implemented in the diagnostic workup of SIH.