Background: Post-dural puncture headache (PDPH) might be related to cerebrospinal fluid hypotension. Studies in brain-injured patients have shown a good relationship between optic nerve sheath diameter (ONSD) measured by ocular sonography and invasively measured intracranial pressure (ICP). The aim of this study was to evaluate changes in ONSD after lumbar epidural blood patch (EBP).
Methods: Consecutive subjects receiving an EBP for PDPH were included. ONSD and pain measurements were performed before (T(0)), 10 min (M(10)), 2 h (H(2)), and 20 h (H(20)) after the EBP.
Results: Ten subjects were included. ONSD [median (inter-quartile range)] increased with time after EBP, from 4.8 mm (4.5-5.1) at T(0) to 5.2 mm (4.9-5.7) at M(10) (P=0.005 vs T(0)), 5.5 mm (5.1-6.0) at H(2) (P=0.007 vs T(0)), and 5.8 mm (5.2-6.3) at H(20) (P=0.02 vs T(0)). EBP was clinically successful in nine of 10 subjects. In subjects in whom EBP was successful, ONSD significantly increased at M(10) and T(2) compared with T(0) (P=0.004 and 0.008, respectively) but did not reach statistical significance at H(20) (P=0.06). In the subject in whom EBP failed, a small increase in ONSD was observed over time.
Conclusions: In this preliminary report, EBP was followed by ONSD enlargement in subjects with successful EBP, but not in the subject with EBP failure. Since ONSD is a surrogate marker of ICP, this suggests that a sustained increase in ICP is associated with successful EBP.