Prediction of Target Epidural Blood Patch Treatment Efficacy in Spontaneous Intracranial Hypotension Using Follow-Up MRI

Abstract

Objectives: Epidural blood patching (EBP) is the mainstay therapy for spontaneous intracranial hypotension (SIH). MRI is used for evaluating spinal CSF leakage. Post-EBP MRI has been. shown to be effective in predicting the efficacy of EBP. However, there are few reports on how post-EBP MRI findings may change with time. The aim of this study was to evaluate the relationship between post-EBP MRI findings at different time points and the corresponding effectiveness of EBP.

Methods: We retrospectively reviewed 63 SIH patients who had received target EBP. All patients received an MRI follow-up within 10 days (post-EBP MRI) and at 3 months after EBP (3-month MRI). A sub-group analysis was performed at different post-EBP MRI time points (0-2, 3-6, and 7-10 days). The relationships between the post-EBP MRI findings and the EBP effectiveness were evaluated.

Results: Thirty-five (55.56%) patients were assigned to the EBP-effective group, and 28 (44.44%) were assigned to the EBP non-effective group according to the 3-month MRI. Compared to the EBP non-effective group, the EBP-effective group had significantly lower numbers of spinal CSF leakage in the post-EBP MRI (4.49 vs. 11.71; p = 0.000) and greater numbers of leakage improvement (7.66 vs. 2.96; p = 0.003). For patients who received post-EBP MRI during periods of 0-10, 0-2, 3-6, and 7-10 days, the cutoff values of numbers of spinal CSF leakage for predicting EBP failure were 4, 6, 4, and 5, respectively, with an AUC above 0.77.

Conclusion: By using post-EBP MRI, which only takes approximately 20 min, predicting EBP efficacy became possible in SIH patients. This study provides cutoff values of numbers of spinal CSF leakage at different follow-up times to serve as clues of if further EBP is needed, which provides the novelty of the current study.

Keywords: CSF; EBP; MRM; SIH; leakage.

Figure 1

Distribution of the no. of spinal CSF leakage noted in post-EBP MRI in EBP-effective (●) and EBP non-effective groups (▲). Most EBP non-effective patients had a higher no. of spinal CSF leakage than EBP effective patients. Furthermore, for EBP-effective patients, their no. of spinal CSF leakages seemed stepwise decreased with increased follow-up days.

Figure 2

A 56-year-old male with SIH. (Upper row) Initially, MR myelography revealed CSF leakage at the bilateral C6-7, C7-T1, T1-2, T2-3, T3-4, and T4-5 neural sleeves. (no. of spinal CSF leakage = 12). (Middle row) Post-EBP MR myelography performed three days after EBP revealed CSF leakage at the bilateral C6-7, C7-T1, T1-2, T2-3, T3-4, and T4-5 and new CSF leakage along the bilateral T5-6 neural sleeves with persistent epidural fluid accumulation (no. of spinal CSF leakage = 14) A second epidural blood patch was performed. (Lower row) Three-month MR myelography revealed complete resolution of CSF leakage. (Leakage No = 0).

Figure 3

A 39-year-old male with SIH. (Upper row) Initially, MR myelography revealed CSF leakage in the bilateral T3-4, T4-5, T5-6, T6-7, T7-8, T8-9, and T9-10 neural sleeves. (no. of spinal CSF leakage = 14). (Middle row) Post-EBP MR myelography performed five days after EBP revealed CSF leakage at the right T4-5, T5-6, and T6-7 neural sleeves. (no. of spinal CSF leakage = 3). (Lower row) Three-month MR myelography revealed complete resolution of CSF leakage. (no. of spinal CSF leakage = 0).