We aimed to identify predicting factors associated with the recurrence of spontaneous intracranial hypotension (SIH) after epidural blood patch (EDBP) by comparing SIH patients with recurrence and those without.

SIH may recur after the successful treatment with EDBP. However, the predicting factors associated with symptom recurrence of SIH after the treatment with EDBP are not well established.

Brain MRI findings of SIH before EDBP, midbrain-pons angle was wider in SIH patients with symptom recurrence than those without (55.5 ± 7.8° versus 48.3 ± 11.8°, p = 0.021). In volumetric analysis of brain MRI comparing before and after EDBP, the difference between the two groups was confirmed in intracranial cerebrospinal fluid (CSF) volume (-11.6 ± 15.3 mL versus +4.8 ± 17.1 mL, p = 0.001) and ventricular volume (+1.0 ± 2.0 mL versus +2.0 ± 2.5 mL, p = 0.007). Random forest classifier showed the model constructed with brain structure volume changes after EDBP had a higher accuracy to discriminate SIH patients with symptom recurrence (area of under the receiver operating characteristic curve (AUC) = 0.80) than those without (AUC = 0.52).

Our study suggests that changes in intracranial CSF volume and ventricular volume after the treatment with EDBP are associated with the symptom recurrence in SIH patients. Volumetric analysis of brain structure using brain MRI may be useful to predict the prognosis after EDBP treatment in SIH patients.