title: Factors predicting response to the first epidural blood patch in spontaneous intracranial hypotension.
abstract: Spontaneous intracranial hypotension results from cerebrospinal fluid leakage. Currently, the treatment of choice for spontaneous intracranial hypotension is the epidural blood patch, which has a variable response rate and no clear outcome predictors. This study aimed to identify predictors for response rate of a first targeted epidural blood patch in patients with spontaneous intracranial hypotension. We reviewed cases of patients with spontaneous intracranial hypotension who received targeted epidural blood patch at our hospital between 1 January 2007 and 1 July 2014. The outcome measure was first epidural blood patch response. We analysed demographics, clinical manifestations, neuroimaging findings (non-contrast heavily T2-weighted magnetic resonance myelography and brain magnetic resonance imaging), and blood volume as potential outcome predictors. Significant predictors were tested and a decision tree was used to construct a predictive model. In total, 150 patients with spontaneous intracranial hypotension were included for final analyses. Their overall first targeted epidural blood patch response rate was 58.7%. Among patients with a greater injected blood volume (≥22.5 versus <22.5 ml), the response rate was higher (67.9% versus 47.0%, P = 0.01). In brain and spinal magnetic resonance imaging studies, significant predictors included anterior epidural cerebrospinal fluid collection length (<8 versus ≥8 segments; 72.5% versus 37.3%, odds ratio = 4.4, 95% confidence interval: 2.2-8.9, P < 0.001) and midbrain-pons angle (≥40° versus <40°; 71.3% versus 37.5%, odds ratio = 4.1, 95% confidence interval 2.1-8.3, P < 0.001). Decision tree analyses showed that patients with anterior epidural CSF collection involving <8 segments and an injected blood volume ≥22.5 ml had an 80.0% response rate. Patients with anterior epidural cerebrospinal fluid collection involving ≥8 segments and a midbrain-pons angle <40° had a 21.2% response rate. These three variables predicted first epidural blood patch response in 71.3% of patients. Brain and spinal neuroimaging findings and epidural blood patch blood volume can be used to predict targeted first epidural blood patch response in patients with spontaneous intracranial hypotension.
authors.affiliation: Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, No. 201, Sec. 2, Shi-Pai Road, Taipei, 11217, Taiwan.
authors.forename: Jr-Wei
authors.initials: JW
authors.lastname: Wu
authors.affiliation: Department of Anaesthesiology, Taipei Veterans General Hospital, No. 201, Sec. 2, Shi-Pai Road, Taipei, 11217, Taiwan.|Faculty of Medicine, National Yang-Ming University School of Medicine, No. 155, Sec. 2, Li-Nong Street, Taipei, 11217, Taiwan.
authors.forename: Shu-Shya
authors.initials: SS
authors.lastname: Hseu
authors.affiliation: Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, No. 201, Sec. 2, Shi-Pai Road, Taipei, 11217, Taiwan.|Faculty of Medicine, National Yang-Ming University School of Medicine, No. 155, Sec. 2, Li-Nong Street, Taipei, 11217, Taiwan.
authors.forename: Jong-Ling
authors.initials: JL
authors.lastname: Fuh
authors.affiliation: Faculty of Medicine, National Yang-Ming University School of Medicine, No. 155, Sec. 2, Li-Nong Street, Taipei, 11217, Taiwan.|Department of Radiology, Taipei Veterans General Hospital, No. 201, Sec. 2, Shi-Pai Road, Taipei, 11217, Taiwan.
authors.forename: Jiing-Feng
authors.initials: JF
authors.lastname: Lirng
authors.affiliation: Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, No. 201, Sec. 2, Shi-Pai Road, Taipei, 11217, Taiwan.|Faculty of Medicine, National Yang-Ming University School of Medicine, No. 155, Sec. 2, Li-Nong Street, Taipei, 11217, Taiwan.
authors.forename: Yen-Feng
authors.initials: YF
authors.lastname: Wang
authors.affiliation: Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, No. 201, Sec. 2, Shi-Pai Road, Taipei, 11217, Taiwan.|Faculty of Medicine, National Yang-Ming University School of Medicine, No. 155, Sec. 2, Li-Nong Street, Taipei, 11217, Taiwan.
authors.forename: Wei-Ta
authors.initials: WT
authors.lastname: Chen
authors.affiliation: Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, No. 201, Sec. 2, Shi-Pai Road, Taipei, 11217, Taiwan.|Faculty of Medicine, National Yang-Ming University School of Medicine, No. 155, Sec. 2, Li-Nong Street, Taipei, 11217, Taiwan.
authors.forename: Shih-Pin
authors.initials: SP
authors.lastname: Chen
authors.affiliation: Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, No. 201, Sec. 2, Shi-Pai Road, Taipei, 11217, Taiwan sjwang@vghtpe.gov.tw.|Faculty of Medicine, National Yang-Ming University School of Medicine, No. 155, Sec. 2, Li-Nong Street, Taipei, 11217, Taiwan.|Brain Research Center, National Yang-Ming University, No. 155, Sec. 2, Li-Nong Street, Taipei, 11217, Taiwan.
authors.forename: Shuu-Jiun
authors.initials: SJ
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D017217:Blood Patch, Epidural / Q000379:methods*; D001921:Brain / Q000000981:diagnostic imaging; D065634:Cerebrospinal Fluid Leak / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019585:Intracranial Hypotension / Q000150:complications / Q000000981:diagnostic imaging / Q000628:therapy*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011237:Predictive Value of Tests; D012044:Regression Analysis; D012189:Retrospective Studies; D013116:Spinal Cord / Q000000981:diagnostic imaging; D016896:Treatment Outcome; D055815:Young Adult
keywords: cerebrospinal fluid (CSF) leakage; epidural blood patch; midbrain-pons angle; spontaneous intracranial hypotension