ORIGINAL ARTICLE
Retrospective Study of Epidural Blood Patch Use for Spontaneous Intracranial Hypotension Eun Young Joo, MD,* Bo Young Hwang, MD,† Yu Gyeong Kong, MD,* Jong Hyuk Lee, MD,* Beom Sang Hwang, MD,* and Jeong Hun Suh, MD* Background and Objectives: Spontaneous intracranial hypotension (SIH) is characterized by a severe and disabling headache that is usually orthostatic in nature. Cisternography is a useful diagnostic test for evaluating the presence and location of cerebrospinal fluid (CSF) leakage, and a targeted epidural blood patch (EBP) based on the cisternography findings is a very effective treatment modality for SIH. However, the effects of EBPs are not predictable, making repeat EBPs essential in some cases. The aim of the present study was to find the relationship between the EBP response and cisternographic findings, hypothesizing that the number of required EBPs would increase with an increased number of CSF leakage levels as determined by radionuclide cisternography. Methods: All patients who underwent an EBP and had been discharged with significant improvements in symptoms of SIH during 2006 to 2011 were enrolled. Patients who had no radionuclide cisternographic results were excluded. The demographic variables, number of EBPs, cisternographic findings (location, bilaterality, and number of leakage sites), and preprocedural and postprocedural pain scores were reviewed. Results: There was no correlation found between the cisternographic findings and the number of EBPs. Only the preprocedural pain scores showed a statistically significant correlation with the number of EBPs. Conclusions: Our study suggests that the response to the EBP is related to the severity of symptoms but not to the number and locations of cisternographic CSF leakages. (Reg Anesth Pain Med 2015;40: 58–61)
S
pontaneous intracranial hypotension (SIH) is characterized by spontaneous postural headache with neck stiffness, nausea, vomiting, tinnitus, and vertigo in patients with low cerebrospinal fluid (CSF) pressure.1 Spontaneous intracranial hypotension is caused by spontaneous CSF leaks from the spinal meningeal diverticula or the dural rents along nerve sleeves in the absence of a prior history of head trauma or dural puncture.2–4 Brain magnetic resonance imaging (MRI) using gadolinium has been used as the diagnostic study of choice because of its ability to identify characteristic abnormalities such as diffuse pachymeningeal enhancement, subdural fluid collections or subdural hematomas, engorgement of veins, and pituitary hyperemia and sagging of the brain.5 When SIH is suspected on a brain MRI, radionuclide (RI) cisternography and computed tomography myelography can be used to identify the site of a CSF leak. Although the rate of falsenegative or unclear findings is high, RI cisternography is helpful in pinpointing the leakage site and determining the therapeutic level to target with the initial EBP.6–8 From the *Asan Medical Center and College of Medicine, University of Ulsan, Pungnap-dong, Seoul, Korea; and †Lynn Women’s Hospital, Jangan-dong, Seoul, Korea. Accepted for publication October 22, 2014. Address correspondence to: Jeong Hun Suh, MD, College of Medicine, University of Ulsan, Department of Anesthesiology and Pain Medicine, 86 Asanbyungwongil, Pungnap-dong, Songpa-gu, Seoul, 138-736, Republic of Korea (e‐mail: [email protected]). The authors declare no conflict of interest. Copyright © 2014 by American Society of Regional Anesthesia and Pain Medicine ISSN: 1098-7339 DOI: 10.1097/AAP.0000000000000194
58
Although many cases of SIH resolve spontaneously with conservative treatment including bed rest, hydration, caffeine, or analgesics, others require the injection of autologous blood into the epidural space. To treat refractory cases of SIH, an epidural blood patch (EBP) is a very effective treatment modality.9–13 Although a targeted EBP seems to be effective,14,15 some patients need repeated blood patches because of inadequate control of their postural headache. Curious about the reason for the unresponsiveness to the EBP in such patients, we aimed in this study to find the relationship between EBP responses and cisternographic findings, hypothesizing that the number of EBPs would increase if the number of CSF leakage levels in RI cisternography increased.
METHODS This retrospective study was approved by the institutional review board of Asan Medical Center, and the necessity for obtaining informed consent was waived for as we were only reviewing recorded data in this study. All cases of EBP performed with the fluoroscopy-guided technique for SIH from 2006 to 2011 were reviewed. Patients who met all of the following criteria were included: (1) hospitalized by the neurology department because of symptomatic SIH, (2) had EBP provided under fluoroscopic guidance after consultation with the anesthesiology pain clinic, (3) positive RI cisternographic findings, and (4) discharged with significant symptom improvements. The exclusion criteria were as follows: (1) incomplete medical records such as an absence of preprocedural and postprocedural pain scores and the initial CSF opening pressure or (2) absence of formal reports of RI cisternography. Among 124 patients who underwent EBP, only 76 patients met the inclusion and exclusion criteria. The following data were collected and analyzed by reviewing electronic medical records: demographic variables, number of EBPs, pain scores, and CSF opening pressure at the time of cisternography. The RI cisternography was also reviewed, and the location of leakage, bilaterality, and number of leakage levels in cisternography were analyzed. The leakage levels were classified as cervical, cervicothoracic, thoracic, thoracolumbar, and lumbar. Radionuclide cisternography interpretation was based on formal reports written by a professor of the nuclear medicine department. Patients were diagnosed with SIH if they had at least 2 of the following 3 criteria: orthostatic headache, low CSF pressure, and diffuse pachymeningeal gadolinium enhancement on brain MRI. Orthostatic headache was defined as a headache that occurs or worsens less than 15 minutes after assuming the upright position and disappears or improves less than 30 minutes after resuming the recumbent position. Low CSF pressure was defined as a CSF opening pressure of less than 60 mm H2O in the sitting position. Each patient was initially treated with supportive measures. If these initial supportive measures failed after 5 to 7 days, patients were referred to the pain clinic and treated with EBP. When patients had orthostatic headache 4 to 5 days after EBP, we performed repeated EBP. The target level of EBP was determined as the level of most increased paraspinal activity on RI cisternography. If additional EBP was required in patients with multiple leakage sites, it was performed at the other level that had not been
Regional Anesthesia and Pain Medicine • Volume 40, Number 1, January-February 2015
Copyright © 2014 American Society of Regional Anesthesia and Pain Medicine. Unauthorized reproduction of this article is prohibited.
Regional Anesthesia and Pain Medicine • Volume 40, Number 1, January-February 2015
targeted before. Targeted EBPs were performed using a 21-gauge Tuohy needle via a midline or paramedian approach under fluoroscopic guidance with the patient in the prone position. The epidural space was identified by the loss of resistance technique, and accurate localization was confirmed by ensuring the spread of injected 2 mL of contrast medium over the targeted epidural space. Thereafter, autologous blood was slowly injected until the patient began to complain of back pain and/or radicular pain. The maximal volume of injected blood was limited to 20 mL. Patients remained supine for at least 24 to 48 hours following EBP placement.
Statistical Analysis Correlation analysis was performed to find relationships between the number of EBPs and other variables. For variables correlated with the number of EBPs, regression analysis was also conducted to evaluate the causal relationship.
RESULTS A total of 76 patients who met the inclusion and exclusion criteria were retrospectively reviewed. There were 49 females, and the patients had a mean age of 39 years (range, 22–66 years). The mean height and weight were 165 cm (range, 146–183 cm) and 62 kg (range, 41–93 kg), respectively. The mean CSF pressure at diagnosis was 60 mm H2O (range, 0–180 mm H2O). The mean pain scores (numeric rating scale [NRS]) before and after the first EBP were 6.2 and 0.9, respectively. The mean number of EBPs was 2.1 (range, 1–7) (Fig. 1). The range of number of leakage site was 1 to 3: 1 in 35 patients (46.1%), 2 in 30 patients (39.5%), and 3 in 11 patients (14.5%). The leakage segments on RI cisternography are shown in Figure 2, and the distribution of leak sites in multiple leakage locations was entirely random. By correlation analysis, the preprocedural NRS showed a statistically significant but weak correlation with the number of EBPs (P
Retrospective Study of Epidural Blood Patch Use for Spontaneous Intracranial Hypotension Eun Young Joo, MD,* Bo Young Hwang, MD,† Yu Gyeong Kong, MD,* Jong Hyuk Lee, MD,* Beom Sang Hwang, MD,* and Jeong Hun Suh, MD* Background and Objectives: Spontaneous intracranial hypotension (SIH) is characterized by a severe and disabling headache that is usually orthostatic in nature. Cisternography is a useful diagnostic test for evaluating the presence and location of cerebrospinal fluid (CSF) leakage, and a targeted epidural blood patch (EBP) based on the cisternography findings is a very effective treatment modality for SIH. However, the effects of EBPs are not predictable, making repeat EBPs essential in some cases. The aim of the present study was to find the relationship between the EBP response and cisternographic findings, hypothesizing that the number of required EBPs would increase with an increased number of CSF leakage levels as determined by radionuclide cisternography. Methods: All patients who underwent an EBP and had been discharged with significant improvements in symptoms of SIH during 2006 to 2011 were enrolled. Patients who had no radionuclide cisternographic results were excluded. The demographic variables, number of EBPs, cisternographic findings (location, bilaterality, and number of leakage sites), and preprocedural and postprocedural pain scores were reviewed. Results: There was no correlation found between the cisternographic findings and the number of EBPs. Only the preprocedural pain scores showed a statistically significant correlation with the number of EBPs. Conclusions: Our study suggests that the response to the EBP is related to the severity of symptoms but not to the number and locations of cisternographic CSF leakages. (Reg Anesth Pain Med 2015;40: 58–61)
S
pontaneous intracranial hypotension (SIH) is characterized by spontaneous postural headache with neck stiffness, nausea, vomiting, tinnitus, and vertigo in patients with low cerebrospinal fluid (CSF) pressure.1 Spontaneous intracranial hypotension is caused by spontaneous CSF leaks from the spinal meningeal diverticula or the dural rents along nerve sleeves in the absence of a prior history of head trauma or dural puncture.2–4 Brain magnetic resonance imaging (MRI) using gadolinium has been used as the diagnostic study of choice because of its ability to identify characteristic abnormalities such as diffuse pachymeningeal enhancement, subdural fluid collections or subdural hematomas, engorgement of veins, and pituitary hyperemia and sagging of the brain.5 When SIH is suspected on a brain MRI, radionuclide (RI) cisternography and computed tomography myelography can be used to identify the site of a CSF leak. Although the rate of falsenegative or unclear findings is high, RI cisternography is helpful in pinpointing the leakage site and determining the therapeutic level to target with the initial EBP.6–8 From the *Asan Medical Center and College of Medicine, University of Ulsan, Pungnap-dong, Seoul, Korea; and †Lynn Women’s Hospital, Jangan-dong, Seoul, Korea. Accepted for publication October 22, 2014. Address correspondence to: Jeong Hun Suh, MD, College of Medicine, University of Ulsan, Department of Anesthesiology and Pain Medicine, 86 Asanbyungwongil, Pungnap-dong, Songpa-gu, Seoul, 138-736, Republic of Korea (e‐mail: [email protected]). The authors declare no conflict of interest. Copyright © 2014 by American Society of Regional Anesthesia and Pain Medicine ISSN: 1098-7339 DOI: 10.1097/AAP.0000000000000194
58
Although many cases of SIH resolve spontaneously with conservative treatment including bed rest, hydration, caffeine, or analgesics, others require the injection of autologous blood into the epidural space. To treat refractory cases of SIH, an epidural blood patch (EBP) is a very effective treatment modality.9–13 Although a targeted EBP seems to be effective,14,15 some patients need repeated blood patches because of inadequate control of their postural headache. Curious about the reason for the unresponsiveness to the EBP in such patients, we aimed in this study to find the relationship between EBP responses and cisternographic findings, hypothesizing that the number of EBPs would increase if the number of CSF leakage levels in RI cisternography increased.
METHODS This retrospective study was approved by the institutional review board of Asan Medical Center, and the necessity for obtaining informed consent was waived for as we were only reviewing recorded data in this study. All cases of EBP performed with the fluoroscopy-guided technique for SIH from 2006 to 2011 were reviewed. Patients who met all of the following criteria were included: (1) hospitalized by the neurology department because of symptomatic SIH, (2) had EBP provided under fluoroscopic guidance after consultation with the anesthesiology pain clinic, (3) positive RI cisternographic findings, and (4) discharged with significant symptom improvements. The exclusion criteria were as follows: (1) incomplete medical records such as an absence of preprocedural and postprocedural pain scores and the initial CSF opening pressure or (2) absence of formal reports of RI cisternography. Among 124 patients who underwent EBP, only 76 patients met the inclusion and exclusion criteria. The following data were collected and analyzed by reviewing electronic medical records: demographic variables, number of EBPs, pain scores, and CSF opening pressure at the time of cisternography. The RI cisternography was also reviewed, and the location of leakage, bilaterality, and number of leakage levels in cisternography were analyzed. The leakage levels were classified as cervical, cervicothoracic, thoracic, thoracolumbar, and lumbar. Radionuclide cisternography interpretation was based on formal reports written by a professor of the nuclear medicine department. Patients were diagnosed with SIH if they had at least 2 of the following 3 criteria: orthostatic headache, low CSF pressure, and diffuse pachymeningeal gadolinium enhancement on brain MRI. Orthostatic headache was defined as a headache that occurs or worsens less than 15 minutes after assuming the upright position and disappears or improves less than 30 minutes after resuming the recumbent position. Low CSF pressure was defined as a CSF opening pressure of less than 60 mm H2O in the sitting position. Each patient was initially treated with supportive measures. If these initial supportive measures failed after 5 to 7 days, patients were referred to the pain clinic and treated with EBP. When patients had orthostatic headache 4 to 5 days after EBP, we performed repeated EBP. The target level of EBP was determined as the level of most increased paraspinal activity on RI cisternography. If additional EBP was required in patients with multiple leakage sites, it was performed at the other level that had not been
Regional Anesthesia and Pain Medicine • Volume 40, Number 1, January-February 2015
Copyright © 2014 American Society of Regional Anesthesia and Pain Medicine. Unauthorized reproduction of this article is prohibited.
Regional Anesthesia and Pain Medicine • Volume 40, Number 1, January-February 2015
targeted before. Targeted EBPs were performed using a 21-gauge Tuohy needle via a midline or paramedian approach under fluoroscopic guidance with the patient in the prone position. The epidural space was identified by the loss of resistance technique, and accurate localization was confirmed by ensuring the spread of injected 2 mL of contrast medium over the targeted epidural space. Thereafter, autologous blood was slowly injected until the patient began to complain of back pain and/or radicular pain. The maximal volume of injected blood was limited to 20 mL. Patients remained supine for at least 24 to 48 hours following EBP placement.
Statistical Analysis Correlation analysis was performed to find relationships between the number of EBPs and other variables. For variables correlated with the number of EBPs, regression analysis was also conducted to evaluate the causal relationship.
RESULTS A total of 76 patients who met the inclusion and exclusion criteria were retrospectively reviewed. There were 49 females, and the patients had a mean age of 39 years (range, 22–66 years). The mean height and weight were 165 cm (range, 146–183 cm) and 62 kg (range, 41–93 kg), respectively. The mean CSF pressure at diagnosis was 60 mm H2O (range, 0–180 mm H2O). The mean pain scores (numeric rating scale [NRS]) before and after the first EBP were 6.2 and 0.9, respectively. The mean number of EBPs was 2.1 (range, 1–7) (Fig. 1). The range of number of leakage site was 1 to 3: 1 in 35 patients (46.1%), 2 in 30 patients (39.5%), and 3 in 11 patients (14.5%). The leakage segments on RI cisternography are shown in Figure 2, and the distribution of leak sites in multiple leakage locations was entirely random. By correlation analysis, the preprocedural NRS showed a statistically significant but weak correlation with the number of EBPs (P
