SPINE Volume 39, Number 16, pp E955-E961 ©2014, Lippincott Williams & Wilkins
DIAGNOSTICS
Detrusor Overactivity in Patients With Cauda Equina Syndrome Seo-Young Kim, MD,* Hee Chung Kwon, MD,* and Jung Keun Hyun, MD, PhD*†‡
Study Design. Retrospective cross-sectional study. Objective. To delineate the neurogenic bladder type in patients with cauda equina syndrome (CES) and to suggest, in light of the clinical, radiological, and electrophysiological findings, a possible cause of bladder dysfunction. Summary of Background Data. Many patients with CES experience bladder dysfunction, although the type of neurogenic bladder is quite variable in the clinical setting. Bladder dysfunction in patients with CES is usually areflexic or acontractile detrusor. However, detrusor overactivity (DOA) also reported the cases that cannot be explained by pure root injuries in the cauda equina region. Methods. Patients with CES with neurogenic bladder were studied, all of whom (n = 61; mean age ± SD, 48.0 ± 15.9 yr) underwent urodynamic analysis, magnetic resonance imaging (MRI), and electrophysiology. According to the urodynamic findings, the neurogenic bladder was classified into 2 types: DOA and detrusor underactivity or acontractility. The highest level of injury (HLI) or level of injury was determined and analyzed on the basis of the clinical-urodynamic and electrophysiological findings, respectively. Results. Twenty patients with CES (32.8%) showed DOA; in most of them (85.0%, 17/20 patients), the HLI on electrophysiological assessment was L2 or above. Forty-one patients with CES showed detrusor underactivity or acontractility; and most of the patients with CES whose HLI was L3 or below showed detrusor underactivity or acontractility (91.2%, 31/34 patients). None of the HLI or
From the *Department of Rehabilitation Medicine, Dankook University College of Medicine, Cheonan, Republic of Korea; and †Department of Nanobiomedical Science and BK21PLUS NBM Global Research Center for Regenerative Medicine, and ‡Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, Republic of Korea. Acknowledgment date: January 20, 2014. Revision date: April 15, 2014. Acceptance date: April 20, 2014. The manuscript submitted does not contain information about medical device(s)/drug(s). Dankook University grant funds in 2013 were received in support of this work. No relevant financial activities outside the submitted work. Address correspondence and reprint requests to Jung Keun Hyun, MD, PhD, Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, San 16-5 Anseo-dong, Dongnam-gu, Cheonan 330-714, Republic of Korea; E-mail: [email protected] DOI: 10.1097/BRS.0000000000000410 Spine
level of injury from the clinical or magnetic resonance imaging findings correlated with neurogenic bladder type. We also found that urodynamic findings including maximal detrusor pressure and bladder capacity was partially correlated with the HLI on electrophysiological assessment (r2= 0.244, P < 0.001 and r2= 0.330; P < 0.001, respectively). Conclusion. DOA was seen most often in patients with CES whose HLI was L2 or above, and might be associated with combined conus medullaris lesion. Electrophysiology might be the most useful assessment tool for prediction of neurogenic bladder type in patients with CES. Key words: cauda equine syndrome, detrusor overactivity, level of injury, electrophysiology, conus medullaris lesion. Level of Evidence: 4 Spine 2014;39:E955–E961
C
auda equina syndrome (CES) is a clinical condition resulting from damage to the peripheral nerve bundle at the termination of the spinal cord. Most patients with CES experience one or more of the following symptoms: bladder and/or bowel dysfunction, decreased sensation in the saddle area, or sexual dysfunction.1 Bladder dysfunction in patients with CES is usually areflexic or acontractile detrusor, resulting in urinary retention or overflow incontinence.1,2 And yet, detrusor overactivity (DOA) has been reported in 15.4% to 31% of patients with CES,3–7 which cases cannot be explained by pure root injuries in the cauda equina region. The mechanisms of DOA after spinal cord injury are well established8,9; in DOA cases involving cauda equina lesion, however, the myogenic and neurogenic mechanisms are uncertain.5 For CES, the level of injury (LOI) is the critical factor determining bladder type. Because conus medullaris, which is the most caudal part of spinal cord, is located just above cauda equina, and upper motor neuron (UMN) signs including DOA would be prominent when the injury at conus medullaris is combined with CES.10 However, these upper and lower motor neuron symptoms and signs are usually hard to be separated or predictable when conus medullaris and cauda equina lesions are combined.10 In this study, we aimed to delineate the neurogenic bladder types in patients with CES and to suggest, on the basis of our clinical, radiological, and electrophysiological findings, their possible causes. www.spinejournal.com
E955
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. SPINE140124_LR E955
19/06/14 11:00 AM
DIAGNOSTICS MATERIALS AND METHODS This study was approved by the Institutional Review Board of Dankook University. Two hundred sixty-five patients who had CES with one or more of the following: bladder and/or bowel dysfunction, decreased sensation in the saddle area, or sexual dysfunction,1 and confirmed S2–S5 polyradiculopathies on electrophysiology were reviewed; of these, 61 patients with CES showing bladder symptoms and signs and whose neurogenic bladder was confirmed on urodynamic analysis, finally, were selected. The excluded patients included those with a history of spinal deformity, previous spinal cord injury, stroke, dementia, Parkinson disease, systemic polyneuropathy or prostate disease, or those at the spinal shock stage (
DIAGNOSTICS
Detrusor Overactivity in Patients With Cauda Equina Syndrome Seo-Young Kim, MD,* Hee Chung Kwon, MD,* and Jung Keun Hyun, MD, PhD*†‡
Study Design. Retrospective cross-sectional study. Objective. To delineate the neurogenic bladder type in patients with cauda equina syndrome (CES) and to suggest, in light of the clinical, radiological, and electrophysiological findings, a possible cause of bladder dysfunction. Summary of Background Data. Many patients with CES experience bladder dysfunction, although the type of neurogenic bladder is quite variable in the clinical setting. Bladder dysfunction in patients with CES is usually areflexic or acontractile detrusor. However, detrusor overactivity (DOA) also reported the cases that cannot be explained by pure root injuries in the cauda equina region. Methods. Patients with CES with neurogenic bladder were studied, all of whom (n = 61; mean age ± SD, 48.0 ± 15.9 yr) underwent urodynamic analysis, magnetic resonance imaging (MRI), and electrophysiology. According to the urodynamic findings, the neurogenic bladder was classified into 2 types: DOA and detrusor underactivity or acontractility. The highest level of injury (HLI) or level of injury was determined and analyzed on the basis of the clinical-urodynamic and electrophysiological findings, respectively. Results. Twenty patients with CES (32.8%) showed DOA; in most of them (85.0%, 17/20 patients), the HLI on electrophysiological assessment was L2 or above. Forty-one patients with CES showed detrusor underactivity or acontractility; and most of the patients with CES whose HLI was L3 or below showed detrusor underactivity or acontractility (91.2%, 31/34 patients). None of the HLI or
From the *Department of Rehabilitation Medicine, Dankook University College of Medicine, Cheonan, Republic of Korea; and †Department of Nanobiomedical Science and BK21PLUS NBM Global Research Center for Regenerative Medicine, and ‡Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, Republic of Korea. Acknowledgment date: January 20, 2014. Revision date: April 15, 2014. Acceptance date: April 20, 2014. The manuscript submitted does not contain information about medical device(s)/drug(s). Dankook University grant funds in 2013 were received in support of this work. No relevant financial activities outside the submitted work. Address correspondence and reprint requests to Jung Keun Hyun, MD, PhD, Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University, San 16-5 Anseo-dong, Dongnam-gu, Cheonan 330-714, Republic of Korea; E-mail: [email protected] DOI: 10.1097/BRS.0000000000000410 Spine
level of injury from the clinical or magnetic resonance imaging findings correlated with neurogenic bladder type. We also found that urodynamic findings including maximal detrusor pressure and bladder capacity was partially correlated with the HLI on electrophysiological assessment (r2= 0.244, P < 0.001 and r2= 0.330; P < 0.001, respectively). Conclusion. DOA was seen most often in patients with CES whose HLI was L2 or above, and might be associated with combined conus medullaris lesion. Electrophysiology might be the most useful assessment tool for prediction of neurogenic bladder type in patients with CES. Key words: cauda equine syndrome, detrusor overactivity, level of injury, electrophysiology, conus medullaris lesion. Level of Evidence: 4 Spine 2014;39:E955–E961
C
auda equina syndrome (CES) is a clinical condition resulting from damage to the peripheral nerve bundle at the termination of the spinal cord. Most patients with CES experience one or more of the following symptoms: bladder and/or bowel dysfunction, decreased sensation in the saddle area, or sexual dysfunction.1 Bladder dysfunction in patients with CES is usually areflexic or acontractile detrusor, resulting in urinary retention or overflow incontinence.1,2 And yet, detrusor overactivity (DOA) has been reported in 15.4% to 31% of patients with CES,3–7 which cases cannot be explained by pure root injuries in the cauda equina region. The mechanisms of DOA after spinal cord injury are well established8,9; in DOA cases involving cauda equina lesion, however, the myogenic and neurogenic mechanisms are uncertain.5 For CES, the level of injury (LOI) is the critical factor determining bladder type. Because conus medullaris, which is the most caudal part of spinal cord, is located just above cauda equina, and upper motor neuron (UMN) signs including DOA would be prominent when the injury at conus medullaris is combined with CES.10 However, these upper and lower motor neuron symptoms and signs are usually hard to be separated or predictable when conus medullaris and cauda equina lesions are combined.10 In this study, we aimed to delineate the neurogenic bladder types in patients with CES and to suggest, on the basis of our clinical, radiological, and electrophysiological findings, their possible causes. www.spinejournal.com
E955
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. SPINE140124_LR E955
19/06/14 11:00 AM
DIAGNOSTICS MATERIALS AND METHODS This study was approved by the Institutional Review Board of Dankook University. Two hundred sixty-five patients who had CES with one or more of the following: bladder and/or bowel dysfunction, decreased sensation in the saddle area, or sexual dysfunction,1 and confirmed S2–S5 polyradiculopathies on electrophysiology were reviewed; of these, 61 patients with CES showing bladder symptoms and signs and whose neurogenic bladder was confirmed on urodynamic analysis, finally, were selected. The excluded patients included those with a history of spinal deformity, previous spinal cord injury, stroke, dementia, Parkinson disease, systemic polyneuropathy or prostate disease, or those at the spinal shock stage (
