Journal of Pain & Palliative Care Pharmacotherapy. 2014;28:75–77. Copyright © 2014 Informa Healthcare USA, Inc. ISSN: 1536-0288 print / 1536-0539 online DOI: 10.3109/15360288.2013.869648
J Pain Palliat Care Pharmacother Downloaded from informahealthcare.com by Technische Universiteit Eindhoven on 11/18/14 For personal use only.
PATIENT EDUCATION AND SELF-ADVOCACY: QUESTIONS AND RESPONSES ON PAIN MANAGEMENT Edited by Yvette Col´on
Cauda Equina Syndrome Timothy Strigenz A B STRA CT Questions from patients about pain conditions and analgesic pharmacotherapy and responses from authors are presented to help educate patients and make them more effective self-advocates. The topics addressed in this issue are cauda equina syndrome, a dysfunction of the nerves in the spinal canal, and its symptoms, diagnosis, and treatment. KEYWORDS cauda equina, incontinence, low back pain, nerve compression, spinal injury
these organs and convey information from them back to the brain, and if these signals get disrupted, function gets altered. Cauda equina syndrome is the result of dysfunction of these nerves in the spinal canal, which is most commonly secondary to compression of the nerves. It is a rare complication of any back injury, but if the symptoms persist, they can lead to serious long-term complications for the patient. A patient with cauda equina has symptoms that can vary widely. Generally, however, the term cauda equina syndrome refers to impairment of bladder, bowel, sexual function, and decreased sensation in the groin and in or around the anus and inner thighs, sometimes referred to as “saddle anesthesia.”1,2 The decreased function of bowel or bladder typically refers to either the inability to urinate or defecate or of dribbling incontinence of urine and/or fecal incontinence.3 Additionally, there may be changes to the legs, with weakness of the muscles being the predominant sign.4 Other symptoms that may be present include pain in the low back or legs, although pain in the low back or legs is not required for the diagnosis of cauda equina syndrome.5 The diagnosis of cauda equina is typically made clinically and requires a careful history and clinical examination. The focus should be on the severity, duration, and type of symptoms. The practitioner should determine if an acute injury caused the symptoms or if the time course leading up to the current
QUESTION FROM A PATIENT My nephew was recently involved in a car accident and suffered a serious back injury. He had to be taken urgently to the operating room because of a possible cauda equina syndrome. What is the cauda equina and what is the syndrome? How does it occur? Why was there such urgency to take him to surgery?
ANSWER The cauda equina (Latin for “horse’s tail”) is a bundle of spinal nerves below the spinal cord that reside within the lumbar spinal vertebral column. The nerves that compose the cauda equina innervate the pelvic organs and lower limbs to include motor stimulation of the hips, knees, ankles, feet, internal anal sphincter, and external anal sphincter. In addition, the cauda equina extends sensory innervation to the perineum and bladder. The nerves carry signals to
Timothy Strigenz, MD, is a Pain Medicine Fellow, Department of Anesthesiology, Division of Pain Medicine, University of California Davis Medical Center, Sacramento, California, USA. Address correspondence to: Dr. Timothy Strigenz, Division of Pain Medicine, UC Davis Medical Center, Lawrence J. Ellison Ambulatory Care Center, 4860 Y Street, Suite 3020, Sacramento, CA 95817, USA. (E-mail: PainFellowship@ ucdmc.ucdavis.edu).
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presentation was an indolent (slow) process. The patient’s overall medical history and history of previous back problems and surgery are also important. Physical examination should focus on sensation and motor strength of the lower extremities and also sensation of the perineum. The anal wink and bulbocavernosus reflexes are mediated through the sacral nerve roots and should be performed.6 The bulbocavernosus reflex is performed by stimulating the glans penis or clitoris, which should cause a contraction of the anal sphincter. Testing of the anal wink involves initiating a painful stimulus to the perirectal region that results in an involuntary contraction of the anus. Loss of either reflex is suggestive of cauda equina syndrome.7 Imaging of the lumbar spine may also play a role in the diagnosis of cauda equina syndrome, as history and physical examination alone may be insufficient, although this should be done only after a complete examination has been performed.8 A magnetic resonance imaging (MRI) is the imaging modality of choice given its ability to view the soft tissues more readily than a computed tomographic (CT) scan. Cauda equina syndrome is thought to occur in three different pattern types.9 It can present as the first symptom after the acute herniation of a lumbar intervertebral disk (Type 1), as the final symptom in the patient with a long history of low back pain without symptoms extending down the leg (Type 2), or insidiously progressing to numbness and urinary symptoms (Type 3). The most common cause appears to be a central disk herniation, typically above the level of L-410 ; however, there are multiple etiologies that can precipitate the syndrome, including spinal meningitis11 or complications after surgery, spinal manipulation, or epidural injections. Other recognizable causes include trauma with fractures or dislocations in the spine or space-occupying lesions such as tumors, cysts, or hemangiomas. It is more common to see the syndrome in those patients with preexisting congenital or degenerative narrowing of their spinal canal.4 If a patient presents with bowel or bladder incontinence and magnetic resonance imaging shows a lesion compressing on the nerves of the cauda equina, surgery is typically recommended.10 The goal of surgery is preserving and restoring neurologic function by either removing the offending agent, such as a herniated disk, or by creating more space within the spinal canal by performing a laminectomy. Often, a combination of both procedures is performed. The timing of the surgery remains controversial. Some evidence shows that if a patient has bladder incontinence when they present, outcomes are generally poor and the timing of surgery has no
bearing on long-term outcome.12,13 Other evidence shows that early decompression for cauda equina syndrome is important,14 and that recovery of any lost neurologic function is unlikely when a cauda equina syndrome has been present for more than a few hours.15 Historically, cauda equina syndrome is treated as an emergency, and once the diagnosis is made, the patient is taken to the operating room for surgical decompression. Prognosis following emergent treatment for cauda equina syndrome is favorable in most cases. Motor function, sensation, urinary continence, sexual function, and rectal function generally return to preoperative levels following surgery. Persistent symptoms can be devastating, and this stresses the importance of early and accurate diagnosis and intervention. Because of this, mismanagement of cauda equina syndrome is one of the most common causes of litigation in spine surgery.16 In summary, cauda equina syndrome is a rare complication of either an acute or chronic process that results in a constellation of symptoms that can be difficult to diagnose and often requires imaging in the form of an MRI. Once diagnosed, surgical decompression of the nerves is indicated, and, in general, outcomes are favorable. In those cases where the nerves of the cauda equina continue to malfunction, the effects can impact patient in many areas, including their work and their social lives, thus stressing the need to have a high index of suspicion when a patient presents with back pain, numbness, and urinary retention or incontinence. Declaration of interest: The author reports no conflicts of interest. The author alone is responsible for the content and writing of this paper.
REFERENCES [1] Jensen RL. Cauda equina as a postoperative complication of lumbar spine surgery. Neurosurg Focus. 2004;16:e7. [2] Epidural hematoma: hospital not liable for spinal cord compression—court based its ruling on post-op nursing documentation. Legal Eagle Eye News Nurs Prof. 2004;12:7. [3] Mosdal C, Iversen P, Iversen-Hansen R. Bladder neuropathy in lumbar disc disease. Acta Neurochir. 1979;46:281–286. [4] Shapiro S. Medical realities in cauda equina syndrome secondary to lumbar disk herniation. Spine. 2000;25:348–351. [5] Fraser S, Roberts L, Murphy E. Cauda equina syndrome: a literature review of its definition and clinical presentation. Arch Phys Med Rehabil. 2009;90:1964–1968. [6] Schmidt RH, Grady MS, Cohen W, Wright S, Winn HR. Acute cauda equina syndrome from a ruptured aneurysm in the sacral canal: case report. J Neurosurg. 1992;77:945–948. [7] Radcliff KE, Kepler CK, Delasotta LA, et al. Current management review of thoracolumbar cord syndromes. Spine J. 2011;11:884–892.
Journal of Pain & Palliative Care Pharmacotherapy
J Pain Palliat Care Pharmacother Downloaded from informahealthcare.com by Technische Universiteit Eindhoven on 11/18/14 For personal use only.
T. Strigenz [8] Bell DA, Collie D, Statham, PF. Cauda equina syndrome: what is the correlation between clinical assessment and MRI scanning? Br J Neurosurg. 2007;21:201–203. [9] DeLong WB, Polissar N, Neradilek B. Timing of surgery in cauda equina syndrome with urinary retention: meta-analysis of observational studies. J Neurosurg Spine. 2008;8:305–320. [10] Ahn UM, Ahn NU, Buchowski JM, Garrett ES, Sieber AN, Kostuik JP. Cauda equina syndrome secondary to lumbar disc herniation: a meta-analysis of surgical outcomes. Spine. 2000;25:1515–1522. [11] Cooper AB, Sharpe MD. Bacterial meningitis and cauda equina syndrome after epidural steroid injections. Can J Anaesth. 1996;43(5 Pt 1):471–474.
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[12] McCarthy MJ, Aylott CE, Grevitt MP, Hegarty J. Cauda equina syndrome: factors affecting long-term functional and sphincteric outcome. Spine. 2007;32:207–216. [13] Qureshi A, Sell P. Cauda equina syndrome treated by surgical decompression: the influence of timing on surgical outcome. Eur Spine J. 2007;16:2143–2151. [14] Choudhury AR, Taylor JC. Cauda equina syndrome in lumbar disc disease. Acta Orthop Scand. 1980;51:493–499. [15] Schaeffer HR. Cauda equina compression resulting from massive lumbar disc extrusion. Aust N Z J Surg. 1966;35:300– 306. [16] Markham DE. Cauda equina syndrome: diagnosis, delay and litigation risk. Curr Orthop. 2004;18:58–62.
J Pain Palliat Care Pharmacother Downloaded from informahealthcare.com by Technische Universiteit Eindhoven on 11/18/14 For personal use only.
PATIENT EDUCATION AND SELF-ADVOCACY: QUESTIONS AND RESPONSES ON PAIN MANAGEMENT Edited by Yvette Col´on
Cauda Equina Syndrome Timothy Strigenz A B STRA CT Questions from patients about pain conditions and analgesic pharmacotherapy and responses from authors are presented to help educate patients and make them more effective self-advocates. The topics addressed in this issue are cauda equina syndrome, a dysfunction of the nerves in the spinal canal, and its symptoms, diagnosis, and treatment. KEYWORDS cauda equina, incontinence, low back pain, nerve compression, spinal injury
these organs and convey information from them back to the brain, and if these signals get disrupted, function gets altered. Cauda equina syndrome is the result of dysfunction of these nerves in the spinal canal, which is most commonly secondary to compression of the nerves. It is a rare complication of any back injury, but if the symptoms persist, they can lead to serious long-term complications for the patient. A patient with cauda equina has symptoms that can vary widely. Generally, however, the term cauda equina syndrome refers to impairment of bladder, bowel, sexual function, and decreased sensation in the groin and in or around the anus and inner thighs, sometimes referred to as “saddle anesthesia.”1,2 The decreased function of bowel or bladder typically refers to either the inability to urinate or defecate or of dribbling incontinence of urine and/or fecal incontinence.3 Additionally, there may be changes to the legs, with weakness of the muscles being the predominant sign.4 Other symptoms that may be present include pain in the low back or legs, although pain in the low back or legs is not required for the diagnosis of cauda equina syndrome.5 The diagnosis of cauda equina is typically made clinically and requires a careful history and clinical examination. The focus should be on the severity, duration, and type of symptoms. The practitioner should determine if an acute injury caused the symptoms or if the time course leading up to the current
QUESTION FROM A PATIENT My nephew was recently involved in a car accident and suffered a serious back injury. He had to be taken urgently to the operating room because of a possible cauda equina syndrome. What is the cauda equina and what is the syndrome? How does it occur? Why was there such urgency to take him to surgery?
ANSWER The cauda equina (Latin for “horse’s tail”) is a bundle of spinal nerves below the spinal cord that reside within the lumbar spinal vertebral column. The nerves that compose the cauda equina innervate the pelvic organs and lower limbs to include motor stimulation of the hips, knees, ankles, feet, internal anal sphincter, and external anal sphincter. In addition, the cauda equina extends sensory innervation to the perineum and bladder. The nerves carry signals to
Timothy Strigenz, MD, is a Pain Medicine Fellow, Department of Anesthesiology, Division of Pain Medicine, University of California Davis Medical Center, Sacramento, California, USA. Address correspondence to: Dr. Timothy Strigenz, Division of Pain Medicine, UC Davis Medical Center, Lawrence J. Ellison Ambulatory Care Center, 4860 Y Street, Suite 3020, Sacramento, CA 95817, USA. (E-mail: PainFellowship@ ucdmc.ucdavis.edu).
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J Pain Palliat Care Pharmacother Downloaded from informahealthcare.com by Technische Universiteit Eindhoven on 11/18/14 For personal use only.
76
Journal of Pain & Palliative Care Pharmacotherapy
presentation was an indolent (slow) process. The patient’s overall medical history and history of previous back problems and surgery are also important. Physical examination should focus on sensation and motor strength of the lower extremities and also sensation of the perineum. The anal wink and bulbocavernosus reflexes are mediated through the sacral nerve roots and should be performed.6 The bulbocavernosus reflex is performed by stimulating the glans penis or clitoris, which should cause a contraction of the anal sphincter. Testing of the anal wink involves initiating a painful stimulus to the perirectal region that results in an involuntary contraction of the anus. Loss of either reflex is suggestive of cauda equina syndrome.7 Imaging of the lumbar spine may also play a role in the diagnosis of cauda equina syndrome, as history and physical examination alone may be insufficient, although this should be done only after a complete examination has been performed.8 A magnetic resonance imaging (MRI) is the imaging modality of choice given its ability to view the soft tissues more readily than a computed tomographic (CT) scan. Cauda equina syndrome is thought to occur in three different pattern types.9 It can present as the first symptom after the acute herniation of a lumbar intervertebral disk (Type 1), as the final symptom in the patient with a long history of low back pain without symptoms extending down the leg (Type 2), or insidiously progressing to numbness and urinary symptoms (Type 3). The most common cause appears to be a central disk herniation, typically above the level of L-410 ; however, there are multiple etiologies that can precipitate the syndrome, including spinal meningitis11 or complications after surgery, spinal manipulation, or epidural injections. Other recognizable causes include trauma with fractures or dislocations in the spine or space-occupying lesions such as tumors, cysts, or hemangiomas. It is more common to see the syndrome in those patients with preexisting congenital or degenerative narrowing of their spinal canal.4 If a patient presents with bowel or bladder incontinence and magnetic resonance imaging shows a lesion compressing on the nerves of the cauda equina, surgery is typically recommended.10 The goal of surgery is preserving and restoring neurologic function by either removing the offending agent, such as a herniated disk, or by creating more space within the spinal canal by performing a laminectomy. Often, a combination of both procedures is performed. The timing of the surgery remains controversial. Some evidence shows that if a patient has bladder incontinence when they present, outcomes are generally poor and the timing of surgery has no
bearing on long-term outcome.12,13 Other evidence shows that early decompression for cauda equina syndrome is important,14 and that recovery of any lost neurologic function is unlikely when a cauda equina syndrome has been present for more than a few hours.15 Historically, cauda equina syndrome is treated as an emergency, and once the diagnosis is made, the patient is taken to the operating room for surgical decompression. Prognosis following emergent treatment for cauda equina syndrome is favorable in most cases. Motor function, sensation, urinary continence, sexual function, and rectal function generally return to preoperative levels following surgery. Persistent symptoms can be devastating, and this stresses the importance of early and accurate diagnosis and intervention. Because of this, mismanagement of cauda equina syndrome is one of the most common causes of litigation in spine surgery.16 In summary, cauda equina syndrome is a rare complication of either an acute or chronic process that results in a constellation of symptoms that can be difficult to diagnose and often requires imaging in the form of an MRI. Once diagnosed, surgical decompression of the nerves is indicated, and, in general, outcomes are favorable. In those cases where the nerves of the cauda equina continue to malfunction, the effects can impact patient in many areas, including their work and their social lives, thus stressing the need to have a high index of suspicion when a patient presents with back pain, numbness, and urinary retention or incontinence. Declaration of interest: The author reports no conflicts of interest. The author alone is responsible for the content and writing of this paper.
REFERENCES [1] Jensen RL. Cauda equina as a postoperative complication of lumbar spine surgery. Neurosurg Focus. 2004;16:e7. [2] Epidural hematoma: hospital not liable for spinal cord compression—court based its ruling on post-op nursing documentation. Legal Eagle Eye News Nurs Prof. 2004;12:7. [3] Mosdal C, Iversen P, Iversen-Hansen R. Bladder neuropathy in lumbar disc disease. Acta Neurochir. 1979;46:281–286. [4] Shapiro S. Medical realities in cauda equina syndrome secondary to lumbar disk herniation. Spine. 2000;25:348–351. [5] Fraser S, Roberts L, Murphy E. Cauda equina syndrome: a literature review of its definition and clinical presentation. Arch Phys Med Rehabil. 2009;90:1964–1968. [6] Schmidt RH, Grady MS, Cohen W, Wright S, Winn HR. Acute cauda equina syndrome from a ruptured aneurysm in the sacral canal: case report. J Neurosurg. 1992;77:945–948. [7] Radcliff KE, Kepler CK, Delasotta LA, et al. Current management review of thoracolumbar cord syndromes. Spine J. 2011;11:884–892.
Journal of Pain & Palliative Care Pharmacotherapy
J Pain Palliat Care Pharmacother Downloaded from informahealthcare.com by Technische Universiteit Eindhoven on 11/18/14 For personal use only.
T. Strigenz [8] Bell DA, Collie D, Statham, PF. Cauda equina syndrome: what is the correlation between clinical assessment and MRI scanning? Br J Neurosurg. 2007;21:201–203. [9] DeLong WB, Polissar N, Neradilek B. Timing of surgery in cauda equina syndrome with urinary retention: meta-analysis of observational studies. J Neurosurg Spine. 2008;8:305–320. [10] Ahn UM, Ahn NU, Buchowski JM, Garrett ES, Sieber AN, Kostuik JP. Cauda equina syndrome secondary to lumbar disc herniation: a meta-analysis of surgical outcomes. Spine. 2000;25:1515–1522. [11] Cooper AB, Sharpe MD. Bacterial meningitis and cauda equina syndrome after epidural steroid injections. Can J Anaesth. 1996;43(5 Pt 1):471–474.
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[12] McCarthy MJ, Aylott CE, Grevitt MP, Hegarty J. Cauda equina syndrome: factors affecting long-term functional and sphincteric outcome. Spine. 2007;32:207–216. [13] Qureshi A, Sell P. Cauda equina syndrome treated by surgical decompression: the influence of timing on surgical outcome. Eur Spine J. 2007;16:2143–2151. [14] Choudhury AR, Taylor JC. Cauda equina syndrome in lumbar disc disease. Acta Orthop Scand. 1980;51:493–499. [15] Schaeffer HR. Cauda equina compression resulting from massive lumbar disc extrusion. Aust N Z J Surg. 1966;35:300– 306. [16] Markham DE. Cauda equina syndrome: diagnosis, delay and litigation risk. Curr Orthop. 2004;18:58–62.
