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SCIWORA: An antiquated acronym
SCIWORA: An Antiquated Acronym Eric M. Horn, MD, PhD, Nicholas Theodore, MD, and Volker K. H. Sonntag, MD SCIWORA is used to describe occult spinal cord injuries without bony abnormalities in traumatically injured patients. The pathophysiology diverges between adult and pediatric populations, which also determines the treatment. Since the use of magnetic resonance imaging became more common in these patients, cases without imaging abnormalities are rare. Thus, the term SCIWORA is no longer appropriate and is useful for historical purposes only. Semin Spine Surg 17:46-48 © 2005 Elsevier Inc. All rights reserved. KEYWORDS spinal cord injury, magnetic resonance imaging
T
ypically, spinal cord injury without radiographic abnormality (SCIWORA) occurs in children. The term refers to the presence of a posttraumatic spinal cord injury despite the appearance of a normal spine on plain radiographic (including flexion and extension views) and computed tomographic (CT) studies. SCIWORA is diagnosed by obtaining a careful history and physical examination of the patient and by ruling out the presence of a vertebral fracture, subluxation, or acute instability on plain radiography or CT. The spinal cord injury can be mild or severe; it can have permanent sequelae or recover completely. After trauma, the onset of SCIWORA can be immediate or delayed. Recurrent SCIWORA has also been described, usually after another trauma.
Adult and Pediatric Pathophysiology Although the SCIWORA entity has been known for almost a century, the first substantial case series was not documented until the 1980s. The incidence of SCIWORA ranges from about 28 to 67% of all pediatric spinal cord injuries. The highest incidence seems to be in children younger than 9 years. All levels of the spinal cord can be affected, but the most common site is the cervical spine followed by the thoracic and lumbosacral spine, respectively. SCIWORA can manifest with symptoms that range from transient paresthesias (numbness and tingling) to complete motor paralysis and sensory loss.1,2
Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, Phoenix, AZ. Address reprint requests to Volker K.H. Sonntag, MD, c/o Neuroscience Publications, Barrow Neurological Institute, 350 W. Thomas Road, Phoenix, AZ 85013. E-mail: [email protected].
46
1040-7383/05/$-see front matter © 2005 Elsevier Inc. All rights reserved. doi:10.1053/j.semss.2005.01.006
Common causes of SCIWORA vary with age group and include birth trauma, falls, and motor vehicle accidents. The mechanism underlying SCIWORA, however, is unknown. It may be related to the relative hypermobility of the spine in children and to their immature bones, which make fractures less likely.
SCIWORA in the Era of MRI SCIWORA was first described in the pediatric population when magnetic resonance (MR) imaging was a nascent technology.2 Since then, MR imaging has changed the very definition of SCIWORA. Indeed, MR images have shown extensive soft-tissue, ligamentous, and spinal cord parenchymal damage immediately after injury.3,4 Importantly, MR images show the presence of disc herniations not usually apparent on radiographs or CT scans (Fig. 1). In fact, Koyanagi and coworkers5 recently demonstrated the presence of disc herniation in 76% of adult patients with SCIWORA. Moreover, 93% of these patients had significant spinal cord compression on MR images that had not been apparent on radiographs or CT scans. Thus, MR imaging should be a standard examination obtained when these patients are evaluated. Specifically, patients with subjective or objective neurological deficits with no evidence of fracture subluxation or other abnormalities on plain radiographs or CT scans should undergo MR imaging. MR imaging also has been helpful in determining the extent of spinal cord injury and in estimating prognosis. In pediatric patients, the presence of contusions or edema in the spinal cord was highly correlated with an initial complete spinal cord injury.6 In the same study, patients with an incomplete injury had no abnormalities on MR imaging. This finding highlights the mechanism of injury in pediatric pa-
SCIWORA: an antiquated acronym
47 tion for identifying the severity of injury, localizing the lesion, and determining a prognosis. The issue of spinal instability in patients with SCIWORA is important in determining the type of treatment needed. The literal definition of SCIWORA should exclude all patients with gross instability. However, stability may be difficult to determine in patients with limited mobility or severe spinal stenosis associated with spinal cord compression, which is a contraindication to obtaining dynamic radiographs. Recently, MR imaging has been used to determine spinal instability after trauma. This modality is much more sensitive than radiography or CT for determining ligamentous and joint abnormalities in traumatically injured patients.8 MR imaging, however, may be too sensitive: The number of false positives is unacceptably high in this patient population.9 Although an abnormal MR image does not correlate with cervical instability, the absence of ligamentous injury on MR imaging strongly correlates with cervical stability.9,10 This correlation is especially high in children, most of whom have no paraspinal soft-tissue or ligamentous injury associated with SCIWORA.6 Thus, dynamic radiographs remain the best method to determine instability and the need for bracing or internal fixation.
Treatment Options
Figure 1 (A) In this 48-year-old man with an incomplete spinal cord injury, CT imaging only showed mild cervical stenosis. (B) MR imaging of same patient shows multiple disc herniations.
tients as involving ligamentous laxity, which is a major difference from the pathophysiology of adults with this syndrome. MR imaging, however, can help determine the extent of injury and prognosis in adults. Severe spinal cord compression or T1- or T2-weighted abnormalities in the spinal cord on MR imaging correlate with poor neurological function and outcome in patients with SCIWORA.5,7 Despite the difference in pathophysiology between adults and pediatric patients with SCIWORA, the common finding of spinal cord abnormalities on MR imaging offers the most useful informa-
There is no universal treatment for SCIWORA. Approaches differ depending on the underlying pathophysiology. In general, acute spinal cord injuries are treated with intravenous administration of high-dose steroids (methylprednisolone) according to the protocol established by the National Acute Spinal Cord Injury Study.11 This treatment, however, is controversial and remains only an option according to the recent Guidelines for the Management of Acute Cervical Spine Injuries.12 External spinal immobilization (bracing) is important both in the prehospital setting and during evaluation. After SCIWORA has been diagnosed, the decision to immobilize becomes less clear. In adults with severe spinal stenosis and spinal cord edema, early immobilization is recommended to prevent further traumatic injury from micromotion.13 Children, however, rarely have a stenotic component or instability and therefore no legitimate reason for long-term immobilization.14 Even though there is no indication for bracing from the perspective of stability, many clinicians express concern about allowing mobility during recovery and prefer patients to wear a brace for 4 to 12 weeks.1,2 Operative intervention for SCIWORA is extremely rare in the pediatric population unless MR imaging documents the presence of a herniated disc, extra-axial hematoma, or other lesion compressing the spinal cord. In adults, however, a compressive spinal component usually is responsible for the spinal cord injury. The specific type of pathology dictates the type of operative management. These patients are similar to central cord syndrome patients, and a similar algorithm can be used for their treatment.13 Most adults should be immobilized in a collar or halo until their neurological improvement plateaus; surgical intervention can then follow.13 Immediate decompression and stabilization would be the
48 appropriate course of action for large herniations involving one or two levels. The neurological condition of these patients improves dramatically after anterior decompression.3 Multilevel spondylosis can be decompressed anteriorly or posteriorly, depending on the amount of cervical lordosis and localization of the compressive pathology. When stenosis is present without disc herniation (either congenital or degenerative), posterior decompression with or without instrumentation and fusion (depending on the amount of lordosis) is the treatment of choice.
Conclusions The term SCIWORA was developed before the era of MR imaging to describe a syndrome of spinal cord injury without bony abnormality. Although the pathophysiology underlying injury is different in children and adults, the presence of abnormalities on MR imaging is a common feature. A modification of the term to spinal cord injury without radiographic evidence of trauma (SCIWORET) was introduced to encompass all radiographic findings in these patients while suggesting a nontraumatic origin of the syndrome. However, all of these patients are victims of traumatic injuries, even if minor. Therefore, the term SCIWORET is misleading. Thus, we propose retiring the terms SCIWORA and SCIWORET. The syndrome can then be referred to in a descriptive manner with respect to the underlying spinal cord injury. Alternatively, of course, a new and appropriate acronym for this syndrome could be introduced: spinal cord injury without fracture and with abnormal magnetic resonance imaging (SCIWOFAWAMRI). This term, however, would be absurd.
References 1. Pang D, Pollack IF: Spinal cord injury without radiographic abnormality in children—the SCIWORA syndrome. J Trauma 29:654-664, 1989
E.M. Horn, N. Theodore, and V.K.H. Sonntag 2. Pang D, Wilberger JE Jr: Spinal cord injury without radiographic abnormalities in children. J Neurosurg 57:114-129, 1982 3. Gupta SK, Rajeev K, Khosla VK et al: Spinal cord injury without radiographic abnormality in adults. Spinal Cord 37:726-729, 1999 4. Kothari P, Freeman B, Grevitt M, Kerslake R: Injury to the spinal cord without radiological abnormality (SCIWORA) in adults. J Bone Joint Surg Br 82:1034-1037, 2000 5. Koyanagi I, Iwasaki Y, Hida K, Akino M, Imamura H, Abe H: Acute cervical cord injury without fracture or dislocation of the spinal column. J Neurosurg Spine 93:15-20, 2000 6. Dare AO, Dias MS, Li V: Magnetic resonance imaging correlation in pediatric spinal cord injury without radiographic abnormality. J Neurosurg Spine 97:33-39, 2002 7. Hayashi K, Yone K, Ito H, Yanase M, Sakou T: MRI findings in patients with a cervical spinal cord injury who do not show radiographic evidence of a fracture or dislocation. Paraplegia 33:212-215, 1995 8. Ghanta MK, Smith LM, Polin RS, Marr AB, Spires WV: An analysis of Eastern Association for the Surgery of Trauma practice guidelines for cervical spine evaluation in a series of patients with multiple imaging techniques. Am Surg 68:563-567, 2002 9. Horn EM, Lekovic GP, Feiz-Erfan I, Sonntag VK, Theodore N: Cervical magnetic resonance imaging abnormalities not predictive of cervical spine instability in traumatically injured patients. Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004. J Neurosurg Spine 1:39-42, 2004 10. Frank JB, Lim CK, Flynn JM, Dormans JP: The efficacy of magnetic resonance imaging in pediatric cervical spine clearance. Spine 27:11761179, 2002 11. Bracken MB, Shepard MJ, Collins WF, et al: A randomized, controlled trial of methylprednisolone or naloxone in the treatment of acute spinal-cord injury. Results of the Second National Acute Spinal Cord Injury Study. N Engl J Med 322:1405-1411, 1990 12. Hadley MN, Apuzzo MLJ, McCormick PC: Guidelines for the management of acute cervical spinal injuries. Spinal cord injury without radiographic abnormality. Neurosurgery 50:S100-S104, 2002 13. Guest J, Eleraky MA, Apostolides PJ, Dickman CA, Sonntag VK: Traumatic central cord syndrome: results of surgical management. J Neurosurg Spine 97:25-32, 2002 14. Bosch PP, Vogt MT, Ward WT: Pediatric spinal cord injury without radiographic abnormality (SCIWORA): the absence of occult instability and lack of indication for bracing. Spine 27:2788-2800, 2002
T
ypically, spinal cord injury without radiographic abnormality (SCIWORA) occurs in children. The term refers to the presence of a posttraumatic spinal cord injury despite the appearance of a normal spine on plain radiographic (including flexion and extension views) and computed tomographic (CT) studies. SCIWORA is diagnosed by obtaining a careful history and physical examination of the patient and by ruling out the presence of a vertebral fracture, subluxation, or acute instability on plain radiography or CT. The spinal cord injury can be mild or severe; it can have permanent sequelae or recover completely. After trauma, the onset of SCIWORA can be immediate or delayed. Recurrent SCIWORA has also been described, usually after another trauma.
Adult and Pediatric Pathophysiology Although the SCIWORA entity has been known for almost a century, the first substantial case series was not documented until the 1980s. The incidence of SCIWORA ranges from about 28 to 67% of all pediatric spinal cord injuries. The highest incidence seems to be in children younger than 9 years. All levels of the spinal cord can be affected, but the most common site is the cervical spine followed by the thoracic and lumbosacral spine, respectively. SCIWORA can manifest with symptoms that range from transient paresthesias (numbness and tingling) to complete motor paralysis and sensory loss.1,2
Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, Phoenix, AZ. Address reprint requests to Volker K.H. Sonntag, MD, c/o Neuroscience Publications, Barrow Neurological Institute, 350 W. Thomas Road, Phoenix, AZ 85013. E-mail: [email protected].
46
1040-7383/05/$-see front matter © 2005 Elsevier Inc. All rights reserved. doi:10.1053/j.semss.2005.01.006
Common causes of SCIWORA vary with age group and include birth trauma, falls, and motor vehicle accidents. The mechanism underlying SCIWORA, however, is unknown. It may be related to the relative hypermobility of the spine in children and to their immature bones, which make fractures less likely.
SCIWORA in the Era of MRI SCIWORA was first described in the pediatric population when magnetic resonance (MR) imaging was a nascent technology.2 Since then, MR imaging has changed the very definition of SCIWORA. Indeed, MR images have shown extensive soft-tissue, ligamentous, and spinal cord parenchymal damage immediately after injury.3,4 Importantly, MR images show the presence of disc herniations not usually apparent on radiographs or CT scans (Fig. 1). In fact, Koyanagi and coworkers5 recently demonstrated the presence of disc herniation in 76% of adult patients with SCIWORA. Moreover, 93% of these patients had significant spinal cord compression on MR images that had not been apparent on radiographs or CT scans. Thus, MR imaging should be a standard examination obtained when these patients are evaluated. Specifically, patients with subjective or objective neurological deficits with no evidence of fracture subluxation or other abnormalities on plain radiographs or CT scans should undergo MR imaging. MR imaging also has been helpful in determining the extent of spinal cord injury and in estimating prognosis. In pediatric patients, the presence of contusions or edema in the spinal cord was highly correlated with an initial complete spinal cord injury.6 In the same study, patients with an incomplete injury had no abnormalities on MR imaging. This finding highlights the mechanism of injury in pediatric pa-
SCIWORA: an antiquated acronym
47 tion for identifying the severity of injury, localizing the lesion, and determining a prognosis. The issue of spinal instability in patients with SCIWORA is important in determining the type of treatment needed. The literal definition of SCIWORA should exclude all patients with gross instability. However, stability may be difficult to determine in patients with limited mobility or severe spinal stenosis associated with spinal cord compression, which is a contraindication to obtaining dynamic radiographs. Recently, MR imaging has been used to determine spinal instability after trauma. This modality is much more sensitive than radiography or CT for determining ligamentous and joint abnormalities in traumatically injured patients.8 MR imaging, however, may be too sensitive: The number of false positives is unacceptably high in this patient population.9 Although an abnormal MR image does not correlate with cervical instability, the absence of ligamentous injury on MR imaging strongly correlates with cervical stability.9,10 This correlation is especially high in children, most of whom have no paraspinal soft-tissue or ligamentous injury associated with SCIWORA.6 Thus, dynamic radiographs remain the best method to determine instability and the need for bracing or internal fixation.
Treatment Options
Figure 1 (A) In this 48-year-old man with an incomplete spinal cord injury, CT imaging only showed mild cervical stenosis. (B) MR imaging of same patient shows multiple disc herniations.
tients as involving ligamentous laxity, which is a major difference from the pathophysiology of adults with this syndrome. MR imaging, however, can help determine the extent of injury and prognosis in adults. Severe spinal cord compression or T1- or T2-weighted abnormalities in the spinal cord on MR imaging correlate with poor neurological function and outcome in patients with SCIWORA.5,7 Despite the difference in pathophysiology between adults and pediatric patients with SCIWORA, the common finding of spinal cord abnormalities on MR imaging offers the most useful informa-
There is no universal treatment for SCIWORA. Approaches differ depending on the underlying pathophysiology. In general, acute spinal cord injuries are treated with intravenous administration of high-dose steroids (methylprednisolone) according to the protocol established by the National Acute Spinal Cord Injury Study.11 This treatment, however, is controversial and remains only an option according to the recent Guidelines for the Management of Acute Cervical Spine Injuries.12 External spinal immobilization (bracing) is important both in the prehospital setting and during evaluation. After SCIWORA has been diagnosed, the decision to immobilize becomes less clear. In adults with severe spinal stenosis and spinal cord edema, early immobilization is recommended to prevent further traumatic injury from micromotion.13 Children, however, rarely have a stenotic component or instability and therefore no legitimate reason for long-term immobilization.14 Even though there is no indication for bracing from the perspective of stability, many clinicians express concern about allowing mobility during recovery and prefer patients to wear a brace for 4 to 12 weeks.1,2 Operative intervention for SCIWORA is extremely rare in the pediatric population unless MR imaging documents the presence of a herniated disc, extra-axial hematoma, or other lesion compressing the spinal cord. In adults, however, a compressive spinal component usually is responsible for the spinal cord injury. The specific type of pathology dictates the type of operative management. These patients are similar to central cord syndrome patients, and a similar algorithm can be used for their treatment.13 Most adults should be immobilized in a collar or halo until their neurological improvement plateaus; surgical intervention can then follow.13 Immediate decompression and stabilization would be the
48 appropriate course of action for large herniations involving one or two levels. The neurological condition of these patients improves dramatically after anterior decompression.3 Multilevel spondylosis can be decompressed anteriorly or posteriorly, depending on the amount of cervical lordosis and localization of the compressive pathology. When stenosis is present without disc herniation (either congenital or degenerative), posterior decompression with or without instrumentation and fusion (depending on the amount of lordosis) is the treatment of choice.
Conclusions The term SCIWORA was developed before the era of MR imaging to describe a syndrome of spinal cord injury without bony abnormality. Although the pathophysiology underlying injury is different in children and adults, the presence of abnormalities on MR imaging is a common feature. A modification of the term to spinal cord injury without radiographic evidence of trauma (SCIWORET) was introduced to encompass all radiographic findings in these patients while suggesting a nontraumatic origin of the syndrome. However, all of these patients are victims of traumatic injuries, even if minor. Therefore, the term SCIWORET is misleading. Thus, we propose retiring the terms SCIWORA and SCIWORET. The syndrome can then be referred to in a descriptive manner with respect to the underlying spinal cord injury. Alternatively, of course, a new and appropriate acronym for this syndrome could be introduced: spinal cord injury without fracture and with abnormal magnetic resonance imaging (SCIWOFAWAMRI). This term, however, would be absurd.
References 1. Pang D, Pollack IF: Spinal cord injury without radiographic abnormality in children—the SCIWORA syndrome. J Trauma 29:654-664, 1989
E.M. Horn, N. Theodore, and V.K.H. Sonntag 2. Pang D, Wilberger JE Jr: Spinal cord injury without radiographic abnormalities in children. J Neurosurg 57:114-129, 1982 3. Gupta SK, Rajeev K, Khosla VK et al: Spinal cord injury without radiographic abnormality in adults. Spinal Cord 37:726-729, 1999 4. Kothari P, Freeman B, Grevitt M, Kerslake R: Injury to the spinal cord without radiological abnormality (SCIWORA) in adults. J Bone Joint Surg Br 82:1034-1037, 2000 5. Koyanagi I, Iwasaki Y, Hida K, Akino M, Imamura H, Abe H: Acute cervical cord injury without fracture or dislocation of the spinal column. J Neurosurg Spine 93:15-20, 2000 6. Dare AO, Dias MS, Li V: Magnetic resonance imaging correlation in pediatric spinal cord injury without radiographic abnormality. J Neurosurg Spine 97:33-39, 2002 7. Hayashi K, Yone K, Ito H, Yanase M, Sakou T: MRI findings in patients with a cervical spinal cord injury who do not show radiographic evidence of a fracture or dislocation. Paraplegia 33:212-215, 1995 8. Ghanta MK, Smith LM, Polin RS, Marr AB, Spires WV: An analysis of Eastern Association for the Surgery of Trauma practice guidelines for cervical spine evaluation in a series of patients with multiple imaging techniques. Am Surg 68:563-567, 2002 9. Horn EM, Lekovic GP, Feiz-Erfan I, Sonntag VK, Theodore N: Cervical magnetic resonance imaging abnormalities not predictive of cervical spine instability in traumatically injured patients. Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004. J Neurosurg Spine 1:39-42, 2004 10. Frank JB, Lim CK, Flynn JM, Dormans JP: The efficacy of magnetic resonance imaging in pediatric cervical spine clearance. Spine 27:11761179, 2002 11. Bracken MB, Shepard MJ, Collins WF, et al: A randomized, controlled trial of methylprednisolone or naloxone in the treatment of acute spinal-cord injury. Results of the Second National Acute Spinal Cord Injury Study. N Engl J Med 322:1405-1411, 1990 12. Hadley MN, Apuzzo MLJ, McCormick PC: Guidelines for the management of acute cervical spinal injuries. Spinal cord injury without radiographic abnormality. Neurosurgery 50:S100-S104, 2002 13. Guest J, Eleraky MA, Apostolides PJ, Dickman CA, Sonntag VK: Traumatic central cord syndrome: results of surgical management. J Neurosurg Spine 97:25-32, 2002 14. Bosch PP, Vogt MT, Ward WT: Pediatric spinal cord injury without radiographic abnormality (SCIWORA): the absence of occult instability and lack of indication for bracing. Spine 27:2788-2800, 2002