The Journal of Emergency Medicine, Vol. 47, No. 6, pp. 692–693, 2014 Copyright Ó 2014 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/$ - see front matter
http://dx.doi.org/10.1016/j.jemermed.2014.07.058
Visual Diagnosis in Emergency Medicine
INVERTED MERCEDES BENZ SIGN IN LUMBAR SPINAL SUBDURAL HEMATOMA Manish K. Kasliwal, MD, MCH, Larry R. Shannon, MD, John E. O’Toole, MD, MS, and Richard W. Byrne, MD Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois Reprint Address: Manish K. Kasliwal, MD, MCH, Department of Neurosurgery, Rush University Medical Center, 1725 W. Harrison Street, Suite 855, Rush University Medical Center, Chicago, IL 60612
CASE REPORT
DISCUSSION
A previously healthy 27-year-old male boxer developed lower back pain 3 days after a fight, which progressed during the next several days to the point that the patient was unable to walk secondary to pain. This was followed by pain and paresthesias radiating down both the legs when he presented to the emergency department. A lumbar magnetic resonance imaging (MRI) was performed, suspecting acute disc herniation. MRI, however, demonstrated the presence of signal intensity consistent with blood and a diagnosis of spinal hematoma, possibly subdural, was considered (Figure 1). Careful evaluation of the axial MRI demonstrated the presence of an inverted Mercedes Benz sign, suggestive of a spinal subdural hematoma (Figure 2). He denied being on any anticoagulant medications. He did realize that he was being hit in the belly a number of times during the fight. On examination, the patient was in moderate discomfort, but with an essentially normal neurologic examination with no focal deficits and preserved rectal tone and sensation. He was admitted with close neurologic monitoring. Post void residual was obtained and found to be normal. His pain was adequately controlled with medications resulting in symptomatic relief. The patient maintained his neurologic examination with gradual resolution of his symptoms over a couple of days and was discharged home. He was completely intact with no pain or neurologic deficits at 2 months follow-up.
Lumbar spinal subdural hematoma (SSH) is a relatively rare but potentially devastating entity that can be associated with anticoagulation, lumbar puncture, intracranial subdural hematoma, subarachnoid hemorrhage, trauma, postoperative complications, or may be spontaneous (1– 3). In a meta-analysis of all spinal hematomas reported in the literature (epidural, subarachnoid, and subdural) by Kreppel et al., SSH made up only 4.1% of all reported cases (4). Considering the potential for irreversible neurologic injury, the ability to recognize the symptoms and radiographic findings are of the utmost importance. Presenting symptoms may include back pain, radicular leg pain, lower-extremity weakness and paralysis, sensory disturbances, urinary retention, and incontinence, which are no different from any other spinal pathology, making radiologic diagnosis of paramount importance. Imaging findings may show a crescent-shaped collection in the posterior aspect of the thecal sac and, depending on the timing of imaging, subdural hematoma can have variable appearances on MRI, depending on the age of the hematoma (1– 3,5–7). In the absence of an obvious predisposing factor, diagnosis can be difficult, as the history of trauma might be nonspecific, as described in the present case, the rarity of SSH and also because of the frequency of back pain, which accounts for one of the most common causes of hospital and emergency department visits. Various
RECEIVED: 24 February 2014; ACCEPTED: 29 July 2014 692
Inverted Mercedes Benz Sign
693
Figure 1. Sagittal T2W (left), sagittal T1W (middle), and axial T1W magnetic resonance image showing T2 hypointense and T1 hyperintense collection extending from L2 to S1 causing compression of the cauda equina (arrows).
differential diagnoses for spinal hematoma include epidural hematomas, lipomatosis, abscess, phlegmon, angiolipoma, and tumor (particularly lymphoma). It can often be confused with an epidural spinal hematoma and, in a patient with preserved neurologic examination, a subdural hematoma can be misdiagnosed as lipomatosis and vice versa (6). Although classic radiologic findings are rare, when present they are easy to recognize and facilitate the diagnoses (8,9). This case of SSH clearly demonstrates the presence of an inverted Mercedes Benz sign on axial MRI—a valuable radiologic sign. This appearance has not been described often and is due to encasement of the nerve roots and filum terminale by the hyperintense acute or early subacute blood in the
subdural hematomas and helps differentiate SSH from an epidural hematoma. Although there had been a strong consideration in the past that the management of SSH is mainly surgical, there has been increasing reports of patients with SSH who have been managed conservatively with good outcomes, as also described in the present report (5,6,10). Regardless of the modality of further management, the importance of recognizing this radiologic sign of SSH for emergency physicians and radiologists who often evaluate a significant number of patients with back pain in the middle of the night cannot be overemphasized, and should be carefully looked for when this condition is suspected. REFERENCES
Figure 2. Axial T1W magnetic resonance image below the conus showing the resultant inverted Mercedes-Benz sign (schematic drawing demonstrating the sign) formed due to encasement of the nerve roots (antero-lateral) and filum terminale (dorsal) by the hyperintense subdural hematomas.
1. Bruce-Brand RA, Colleran GC, Broderick JM, et al. Acute nontraumatic spinal intradural hematoma in a patient on warfarin. J Emerg Med 2013;45:695–7. 2. Domenicucci M, Ramieri A, Ciappetta P, et al. Nontraumatic acute spinal subdural hematoma: report of five cases and review of the literature. J Neurosurg 1999;91:65–73. 3. Kyriakides AE, Lalam RK, El Masry WS. Acute spontaneous spinal subdural hematoma presenting as paraplegia: a rare case. Spine 2007;32:E619–22. 4. Kreppel D, Antoniadis G, Seeling W. Spinal hematoma: a literature survey with meta-analysis of 613 patients. Neurosurg Rev 2003;26: 1–49. 5. Al B, Yildirim C, Zengin S, et al. Acute spontaneous spinal subdural haematoma presenting as paraplegia and complete recovery with non-operative treatment. BMJ Case Rep 2009;2009. 6. Kamo M, Watanabe Y, Numaguchi Y, Saida Y. Spinal subdural hematoma mimicking epidural lipomatosis. Magn Reson Med Sci 2012;11:197–9. 7. Duprez T, Grandin C, Malghen J. MRI monitoring of acute spinal subdural haematoma with spontaneus resolution. Acta Neurol Belg 1995;95:101–3. 8. Kurisu S, Inoue I. Mercedes-Benz mark sign in the aorta. Intern Med 2008;47:1751–2. 9. Longley JD. The Mercedes-Benz sign. CMAJ 2002;167:172. 10. Kulkarni AV, Willinsky RA, Gray T, et al. Serial magnetic resonance imaging findings for a spontaneously resolving spinal subdural hematoma: case report. Neurosurgery 1998;42:398–400.
http://dx.doi.org/10.1016/j.jemermed.2014.07.058
Visual Diagnosis in Emergency Medicine
INVERTED MERCEDES BENZ SIGN IN LUMBAR SPINAL SUBDURAL HEMATOMA Manish K. Kasliwal, MD, MCH, Larry R. Shannon, MD, John E. O’Toole, MD, MS, and Richard W. Byrne, MD Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois Reprint Address: Manish K. Kasliwal, MD, MCH, Department of Neurosurgery, Rush University Medical Center, 1725 W. Harrison Street, Suite 855, Rush University Medical Center, Chicago, IL 60612
CASE REPORT
DISCUSSION
A previously healthy 27-year-old male boxer developed lower back pain 3 days after a fight, which progressed during the next several days to the point that the patient was unable to walk secondary to pain. This was followed by pain and paresthesias radiating down both the legs when he presented to the emergency department. A lumbar magnetic resonance imaging (MRI) was performed, suspecting acute disc herniation. MRI, however, demonstrated the presence of signal intensity consistent with blood and a diagnosis of spinal hematoma, possibly subdural, was considered (Figure 1). Careful evaluation of the axial MRI demonstrated the presence of an inverted Mercedes Benz sign, suggestive of a spinal subdural hematoma (Figure 2). He denied being on any anticoagulant medications. He did realize that he was being hit in the belly a number of times during the fight. On examination, the patient was in moderate discomfort, but with an essentially normal neurologic examination with no focal deficits and preserved rectal tone and sensation. He was admitted with close neurologic monitoring. Post void residual was obtained and found to be normal. His pain was adequately controlled with medications resulting in symptomatic relief. The patient maintained his neurologic examination with gradual resolution of his symptoms over a couple of days and was discharged home. He was completely intact with no pain or neurologic deficits at 2 months follow-up.
Lumbar spinal subdural hematoma (SSH) is a relatively rare but potentially devastating entity that can be associated with anticoagulation, lumbar puncture, intracranial subdural hematoma, subarachnoid hemorrhage, trauma, postoperative complications, or may be spontaneous (1– 3). In a meta-analysis of all spinal hematomas reported in the literature (epidural, subarachnoid, and subdural) by Kreppel et al., SSH made up only 4.1% of all reported cases (4). Considering the potential for irreversible neurologic injury, the ability to recognize the symptoms and radiographic findings are of the utmost importance. Presenting symptoms may include back pain, radicular leg pain, lower-extremity weakness and paralysis, sensory disturbances, urinary retention, and incontinence, which are no different from any other spinal pathology, making radiologic diagnosis of paramount importance. Imaging findings may show a crescent-shaped collection in the posterior aspect of the thecal sac and, depending on the timing of imaging, subdural hematoma can have variable appearances on MRI, depending on the age of the hematoma (1– 3,5–7). In the absence of an obvious predisposing factor, diagnosis can be difficult, as the history of trauma might be nonspecific, as described in the present case, the rarity of SSH and also because of the frequency of back pain, which accounts for one of the most common causes of hospital and emergency department visits. Various
RECEIVED: 24 February 2014; ACCEPTED: 29 July 2014 692
Inverted Mercedes Benz Sign
693
Figure 1. Sagittal T2W (left), sagittal T1W (middle), and axial T1W magnetic resonance image showing T2 hypointense and T1 hyperintense collection extending from L2 to S1 causing compression of the cauda equina (arrows).
differential diagnoses for spinal hematoma include epidural hematomas, lipomatosis, abscess, phlegmon, angiolipoma, and tumor (particularly lymphoma). It can often be confused with an epidural spinal hematoma and, in a patient with preserved neurologic examination, a subdural hematoma can be misdiagnosed as lipomatosis and vice versa (6). Although classic radiologic findings are rare, when present they are easy to recognize and facilitate the diagnoses (8,9). This case of SSH clearly demonstrates the presence of an inverted Mercedes Benz sign on axial MRI—a valuable radiologic sign. This appearance has not been described often and is due to encasement of the nerve roots and filum terminale by the hyperintense acute or early subacute blood in the
subdural hematomas and helps differentiate SSH from an epidural hematoma. Although there had been a strong consideration in the past that the management of SSH is mainly surgical, there has been increasing reports of patients with SSH who have been managed conservatively with good outcomes, as also described in the present report (5,6,10). Regardless of the modality of further management, the importance of recognizing this radiologic sign of SSH for emergency physicians and radiologists who often evaluate a significant number of patients with back pain in the middle of the night cannot be overemphasized, and should be carefully looked for when this condition is suspected. REFERENCES
Figure 2. Axial T1W magnetic resonance image below the conus showing the resultant inverted Mercedes-Benz sign (schematic drawing demonstrating the sign) formed due to encasement of the nerve roots (antero-lateral) and filum terminale (dorsal) by the hyperintense subdural hematomas.
1. Bruce-Brand RA, Colleran GC, Broderick JM, et al. Acute nontraumatic spinal intradural hematoma in a patient on warfarin. J Emerg Med 2013;45:695–7. 2. Domenicucci M, Ramieri A, Ciappetta P, et al. Nontraumatic acute spinal subdural hematoma: report of five cases and review of the literature. J Neurosurg 1999;91:65–73. 3. Kyriakides AE, Lalam RK, El Masry WS. Acute spontaneous spinal subdural hematoma presenting as paraplegia: a rare case. Spine 2007;32:E619–22. 4. Kreppel D, Antoniadis G, Seeling W. Spinal hematoma: a literature survey with meta-analysis of 613 patients. Neurosurg Rev 2003;26: 1–49. 5. Al B, Yildirim C, Zengin S, et al. Acute spontaneous spinal subdural haematoma presenting as paraplegia and complete recovery with non-operative treatment. BMJ Case Rep 2009;2009. 6. Kamo M, Watanabe Y, Numaguchi Y, Saida Y. Spinal subdural hematoma mimicking epidural lipomatosis. Magn Reson Med Sci 2012;11:197–9. 7. Duprez T, Grandin C, Malghen J. MRI monitoring of acute spinal subdural haematoma with spontaneus resolution. Acta Neurol Belg 1995;95:101–3. 8. Kurisu S, Inoue I. Mercedes-Benz mark sign in the aorta. Intern Med 2008;47:1751–2. 9. Longley JD. The Mercedes-Benz sign. CMAJ 2002;167:172. 10. Kulkarni AV, Willinsky RA, Gray T, et al. Serial magnetic resonance imaging findings for a spontaneously resolving spinal subdural hematoma: case report. Neurosurgery 1998;42:398–400.
