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Intracranial Hypertension After Spinal Cord Injury and Suboptimal Cervical Fusion
Case Presentation
Intracranial Hypertension After Spinal Cord Injury and Suboptimal Cervical Fusion Walter I. Sussman, DO, Erik Shaw, DO Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a syndrome of increased intracranial pressure. Secondary causes have been associated with IIH, but the pathogenesis is poorly understood, and most cases are idiopathic. We present a case of IIH after suboptimal surgical stabilization of a traumatic C5 spinal cord injury, American Spinal Injury Association Impairment Scale grade A. The patient underwent a posterior arthrodesis and fusion to stabilize the spine, and his symptoms gradually resolved. To our knowledge, we present the first reported case of intracranial hypertension after a traumatic spinal cord injury and failed surgical stabilization. PM R 2014;6:199-202
INTRODUCTION Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a syndrome of increased intracranial pressure (ICP). The pathogenesis of IIH is poorly understood. A number of secondary causes have been associated with IIH, but IIH after a traumatic spinal cord injury (SCI) and spinal stabilization has not previously been reported, to our knowledge.
CASE PRESENTATION A 26-year-old man with a C5 SCI (American Spinal Injury Association Impairment Scale grade A) presented to acute rehabilitation with headaches, nausea, and diplopia that he had experienced for 96 hours. The patient had no history of headaches or vision changes. Fifteen days before the current presentation, the patient sustained C5, C6, and C7 burst fractures with SCI as the result of a diving injury (Figure 1). The patient did not lose consciousness, and he was promptly pulled from the water. No signs of near drowning or evidence of a traumatic brain injury were observed. The patient underwent an anterior cervical corpectomy (C5 to C7) and fusion (C4 to T1) via a titanium cage (12 mm, VBOSS System; Stryker, Kalamazoo, MI) filled with 20 mL of demineralized bone matrix and autograft morcellized bone covered by a 4-level anterior titanium plate. The postoperative course was uncomplicated until day 12, when the patient experienced headaches, nausea, and diplopia. Funduscopic examination showed papilledema, and a subsequent computed tomography scan of the head failed to show any mass lesions or secondary cause of ICP. A presumptive diagnosis of IIH was made, and the patient was discharged to acute rehabilitation. At admission, all vital signs were within normal limits and the patient was afebrile. His body mass index was 32. A lumbar puncture was completed, and the opening pressure was 280 mmH2O. After removing 18 mL of cerebral spinal fluid (CSF), the patient’s pressure decreased to 90 mmH2O, and he reported transient resolution of symptoms. CSF analysis was within normal limits. The patient was not taking any medications associated with IIH. Acetazolamide, 500 mg twice daily, was prescribed. Cervical radiographs on day 2 of admission showed 10-mm PM&R 1934-1482/13/$36.00 Printed in U.S.A.
W.I.S. Department of Rehabilitation Medicine, Emory University School of Medicine, Center for Rehabilitation Medicine, 1441 Clifton Rd NE, Atlanta, GA 30322. Address correspondence to: W.I.S.; e-mail: walter. [email protected] Disclosure: nothing to disclose E.S. Shepherd Pain Institute, Shepherd Center, Atlanta, GA Disclosure: nothing to disclose Submitted for publication June 4, 2013; accepted August 4, 2013.
ª 2014 by the American Academy of Physical Medicine and Rehabilitation Vol. 6, 199-202, February 2014 http://dx.doi.org/10.1016/j.pmrj.2013.08.595
199
200
Sussman and Shaw
IIH AFTER SCI AND SUBOPTIMAL CERVICAL FUSION
Figure 1. The initial computed tomography scan showing coronal, sagittal, and axial images of the C5, C6, and C7 fractures. Maximal canal compromise occurred at C7 with a 38% reduction in the size of the cervical canal because of osseous displacement.
anterior displacement of the inferior portion of the anterior body cage (Figure 2). The patient underwent a posterior cervical arthrodesis (C3 to T3) with internal fixation (C5, C6, and C7) for stabilization. The anterior interbody cage was not repaired because it was not functionally affecting the patient’s ability to swallow. On day 53 after diagnosis of IIH and day 32 after surgery, the patient’s symptoms had resolved and an ophthalmologic examination showed no papilledema. Acetazolamide was discontinued, and the patient remained free of symptoms at the 6-month follow-up visit.
DISCUSSION IIH is defined by the symptoms and signs associated with ICP (Table 1). Headache, which is present in up to 94% of cases, is the most common symptom and can be associated with nausea, vomiting, and photophobia [1,2]. Visual complaints also are common. Transient visual obscurations from optic nerve ischemia can be seen in up to 75% of cases,
which, if progressive, can result in blindness [2]. Diplopia can be seen in 20%e38% of patients with IIH as a result of abducens nerve paresis [1]. The diagnostic evaluation should include a funduscopic examination, because papilledema is a hallmark of IIH [2]. If papilledema is suspected, neuroimaging should be performed immediately to exclude secondary causes of ICP. Once intracranial mass lesions, obstructive hydrocephalus, or venous outflow obstruction have been excluded, a lumbar puncture should be performed to confirm increased ICP and rule out inflammatory, infectious, or malignant pathology. An opening pressure greater than 250 mmH2O is suggestive of IIH [2]. The pathogenesis of IIH is not well understood. Hypotheses include abnormal CSF homeostasis, excessive CSF production, reduced CSF absorption, and outflow obstruction increasing cerebral venous pressure [3]. Obesity and sudden weight gain are the only risk factors demonstrated in case-control studies [3,4]. The patient in this case had an elevated body mass index, which may have placed him at an
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Vol. 6, Iss. 2, 2014
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Figure 2. Radiographs taken after definitive posterior stabilization. Because the anterior fusion was not addressed during the second stabilization, the 10-mm anterior displacement of the inferior portion of the anterior body cage is still present.
increased risk for IIH. Intracranial hypertension is also known to occur after even mild traumatic brain injuries through various mechanisms; in this case, however, no evidence of a traumatic brain injury was found [5,6]. Although case reports have linked IIH to medications or various rheumatologic, endocrine, and hematologic conditions, most cases remain idiopathic [2]. To our knowledge, this article represents the first reported case of intracranial hypertension after an SCI and suboptimal surgical stabilization. Venous outflow obstruction is a known mechanism for IIH and has been reported after disruption of venous drainage through the carotid veins after radical neck dissection and subclavian vein thrombosis [7,8]. Injury to the vertebral venous plexus may similarly increase venous sinus pressure (Figure 3). In this case, retropulsion of vertebral bony fragments may have altered flow dynamics in
the vertebral venous plexus. Soft tissue or ligamentous injury, cord swelling, and associated edema commonly are associated with cervical SCI and may have contributed to
Table 1. Diagnostic characteristics of idiopathic intracranial hypertension Symptoms of IIH Headaches Nausea and vomiting Vision changes: transient visual changes, diplopia Pulsatile tinnitus Signs of IIH Papilledema Visual field loss Abducens nerve palsy Elevated ICP with lumbar puncture (>250 mmH2O) Normal CSF composition Secondary causes of IIH have been ruled out IIH ¼ idiopathic intracranial hypertension; ICP ¼ intracranial pressure; CSF ¼ cerebrospinal fluid.
Figure 3. Venous outflow obstruction at the level of the vertebral venous plexus causing increased venous sinus pressure.
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Sussman and Shaw
extrinsic compression of the vertebral plexus, although magnetic resonance imaging was not performed to demonstrate the extent of soft tissue injury [9]. The additional trauma of the spinal fixation surgery also would have increased existing edema. IIH has been reported as a complication of spinal surgery, including occipitocervical arthrodesis after an odontoid fracture, uncomplicated scoliosis surgery, and surgery for Scheuermann kyphosis [10,11]. In these cases, the authors also theorized that a temporary alteration in CSF dynamics or venous outflow obstruction triggered IIH. In the case of IIH associated with occipitocervical arthrodesis, Daftari et al [11] presented a patient who had a traumatic type II odontoid fracture with nonunion after three failed surgical attempts at stabilization. Although that patient was diagnosed with IIH after the fourth and definitive surgery, she had initially presented with neck pain and headaches, and it is possible that IIH was present at that time. Stability is necessary for resolution of soft tissue edema, and similar to our case, suboptimal fixation may have played a role in the development of IIH [12]. The persistent edema surrounding the vertebral plexus ultimately may have been the definitive trigger in both of these cases. Treatment is dictated by the severity of symptoms. Acetazolamide decreases the production of CSF and is usually the first-line drug for treatment. Surgical intervention is indicated in cases in which the patient does not respond to medical management or has severe papilledema with loss of vision [3]. Optic nerve sheath fenestration and shunting are the most commonly used surgical treatments, and the decision to use one procedure over the other is often based on local expertise [13]. Possible precipitating factors should also be identified and addressed as part of the treatment plan. In this case, no known precipitating factor was identified, but the patient’s symptoms improved after he underwent a second surgery to ensure cervical stabilization.
CONCLUSION In this article we present the first reported case of IIH after a traumatic SCI and surgical stabilization. This case is
IIH AFTER SCI AND SUBOPTIMAL CERVICAL FUSION
important because it alerts practitioners that IIH can occur in this select population. Prompt recognition and diagnosis of this condition is important because failure to treat IIH can result in permanent optic nerve damage and blindness. IIH should be included in the differential diagnosis for any patient after an SCI and cervical stabilization, and the workup should include evaluation of the cervical hardware.
REFERENCES 1. Binder DK, Horton JC, Lawton MT, et al. Idiopathic intracranial hypertension. Neurosurgery 2004;54:538-551. 2. Friedman DI. Pseudotumor cerebri. Neurol Clin 2004;22:99-131. 3. Skau M, Brennum J, Gjerris F, et al. What is new about idiopathic intracranial hypertension? An updated review of mechanism and treatment. Cephalalgia 2005;26:384-399. 4. Daniels AB, Liu GT, Volpe NJ, et al. Profiles of obesity, weight gain, and quality of life in idiopathic intracranial hypertension (pseudotumor cerebri). Am J Ophthalmol 2007;143:635-641. 5. Selhorst JB, Gudeman SK, Butterworth JF, et al. Papilledema after acute head injury. Neurosurgery 1985;16:357-363. 6. Miller JD, Piper IR, Dearden NM. Management of intracranial hypertension in head injury: Matching treatment with cause. Acta Neurochir Suppl (Wien) 1993;57:152-159. 7. Birdwell BG, Yeager R, Whitsett TL. Pseudotumor cerebri: A complication of catheter-induced subclavian vein thrombosis. Arch Intern Med 1994;154:808-811. 8. Marr WG, Chambers RG. Pseudotumor cerebri syndrome: Following unilateral radical neck dissection. Am J Ophthalmol 1961;51: 605-611. 9. Miyanji F, Furlan JC, Aarabi B, Arnold PM, Fehlings MG. Acute cervical traumatic spinal cord injury: MR imaging findings correlated with neurologic outcome—prospective study with 100 consecutive patients. Radiology 2007;243:820-827. 10. Kunes J, Thompson GH, Manjila S, et al. Idiopathic intracranial hypertension following spinal deformity surgery in children. Neurosurg Focus 2011;31:E20. 11. Daftari TK, Heller JG, Newman NJ. Pseudotumor cerebri after occipitocervical arthrodesis and immobilization in a halo vest. J Bone Joint Surg 1995;77A:455-458. 12. D’Alise MD, Benzel EC, Hart BL. Magnetic resonance imaging evaluation of the cervical spine in the comatose or obtunded trauma patient. J Neurosurg 1999;91(suppl 1):54-59. 13. Friedman DI. Idiopathic intracranial hypertension. Curr Pain Headache Rep 2007;11:62-68.
Intracranial Hypertension After Spinal Cord Injury and Suboptimal Cervical Fusion Walter I. Sussman, DO, Erik Shaw, DO Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a syndrome of increased intracranial pressure. Secondary causes have been associated with IIH, but the pathogenesis is poorly understood, and most cases are idiopathic. We present a case of IIH after suboptimal surgical stabilization of a traumatic C5 spinal cord injury, American Spinal Injury Association Impairment Scale grade A. The patient underwent a posterior arthrodesis and fusion to stabilize the spine, and his symptoms gradually resolved. To our knowledge, we present the first reported case of intracranial hypertension after a traumatic spinal cord injury and failed surgical stabilization. PM R 2014;6:199-202
INTRODUCTION Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a syndrome of increased intracranial pressure (ICP). The pathogenesis of IIH is poorly understood. A number of secondary causes have been associated with IIH, but IIH after a traumatic spinal cord injury (SCI) and spinal stabilization has not previously been reported, to our knowledge.
CASE PRESENTATION A 26-year-old man with a C5 SCI (American Spinal Injury Association Impairment Scale grade A) presented to acute rehabilitation with headaches, nausea, and diplopia that he had experienced for 96 hours. The patient had no history of headaches or vision changes. Fifteen days before the current presentation, the patient sustained C5, C6, and C7 burst fractures with SCI as the result of a diving injury (Figure 1). The patient did not lose consciousness, and he was promptly pulled from the water. No signs of near drowning or evidence of a traumatic brain injury were observed. The patient underwent an anterior cervical corpectomy (C5 to C7) and fusion (C4 to T1) via a titanium cage (12 mm, VBOSS System; Stryker, Kalamazoo, MI) filled with 20 mL of demineralized bone matrix and autograft morcellized bone covered by a 4-level anterior titanium plate. The postoperative course was uncomplicated until day 12, when the patient experienced headaches, nausea, and diplopia. Funduscopic examination showed papilledema, and a subsequent computed tomography scan of the head failed to show any mass lesions or secondary cause of ICP. A presumptive diagnosis of IIH was made, and the patient was discharged to acute rehabilitation. At admission, all vital signs were within normal limits and the patient was afebrile. His body mass index was 32. A lumbar puncture was completed, and the opening pressure was 280 mmH2O. After removing 18 mL of cerebral spinal fluid (CSF), the patient’s pressure decreased to 90 mmH2O, and he reported transient resolution of symptoms. CSF analysis was within normal limits. The patient was not taking any medications associated with IIH. Acetazolamide, 500 mg twice daily, was prescribed. Cervical radiographs on day 2 of admission showed 10-mm PM&R 1934-1482/13/$36.00 Printed in U.S.A.
W.I.S. Department of Rehabilitation Medicine, Emory University School of Medicine, Center for Rehabilitation Medicine, 1441 Clifton Rd NE, Atlanta, GA 30322. Address correspondence to: W.I.S.; e-mail: walter. [email protected] Disclosure: nothing to disclose E.S. Shepherd Pain Institute, Shepherd Center, Atlanta, GA Disclosure: nothing to disclose Submitted for publication June 4, 2013; accepted August 4, 2013.
ª 2014 by the American Academy of Physical Medicine and Rehabilitation Vol. 6, 199-202, February 2014 http://dx.doi.org/10.1016/j.pmrj.2013.08.595
199
200
Sussman and Shaw
IIH AFTER SCI AND SUBOPTIMAL CERVICAL FUSION
Figure 1. The initial computed tomography scan showing coronal, sagittal, and axial images of the C5, C6, and C7 fractures. Maximal canal compromise occurred at C7 with a 38% reduction in the size of the cervical canal because of osseous displacement.
anterior displacement of the inferior portion of the anterior body cage (Figure 2). The patient underwent a posterior cervical arthrodesis (C3 to T3) with internal fixation (C5, C6, and C7) for stabilization. The anterior interbody cage was not repaired because it was not functionally affecting the patient’s ability to swallow. On day 53 after diagnosis of IIH and day 32 after surgery, the patient’s symptoms had resolved and an ophthalmologic examination showed no papilledema. Acetazolamide was discontinued, and the patient remained free of symptoms at the 6-month follow-up visit.
DISCUSSION IIH is defined by the symptoms and signs associated with ICP (Table 1). Headache, which is present in up to 94% of cases, is the most common symptom and can be associated with nausea, vomiting, and photophobia [1,2]. Visual complaints also are common. Transient visual obscurations from optic nerve ischemia can be seen in up to 75% of cases,
which, if progressive, can result in blindness [2]. Diplopia can be seen in 20%e38% of patients with IIH as a result of abducens nerve paresis [1]. The diagnostic evaluation should include a funduscopic examination, because papilledema is a hallmark of IIH [2]. If papilledema is suspected, neuroimaging should be performed immediately to exclude secondary causes of ICP. Once intracranial mass lesions, obstructive hydrocephalus, or venous outflow obstruction have been excluded, a lumbar puncture should be performed to confirm increased ICP and rule out inflammatory, infectious, or malignant pathology. An opening pressure greater than 250 mmH2O is suggestive of IIH [2]. The pathogenesis of IIH is not well understood. Hypotheses include abnormal CSF homeostasis, excessive CSF production, reduced CSF absorption, and outflow obstruction increasing cerebral venous pressure [3]. Obesity and sudden weight gain are the only risk factors demonstrated in case-control studies [3,4]. The patient in this case had an elevated body mass index, which may have placed him at an
PM&R
Vol. 6, Iss. 2, 2014
201
Figure 2. Radiographs taken after definitive posterior stabilization. Because the anterior fusion was not addressed during the second stabilization, the 10-mm anterior displacement of the inferior portion of the anterior body cage is still present.
increased risk for IIH. Intracranial hypertension is also known to occur after even mild traumatic brain injuries through various mechanisms; in this case, however, no evidence of a traumatic brain injury was found [5,6]. Although case reports have linked IIH to medications or various rheumatologic, endocrine, and hematologic conditions, most cases remain idiopathic [2]. To our knowledge, this article represents the first reported case of intracranial hypertension after an SCI and suboptimal surgical stabilization. Venous outflow obstruction is a known mechanism for IIH and has been reported after disruption of venous drainage through the carotid veins after radical neck dissection and subclavian vein thrombosis [7,8]. Injury to the vertebral venous plexus may similarly increase venous sinus pressure (Figure 3). In this case, retropulsion of vertebral bony fragments may have altered flow dynamics in
the vertebral venous plexus. Soft tissue or ligamentous injury, cord swelling, and associated edema commonly are associated with cervical SCI and may have contributed to
Table 1. Diagnostic characteristics of idiopathic intracranial hypertension Symptoms of IIH Headaches Nausea and vomiting Vision changes: transient visual changes, diplopia Pulsatile tinnitus Signs of IIH Papilledema Visual field loss Abducens nerve palsy Elevated ICP with lumbar puncture (>250 mmH2O) Normal CSF composition Secondary causes of IIH have been ruled out IIH ¼ idiopathic intracranial hypertension; ICP ¼ intracranial pressure; CSF ¼ cerebrospinal fluid.
Figure 3. Venous outflow obstruction at the level of the vertebral venous plexus causing increased venous sinus pressure.
202
Sussman and Shaw
extrinsic compression of the vertebral plexus, although magnetic resonance imaging was not performed to demonstrate the extent of soft tissue injury [9]. The additional trauma of the spinal fixation surgery also would have increased existing edema. IIH has been reported as a complication of spinal surgery, including occipitocervical arthrodesis after an odontoid fracture, uncomplicated scoliosis surgery, and surgery for Scheuermann kyphosis [10,11]. In these cases, the authors also theorized that a temporary alteration in CSF dynamics or venous outflow obstruction triggered IIH. In the case of IIH associated with occipitocervical arthrodesis, Daftari et al [11] presented a patient who had a traumatic type II odontoid fracture with nonunion after three failed surgical attempts at stabilization. Although that patient was diagnosed with IIH after the fourth and definitive surgery, she had initially presented with neck pain and headaches, and it is possible that IIH was present at that time. Stability is necessary for resolution of soft tissue edema, and similar to our case, suboptimal fixation may have played a role in the development of IIH [12]. The persistent edema surrounding the vertebral plexus ultimately may have been the definitive trigger in both of these cases. Treatment is dictated by the severity of symptoms. Acetazolamide decreases the production of CSF and is usually the first-line drug for treatment. Surgical intervention is indicated in cases in which the patient does not respond to medical management or has severe papilledema with loss of vision [3]. Optic nerve sheath fenestration and shunting are the most commonly used surgical treatments, and the decision to use one procedure over the other is often based on local expertise [13]. Possible precipitating factors should also be identified and addressed as part of the treatment plan. In this case, no known precipitating factor was identified, but the patient’s symptoms improved after he underwent a second surgery to ensure cervical stabilization.
CONCLUSION In this article we present the first reported case of IIH after a traumatic SCI and surgical stabilization. This case is
IIH AFTER SCI AND SUBOPTIMAL CERVICAL FUSION
important because it alerts practitioners that IIH can occur in this select population. Prompt recognition and diagnosis of this condition is important because failure to treat IIH can result in permanent optic nerve damage and blindness. IIH should be included in the differential diagnosis for any patient after an SCI and cervical stabilization, and the workup should include evaluation of the cervical hardware.
REFERENCES 1. Binder DK, Horton JC, Lawton MT, et al. Idiopathic intracranial hypertension. Neurosurgery 2004;54:538-551. 2. Friedman DI. Pseudotumor cerebri. Neurol Clin 2004;22:99-131. 3. Skau M, Brennum J, Gjerris F, et al. What is new about idiopathic intracranial hypertension? An updated review of mechanism and treatment. Cephalalgia 2005;26:384-399. 4. Daniels AB, Liu GT, Volpe NJ, et al. Profiles of obesity, weight gain, and quality of life in idiopathic intracranial hypertension (pseudotumor cerebri). Am J Ophthalmol 2007;143:635-641. 5. Selhorst JB, Gudeman SK, Butterworth JF, et al. Papilledema after acute head injury. Neurosurgery 1985;16:357-363. 6. Miller JD, Piper IR, Dearden NM. Management of intracranial hypertension in head injury: Matching treatment with cause. Acta Neurochir Suppl (Wien) 1993;57:152-159. 7. Birdwell BG, Yeager R, Whitsett TL. Pseudotumor cerebri: A complication of catheter-induced subclavian vein thrombosis. Arch Intern Med 1994;154:808-811. 8. Marr WG, Chambers RG. Pseudotumor cerebri syndrome: Following unilateral radical neck dissection. Am J Ophthalmol 1961;51: 605-611. 9. Miyanji F, Furlan JC, Aarabi B, Arnold PM, Fehlings MG. Acute cervical traumatic spinal cord injury: MR imaging findings correlated with neurologic outcome—prospective study with 100 consecutive patients. Radiology 2007;243:820-827. 10. Kunes J, Thompson GH, Manjila S, et al. Idiopathic intracranial hypertension following spinal deformity surgery in children. Neurosurg Focus 2011;31:E20. 11. Daftari TK, Heller JG, Newman NJ. Pseudotumor cerebri after occipitocervical arthrodesis and immobilization in a halo vest. J Bone Joint Surg 1995;77A:455-458. 12. D’Alise MD, Benzel EC, Hart BL. Magnetic resonance imaging evaluation of the cervical spine in the comatose or obtunded trauma patient. J Neurosurg 1999;91(suppl 1):54-59. 13. Friedman DI. Idiopathic intracranial hypertension. Curr Pain Headache Rep 2007;11:62-68.