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10. SPINE Allan D. Levi pine cases form a significant component of the neu rosurgery Oral Board Examination. Familiarity with the common cases is essential in preparing for the boards. Covering the gamut of spine is difficult in one reference text. Spine includes cases that span from the skull base to the sacrum. Degenerative, congenital, trauma, tumors, infections, and inflammatory pathologies are all important in the differential diagnosis. Pediatric spine conditions are unique, and some congenital conditions present in adult hood, including congenital anomalies of the skull base and lumbar spondylolysthesis due to a pars defect. Neurological disorders that can mimic neurosurgical spine and spinal cord conditions are also seen and include amyotrophic lateral sclerosis, Guillain- Barré syndrome, and multiple sclerosis. Another component of spine includes an understand ing of spine stability as well as the use of spinal instru mentation. In some cases, spine instability is determined by the presenting pathology (e.g., bilateral cervical facet dislocation). At other times, the effects of the decompres sion on spine stability (e.g., removal of a tumor sacrific ing posterior elements at the level of the thoracolumbar junction) must be considered in addition to the existing pathology. Spine technologies and instrumentation continue to evolve. T wenty- five years ago, anterior cervical plating and pedicle screws were considered new technologies and likely not to be tested in detail on the Oral Board Examination. Now these instrumentation techniques are a standard part of the neurosurgical armamentarium. Current new technologies or approaches to the spine, whether minimally invasive techniques or surgery for deformity, are a growing part of standard neurosurgical practice and will continue to form a larger part of the Oral Board Examination. CASE 1 HISTORY AND PHYSICAL EXAMINA TION An 18- year- old man fell when waterskiing and became paralyzed in the upper and lower extremities. He was transported on a board to a local hospital in a collar, and on examination he was diagnosed with C5 quadriplegia AIS A (American Spinal Cord Injury Association (A) Impairment Scale (AIS)). He was stabilized in a halo vest and transferred to your institution 24 hours after injury. IMAGING STUDIES The imaging studies demonstrate a lateral cervical spine radiograph to the level of C6 (Figure 10.1). Imaging would need to extend down to T1 to completely image the cer vical spine. There are bilateral cervical locked facets at the C5- C6 level, with significant narrowing of the spinal canal. The superior articular process of C6 is locked behind the inferior articular process of C5. Axial computed tomography (CT) also demonstrates bilateral locked facets (Figure 10.2). ANALYSIS OF CASE AND SURGICAL PLAN This case illustrates many of the common themes in the management of acute cervical spinal cord injury (SCI). The first is that in emergency management of such patients. It is important to recognize that the patient has a complete cervical SCI. It is common for these patients to have hemodynamic issues on presentation, including bradycardia and hypotension related to neurogenic shock. This is com monly seen in patients with SCI above T6, injuring the sympathetic outflow. The management includes diagnosis,

ecognize that the patient has a complete cervical SCI. It is common for these patients to have hemodynamic issues on presentation, including bradycardia and hypotension related to neurogenic shock. This is com monly seen in patients with SCI above T6, injuring the sympathetic outflow. The management includes diagnosis, 104 • G OODMAN ’S N EUROSURGERY O RAL B OARD R E v IEW placement of an arterial line, replacement of volume with fluids, and at times the administration of vasopressors such as dopamine or dobutamine or phenylephrine. There is level II evidence that treating hypotension to achieve mean arterial pressures of 80 to 85 mm Hg can improve neurological outcomes after SCI. 1 Respiratory failure is also common, particularly after cervical SCI, because of loss of the acces sory muscles of respiration. High cervical SCI at C4 and above can affect diaphragmatic function, and the physi cian needs to be ready to intubate with spinal precautions, including in- line traction or awake fiberoptic intubation. The next issues that are important to address after stabilizing the patient and evaluating his airway, breathing, and circulation are the use of additional imaging studies and the role of emergency reduction. The patient has bilateral C5- C6 locked facets and a complete cervical SCI. In this setting, it is more valua ble to try an urgent closed cranial tong reduction in an attempt to provide immediate decompression of the spi nal cord, particularly when the patient presents soon after the injury. In patients with bilateral facet dislocations that are complete, we now tend to perform early manual reduc tion; after a successful reduction, we obtain postreduction cervical magnetic resonance imaging (MRI). If a patient has an incomplete SCI (AIS levels B- D) or a normal neu rological examination (AIS level E) and has a bilateral facet dislocation, we tend to perform imaging first to rule out an impending disk herniation, which has been rarely reported in the literature.2,3 In this patient, an attempted reduction was tried, with successive weights starting at 30 lb, adding 5 lb per level, and extending to 80 lb without success in reducing the fracture dislocation. The weights can be increased to 120 lb if two Gardner- W ells tongs are used. In our practice, we rarely use a protocol with ascending weights because of time considerations, and we prefer to use manual traction with fluoroscopy either in the trauma center or in the operating room. Sedation may enhance the reduction process, and ultimately some patients will need general anesthesia. In an article by Grant and colleagues, 4 preoperative reduction with cranial tongs was shown to be safe after SCI. The role of intravenous steroids in these cases remains controversial. Clearly, in this patient who was transferred 24 hours after injury, there is no role for steroids because the upper time limit for administering steroids according to the National Acute Spinal Cord Injury Study (NASCIS) II protocol is 8 hours.5 In patients who are seen with SCI in less than 8 hours, steroid administration is now considered by the Neurological Surgery guidelines not recommended because the evidence for complications due to steroids is more evident than its benefits.6 Because this is controversial, you should have a ready response, and if you use steroids Figure 10.1 Lateral cervical spine radiograph demonstrating bilateral C5- C6 locked facets. There is a high- grade anterolisthesis of C5 on C6. The patient has been stabilized in a halo vest for transfer. Figure 10.2 Thin- cut axial computed tomographic scan with bilateral locked “naked” facets.

and if you use steroids Figure 10.1 Lateral cervical spine radiograph demonstrating bilateral C5- C6 locked facets. There is a high- grade anterolisthesis of C5 on C6. The patient has been stabilized in a halo vest for transfer. Figure 10.2 Thin- cut axial computed tomographic scan with bilateral locked “naked” facets. SPINE • 105 as a neuroprotective strategy, you must be prepared to cite the dose (e.g., methylprednisolone [Solu- Medrol], 5.4- mg/ kg intravenous loading dose over 15 minutes followed by 30 mg/ kg per hour over 23 hours). This patient subsequently underwent spinal surgery with a posterior approach in which a portion of the facet joint (i.e., the superior articular process of C6) was drilled. As soon as a small amount of the joint was drilled, the facet joints “popped” back in to alignment and was then stabi lized by posterior cervical instrumentation consisting of lateral mass screws at one level above and one level below (Figure 10.3). Identifying the typical entry point for the lateral mass screws involves determining the midpoint of the lateral mass and entering the bone 1 mm inferior and 1  mm medial to this point. The drill trajectory is upward and outward. The typical screw length in an adult male is 14 to 18 mm. Supplementing the instrumented fusion with bone graft, either local graft, autograft, or allograft, and possibly a bone extender is important for ultimately obtaining a bone fusion. A cervical collar after an instrumented fusion for a fracture is typically 6 to 12 weeks. Many patients with bilateral cervical facet dislocation can undergo surgical reduction after an anterior approach and removal of the intervening disk. This can be accom plished with either tong reduction or by using Caspar vertebral distraction pins or by placing a Cobb elevator or a similar instrument and distracting. In approximately 95% of cases, the surgeon can obtain an anatomic reduction after an anterior approach, then fuse with a bone graft and an anterior cervical plate.7 If an anterior reduction was unsuccessful in reducing the fracture dislocation, an interbody graft can be placed; the patient can then be flipped posteriorly and the same procedure performed by drilling the superior articular process of C6. COMPLICA TIONS One potential complication in this case is the development of infection. The infection rate after spinal instrumentation ranges from 1% to 8%.8 Infection usually occurs 1 to 4 weeks after surgery and typically manifests with egress of turbid fluid (Figure 10.4), fever, chills, and malaise. Additional studies that can help support the diagnosis include a white blood cell count, erythrocyte sedimentation rate, and C- reactive protein. When the suspicion of a deep- seeded infection is high, it is prudent to proceed with aggressive debridement of the wound. This usually requires operative intervention, exploration of the wound, removal of any obviously infected bone graft or dead necrotic tissues, irrigation of the wound, placement of drains, and then primary closure. Identification of the bacterial pathogen is key. A diag nosis can be obtained with blood cultures if the patient is septic and also with intraoperative cultures. The intrave nous antibiotics can then be tailored according to the cul tured organism. The patient generally receives 6 weeks of intravenous antibiotics or treatment until the erythrocyte sedimentation rate normalizes for a deep- seated infection with spinal instrumentation. Figure 10.3 Postoperative anteroposterior radiograph with the presence of a lateral mass screws and a plate stabilizing the fracture after intraoperative reduction. Figure 10.4 T wo- week postoperative incision with evidence of purulent drainage from the wound.

for a deep- seated infection with spinal instrumentation. Figure 10.3 Postoperative anteroposterior radiograph with the presence of a lateral mass screws and a plate stabilizing the fracture after intraoperative reduction. Figure 10.4 T wo- week postoperative incision with evidence of purulent drainage from the wound. 106 • G OODMAN ’S N EUROSURGERY O RAL B OARD R E v IEW CASE 2 HISTORY AND PHYSICAL EXAMINA TION A 72- year- old woman presents with progressive bilateral lower extremity numbness and weakness. On neurological examination, she demonstrates generalized bilateral lower extremity weakness, and the most severe involvement seen is ankle dorsiflexion at 3 and 5 strength, with the remainder of motor strength - 4/ 5 . She had hyperreflexia at the knees and ankles at 3 to 4+/ 4, and she had up- going toes. She also had sensory level to pinprick at T10. IMAGING STUDIES The patient has a central thoracic disk herniation at the T10- T11 level, which is ventral to the dural sac and calci fied (Figure 10.5). It has significantly compressed the ven tral spinal cord on MRI (Figure 10.6, Figure  10.7). The differential diagnosis includes a ventral calcified meningi oma, but the absence of a dural tail and the presence of the lesion at the disk space make this much less likely. ANALYSIS OF CASE AND SURGICAL PLAN This is a classical Oral Board Examination question in which the examiners want to determine your surgical approach and safety. One of the clear- cut wrong answers is the per formance of a midline thoracic laminectomy in the face of a central calcified disk. Please do not entertain this response! The surgical options include a lateral approach, some times referred to as an anterior approach, which would consist of a thoracotomy. The thoracotomy can be done from the right or the left depending on whether the disk is eccentric to the right or the left, respectively. If it is central and all things being equal, it is preferable to go on the left side because the thoracic aorta is easier to mobilize than the inferior vena cava. This often will require a rib resection (typi cally, the 9th rib), which can be done through a full open or minimally invasive approach. After deflating the ipsilateral lung, it is critical to identify the 11th rib head because this will lead you to the location of the underlying 11th pedicle. Y ou can then safely enter the lateral spinal canal by drilling away the pedicle. Y ou can then proceed with a lateral discectomy and a partial corpectomy of T11 and T10 above and below the target disk level. Y ou can then identify the ventral compression of the thecal sac by the calcified thoracic disk. Y ou can then empty the disk material into the decompression area, which was created by the partial corpectomy. It is not uncommon to have calcified disk that is adherent to the dura, which may result in an inadvertent cerebrospinal fluid (CSF) leak. Another approach to this central calcified disk would be a “posterolateral approach, ” and this is very different from a laminectomy. This approach requires a transpedicular Figure 10.5 Actual thin- cut computed tomographic scan with a large ventral thoracic calcified disc. Figure 10.6 Sagittal T2- weighted magnetic resonance imaging showing severe ventral thoracic spinal cord compression and a calcified disk opposite the disk space.

m a laminectomy. This approach requires a transpedicular Figure 10.5 Actual thin- cut computed tomographic scan with a large ventral thoracic calcified disc. Figure 10.6 Sagittal T2- weighted magnetic resonance imaging showing severe ventral thoracic spinal cord compression and a calcified disk opposite the disk space. SPINE • 107 decompression, facetectomy, partial rib resection, partial corpectomy, and reaching somewhat blindly in front of the dural sac with reverse- angle curettes and decompress ing the ventral disk into the corpectomy defect. This often is supplemented by a posterior instrumented pedicle screw fusion. A spinal fluid leak is not uncommon and requires further management with indirect repair and a CSF drain. COMPLICA TIONS Correction of a CSF leak into the thoracic cavity can be problematic. It is very difficult to perform a direct repair of the dura after a thoracotomy and an anterior approach, but you can consider an indirect repair by placement of collagen dural substitute or glue. Y ou can also consider placing either a lumbar or a cervical CSF drain to reduce the pressure head of the CSF leak on the dural repair. W e usually place a no. 28 or no. 32 chest tube on suction and then switch to water seal in the subsequent 24 hours to prevent a CSF fistula into the chest cavity from forming. Although intraoperative monitoring is not standard of care for every spine case, the use of intraoperative moni toring (Figure 10.8) for high- risk cases such as a calcified thoracic disk or an intramedullary tumor can be helpful. In this particular case, there was a decline of motor evoked potentials (MEPs) during the surgery on the contralateral side from where the disk was being removed as rotation of the calcified disk fragment impinged on the right side of the spinal cord. This is a true- positive finding with a decline, reflecting an injury to the spinal cord. Additional bone removal allowed better access to the ventral dura, and we had to resect the dura along with the calcified disk to adequately decompress the spinal cord. Comparing Figure 10.8C and D, the lower extremity right MEPs to the quadricep at 350 mA stimulation is gone. There are many reasons that intraoperative potentials can change during surgery. The first step would be to rule out spinal cord– unrelated causes for the intraoperative changes. Low core body temperature (e.g., hypothermia) can result in reduced somatosensory evoked potentials (SSEPs) but not MEPs; increased concentration of gas anesthetic and hypotension are alternative causes of decreased MEPs (false- positive findings) and need to be ruled out. It is important to have a management algorithm when there are intraoperative changes in evoke potentials. The patient ultimately returned with shortness of breath and worsening headache, especially when upright. The chest radiograph (Figure 10.9) demonstrated a large left- sided pleural effusion and a significant left- sided chronic subdural hematoma (Figure 10.10). The patient then required a repair of the ventral CSF leak through a repeat thoracotomy and placement of a cer vical CSF drain for 5  days to reduce the pressure head at the repair site. Drainage of the subdural hematoma was not required because the patient was neurologically stable, and CSF leak repair resulted in disappearance of the subdural over a period of 12 weeks. CASE 3 HISTORY AND PHYSICAL EXAMINA TION This is a 56- year- old man who has had a longstanding his tory of low back pain since adolescence. He now presents with low back pain and right greater than left leg pain that radiates down the lateral aspect of the legs. On examination, he is neurologically intact. Imaging studies are presented.

PHYSICAL EXAMINA TION This is a 56- year- old man who has had a longstanding his tory of low back pain since adolescence. He now presents with low back pain and right greater than left leg pain that radiates down the lateral aspect of the legs. On examination, he is neurologically intact. Imaging studies are presented. IMAGING STUDIES The imaging studies demonstrate evidence of a grade I L5- S1 spondylolisthesis (Figure 10.11). The most common form of spondylolisthesis at this level is a congenital isthmic spondylolysis with subsequent spondylolisthesis. This can be diagnosed using oblique images in which a Scotty dog is seen, and Figure 10.7 Demonstrates an axial T2 weighted image with the central disc seen compressing the ventral spinal cord. 108 • G OODMAN ’S N EUROSURGERY O RAL B OARD R E v IEW typically the fracture line goes along or across the neck of the Scotty dog (Figure 10.12 and 10.13). Similarly, a fine cut CT scan shows the chronic pars fracture (Figure 10.14). The fracture is best appreciated on sagittal CT scans in which the superior and inferior articular process appears separated. ANALYSIS OF CASE AND SURGICAL PLAN Patients with isthmic spondylolysis typically have a chronic history of low back pain, and as they age, they develop inflammatory or arthritic changes around the fracture with resultant lateral recess stenosis due to a combination of the slip and the facet arthroplasty. They may eventually develop radiculopathy. In general, patients who present with radicular symptoms complain of pain and numbness along the L5 nerve root as it is entrapped and as it exits around the L5 pedicle. In these conditions, it is always important to initially advocate for conservative treatments, such as physical therapy, epidural injections, antiinflammatory drugs, and the like. Figure 10.8 A– D: Baseline and intraoperative showing somatosensory evoked potentials (SSEPs, upper A/ B, left and right) and motor evoked potentials (MEPs, lower C/ D). A and B: SSEPs. C: Pre- operative baseline MEPs. D: Intra- operative MEPs loss of on the right- sided MEPs, there is a decrement or loss of the quadriceps MEP (red oval) at the time when the calcified disk was rotated into the spinal cord in an attempt to deliver the calcified disc into the thoracic corpectomy site.

). A and B: SSEPs. C: Pre- operative baseline MEPs. D: Intra- operative MEPs loss of on the right- sided MEPs, there is a decrement or loss of the quadriceps MEP (red oval) at the time when the calcified disk was rotated into the spinal cord in an attempt to deliver the calcified disc into the thoracic corpectomy site. SPINE • 109 Figure 10.9 Anteroposterior chest radiograph with a large left- sided plural fusion obscuring the heart shadow. Figure 10.10 Axial computed tomographic scan of the brain showing a large acute- on- chronic subdural hematoma, with left- sided frontal with midline shift. Figure 10.11 Grade I spondylolisthesis at L5- S1 due to a congenital isthmic spondylolysis. Figure 10.12 Oblique view with a Scotty dog appearance incorporating the L5 superior and inferior articular process.

of the brain showing a large acute- on- chronic subdural hematoma, with left- sided frontal with midline shift. Figure 10.11 Grade I spondylolisthesis at L5- S1 due to a congenital isthmic spondylolysis. Figure 10.12 Oblique view with a Scotty dog appearance incorporating the L5 superior and inferior articular process. 110 • G OODMAN ’S N EUROSURGERY O RAL B OARD R E v IEW Ultimately, patients often require surgical intervention. There are a number of surgical approaches that can be considered. From a historical perspective, an L5 laminectomy alone or a Gill procedure (named after the initial surgeon who described it) is a historical option. The most common or favored options are those that involve a laminectomy and fusion. The fusion options would include a laminectomy of L5 and posterolateral fusion at L5- S1, a laminectomy with posterolateral fusion with pedicle screws, or a laminectomy with interbody fusion and pedicle screw instrumentation. The advantage of an interbody graft for this procedure is that the placement of such grafts will allow you to distract the disk space, thereby indirectly decompressing the L5 nerve root underneath the pedicle as it exits the foramen, as well as enhancing the overall fusion rate for these conditions. One of the most difficult levels to fuse is the L5- S1 interspace, and the interbody graft will substantially increase the fusion rate. This should be supplemented by a placement at L5- S1 pedicle screw instrumentation (Figure 10.15). T ypically, when we place pedicle screws, we identify the mammary tubercle of L5 and use a gear shift followed by a tap and then placement of the pedicle screws, which measure from 5 to 7.5  mm in width. One can consider monitoring, fluoroscopy, or both to improve the accuracy of placement of the screws. Impedance monitoring typi cally produces a current to the pedicle screw, and if there is a breach in the medial pedicle screw wall, one can detect a lower impedance (<20 mA). Similarly, anteroposterior and lateral fluoroscopy images can help localize the pedicle screw within the pedicle. COMPLICA TIONS The patient awakens with severe paresthesias, burning, and an incomplete unilateral foot dorsiflexion weak ness after surgery. The differential diagnosis includes a retraction injury to the L5 nerve root when placing the interbody grafts, a malpositioned pedicle screw at L5, and a hematoma or retained disk fragment. These various possibilities can be ruled out with postoperative CT and MRI. Should the investigations fail to reveal a structural cause for the L5 radiculopathy, the pain can be treated with medications such as gabapentin. The most common side effects of gabapentin in adult patients include dizziness, fatigue, drowsiness, weight gain, and peripheral edema. CASE 4 HISTORY AND PHYSICAL EXAMINA TION A 56- year- old man presents with a history of severe and incapacitating neck pain that is worse at night or when upright over a period of 4 weeks. In addition, he complains of weakness in his hands and gait instability. Figure 10.14 Axial computed tomographic scan of L5; the arrows point to the pars fracture. The L5- S1 joint is also seen posteriorly. Figure 10.13 The Scotty dog outline with a fracture along the neck of the dog.

upright over a period of 4 weeks. In addition, he complains of weakness in his hands and gait instability. Figure 10.14 Axial computed tomographic scan of L5; the arrows point to the pars fracture. The L5- S1 joint is also seen posteriorly. Figure 10.13 The Scotty dog outline with a fracture along the neck of the dog. SPINE • 111 On examination, he is hyperreflexic in both the upper and lower extremities with bilateral intrinsic muscle weak ness in the hands. IMAGING STUDIES Imaging shows a lateral cervical spine radiograph with destruction of the vertebral body of C6. The end plates of C5 and C7 are relatively intact (Figure 10.16). The appearance is most suggestive of a metastatic lesion and less likely a primary tumor or tuberculoma (which also tends to preserve the end plates above and below). CT scan dem onstrates a destruction of the C6 vertebral body (Figures 10.17 and 10.18). The facet joints and posterior elements are relatively intact. There is some prevertebral soft tissue swelling consistent with the tumor. The next logical test to be ordered would be MRI of the cervical spine with gadolinium. MRI demonstrates a tumor that involves the C6 vertebral body with significant bilat eral anterior ventral epidural compression and deformation of the spinal cord (Figures 10.19 and 10.20). ANALYSIS OF CASE AND SURGICAL PLAN The initial question is always whether this is a primary or a metastatic bone lesion. The patient’s advanced age and short duration of presentation are more suggestive of a metastasis. In trying to ascertain the diagnosis, it would be prudent to order further imaging studies, including a metastatic survey, which would include a bone scan; CT of the chest, abdomen, and pelvis; prostate- specific antigen; and multiple myeloma markers. In patients with emergency department presentation of a pathologic spine fracture, new neurological deficit, and no history of a primary tumor, multiple myeloma is one of the most frequent diagnoses. This diagnosis would be sup ported if multiple lytic lesions were seen on the skeletal survey. That was not the case here. The medical management of this patient who has severe pain that appears to be position dependent as well as cord compression and neurological deficit would include the Figure 10.15 A: Lateral intra- operative fluoroscope image demonstrates bilateral pedicle screws at L5 and S1 with an interbody graft at L5- S1 that results in an increase of disk space height. B: Anteroposterior fluoroscopic image of the lumbar spine with bilateral paired pedicle screws and two interbody grafts. Figure 10.16 Lateral cervical spine radiograph showing a destructive lesion involving the C6 vertebral body.

and S1 with an interbody graft at L5- S1 that results in an increase of disk space height. B: Anteroposterior fluoroscopic image of the lumbar spine with bilateral paired pedicle screws and two interbody grafts. Figure 10.16 Lateral cervical spine radiograph showing a destructive lesion involving the C6 vertebral body. 112 • G OODMAN ’S N EUROSURGERY O RAL B OARD R E v IEW application of a rigid cervical collar. The patient should be started on intravenous steroids. A  study by Slatkin and Posner9 recommended high doses of dexamethasone (Decadron):  100 mg intravenous loading dose 10 followed by 10 mg four times daily. This dosage is relatively large, but steroids certainly will provide the patient pain relief and the possibility of neurological improvement. The additional imaging studies were negative. Therefore, this appears to be a solitary vertebral lesion, and the question becomes what additional treatment is required. The options always are surgery, radiotherapy, and chemotherapy. The indication for surgery in this case is quite strong: 1. T o obtain a pathologic diagnosis 2. T o treat severe and intractable neck pain secondary to the pathologic fracture 3. Spinal cord decompression to improve neurological function Other indications for surgery that this patient does not have as of yet are spinal deformity and failure of other forms of adjuvant treatment, such as chemotherapy and radiotherapy. The simplest way to reach this tumor would be from an anterior approach to perform a C6 corpectomy and recon struction. There are many different options for the recon struction material, including iliac crest structural autograft, allograft, expandable or stackable cages, or what was done here from this relatively old slide, but a very tenable solu tion is cement and Steinman pins. Any of these interbody options should be supplemented by an anterior plating system (Figure 10.21). After the patient’s incisions are well healed, adju vant therapy certainly can be considered, depending on the pathology. In this case, the patient was found to have adenocarcinoma with an unknown primary tumor, and he received adjuvant radiation therapy. COMPLICA TIONS The patient presented 2 weeks later with fever, difficulty swallowing, and pustulous discharge from the wound. When such a patient is seen in the emergency depart ment with this presentation; the most likely diagnosis is an infection. A wound infection after an anterior cervical spine surgery is secondary to an esophageal injury until proved otherwise. This is almost always secondary to an unrecognized perforation during the initial dissection or reconstruction. The frequency is increased with anterior revision surgery. Lateral radiography and contrast esophagography remain Figure 10.17 Axial computed tomographic scan, again showing destruction of the C6 vertebral body by the metastatic lesion. Figure 10.18 Sagittal computed tomographic scan showing the vertebral C6 vertebral body destruction.

increased with anterior revision surgery. Lateral radiography and contrast esophagography remain Figure 10.17 Axial computed tomographic scan, again showing destruction of the C6 vertebral body by the metastatic lesion. Figure 10.18 Sagittal computed tomographic scan showing the vertebral C6 vertebral body destruction. SPINE • 113 the “gold standard” for the diagnosis of a perforation, but they lack sensitivity. A CT scan of the neck (Figure 10.22) to look for swelling or free air within the neck is useful. Although flexible esophagoscopy can be used to assess mucosal integrity, rigid esophagoscopy is more sensitive in assessing a perforation but may not be possible if the spine is deemed “unstable.” W e often perform a combination of these diagnostic modalities to establish the diagnosis. In addition to broad- spectrum antibiotics to include anaerobe coverage, successful management of an esophageal perforation has to fulfill the following conditions:  func tional closure of the perforation (patient is able to eat), control or prevention of infection (local abscess, spondylodiscitis, septicemia, and mediastinitis), and stabilization of the cervical spine. In general, a fistula is most likely to close when a patient’s nutritional requirements are met and no obstruction exists below the leak. Our general bias is toward cervical exploration, repair of the esophageal perforation with inverted sutures, and rein forcement with a rotational sternocleidomastoid (SCM) muscle flap (Figure 10.23). The muscle functions as a bolster for the repair: it provides a layer of separation between the esophagus and the graft and instrumentation, and it increases the antibiotic delivery because of its vascularized nature. The SCM muscle is a useful tool in these cases because of its pliable nature, its multifocal blood supply, the ease with which it is raised and can be brought in to the esophageal defect, good cosmetic result, and the lack of significant donor site morbidity. Other flaps have also been used, such as a sternohyoid muscle, sternothyroid muscle, pectoralis muscle, and free omentum. A primary repair without reinforcement can take a long time to heal, preventing the patient from start ing oral feedings. In addition, direct primary repair has a significant failure rate. In our series,11 all the SCM- reinforced esophageal repairs were successful, and the time for return to oral feedings was significantly shorter (mean of 59 days) than when a primary repair was attempted (mean of 153 days). CASE 5 HISTORY AND PHYSICAL EXAMINA TION A 16- year- old girl presents to you with a 2- month history of progressive neck pain as well as arm and leg paresthesias. On examination, she has hyperreflexia both in the upper and lower extremities as well as some gait imbalance. An MRI with and without gadolinium is obtained, and this demonstrates a large intramedullary lesion with a central enhancing component and a large associated syrinx (Figures 10.24 and 10.25). ANALYSIS OF CASE AND SURGICAL PLAN The differential diagnosis of an intramedullary tumor that has a cystic component is fairly limited. Potential diagnoses Figure 10.19 Axial T2- weighted magnetic resonance imaging showing soft tissue tumor along with vertebral body destruction at C6 with ventral cord compression. Figure 10.20 Sagittal T2- weighted magnetic resonance imaging showing ventral cord compression by the tumor.

ic component is fairly limited. Potential diagnoses Figure 10.19 Axial T2- weighted magnetic resonance imaging showing soft tissue tumor along with vertebral body destruction at C6 with ventral cord compression. Figure 10.20 Sagittal T2- weighted magnetic resonance imaging showing ventral cord compression by the tumor. 114 • G OODMAN ’S N EUROSURGERY O RAL B OARD R E v IEW include ependymoma, which commonly has a syrinx, and hemangioblastoma, which typically has a small mural nod ule and a large associated syrinx or cyst. Astrocytomas cer tainly can be seen in children, including juvenile pilocytic astrocytomas; however, they are less likely to be cystic or have an associated syrinx. In this particular case, the most likely etiology is an ependymoma. A discussion with the patient’s family about the natural history and the risks and benefits of the sur gery should ensue. The natural history is tumor enlarge ment, and progressive symptoms and hence surgery are appropriate. Figure 10.21 A, B: Cervical spine after a C6 corpectomy. Placement of methyl methacrylate and Steinman pins, as well as an anterior cervical plate from C5 through C7, is shown. Figure 10.22 Axial computed tomographic scan after intravenous contrast demonstrating an abscess in the prevertebral space just posterior to the esophagus. Flap to esophagus XI nerve Figure 10.23 Placement of a sternocleidomastoid flap to repair an esophageal fistula flap. (From Navarro R, Javahery R, Eismont F, et al. The role of sternocleidomastoid muscle flap for esophageal fistula repair in anterior cervical spine surgery. Spine [Phila Pa 1976]. 2005;30:E617– E622. Republished with permission of W olters Kluwer Health; permission conveyed through Copyright Clearance Center, Inc.)

ap. (From Navarro R, Javahery R, Eismont F, et al. The role of sternocleidomastoid muscle flap for esophageal fistula repair in anterior cervical spine surgery. Spine [Phila Pa 1976]. 2005;30:E617– E622. Republished with permission of W olters Kluwer Health; permission conveyed through Copyright Clearance Center, Inc.) SPINE • 115 Figure 10.25 A, B: Axial T1- weighted magnetic resonance imaging after gadolinium demonstrating the heterogeneous enhancement of the spinal cord with enlargement of the cord at the C5- C6 level. Figure 10.24 Sagittal T1- weighted magnetic resonance imaging after gadolinium that demonstrates an intramedullary enhancing tumor behind the C5 and C6 vertebral bodies associated with a large peritumoral cyst (syrinx), particularly above and somewhat below the lesion. A detailed discussion regarding how to prepare for surgery is important, as is the knowledge of the compli cations. The surgery should be done in the prone posi tion. Intraoperative electrophysiologic monitoring is critical in these cases to help determine the safety of a resection, and again, knowing what to do in advance of any changes in either SSEPs or MEPs must be considered (see Case 3). In most cases, these tumors are resected through the posterior approach, and then a decision needs to be made about where to perform a myelotomy (Figure 10.26). If the intramedullary tumor does come right to the surface, then resection should start at the surface. These tumors have the least postoperative morbidity with regard to dorsal column dysfunction. The most common areas for which a myelotomy will be considered are the midline raphae, which is often partially covered by the midline dorsal medullary vein, and, if it was an eccentric tumor, the dorsal root entry zone. It is important to under stand that the cord may be shifted or rotated because of the tumor. After the myelotomy is performed, you can place pial retention sutures. Resection is performed using a combination of suction bipolar, the Cavitron Ultrasonic Surgical Aspirator, and the Sonopet Ultrasonic Aspirator. The goal is to achieve a gross total removal of the tumor in a safe fashion. Occasionally, it is better to leave a small residual tumor attached to the white matter than risking permanent neu rological deficit. After gross total removal of the ependymoma is achieved, no further adjuvant therapy is required. Small amounts of residual tumor can be followed with serial MRI for growth or development of new symptoms. In cases with a high Ki- 67 labeling index, adjuvant radiation can be considered if there is a residual tumor.

cit. After gross total removal of the ependymoma is achieved, no further adjuvant therapy is required. Small amounts of residual tumor can be followed with serial MRI for growth or development of new symptoms. In cases with a high Ki- 67 labeling index, adjuvant radiation can be considered if there is a residual tumor. A B Figure 10.26 A– C: A midline myelotomy after opening of the dura and removal of the purplish tumor consistent with an ependymoma. Numbness*** (yellow) Pins & Needles ooo (purple) Burning xxx (red) NO PAIN RIGHTR IGHTLEFT LEFT FRONTB ACK Aching +++ (blue) Stabbing /// (green) Other*** (brown) Figure 10.27 Postoperative diagram after resection of a thoracic ependymoma in different patients with complaints of numbness in the lower body at the ribcage and below, consistent with a T8 lesion dorsal column dysfunction after the midline myelotomy.

FRONTB ACK Aching +++ (blue) Stabbing /// (green) Other*** (brown) Figure 10.27 Postoperative diagram after resection of a thoracic ependymoma in different patients with complaints of numbness in the lower body at the ribcage and below, consistent with a T8 lesion dorsal column dysfunction after the midline myelotomy. SPINE • 117 COMPLICA TIONS Complications are common with this type of surgery because it involves sectioning into the spinal cord. In fact, almost every case has a certain element of dorsal column dysfunction that may present with proprioceptive loss, numbness, or a gait disturbance (Figure 10.27). It is important to discuss this with the patient before surgery. Motor deficits can be sustained with removal of the tumor, and this is to be avoided at all cost. In this particular case, you may be faced with dealing with postoperative CSF leak. Delayed complications can include a postlaminectomy kyphotic deformity months to years down the road. This often requires anterior- posterior reconstruction. Performing an osteoplastic cervical laminoplasty can help reduce this risk. REf ERENCES 1. V ale FL, Burns J, Jackson AB, Hadley MN. Combined medical and surgical treatment after acute spinal cord injury:  Results of a prospective pilot study to assess the merits of aggressive medi cal resuscitation and blood pressure management. J Neurosurg . 1997;87(2):239– 246. 2. Doran SE, Papadopoulos SM, Ducker TB, Lillehei KO. Magnetic resonance imaging documentation of coexistent traumatic locked facets of the cervical spine and disc herniation. J Neurosurg . 1993;79(3):341– 345. 3. Eismont FJ, Arena MJ, Green BA. Extrusion of an intervertebral disc associated with traumatic subluxation or dislocation of cervical facets: Case report. J Bone Joint Surg Am. 1991;73(10):1555– 1560. 4. Grant GA, Mirza SK, Chapman JR, et al. Risk of early closed reduction in cervical spine subluxation injuries. J Neurosurg. 1999;90(1 suppl):13– 18. 5. Bracken MB, Shepard MJ, Collins WF, et  al. A randomized, con trolled 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. 1990;322(20):1405– 1411. 6. Hurlbert RJ, Hadley MN, W alters BC, et  al. Pharmacological therapy for acute spinal cord injury. Neurosurgery. 2013;72(suppl 2):93– 105. 7. Razack N, Green BA, Levi AD. The management of traumatic cer vical bilateral facet fracture- dislocations with unicortical anterior plates. J Spinal Disord. 2000;13(5):374– 381. 8. Levi AD, Dickman CA, Sonntag VK. Management of post operative infections after spinal instrumentation. J Neurosurg . 1997;86(6):975– 980. 9. Slatkin NE, Posner JB. Management of spinal epidural metastases. Clin Neurosurg. 1983;30:698– 716. 10. Greenberg HS, Kim JH, Posner JB. Epidural spinal cord compres sion from metastatic tumor: Results with a new treatment protocol. Ann Neurol. 1980;8(4):361– 366. 11. Navarro R, Javahery R, Eismont F, et al. The role of the sternocleidomastoid muscle flap for esophageal fistula repair in anterior cervical spine surgery. Spine. 2005;30(20):E617– 622.