Neck-Tongue Syndrome.

Neck-tongue syndrome (NTS) is a headache disorder often initiated by rapid axial rotation of the neck resulting in unilateral neck and/or occipital pain and transient ipsilateral tongue sensory disturbance. In this review, we examine reported cases of NTS since its initial description in 1980 to highlight the significance of this condition in the differential diagnosis of headache in patients presenting with neck pain and altered tongue sensation. The anatomical basis of NTS centers on the C1-C2 facet joint, C2 ventral ramus, and inferior oblique muscle in the atlanto-axial space. NTS may be categorized as complicated (secondary to another disease process) or uncomplicated (hereditary, related to trauma, or idiopathic). Diagnosis is based on clinical suspicion after a thorough history and physical without a pathognomonic radiologic finding. It is typically treated conservatively with medications, local injections, immobilization with cervical collars, or physical therapy; rarely is surgical intervention pursued.

Sagittal Reconstruction of the Atlantoaxial Lateral Mass Complex with an Intra-Articular Cage Fusion Technique for Degenerative Atlantoaxial Instability.

OBJECTIVE: To evaluate outcomes of sagittal reconstruction of the atlantoaxial lateral mass complex using a modified intra-articular cage fusion technique for treating degenerative atlantoaxial instability. METHODS: Data from 15 patients with degenerative atlantoaxial instability were retrospectively reviewed. All patients underwent posterior reduction and intra-articular fusion with a cage filled with local autologous bone. Atlantodental interval values on plain radiography in flexion before and after surgery were recorded. Bone fusion was evaluated on computed tomography reconstruction, and bone fusion time was recorded. Lateral atlantoaxial joint space height before and after surgery was measured on coronal computed tomography reconstruction. Japanese Orthopaedic Association score and visual analog scale score for neck pain before surgery and at final follow-up were compared. RESULTS: Mean follow-up time was 40.7 ± 13.4 months. All patients achieved good reduction and solid bone fusion at follow-up. Mean fusion time was 4.4 ± 1.1 months. Atlantodental interval decreased from 8.6 ± 1.5 mm preoperatively to 1.9 ± 0.5 mm at final follow-up (P < 0.05). Lateral atlantoaxial joint space height significantly improved from 1.7 ± 0.5 mm preoperatively to 4.7 ± 0.3 mm at final follow-up (P < 0.05). Japanese Orthopaedic Association score significantly improved from 14.9 ± 1.5 preoperatively to 16.7 ± 0.6 at final follow-up (P < 0.05). Visual analog scale score for neck pain markedly decreased from 4.5 ± 1.8 preoperatively to 0.5 ± 0.6 at final follow-up (P < 0.05). CONCLUSIONS: Posterior reduction and intra-articular cage fusion with a C2 nerve root preservation technique is effective in treatment of degenerative atlantoaxial instability. Satisfactory reconstruction of the sagittal alignment and the height of atlantoaxial complex can be achieved.

Technique of C2 Nerve Root Preservation in the Presence of Anomalous Vertebral Artery in Atlantoaxial Operations.

While accessing the C1-C2 joint during posterior atlantoaxial fixation, the C2 nerve root along with its perineural venous plexus remains an obstacle for a panoramic visualization of the entry point of the C1 lateral mass and joint preparation. Therefore, many surgeons frequently advocate its intentional sectioning during this approach, with no related major complications.1,2 However, this sectioning has at times been associated with symptoms such as hypoesthesia, numbness, dysesthesia, and neuropathic ulcers.3 Thus C2 nerve root preservation during posterior approach for atlantoaxial dislocation (AAD) could potentially avoid such consequences.4 Its preservation has been described for AAD cases with relatively normal C1-C2 joint anatomy with no osseovascular abnormalities.2 In contrast, attempt at C2 nerve root preservation in patients with congenital AAD harboring bony and vascular anomalies poses a greater challenge owing to a restricted operative space and the potential for perineural venous bleeding during dissection. This is more so for young neurosurgeons in the initial part of their learning curve. Video 1 details the technique of C2 nerve root dissection and preservation in a case of congenital AAD with an anomalous vertebral artery (VA). Computed tomography (CT) of this 30-year-old male patient with spastic quadriparesis showed AAD/basilar invagination with an assimilated C1-arch and right anomalous VA on CT angiography. He underwent C1-C2 joint manipulation and short-segment fixation. At 1-year follow-up, the patient's limb weakness had improved and CT showed good bony fusion. The salient operative steps involve gentle teasing and dissection of perineural soft tissues above and below the nerve root; the key to minimize venous bleeding is to dissect, coagulate, and divide them sequentially. A thorough release of the perineural soft tissues allows adequate nerve root mobilization, which in turn provides clear visualization of the C1-C2 joint space, preventing an undue nerve stretching during the C1-lateral mass screw insertion. The anomalous VA usually lies anterior to the C2 nerve root, and careful imaging evaluation allows its anticipation.3 We do not prefer the easy alternative of C2 nerve root sacrifice because of its inherent complications we noticed in our earlier clinical practice.3.

C2 Nerve Root Preservation During Posterior Fixation for Instability Secondary to Congenital Craniovertebral Junction Anomalies: Feasibility Factors and Related Outcomes.

OBJECTIVE: Patients with instability because of congenital craniovertebral anomalies often have complex C1-C2 osseovascular anomalies. C2 nerve root sacrifice has been described to address such difficult anatomy during posterior C1-C2 fixation and has its own downsides. Its preservation as a recent alternative poses greater surgical challenge, and the considerations differ from other causes of craniovertebral junctional instability; the pertaining outcomes have been scarcely studied. The objective of this study was to prospectively determine the feasibility and outcomes related to C2 nerve root preservation in patients with congenital atlantoaxial dislocation (CAAD) after posterior C1-C2 fixation. METHODS: In this observational study, 63 patients (126 nerve roots) with CAAD after posterior fixation were prospectively assessed. Underlying osseovascular anomalies affecting the feasibility of C2 nerve root preservation, and C2 nerve-related dysfunction at 12 months follow-up were analyzed. RESULTS: The overall C2 nerve root preservation rate was 89.7%. Even in the presence of extreme joint obliquity/spondyloptosis and anomalous vertebral artery, it was feasible in about three fourths. After preservation, 28.3% patients developed new-onset C2 nerve root dysfunction: neuralgia in 2, dysesthesia in 6, and hypoesthesia/paresthesia in 9. The symptoms were not disabling in most patients. CONCLUSIONS: In most patients with CAAD, C2 nerve root preservation is feasible despite an aberrant bony and vascular anatomy. A few patients after nerve root preservation develop related symptoms that are conservatively manageable, with no significant adverse consequences. Given the controversy in the literature on C2 nerve sacrifice-related outcomes, we favor an attempt at C2 nerve root preservation.

Sectioning of C2 nerve roots during C1-2 fusion: report of aberrant vertebral artery during C2 nerve root sectioning. Illustrative case.

BACKGROUND: Sectioning the C2 nerve root is increasingly utilized during posterior C1-2 fusion, as the nerve overlies the entry point for C1 lateral mass screws and the C1-2 joint. Nerve sectioning improves visualization for screw placement and enables joint decortication for arthrodesis. While rare, vascular injury is a devastating complication of atlantoaxial fusion. Anomalous vascular anatomy at C1-2 greatly increases risk of iatrogenic injury. OBSERVATIONS: A 78-year-old female with rheumatoid arthritis and prior C2-7 fusion presented with myelopathy from a compressive pannus at C1-2. She underwent C1 laminectomy and C1-2 posterior instrumented fusion. Intraoperatively, arterial bleeding occurred as the right C2 nerve root was sectioned. Vertebral artery injury was suspected, and tamponade was performed while vascular control was established. The artery passed aberrantly beneath the nerve root in the C1-2 foramen. It was repaired microsurgically, and patency was confirmed using indocyanine green. The remainder of the fusion was aborted. The patient wore a cervical collar and was treated with aspirin for 6 weeks before undergoing instrumented fusion. The patient suffered no deficits. LESSONS: Although rare, anomalous vertebral artery anatomy increases risk of injury at time of C2 nerve root sectioning. Preoperative assessment of the vasculature is vital.

Occipital neuralgia: A neurosurgical perspective.

Occipital neuralgia typically arises in the setting of nerve compression by fibrosis, surrounding anatomic structures, or osseous pathology, such as bone spurs or hypertrophic atlanto-epistropic ligament. It generally presents as paroxysmal bouts of sharp pain in the sensory distribution of the first three occipital nerves. Due to the long course of the greater occipital nerve (GON), and its peculiar anatomy, and location in a mobile region of the neck, it is unsurprising that the GON is at high risk for compression. Little is known how to diagnose or treat this neuropathic pain syndrome. The objective of this paper is to isolate the etiology involved, and treat this condition promptly. After all nonoperative efforts are exhausted, surgical transection of the nerve is the treatment of choice in these cases. An isolated C2 neurectomy or ganglionectomy is performed for an optimal pain relief. C1-2 instrumented fusion can be considered if, extensive facet arthropathy with instability is identified. Authors review the spectrum of treatment options for this debilitating condition, and discuss the case example of a patient who required conversion to a C1-C2 instrumented fusion following C2 ganglionectomy due to an underlying extensive degenerative disease and intraoperative findings suggestive of atlantoaxial instability.

Bow Hunter's Syndrome: Complete Microsurgical Decompression of Vertebral Artery by Far Lateral Retrocondylar Approach: 3-Dimensional Operative Video.

This 50-yr-old man had a 15-yr history of presyncopal episodes that were precipitated by turning his head to the right, and had worsened recently. Cerebral angiogram demonstrated complete cessation of anterograde flow in left vertebral artery (VA) at the level of the C1 sulcus arteriosus while turning head to right, indicating dynamic compression at the C1 level. Patient underwent left extreme lateral retrocondylar approach, partial C1 laminectomy and opening of the C1 foramen with complete microsurgical decompression of the VA. After skin incision, meticulous muscle dissection was performed and superior and inferior oblique muscles were disconnected from the tubercle of C1. The VA was exposed, and three areas of constriction were visible, first at the atlanto-occipital membrane laterally; second, located more medially as the artery curved around the occipital condyle to enter the posterior fossa; and third, located anterior to C2 nerve root. The artery was dissected from all the surrounding tissues, preserving the C2 nerve root, and the Cl foramen was opened completely. The Cl lamina was also partially resected and grooved to allow free placement of the VA. The VA was also decompressed near the C2 foramen. Postoperative computed tomography angiogram of the head and neck showed complete decompression of VA. The patient had no episodes of presyncope or dizziness while turning head to right and his mRs was 0 at 8 mo follow up. This 3D video shows the technical nuances of decompression of V3 segment of VA in bow hunters's syndrome. Informed consent was obtained from the patient prior to the surgery that included videotaping of the procedure and its distribution for educational purposes. All relevant patient identifiers have also been removed from the video and accompanying radiology slides.

Analysis of Risk Factors for Posterior C1 Screw-Related Complication: A Retrospective Study of 358 Posterior C1 Screws.

BACKGROUND: Although C1 screw fixation is becoming popular, only a few studies have discussed about the risk factors and the patterns of C1 screw complications. OBJECTIVE: To investigate the incidence of C1 screw complications and analyze the risk factors of the C1 screw complications. METHODS: A total of 358 C1 screws in 180 consecutive patients were analyzed for C1 screw complications. Screw malposition, occipital neuralgia, major complications, and total C1 screw complications were analyzed. RESULTS: The distribution of C1 screw entry point is as follows: inferior lateral mass, 317 screws (88.5 %); posterior arch (PA), 38 screws (10.7 %); and superior lateral mass, 3 screws (0.8 %). We sacrificed the C2 root for 127 screws (35.5 %). C1 instrumentation induced 3.1 % screw malposition, 6.4 % occipital neuralgia, 0.6 % vascular injury, and 3.4 % major complications. In multivariate analysis, deformity (odds ratio [OR]: 2.10, P = .003), traumatic pathology (OR: 4.97, P = .001), and PA entry point (OR: 3.38, P = .001) are independent factors of C1 screw malposition. C2 root resection can decrease the incidence of C1 screw malposition (OR: 0.38, P = .012), but it is a risk factor of occipital neuralgia (OR: 2.62, P = .034). Advanced surgical experience (OR: 0.09, P = .020) correlated with less major complication. CONCLUSION: The incidence of C1 screw complications might not be uncommon, and deformity or traumatic pathology and PA entry point could be the risk factors to total C1 screw complications. The PA screw induces more malposition, but less occipital neuralgia. C2 root resection can reduce screw malposition, but increases occipital neuralgia.

Pros and Cons of C2 Nerve Sectioning/Preservation in Posterior Fusion for Congenital Atlantoaxial Dislocation.

OBJECTIVE: Deliberate C2 nerve root sectioning and its preservation have been described during posterior fusion for atlantoaxial dislocation (AAD). However, the associated outcomes have been less studied, especially in congenital AAD. Our objective was to study the clinical outcomes after C2 nerve root sectioning and the feasibility of C2 preservation in these patients. METHODS: The data from 190 patients were retrospectively studied. The decision to cut or preserve the C2 nerve root was determined by the preoperative radiologic findings and intraoperative suitability of its preservation. During follow-up, the patients were questioned about C2 nerve-related dysfunction. The pros and cons of sectioning or preservation of the C2 nerve root and the related feasibility factors are also described. RESULTS: Complex C1-C2 anatomy that required extensive dissection and drilling was seen in 139 patients. After C2 nerve root sectioning in 178 patients, none reported bothersome hypoesthesia, paresthesia, or dysesthesia that required medication. However, 9 patients (5.1%) developed nonhealing occipital ulcers and most required flap coverage or a skin graft. C2 nerve root preservation is feasible with an adequate inferior C1 lateral mass and normal-size ganglion. In patients with C1-occipital condyle hypoplasia, extremely oblique joints, spondyloptosis, incurved occiput, pseudofacets, and anomalous vertebral artery, preservation of the C2 nerve root is difficult. CONCLUSIONS: The advantages of sectioning the C2 nerve root are many. However, a subset of patients is prone to morbid occipital neuropathic ulcers. After C2 nerve sectioning, one should be cautious of such complications. C2 nerve root preservation should be strongly considered for patients with favorable anatomy.

Detethering of the C2 Nerve Root and Avoidance of Transection and Injury During C1 Screw Placement: A Cadaveric Feasibility Study.

INTRODUCTION: Regional neurovascular structures must be avoided during invasive spine hardware placement. During C1 lateral mass screw placement, the C2 nerve root is put in harm's way. Therefore the current anatomic study was performed to identify techniques that might avoid such neural injury. MATERIALS AND METHODS: On 10 cadaveric sides, dissection was carried down to the craniocervical junction. The C2 nerve root was identified, and its distal branches were traced out into the surrounding posterior cervical musculature. Once dissected, the nerve was displaced inferiorly away from the lateral mass of C1. RESULTS: On all sides, the C2 nerve root could be easily detethered from surrounding tissues. On all sides, this allowed lateral mass screw placement without compression of the nerve. CONCLUSION: On the basis of our cadaveric study, the C2 nerve root can be detethered enough at the level of the posterior lateral mass of C1 to avoid its injury during screw placement into this area.

Modified Posterior C1 Lateral Mass Screw Insertion for Type II Odontoid Process Fractures Using Intraoperative Computed Tomography-Based Spinal Navigation to Minimize Postoperative Occipital Neuralgia.

BACKGROUND: Various surgical techniques have been described for treating odontoid instability and achieving effective stabilization. The earliest technique to be described proposed a C1 lateral mass entry point including neurectomy of the C2 nerve roots to ensure hemostasis. Because C2 neurectomy remains controversial, preservation of the C2 nerve root as described in Goel-Harms technique can lead to intractable occipital neuralgia and significant blood loss. The aim of this study was to modify the Goel-Harms technique with a high C1 lateral mass screw entry point to enhance overall intraoperative safety. METHODS: Sixty-three patients (average age, 70 ± 16 years) with acute traumatic odontoid fracture type II underwent posterior stabilization with a modified posterior C1 lateral mass entry point using intraoperative computed tomography (CT)-guided spinal navigation. Complications were recorded, especially bleeding from the epidural venous plexus and development of occipital neuralgia. All patients were followed up for a minimum of 6 months. RESULTS: None of the patients developed occipital neuralgia or numbness. Blood transfusion was necessary in 1 patient because of a coagulation disorder. There was no bleeding from the epidural venous plexus. All screws were correctly placed. Two patients needed surgical revision (wound infection, dural tear). Two developed cardiopulmonary complications. Solid bony fusion was achieved in all patients. CONCLUSIONS: This study confirms that changing the C1 entry point to the junction of the posterior arch and superior-posterior part of the C1 lateral mass by using intraoperative CT navigation yields a safe and effective procedure with few complications. The overall complication rate was 6%.

Postoperative occipital neuralgia with and without C2 nerve root transection during atlantoaxial screw fixation: a post-hoc comparative outcome study of prospectively collected data.

BACKGROUND CONTEXT: Although routine transection of the C2 nerve root during atlantoaxial segmental screw fixation has been recommended by some surgeons, it remains controversial and to our knowledge no comparative studies have been performed to determine whether transection or preservation of the C2 nerve root affects patient-derived sensory outcomes. PURPOSE: The purpose of this study is to specifically analyze patient-derived sensory outcomes over time in patients with intentional C2 nerve root transection during atlantoaxial segmental screw fixation compared with those without transection. STUDY DESIGN: This is a post-hoc comparative analysis of prospectively collected patient-derived outcome data. PATIENT SAMPLE: The sample consists of 24 consecutive patients who underwent intentional bilateral transection of the C2 nerve root during posterior atlantoaxial segmental screw fixation (transection group) and subsequent 41 consecutive patients without transection (preservation group). OUTCOME MEASURES: A visual analog scale (VAS) score was used for occipital neuralgia as the primary outcome measure and VAS score for neck pain, neck disability index score and Japanese Orthopedic Association score for cervical myelopathy and recovery rate, with bone union rate as the secondary outcome measure. METHODS: Patient-derived outcomes including change in VAS score for occipital neuralgia over time were statistically compared between the two groups. This study was not supported by any financial sources and there is no topic-specific conflict of interest related to the authors of this study. RESULTS: Seven (29%) of the 24 patients in the transection group experienced increased neuralgic pain at 1 month after surgery either because of newly developed occipital neuralgia or aggravation of preexisting occipital neuralgia. Four of the seven patients required almost daily medication even at the final follow-up (44 and 80 months). On the other hand, only four (10%) of 41 patients in the preservation group had increased neuralgic pain at 1 month after surgery, and at ≥ 1 year, no patients had increased neuralgic pain. The difference in the prevalence of increased neuralgic pain between the two groups was statistically significant at all time points (3, 6, 12, and 24 months postoperatively) except at 1 month postoperatively. The intensity of neuralgic pain, which preoperatively had not been significantly different between the two groups, was significantly higher in the transection group at the final follow-up. CONCLUSIONS: C2 nerve root transection is not a benign procedure and, in our experience, more than a quarter of the patients experience increased neuralgic pain following C2 nerve root transection. Because the prevalence and intensity of postoperative neuralgia was significantly higher with C2 nerve root transection than with its preservation, we recommend against routine C2 nerve root transection when performing atlantoaxial segmental screw fixation.