Magnetic resonance imaging study on the results of surgery for cervical compression myelopathy

The morphologic changes and signal intensity of the spinal cord on preoperative magnetic resonance images were correlated with postoperative outcomes in 74 patients undergoing decompressive cervical surgery for compressive myelopathy. The transverse area of the spinal cord on T1-weighted images at the level of maximum compression was closely correlated with the severity of myelopathy, duration of disease, and recovery rate as determined by the Japanese Orthopaedic Association score. In patients with ossification of the posterior longitudinal ligament or cervical spondylotic myelopathy, the increased intramedullary T2-weighted magnetic resonance imaging signal at the site of maximal cord compression and duration of disease significantly influenced the rate of recovery. A multiple regression equation was then developed with these three variables to predict surgical outcomes.     

Anterior cervical corpectomy for cervical spondylotic myelopathy

OBJECTIVE: To evaluate the efficacy of anterior surgery for the treatment of cervical spondylotic myelopathy, we have reviewed our experience with anterior cervical corpectomy (ACC) at the University of Florida, specifically analyzing neurological outcomes and complications. These results have been compared with historical control subjects receiving laminectomy or "no treatment." METHODS: Between 1982 and 1992, 93 ACC operations were performed for the primary diagnosis of cervical spondylotic myelopathy. This consecutive series of patients was reviewed retrospectively. Age, gender, pre- and postoperative myelopathy severity, number of levels decompressed, and neurological complications were assessed. Myelopathy severity was graded using the Nurick myelopathy grading system. The average follow-up period was 39 months (range, 2-137 mo). RESULTS: Symptomatic improvement was achieved for 92% of patients (F = 28.9, df = 2172, P < 0.001). Nurick scores reflected improvement for 86% of patients, with the conditions of 13% remaining unchanged and only one patient showing worsening. Preoperative myelopathy severity was weakly correlated with age (P < 0.05) but was not correlated with gender or number of levels decompressed. Similarly, postoperative myelopathy severity was not significantly correlated with age, gender, preoperative myelopathy severity, or number of levels decompressed. ACC-treated patients showed an average improvement of 1.24 points on the Nurick scale, compared with an improvement of 0.07 points for patients treated with laminectomy (P < 0.001) and a deterioration of 0.23 points for patients undergoing conservative treatment (P < 0.001). Complications were slightly more likely to occur in older patients (P < 0.05). The number of levels decompressed was not significantly correlated with complications. Only one permanent neurological complication was seen in this series of patients. CONCLUSION: We conclude that ACC is a safe and effective treatment for cervical spondylotic myelopathy. In an average of 39 months, ACC showed improved results in terms of myelopathy scores, compared with historical control subjects receiving either no treatment or laminectomy. Age, gender, preoperative myelopathy severity, and extent of disease were not negative predictors of clinical outcomes.     

Spinal cord decompression via microsurgical anterior foraminotomy for spondylotic cervical myelopathy

A microsurgical anterior foraminotomy, as a direct decompressive and motion-segment preserving technique, has been developed by the author and used successfully in many patients with spondylotic cervical radiculopathy for the past several years. From the author's increasing experience with anterior foraminotomy for cervical radiculopathy, it was noted that the spinal cord canal could be effectively decompressed utilizing the holes of anterior foraminotomy. This new technique accomplishes widening of the spinal cord canal anteriorly to the spinal cord in the transverse and longitudinal axis by direct removal of the compressive lesions through the holes of unilateral anterior foraminotomies. This technique does not require bone fusion or postoperative immobilization. 14 patients with spondylotic cervical myelopathy have been treated by this technique. 9 were males and 5 were females, and all presented with cervical myelopathy with or without radiculopathy. Age ranged from 32 to 68 years (median 55 years). 6 patients had spinal cord compression at one level, six patients experienced it at two levels, and two patients had it at three levels. Postoperatively, all patients showed improvement in their myelopathic symptomatology as well as gaining relief of their radicular symptoms. Corresponding MR scans confirmed satisfactory anatomical decompression in all patients. Postoperative dynamic roentgenograms confirmed spinal stability in all patients as well. Patients stayed in the hospital overnight postoperatively, and cervical braces were not used. This new surgical technique has shown excellent clinical outcomes with fast recovery and adequate anatomical decompression in 14 patients with spondylotic cervical myelopathy.     

Neuroimaging and pathology of the spinal cord in compressive cervical myelopathy

Magnetic resonance imaging (MRI) has enabled us to see the spinal intramedullary pathology as differences in signal intensity. Intramedullary high intensity lesions were observed on T2-weighted MRI in patients with cervical spondylotic myelopathy (20.0%) and ossification of the posterior longitudinal ligament (OPLL) of the cervical spine (25.7%). The frequency of this findings was proportional to the clinical severity of myelopathy and degree of spinal cord compression. The pathophysiological basis of such signal abnormality was presumed to vary from acute edema to chronic myelomalacia. The intramedullary lesion on MRI is considered to be the main site of lesion responsible for the neurological symptom because of a good correlation between the neurological level and high intensity level. We found from nine autopsy cases of OPLL that there are distinct differences in severity and extent of pathological changes between the spinal cord with a boomerang-shaped cross-section and that with a triangular-shaped cross-section. In the boomerang-shaped cases, major pathological changes were restricted to the gray matter and the white matter was relatively well preserved. Secondary wallerian degeneration was restricted to the fasciclus cuneatus the fibers of which were derived from the affected segments. In the cases of a triangular shape, pathological changes were more severe, both white and gray matter were involved. There were severe pathological changes over more than one segment, and both descending degeneration of the lateral pyramidal tracts and ascending degeneration of the posterior column, including the fasciclus gracilis, were observed. In conclusion, it is clinically very important to understand the pathological basis of the compressed spinal cord on neuroimages.     

Magnetic resonance imaging in cervical spinal cord compression

In patients with cervical spondylotic myelopathy MRI sometimes shows increased signal intensity zones on the T2-weighted images. It has been suggested that these findings carry prognostic significance. We studied 56 subjects with cervical spinal cord compression. Twelve patients showed an increased signal intensity (21.4%) and a prevalence of narrowing of the AP-diameter (62% vs 24%). Furthermore, in this group, there was evidence of a longer mean duration of the symptoms and, in most of the patients, of more serious clinical conditions. The importance of these predisposing factors remains, however, to be clarified since they are also present in some patients without the increased signal intensity.     

Pulmonary complications in AIDS: CT appearances

We investigated 33 cervical spinal cord injury patients (25 males and eight females) without bony injury. Patients whose neurologic recovery had reached a plateau and who had evidence on imaging of persistent spinal cord compression were considered candidates for surgical decompression. When imaging did not show spinal cord compression or patients were maintaining a good neurologic recovery from the early days after injury, we pursued conservative treatment. Age at injury varied from 20 to 76 years (mean, 55.6). Average follow-up was 31 months. Twelve patients were treated conservatively (Group 1). Groups 2 and 3 had surgery. Group 2 (14 cases) had multi-level compression of spinal cord due to pre-existing cervical spine conditions such as ossification of posterior longitudinal ligament, cervical canal stenosis, and cervical spondylosis. Group 3 (7 cases) patients existed single-level compression of spinal cord by cervical disc herniations or spondylosis. We evaluated clinical results according to the Frankel classification, the American Spinal Injury Association (ASIA) scales and Japanese Orthopaedic Association (JOA) scores. Overall improvement of JOA and ASIA scores after treatment was 56.3 +/- 35.5% and 67.1 +/- 38.0%, respectively. Patients in Group 1 showed very good recovery after conservative treatment, with improvement of JOA and ASIA scores being 70.4 +/- 40.2% and 77.4 +/- 34.2%, respectively. The average interval between injury and operation was 4.3 +/- 4.4 months. The improvement of the surgically treated patients (Groups 2 and 3) in JOA and ASIA score was 48.2 +/- 30.7% and 61.2 +/- 39.6% respectively. We obtained good neurological recovery after operation, with significantly more improvement in Group 3 than in Group 2. No significant neurologic recovery had occurred preoperatively in these groups. In such patients operative intervention is essential for neurologic recovery.     

A review of the pathophysiology of cervical spondylotic myelopathy with insights for potential novel mechanisms drawn from traumatic spinal cord injury

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction. Despite advances in diagnosis and surgical treatment, many patients still have severe permanent neurologic deficits caused by this condition. An improved understanding of the pathophysiology of cervical spondylotic myelopathy, particularly at a cellular and molecular level, may allow improved treatments in the future. A detailed review of articles in the literature pertaining to cervical spondylotic myelopathy was supplemented by an analysis of relevant mechanisms of spinal cord injury. The pathologic course of cervical spondylotic myelopathy is characterized by early involvement of the corticospinal tracts and later destruction of anterior horn cells, demyelination of lateral and dorsolateral tracts, and relative preservation of anterior columns. Static and mechanical factors and ischemia are critical to the development of cervical spondylotic myelopathy. Free radical-and cation-mediated cell injury, glutamatergic toxicity, and apoptosis may be of relevance to the pathophysiology of cervical spondylotic myelopathy. To date, research in cervical spondylotic myelopathy has focused exclusively on the role of mechanical factors and ischemia. Fundamental research at a cellular and molecular level, particularly in the areas of glutamatergic toxicity and apoptosis may result in clinically relevant treatments for this condition.     

Anterior cervical decompression and arthrodesis for the treatment of cervical spondylotic myelopathy. Two to seventeen-year follow-up

We reviewed the cases of 108 patients with cervical spondylotic myelopathy who had been managed with anterior decompression and arthrodesis at our institution. Operative treatment consisted of anterior discectomy, partial corpectomy, or subtotal corpectomy at one level or more, followed by placement of autogenous bone graft from the iliac crest or the fibula. At the latest follow-up examination, thirty-eight of the eighty-two patients who had had a preoperative gait abnormality had a normal gait, thirty-three had an improvement in gait, six had no change, four had improvement and later deterioration, and one had a worse gait abnormality. Of the eighty-seven patients who had had a preoperative motor deficit, fifty-four had complete recovery; twenty-six, partial recovery; six, no change; and one had a worse deficit. The average grade according to the system of Nurick improved from 2.4 preoperatively to 1.2 (range, 0.0 to 5.0) postoperatively. A pseudarthrosis developed in sixteen patients, thirteen of whom had had a multilevel discectomy. Only one of thirty-eight arthrodeses that had been performed with use of a fibular strut graft was followed by a non-union. An unsatisfactory outcome with respect to pain was significantly associated with pseudarthrosis (p < 0.001). The development of complications other than non-union was associated with a history of one previous operative procedure or more (p = 0.005). Recurrent myelopathy was rare, but when it occurred it was associated with a pseudarthrosis or stenosis at a new level. The strongest predictive factor for recovery from myelopathy was the severity of the myelopathy before the operative intervention--that is, better preoperative neurological function was associated with a better neurological outcome. Anterior decompression and arthrodesis with autogenous bone-grafting can be performed safely, and is associated with a high rate of neurological recovery, functional improvement, and pain relief, in patients who have cervical spondylotic myelopathy.     

Radiation myelopathy: a clinicopathological study with special reference to correlation between MRI findings and neuropathology

We describe magnetic resonance imaging (MRI) and neuropathological findings in a patient with chronic progressive radiation myelopathy (CPRM). An 81-year-old man with esophageal cancer underwent radiotherapy. Four years later he developed a progressive neurological deficit below the irradiated level of the spinal cord. Neurological examination revealed spastic paraplegia. MRI findings showed an area of high signal intensity on T2-weighted images of the thoracic spinal cord. On the basis of clinical and MRI findings, we diagnosed his condition as CPRM. MRI performed thirteen months after onset of neurological signs revealed mild atrophy of the spinal cord detected on T1-weighted images and an area of high signal intensity within the spinal cord detected on T2-weighted images. Neuropathological examination revealed findings consistent with radiation myelopathy. We speculate that the area of high signal intensity within the spinal cord detected on T2-weighted images might be a result of proliferation of small vessels, which was discovered upon autopsy.     

Clinical experience with early enteral feeding in very-low-birth-weight infants

We investigated dorsal shift and anteroposterior spinal cord diameter after expansive open-door laminoplasty, comparing pre- and postoperative computed tomographic myelographic images to clarify the relationships between surgical outcome and these changes. Dorsal shift occurred at the midcervical spine in cervical spondylotic myelopathy (CSM) but was less extensive in ossification of the posterior longitudinal ligament (OPLL). Spinal cord anteroposterior diameter expanded for OPLL but did not for CSM. Correlation of outcome and dorsal shift was not significant for OPLL or CSM. Correlation of outcome and expansion was significant for OPLL, but not for CSM.     

Clinical and technical assessment of the cervical spine

In analysis of the cervical and cervicobrachial syndrome with or without signs of compression of the nerve root or spinal cord, functional assessment of the cervical spine is of great importance. Comparisons between actively performed and passively induced motion can be verified by using standardized computer-assisted assessment allowing precise documentation of the range of motion and coupled motion. The age-related normal values should be considered. The neurological assessment includes not only the cranial nerves and upper extremities but also lower extremities to avoid overlooking the signs of cervical myelopathy. In patients with compression of nerve roots or the spinal cord neurophysiology might be helpful in identifying or verifying compression. In patients with suspected myelopathy sensory evoked potentials will allow assessment of the function of the ascending spinal pathways and motor evoked potentials, assessment of the function of the descending cortical spinal pathways.     

Tetraparesis following dental extraction: case report and discussion of preventive measures for cervical spinal hyperextension injury

This concerns a patient with compression myelopathy following passive hyperextension of the cervical spine during a dental procedure. Although he had been asymptomatic prior to the procedure, subsequent cervical spinal imaging revealed advanced spondylosis and spinal stenosis. Spinal stenosis is often asymptomatic for a long time. However, when radiculomyelopathy occurs after minor trauma to the head or neck, the patient is often found to have spinal stenosis. Specifically, hyperextension of a cervical spine with spondylotic changes can lead to compression myelopathy. Acquired spinal stenosis correlates positively with aging. As the size of the elderly population continues to increase the prevalence of cervical spondylotic radiculo-myelopathy will likely increase as well. Since appropriate precautions against potential neurologic damage can be undertaken, we suggest radiographic screening for pre-existing spinal stenosis prior to a procedure requiring hyperextension of the neck. Preventive measures for individuals with asymptomatic spondylotic changes and education of all health-care professionals to avoid abrupt or prolonged hyperextension of the cervical spine is emphasized.     

Value of increased MRI signal intensity in cervical arthrosis in myelopathies

The case of 52 patients with cervical myelopathy were reviewed to determine whether a high signal intensity lesion present on T2 weighted spin echo imaging appears to be an important indicator for predicting prognosis. Preoperatively, there were areas of increased signal intensity in 23 patients. The lesion was clearly demonstrated on T1 weighted images in only one case. Postoperatively, MRI was performed in 9 cases, one showed decreased signal intensity compared to the preoperative levels, and 8 had no change. The pre and postoperative clinical conditions of the patients whose preoperative MR images showed areas of increase signal intensity were not worse than those patients who did not have these areas of increased signal intensity. The postoperative recovery of the eight patients who exhibited no change of the signal intensity was very satisfactory. The pathophysiology of such an abnormality is presumed to be related to edema, myelomalacia or gliosis. However, the presence of these areas of high signal intensity does not appear to be an indicator of a bad clinical prognosis.     

Magnetic resonance imaging of experimental subacute spinal cord compression

STUDY DESIGN: Subacute compression of the spinal cord was applied to rats. The animals were chronologically observed using magnetic resonance imaging for more than 8 weeks after surgery and were killed for histopathologic examination. OBJECTIVES: To investigate the correlation of changes in signal intensity on magnetic resonance images with those observed in histopathologic study and with the degree of spinal cord compression and paralysis. SUMMARY OF BACKGROUND DATA: No consensus has been reached concerning the correlation of magnetic resonance images to clinical symptoms of compressive myelopathy. Few reports are available in which magnetic resonance imaging findings are compared with histopathologic features in chronic or subacute experiments. METHODS: In rats under general anesthesia, the T11 lamina was thinned and a slow increase in volume was applied. Hind limb paralysis appeared 1 week after the procedure and spontaneously subsided thereafter. The degree of spinal compression and signal intensity was observed chronologically using magnetic resonance imaging. The signal intensity on the final MR images was rated on a four-point scale and compared with histopathologic findings. RESULTS: As spinal compression increased, the incidence of high signal intensity on long spin-echo images became higher. Low signal intensities on short spin-echo images were visible in animals in which compression and paralysis were the most severe. In these animals, cavitation and a dilated central canal were visible. High signal intensities on long spin-echo images reflected various pathologic changes. CONCLUSIONS: Changes in signal intensity on MR images are visible after the induction of myelopathy by high-pressure compression. These signal intensities may be useful in predicting the outcome of compressive myelopathy.     

Myelopathy after intrathecal chemotherapy. A case report with unique magnetic resonance imaging changes

BACKGROUND: Paraplegia caused by intrathecal chemotherapy has no known pathognomonic features and is a diagnosis of exclusion. METHODS: The authors reported the clinical and neuroimaging findings in one patient with this syndrome. RESULTS: The patient had severe paraplegia with urinary retention and impaired pain and touch sensation below T-10 with sparing of proprioception and vibration sense. Magnetic resonance imaging (MRI) scan showed diminished intensity throughout the central cervical spinal cord. Post-gadopentetate dimeglumine enhancement was scattered throughout the cervical spinal cord and in two areas of the dorsal spinal cord. Axial views of the cervical spinal cord showed that this enhancement was limited to the lateral columns. CONCLUSIONS: The MRI in myelopathy due to intrathecal chemotherapy may show a unique pattern of postgadopentetate dimeglumine enhancement limited to the lateral columns of the spinal cord. However, two recently encountered patients with the same syndrome did not show similar changes.     

Clinical study of cervical radiculopathy after laminoplasty for cervical myelopathy

We have retrospectively determined the preoperative risk factors in cervical radiculopathy after laminoplasty for cervical myelopathy using preoperative neuroradiographical findings and electrophysiological studies. Of the 67 patients who underwent laminoplasty, 10 patients (14.9%) postoperatively showed cervical radioculopathy. The preoperative radiographical findings had included cervical lordosis, intraspinal cord centering, and anterior protrusion of the apex of the superior articular process. Needle electromyography, somatosensory evoked potentials (SEPs), sensory nerve action potentials (SNAP) were preoperatively examined in 42 cases. There was no relationship between the postoperative radiculopathy and the preoperative radiographical findings. Six (100%) of 6 cases preoperatively diagnosed as C5 radiculopathy (postganglionic type) with Erb-P 14 interpeak latency of dermatomal SEPs and SNAP, developed postoperative C5 radiculopathy. One (25%) of 4 cases preoperatively diagnosed as C6 radiculopathy developed postoperative C6 radiculopathy. No case preoperatively diagnosed as C7 or C8 radiculopathy developed postoperative radiculopathy. This study suggested that an important risk factor for postoperative radiculopathy was subclinical C5 radiculopathy (postganglionic type) that could be preoperatively evaluated using electrophysiological studies.     

Delayed postoperative tethering of the cervical spinal cord

Tethering of the spinal cord in the lumbar and sacral regions of children with congenital anomalies is a well-recognized problem; however, tethering in the cervical region has rarely been reported. A search of the literature revealed no reports of symptomatic postoperative cervical spinal cord tethering. The authors present five cases of delayed postoperative cervical spinal cord tethering and discuss the benefit of detethering in these patients. All five patients were young (16 to 42 years of age) at presentation. All had done well after an initial surgical procedure but returned between 1 and 31 years postoperatively with symptoms including severe headache, upper-extremity pain, and progressive neurological deficits. In each case, magnetic resonance imaging indicated dorsal tethering of the cord in the cervical region. Surgical exploration with microscopic sharp detethering of the cervical cord was performed on each patient with favorable results. To avoid retethering, wide Tutoplast duraplasty is recommended.     

Multiple sclerosis of the spinal cord: magnetic resonance appearance

OBJECTIVE: To determine the MR appearance of spinal cord multiple sclerosis (MS) plaques in patients presenting with myelopathy by using a high-field (1.5 T) imager. MATERIALS AND METHODS: We studied 119 patients who underwent high-field (1.5 T) MR studies of the spinal cord for evaluation of myelopathy. All 119 patients were thought to have possible findings of spinal cord MS at the time of the MRI interpretation. RESULTS: Sixty-four plaques were studied in 47 patients with clinically definite MS and adequate quality MRI. Of these patients 68% had a single spinal cord plaque, 19% had two plaques, and 13% had three or more plaques. Sixty-two percent of the plaques occurred in the cervical spinal cord and most frequently involved the posterior (41%) and lateral (25%) aspects of the spinal cord. None of the 64 lesions involved the entire thickness of the spinal cord. The lesion length varied from 2 to 60 mm, with 84% of the lesions < 15 mm in length. The spinal cord diameter was unchanged in 84% of plaques, enlarged at the level of the lesion in 14%, and atrophic in 2%. Just over half (55%) of the plaques enhanced with intravenously administered gadolinium. Of the patients who received synchronous head and spinal cord examinations on the same day, 24% had normal findings on the MR study of the head. Follow-up spinal cord studies were available in nine patients. New lesions developed in two patients, while previously described lesions resolved. In three patients only new lesions developed. In four patients no change occurred in the existing number of cord plaques. CONCLUSION: Spinal cord demyelinating plaques present as well-circumscribed foci of increased T2 signal that asymmetrically involve the spinal cord parenchyma. Knowledge of their usual appearance may prevent unnecessary biopsy. An MR examination of the head may confirm the imaging suggestion of spinal cord demyelinating disease, because up to 76% of patients have abnormal intracranial findings. In the remaining 24% of cases in which the clinical diagnosis is not certain and MR findings in the head are negative, a follow-up spinal cord study is recommended, because these lesions evolve and change over time.     

Risks of surgical management for cavernous malformations of the nervous system

OBJECTIVE: As more information evolves regarding the natural history of cavernous malformations (CMs), the risks of operative intervention must be balanced against nonoperative management. In an attempt to better delineate the surgical risks for operable CMs, we undertook a retrospective analysis of 94 patients with 97 CMs surgically excised at the Massachusetts General Hospital. METHODS: Data regarding surgical complications and outcome measures, including neurological status and seizure outcome, were analyzed. RESULTS: The incidence of transient neurological morbidity was 20.6%, but only 4 of the 97 operations (4.1%) resulted in persistent disabling neurological complications and 2 (2.1 %) in nondisabling deficits. There was no operative mortality. Brain stem lesions (n=14) were associated with the highest incidence of neurological complications, both transient and persistent (odds ratio, 4.8; 95% confidence interval, 1.5-15.7). The overall neurological outcome was excellent or good in 89.7% of all lesions: 96.8% of lobar CMs (n=63), 64.2% of brain stem CMs (n=14), 87.5% of cerebellar CMs (n=8), 100% of cranial nerve CMs (n=4), and 75% of spinal cord CMs (n=8). Patients with brain stem and spinal cord CMs were in poorer preoperative neurological condition than were patients with CMs in other locations and therefore had a significantly reduced level of function after surgery (P < 0.01). There was improvement in 35.7% of the patients with brain stem lesions and 62.5% of the patients with spinal cord lesions after surgery. In the 38 patients presenting with seizures, 97% were seizure-free after surgery. CONCLUSION: The risks of operative management of CMs varies based on location. When evaluating patients with operable CMs for surgery, the incidence of complications as well as final neurological outcome should be carefully weighed against the existing knowledge of the natural history of lesions managed expectantly.     

Nucleotide sequence of alkyl-dihydroxyacetonephosphate synthase cDNA from Dictyostelium discoideum

OBJECTIVE AND IMPORTANCE: Congenital anomalies of the posterior arch of the atlas (C1) are uncommon. They range from partial clefts to total agenesis of the posterior arch. Developmental cervical canal stenosis is a congenital anomaly that may cause cervical myelopathy. Myelopathy caused by cervical stenosis at the level of the atlas has been reported in only three cases. We present two cases of nontraumatic cervical myelopathy caused by spinal stenosis at the level of the atlas associated with a hypoplastic but complete posterior arch of C1. CLINICAL PRESENTATION: Two elderly Chinese men developed cervical myelopathy gradually during months to years, without preceding trauma. Imaging revealed a hypoplastic but complete posterior C1 arch associated with changes of spondylosis in both patients, producing severe spinal stenosis and spinal cord compression. Posterior decompression was achieved in both by the removal of the posterior arch of C1 with its surrounding thickened posterior ligaments. Symptoms and clinical findings improved in the two patients during the follow-up period. CONCLUSION: The anomaly presented in our two cases differs from the established classification of congenital abnormalities of the posterior arch of the atlas, suggesting a different embryological defect. The hypoplastic posterior C1 arch created a congenitally narrowed spinal canal in our patients, rendering the spinal cord more susceptible to compression related to degenerative changes of the spine. Surgical removal of the shortened posterior C1 arch and surrounding degenerative ligaments is an effective treatment for symptomatic patients with this condition.