Tumors at the lateral portion of the C1-2 interlaminar space compressing the spinal cord by rotation of the atlantoaxial joint: new aspects of spinal cord compression

Myelopathy secondary to a spinal cord compression induced by C2 nerve tumors during head rotation

INTRODUCTION

It is well known that nerve root tumors developing in the spinal canal can be responsible for spinal cord compression leading to myelopathy and neurological deficits. We report the case of a patient with bilateral C2 neurofibromas presenting with a myelopathy of the upper cervical spine with no spinal cord compression on standard magnetic resonance imaging. The spinal cord compression occurred between the cervical neurofibromas only during head rotation.

CASE REPORT

A patient with bilateral neurofibromas of the C2 nerve roots showed a progressive neurological deterioration with an intramedullary MRI hypersignal without visible compression. Only an additional MRI carried-out with the head in rotation demonstrated the tumoral dynamic compression. A review of the literature showed that only two similar cases had previously been reported. The largest C2 tumor was completely removed uneventfully.

CONCLUSION

Dynamic compression of the spinal cord in patients with bilateral C2 nerve root tumors must be routinely investigated even if the standard MRI shows no compression.

"Dynamic" Rotational Canal Stenosis Caused by Osteoma of the Atlas: A Case Report and Review of Literature

The upper cervical canal stenosis is relatively rare compared to other cervical regions. We report a rare case of upper cervical canal stenosis caused by osteoma of C1 lamina related to dynamic factor of cervical rotation. A 43-year-old woman had a 2-year history of numbness and pain in the right hand. Because of aggravation of the numbness and loss of the fine movement and strength in the right hand, she visited our outpatient clinic. Computed tomographic (CT) scan revealed an ovoid bony lesion at the right side of the C1 lamina. And magnetic resonance (MR) imagings of the cervical spine showed intramedullary high intensity signals in T₂-weighted imaging at a site slightly distant from the bony lesion. Rotational dynamic myelo-CT scan was performed because aggravation of the radiating pain was observed with neck rotation to the right. Dynamic CT scan of the craniocervical junction with neck rotation to the right revealed that the bony lesion was moved to the dorsal side and posteriorly compressed the spinal cord. The symptoms were relieved following surgical removal of this bony lesion. The histopathological examination was compatible for osteoma. The dynamic rotational factor for cervical canal stenosis should be taken in consideration, especially in dealing with upper cervical lesions.