CERVICAL CANAL STENOSIS
Cervical canal stenosis is a narrowing of the spinal canal in the cervical spine, which when severe, results in compression of the cervical spinal cord or the nerves arising from it. This is commonly seen as a part of ageing where multiple discs become hard and bulge into the spinal canal or from a condition called ossified posterior longitudinal ligament (OPLL).
Cervical Canal stenosis presents with neck pain, arm pain and parasthesia (tingling of the arm and fingers). When compression is severe then weakness of the upper and lower limbs may occur and spasticity of gait. Sudden injury in a stenotic patient may cause worsening of symptoms, further weakness of the limbs and even bowel/bladder symptoms.
MRI of the cervical spine shows the spinal cord, the nerve roots arising from it, the vertebra and the discs. MRI shows the degree of degeneration of the disc, the extent of disc herniation and the degree of nerve root compression. Though several discs may show abnormality on MRI the surgeon decides which of the discs is causing the problem and treats accordingly.
X-Ray of the cervical spine shows the vertebra and there alignment. Most commonly this is done in flexion and extension to check for any instability (listhesis).
CT scan of the spine is done in certain cases where, after MRI and X-ray, some more information is required by the surgeon. This is particularly relevant in traumatic disc prolapse to look at associated injuries and the size of the pedicles. In cervical stenosis, CT shows if the compression is bony or from soft tissue thickening.
Electromyography (EMG) / Nerve conduction test (NCV) is an electro-physiological test of the limbs that is done in certain cases where the diagnosis is in doubt, to rule out conditions like neuropathy that may be from diabetes, hypothyroidism or certain vitamin deficiencies. EMG can also give an indication of which nerve root may be involved by compression from a disc or bony spur called osteophyte, resulting in acute or chronic changes on EMG.
Cervical canal stenosis at one or two levels is treated by cervical discectomy / corpectomy (single or multiple vertebral body excision). After removing the compressing element (disc/ vertebra / OPLL), the gap is filled by an implant with bone graft and thus stabilization is achieved using cage and plate.
Cervical canal stenosis at more than three levels is mostly treated by posterior cervical laminectomy. In this procedure spinal decompression is done from the back of the neck where the lamina (the posterior part of the spine) is removed
Cervical laminoplasty. is an operation to widen the spinal canal in cases of cervical stenosis from OPLL or multiple cervical osteophytes causing multi-level cervical cord compression. In this operation the lamina (back part of the spine) is lifted up at a hinge and kept up in the lifted position using mini titanium plates.