Cervical canal stenosis is the tightening of neurological structures in the vertebral (cervical) canal by decreasing the area available for these structures. These structures include the spinal cord as well as the nerve roots that exit from the spine at each level from the base of the skull to the end of the spine. These nerves / roots will innervate not only the limbs but also the bladder and intestines under the motor and sensory aspect.
Squeezing compression of the spinal cord and cervical nerve roots will compromise some of the spinal cord’s functions leading to varying clinical features with pain, stiffness, changes in sensitivity and even muscle strength in the upper and lower limbs. Spinal cord involvement can even compromise bladder and bowel functions.
What are the causes of cervical canal stenosis?
Cervical canal stenosis is usually caused by age-related changes such as the shape / alignment and size of the most common vertebral canal in people over 50 years. Aging discs may cause diffuse diosco protrusion as well as calcification of ligamentous inserts (parrot beaks). This aging process of the intervertebral discs also affects the interapophyseal facets with the typical wear of arthrosis (without cartilage) processes. All of these degenerative changes contribute to the decreased free area within the spinal canal at this level thus causing the tightening and compression of neurological structures.
In rare cases the cervical canal is stenotic at birth considering the size of the vertebrae itself.
What are the symptoms?
Many people over 50 have reduced cervical canal dimensions without having any complaints. The stenosed cervical canal only gives symptoms when there is compression of the spinal cord or cervical nerve roots but the symptoms usually come slowly and gradually and are essentially:
- cervical stiffness and pain with or without shoulder, arm, forearm or hand muscle weakness
- balance and motor coordination changes such as shuffling and frequently tripping
- loss of urine and stool control (in the most severe cases)
Occasionally and in the context of a diagnosed cervical stenotic canal, we may see a sudden worsening of the symptoms with a very exuberant picture of esipnhal ataxia and motor and balance uncoordination that may settle in a few hours only requiring urgent surgical intervention for decompression.
How is the diagnosis made?
Once a compatible clinical condition is diagnosed, the patient should be submitted to imaging exams – X-ray, MRI and CT. However, your doctor should order a series of blood tests to help rule out other diseases with similar symptoms such as Multiple Sclerosis, and Vitamin B12 deficiency.
How should it be treated?
In less severe cases the symptoms can be controlled with the use of pain relieving medication, physical therapy to maintain muscle strength and flexibility, and moist heat to decrease muscle spasm.
If the symptoms are severe enough, there is often a progressive decrease in muscle strength and under these circumstances we should consider the surgical treatment for decompression of neurological structures. This type of surgery can be done either in front of or behind the cervical spine, depending essentially on where the major compressive component is located.
Some surgical techniques to achieve decompression eventually remove more movement of the cervical spine and thus make it an even more rigid spine (anterior cervical arthrodesis with or without corporectomy) but other techniques exist where it is possible to widen the dimensions of the cervical canal while preserving mobility. this segment of the spine (laminoplasty – see surgical techniques).