Cervical myelopathy is also called as cervical spondylotic myelopathy (CSM) and is the result of compression of the spinal cord due to the wear and tear in the vertebras that make up the spinal column. This wear and tear is caused due to old age as the vertebras in the spinal cord face degeneration due to wear and tear along the time.
The spine is made of 24 bone discs (vertebras) that are situated one atop the other in a column. The top 7 vertebras from below the neck consist of the cervical region. Each vertebra has a hole in the middle that acts as a tunnel (central canal) for the spinal cord to run from the base of the neck to the lower back. Nerves branch out from the spinal cord through the foramen (openings in the sides of the vertebras) and are the connection to the muscles from the brain.
The inter-vertebral disks are flexible disk-shaped bones that provide cushioning between the vertebra disks while walking or running. These consist of two parts – tough and flexible outer ring (annulus fibrosus) and soft jelly-like substance inside the outer ring (nucleus pulposus).
How is Cervical Myelopathy Graded?
The classification of cervical myelopathy is based on the extent and severity of the symptoms basically in various types, such as:
Nurick classification (based on gait and ambulatory function):-
Grade 0 – Root symptoms only
Grade 1 – Signs of cord compression + normal gait
Grade 2 – Gait difficulty + fully employed
Grade 3 – Gait difficulty prevents employment + walks unassisted
Grade 4 – Cannot walk unassisted
Grade 5 – Wheelchair or bedridden
Class I – Pain + absence of neurological deficit
Class II – Subjective weakness + hyperreflexia + dysesthesias
Class IIIA – Objective weakness + long tract signs + ambulatory
Class IIIB – Objective weakness + long tract signs + non-ambulatory
Symptoms for Cervical Myelopathy
The symptoms for cervical spondylotic myelopathy (CSM) develop over a prolonged period of time and the progress is slow yet steady.
These are the commonly seen symptoms in CSM:
- Tingling/numbness in fingers, hands and arms
- Weakness in muscles of hands, arms and shoulders
- Difficulty in grasping/holding objects
- Co-ordination problems
- Trouble walking
- Vertigo (spinning sensation/dizziness)
- Inability to use fine motor skills (difficulty in writing, picking tiny objects, hand-to-eye co-ordination problem)
- Pain/stiffness in the neck
How is Cervical Myelopathy Diagnosed?
The diagnosis for determining cervical spondylotic myelopathy (CSM) involves:
After checking your medical history and general health the doctor will take note of the symptoms that you are experiencing and then conduct a full physical examination to check for:
- Hyperreflexia – Change in reflexes, whether they are overactive or exaggerated
- Numbness in fingers, hands and arms
- Loss of balance, trouble in walking or weak legs
- Atrophy – deterioration of muscles and decrease in muscle size
X-ray – This helps the doctor check for abnormalities in the bone structure of the cervical vertebras in the neck.
Magnetic resonance imaging (MRI) – An MRI helps the doctor get a better view of the soft tissues and can determine whether compression in present due to a herniated disk or bulging.
Computerized tomography (CT) scan – This gives a clearer view as compared to an X-ray and helps the doctor determine the presence of narrowing of spinal canal as well as check for abnormal bone spurs in the cervical region of the spine.
Myelogram – This is a specialized test that uses a special dye injected into the spinal column to highlight the spinal cord and the nerve roots for a better diagnosis.
Treatment Options for Cervical Myelopathy?
There are numerous non-surgical treatment options that are initially advised by the doctor for earlier stages of cervical spondylotic myelopathy (CSM) to relieve its symptoms. In case these non-surgical treatment methods are unsuccessful in relieving the symptoms of CSM the doctor will advise you on the merits and drawbacks of the surgical treatment methods of CSM.
The main aim of the surgical treatment methods is to relieve the pressure from the spinal cord. The exact type of surgical treatment will be determined according to factors such as range of symptoms and the extent of the damage to the spinal cord.
There are four main methods of surgical treatment available for CSM, these are:
- Anterior cervical diskectomy and fusion
- Anterior cervical corpectomy and fusion
The exact procedure to be used for the treatment of your CSM will depend on your overall physical health and the location as well as type of the spondylisis.
Surgery for CSM is either performed from the front of the neck (anterior) or the back of the neck (posterior). Certain cases may require a combination of both the anterior and posterior approach to correct the instability and spinal cord compression.
The types of surgical methods for treatment of CSM are:
This is the surgical method that aims to stabilize the spine through ‘fixing’ two consecutive affected vertebras together to restrict their pain-causing movement.
A spinal fusion surgery requires bone grafts (bone materials) to promote the fusion between the vertebras. These small bone pieces are placed between the gaps in the vertebras to provide structural support. In certain cases the doctor will also implant a ‘spacer’ (synthetic cage-like device) between the two consecutive vertebras to allow the bone graft to take hold and promote the fusion better.
After implanting the spacer or fixing the bone graft the doctor will use medical-grade rods, plates and screws to increase the progress rate of fusion between the vertebras as well as to stabilize the joining.
Anterior Cervical Diskectomy and Fusion
In this procedure the disc replacement surgery of the affected (degenerated) disk and any bone spurs (abnormal bone growths) is done to stabilize the spine with spinal fusion. The doctor will usually fix a set of metal plate and screws to support the front of the spine.
Anterior Cervical Corpectomy and Fusion
This is a similar procedure to a diskectomy, except, the doctor will remove a vertebra rather than a disk. The doctor will then follow with a procedure of spinal fusion to stabilize the vertebras.
In case both the vertebra and the disk are found to be compressing the spine the doctor will perform a combination of diskectomy and corpectomy.
This is a posterior approach surgical method where the doctor will make an incision in the back of the neck to reach to the spinal column. In laminectomy the surgeon will require to remove the arch of bone at the back of the spinal canal known as the ‘lamina’ as well as any bone spurs and ligaments that are compressing the spinal cord. Laminectomy is helpful in relieving the pressure on the spinal cord by making additional space for it at the back.
This procedure inadvertently makes the spinal column less stable and the surgeon will need to perform a spinal fusion to restore strength and stability to the spine.
This procedure does not require to remove the lamina instead it rubs the lamina from one side, making it thin, and then make a cut on the other side to create a hinge-like shape. This allows the surgeon to access the spinal canal and make additional space for it.
This procedure retains at least 30%-50% of neck movement after the spine surgery hence neck pain may still be there post-surgery.