Part of the spine located at the neck, the cervical spine helps both support the head and ensure mobility, but also protects the upper portion of the spinal cord which passes through its center. Trauma, shock, infectious, inflammatory or degenerative causes, the cervical spine can be affected by various pathologies. Dr. Gilles Avenel, rheumatologist, tells us more about the signs that should not be overlooked and the treatments that apply, depending on the pathologies encountered.
What is the cervical spine?
Located between the rib cage and the base of the skull, the cervical spine is one of the five parts of the spine (with the dorsal region, the lumbar region, the sacral region and the coccyx) and corresponds to the upper, mobile part of it.
Its different, more flexible structure from that of the rest of the column allows it to play an important anatomical role: it is in fact responsible for the mobility of the head and helps support it during movements. “Thanks to it, it is possible to maintain your gaze on the horizon, but also your body balance and standing.”, observes Dr. Gilles Avenel, rheumatologist at Rouen University Hospital (Rouennais Spine Institute) and president of the Spine section of the French Society of Rheumatology (SFR). “Like the entire spine, it also forms a bony ring which protects the primordial neurological structure which is the spinal cord and preserves it from possible trauma.
Anatomy: what is the cervical spine made of?
The general term “spine” refers to the spine, which extends from the base of the skull to the pelvis (sacrum) and is made up of a stack of 33 vertebrae: 7 cervical vertebrae, 12 dorsal (or thoracic) vertebrae. , 5 lumbar vertebrae, the sacrum composed of 5 vertebrae fused at the level of the sacrum and finally 4 vertebrae, making up the coccyx at the bottom. Between each vertebra there is a disc which serves as a shock absorber.
The cervical spine therefore includes seven vertebrae stacked on top of each other and named from C1 to C7. These bone discs with holes allow the spinal cord and nerves to connect together. Between each vertebra, a disk of cartilage with a gelatinous core absorbs shock and prevents too much friction between the vertebrae.
C1 is the vertebra located at the top of the spine, just under the skull. C7, on the other hand, is located directly above the first dorsal vertebra (or D1). The first two cervical vertebrae are different from the others because they support the weight of the skull and have a specific role. The first, the atlas, does not include a spinous process (small projections visible in the middle of the vertebrae). Its unique structure ensures the flexibility of the skull: thanks to the atlas, we can nod our head forward or lean it backwards. The second cervical vertebra, the axis, plays a supporting role favoring the pivot. The atlas in fact rests on top of the axis and pivots around it, which allows us to turn our head to the right or left. There is no intervertebral disc between the atlas and the axis.
From C3 to C7, the so-called typical vertebrae are born which form the lower cervical spine. Equipped with the same structure, they play the same role as the other cervical, dorsal or lumbar vertebrae. However, they are smaller and lighter than the dorsal or lumbar vertebrae: this less weight to support makes it easier to maintain the head and its flexibility in movements. Another particularity: the intervertebral space is also smaller between the cervical vertebrae than between the dorsal or lumbar vertebrae.
Around the cervical spine, the muscles participate in stabilizing the whole and control the cervicothoracic and craniocervical hinges.
What is the cervical spine used for?
The cervical spine has two main functions: supporting the head and ensuring its movements (mechanical support function). But also contain and protect essential nervous and vascular elements: the spinal cord, the nerve roots and the vertebral arteries which pass through its center, in the spinal canal, at the level of the neck. At each vertebral level, the nerve roots exit through the foramina (holes located between two contiguous vertebrae).
The cervical spine thus makes the connection between the head and the body and contains most of our postural senses. An essential role which also makes it vulnerable to a number of pathologies.
The flexibility of the neck exposes it to wear and traumatic injuries (example of whiplash). Poor posture can also make head support more difficult. Neck pain, like back pain, is common and increases with aging (osteoarthritis after age 50).
What are the symptoms that indicate a problem at this level?
Pain is the most common symptom. It is most often benign and reflects a global dysfunction of the region which is difficult to attribute to an anatomical origin. It can be associated with muscle stiffness and cracking, particularly in the neck area. “The person then feels difficulty in certain everyday actions, such as checking the blind spot in the car mirror for example.specifies the specialist.
The pain can sometimes radiate towards the back of the head and the forehead, but also towards the upper back or towards the shoulders and arms (this is called “cervico-brachial neuralgia”).
Neurological signs (loss of strength in the limbs, paralysis, loss of urine, etc.) can reflect a sudden or progressive injury to the spinal cord and are a warning sign that should lead to urgent consultation.
Balance disorders can sometimes be linked to stiffness of the cervical spine and justify specific rehabilitation treatment. They can only be linked to cervical pathology after eliminating neurological or inner ear pathology (elimination diagnosis).
What are the pathologies that can affect the cervical spine?
Various pathologies can affect the cervical spine.
Acute neck pain (commonly known as torticollis) is the most common cause of neck pain. It most often reflects a dysfunction of the region associated with muscle contractures. It is favored by stress, postures maintained for prolonged periods (office work, etc.). Neck pain most often disappears within a few days or weeks. They are treated symptomatically with anti-inflammatories and analgesics. They do not require an imaging test.
“This dysfunction can set in and cause chronic neck pain which will require a global approach combining local rehabilitation treatments (muscle strengthening, stretching, etc.), psycho-emotional care and an assessment of the environment (workstation, fight against a sedentary lifestyle…)” notes Dr. Gilles Avenel.
Traumatic causes
Fractures and sprains can also impact the neck and restrict movement. They occur for high-intensity trauma such as road accidents or falls from height (ladders, etc.). Rear impacts responsible for “whiplash” that do not cause visible damage on imaging (fracture or dislocation) can cause pain whose mechanisms are probably related to torticollis.
Degenerative causes
- Cervical disc herniations correspond to the protrusion of a fragment of the intervertebral disc. When the herniated disc comes into contact with a nerve root, it can irritate it and cause pain along the territory innervated by this root in the upper limbs: this is a cervico brachial neuralgia (NCB). The nerve root is often affected, but compression of the spinal cord can sometimes be observed. It must nevertheless be emphasized that disc herniations are common and can be completely asymptomatic. When they are responsible for NCB, the pain most often improves spontaneously, they should therefore only be operated on in cases of persistent NCB despite symptomatic treatment;
- Cervical osteoarthritis or cervicarthrosis is linked to aging and its importance is due to genetic factors. It is responsible for stiffening of the joint structures and a reduction in mobility (difficulty turning the head for example). It is not a pathology as such because it affects the majority of people over 50 and rather reflects normal aging of the cervical spine. However, joint stiffness promotes cervical dysfunction and therefore torticollis and chronic neck pain. Osteoarthritis is responsible for joint hypertrophy (“parrot beaks” or osteophytes) which can irritate the cervical nerve roots and cause cervico-brachial neuralgia. This hypertrophy can, in advanced forms, cause a narrowing of the vertebral canal responsible for cervico-arthritic myelopathy;
- Cervicarthrotic or cervico-arthritic myelopathy : due to compression of the spinal cord at the cervical level, it causes intermittent spinal cord claudication, manifested by various neurological disorders of the lower limbs (loss of strength, bending of the limbs, feeling of instability, etc.) which occur when walking and limit the walking area. It’s a form…