The spine is composed of vertebrae that are cushioned by disks. The disks act as shock absorbers and allow the spine to bend and twist. The cervical spine consists of the top seven vertebrae in the neck. The cervical disks connect the cervical vertebrae and protect the spinal cord and the nerves that branch out from it.
Sometimes, the disks can become damaged or degenerated due to aging, injury, or disease. This can cause the inner material of the disk to bulge or rupture through the outer layer, resulting in a herniated disk. A herniated disk can compress or irritate the nearby nerve roots or the spinal cord, causing pain, numbness, weakness, or tingling in the neck, shoulder, arm, or hand.
ETIOLOGY
The exact cause of cervical disk herniation is not always clear, but some factors that may contribute to it are:
– Aging. As people get older, the disks lose water and elasticity, making them more prone to tearing or rupturing.
– Injury. A sudden trauma, such as a fall, a car accident, or a sports injury, can cause a disk to herniate.
– Repetitive stress. Activities that involve frequent or prolonged bending, twisting, or lifting of the neck can put pressure on the disks and cause them to wear out over time.
– Genetics. Some people may have a predisposition to disk herniation due to inherited traits or conditions that affect the spine.
SYMPTOMS
The symptoms of cervical disk herniation depend on the location and severity of the herniation, as well as the nerve or spinal cord involvement. Some common symptoms are:
– Neck pain. This may be sharp, dull, or burning, and may radiate to the shoulder, arm, or hand.
– Neck stiffness. This may limit the range of motion of the neck and make it difficult to turn or tilt the head.
– Arm pain. This may be felt along the path of the affected nerve, and may be accompanied by numbness, tingling, or weakness.
– Headache. This may occur at the back of the head or behind the eye, and may worsen with neck movement.
– Spinal cord compression. This may cause symptoms such as difficulty walking, loss of balance, loss of bladder or bowel control, or sexual dysfunction.
IMAGING STUDIES FINDINGS
To diagnose cervical disk herniation, a physical exam and a medical history are important to define the syndrome and suspect a discal pathology. However, some imaging tests may be ordered to confirm the diagnosis, rule out other causes of pain, or plan for treatment. Some common imaging tests are:
– X-rays. These can show the alignment of the vertebrae and the presence of any infection, tumor, fracture, or arthritis. Lately the X-ray is rarely used and advanced imaging studies are preferred. Still an x-ray can be used as a first line imaging when the symptoms are mild, the patient is experiencing it for the first time and responds well to conservative treatment.
– CT scan. This can provide detailed cross-sectional images of the spine and the disks, and can show the extent and location of the herniation.
– MRI. This can produce high-resolution images of the spine and the soft tissues, and can show the nerve or spinal cord compression, as well as the inflammation or edema around the herniation. When a discal herniation is found on CT, the patient presents with a neurological deficit and/or the conservative treatment is not successful and a surgery may be a treatment option, an MRI must be preformed.
– Myelogram. This involves injecting a dye into the spinal fluid and then taking a CT scan. This can show the pressure on the spinal cord or the nerve roots due to the herniation or other conditions. Nowadays the MRI provides enough information and myelogram is rarely used.
! Imaging studies results can distinguish discal bulging from herniation. The difference between a herniated disc and a bulging or protrusion disc is that a herniated disc is when the inner, gel-like material of the disc leaks out through a tear in the outer layer, while a bulging disc is when the outer layer of the disc bulges outwards, but the inner material does not leak out. A disc protrusion is a more advanced stage than a bulging disc. Not only does the outer wall bulge outward, but the inner gel has migrated to the very edge of the annulus fibrosus. It can be thought of as a middle stage between a bulging disc and a herniated disc. Both conditions can cause pain and other symptoms if they compress or irritate the nearby nerve roots or the spinal cord.
DIFFERENTIAL DIAGNOSIS
Cervical disk herniation can be confused with other conditions that cause similar symptoms, such as:
– Cervical spondylosis. This is a degenerative condition that affects the joints and bones of the cervical spine, causing pain and stiffness in the neck and arms.
– Cervical radiculopathy. This is a condition that occurs when a nerve root in the cervical spine is irritated or compressed by a bone spur, a tumor, an infection, or a spinal stenosis, causing pain, numbness, or weakness in the arm.
– Cervical myelopathy. This is a condition that occurs when the spinal cord in the cervical spine is compressed by a herniated disk, a bone spur, a tumor, an infection, or a spinal stenosis, causing neurological symptoms in the arms, legs, or trunk.
– Cervical strain or sprain. This is a common injury that affects the muscles or ligaments of the neck, causing pain and stiffness in the neck and shoulders.
– Whiplash. This is a neck injury that occurs when the head is suddenly jerked forward and backward, causing damage to the soft tissues of the neck and the cervical spine.
TREATMENT
The treatment of cervical disk herniation depends on the severity of the symptoms, the degree of nerve or spinal cord compression, and the response to conservative measures. The main goals of treatment are to relieve pain, restore function, and prevent further damage. Some common treatment options are:
– Conservative treatment. This includes modifying activities, avoiding movements that worsen pain, taking pain medications (nonsteroidal anti-inflammatory, analgetics, corticosteroids, opioids), locally administered medications (corticosteroids, anestetics), applying heat or ice, and doing physical therapy or exercises to strengthen the neck muscles and improve posture and flexibility.
– Surgery. This is considered when conservative treatment fails, or when there is severe nerve or spinal cord compression that causes neurological deficits or threatens the spinal cord function. Neurosurgeons and orthopedic surgeons can provide more guidance on the most appropriate method for the specific patient.
CONCLUSION
Cervical disk herniation is a common condition that affects the disks in the neck. It can cause pain, stiffness, and neurological symptoms in the neck, shoulder, arm, or hand. It can be diagnosed by a physical exam, a medical history, and imaging tests. It can be treated by conservative measures, or surgery, depending on the severity and the response to treatment. Medical students should be familiar with the anatomy, pathophysiology, diagnosis, and treatment of cervical disk herniation, as it is a frequent cause of neck pain and disability in the general population. They should also be able to educate their patients about the prevention, management, and prognosis of this condition, and provide them with the best possible care, including directing them to the appropriate specialist for the approproate manamanagement before the part of the nervous system involved is irreversebly damaged.
Verified by Dr. Petya Stefanova
