Many different problems related to spinal degeneration, injuries, or medical conditions can lead to narrowing of the intervertebral foramen (bony canal where spinal nerve exits the spinal canal). Identifying the cause of cervical foraminal stenosis and receiving an accurate diagnosis are important for getting an effective treatment plan.
Common Causes of Cervical Foraminal Stenosis
Common ways for an intervertebral foramen to become narrowed and compress or inflame a spinal nerve in the neck include:
- Bone spurs (osteophytes). In the cervical spine, uncovertebral joints (small bony joints where adjacent vertebral bodies articulate with each other on the side) are common locations for bone spurs to develop and encroach upon the intervertebral foramen. Bone spurs may also develop as a result of facet joint osteoarthritis and narrow the foramen.
- Degenerative disc disease. As part of the aging process, intervertebral discs tend to lose hydration and flatten out over time. As a disc degenerates, the vertebrae get closer together and the foraminal space becomes smaller. The disc may also start to bulge into the foraminal space.
- Herniated disc. When the tough outer layer of a disc tears or cracks, the soft inner gelatinous contents may start to leak outward and compress a spinal nerve. The leaked material may also secrete inflammatory chemicals that can inflame the nerve. While a herniated disc may occur as a result of degeneration, it can also occur due to traumatic injuries.
Various other issues related to spinal degeneration may cause cervical foraminal stenosis, including ligament thickening or buckling.
Less Common Causes of Cervical Foraminal Stenosis
Some less common ways for cervical foraminal stenosis to develop may include:
- Spondylolisthesis. This condition involves one vertebra slipping forward atop another. Spondylolisthesis is rare in the cervical spine. It can occur due to fracture, degeneration, congenital (from birth), or other reasons.
- Synovial cysts. Cysts may develop within a degenerating facet joint and push into the foramen.
- Spinal tumors. Tumors, benign or malignant, might develop on a spinal nerve or the spinal cord and grow into the intervertebral foramen.
It is also possible for multiple problems to contribute to stenosis, such as having both a facet cyst and degenerative disc disease.
Diagnosis of Cervical Foraminal Stenosis
Getting an accurate diagnosis for cervical foraminal stenosis is usually a 3-step process:
- Patient history. A medical professional reviews the patient’s medical history, such as past illnesses or injuries, chronic health conditions, medications, family history, and/or past surgeries. This information gathered, including current symptoms, can help rule out some causes and identify what may need further exploration.
- Physical examination. The neck is palpated (felt) and observed for any tenderness, lesions, or instability. Clinical tests may be done to examine the neck’s range of motion, arm strength, reflexes, and sensation (tingling/numbness). For example, a Spurling’s test involves the doctor rotating the head toward the symptomatic side, moving it into extension, and then gently applying pressure on top of the head to check if the pain is reproduced.
- Medical imaging. While the patient history and physical examination may be enough to begin an effective treatment program, a cervical foraminal stenosis diagnosis requires medical imaging to confirm actual narrowing within the foramen. An MRI is the most common imaging used to diagnose cervical foraminal stenosis. CT with myelography or without myelography may be used in cases where MRI is not an option. Also, many people have cervical foraminal stenosis based on what is seen on medical imaging but have no related symptoms.
To help identify which specific spinal nerve is symptomatic, diagnostic injections and electrodiagnostic testing may also be used.
Once an accurate diagnosis for cervical foraminal stenosis is reached, an effective treatment plan can be devised as described on the next page.