Cervical disc herniation

In one minute

A cervical disc herniation is a tear in one of the cushions between the neck bones that lets the soft centre press on a nerve root or, less often, on the spinal cord. It is most common in middle age; a population study from Rochester, Minnesota found the peak incidence of cervical radiculopathy (arm pain from a pinched neck nerve) at 50 to 54 years. It feels like neck pain plus a sharp pain through the shoulder blade and down one arm, with tingling in particular fingers. The examination makes the diagnosis; MRI (magnetic resonance imaging) confirms it when the result would change treatment. Most people improve within months without an operation. When pain persists or a nerve weakens, an endoscopic foraminotomy through a 7 mm incision, or an operation from the front of the neck, takes the pressure off.

What it is

The neck has seven vertebrae with a disc between each pair from the second down. A disc is a tough outer ring (the annulus fibrosus) around a soft gel core (the nucleus pulposus). Behind the discs runs the spinal cord, and at every level a pair of nerve roots leaves through side openings called foramina. A herniation is a tear in the ring through which the core squeezes out: sideways, it meets the exiting root; straight back, it can press on the cord. The roots most often involved are C7 and C6, which leave at the C6-C7 and C5-C6 levels. Patients call it a slipped disc, a pinched nerve, a protrusion or an extrusion. Many were told years ago that they have cervical osteochondrosis, an umbrella word for wear that does not say whether a nerve is being pressed; the cervical spondylosis page explains that label.

Causes and risk factors

Discs dry out and lose height with age, and the ring cracks long before anything hurts. In an MRI study of volunteers with no neck symptoms, a disc was degenerated or narrowed at one or more levels in 25% of those under 40 and almost 60% of those over 40. A herniation is rarely the result of one bad movement. In the Rochester study only 14.8% of patients recalled exertion or injury before the pain began, and 41% had had a lumbar nerve-root episode earlier in life, which points to a person's discs rather than a single accident. There, a confirmed disc protrusion explained 21.9% of cases and spondylosis, a disc, or both 68.4%, so bony wear and disc material often act together. How much smoking, occupation or heredity add in the neck has not been measured well, and we would rather say so than invent a figure.

How it develops

Radiologists grade the tear: a bulge is the whole disc spreading past its edge, a protrusion a focal bump still held by the outer fibres, an extrusion material that has broken through, a sequestration a free fragment. Pain comes from mechanical pressure on the root and from the inflammatory chemicals that leak from the disc. The root's territory then reports pain, tingling or numbness in a band of skin, and the muscles it supplies can weaken. With time the extruded material is often broken down and the inflammation settles; in a systematic review of the course, substantial improvement tended to occur within the first 4 to 6 months.

Symptoms

The NASS (North American Spine Society) guideline lists the findings that should raise the diagnosis: arm pain, neck pain, pain around the shoulder blade, tingling, numbness, weakness and changed reflexes in the arm. The arm pain is usually one-sided and follows a strip: toward the thumb and index finger for C6, the middle finger for C7, the ring and little fingers for C8. Tilting the head back or toward the painful side makes it worse; resting the hand on top of the head often eases it. A herniation pressing on the cord behaves differently: both hands become clumsy, buttons are hard, walking feels unsteady. That is cervical myelopathy and has its own page.

Diagnosis

Examination first: where the pain runs, which fingers tingle, which muscles are weak, which reflexes are dull, plus the Spurling test (extending and tilting the head toward the painful side), which the guideline says may be considered. Because arm pain alone cannot pin the level, the guideline suggests MRI, CT (computed tomography) or CT myelography before any decompression. MRI is the standard, suggested to confirm a compressive lesion in patients who have not improved with conservative care and may be candidates for an injection or an operation; CT myelography is suggested when symptoms and MRI disagree or MRI cannot be done.

Two cautions. MRI findings are common in people with no symptoms: in the volunteer study, scans were read as abnormal in 19%, and 10% of those under 40 had a herniated disc, so the picture only matters when it matches the examination. And words like foraminal narrowing, Modic changes (signal change in the bone next to the disc) and myelomalacia (signal change inside the cord) describe what is seen, not how much it hurts. When you send a scan, photograph the side-view T2 images, the cross-sections at the level in the report, and the report itself, and tell us which fingers tingle.

Treatment without surgery

The NASS guideline's literature search found no studies adequate to define what drugs, physiotherapy or manipulation do for this condition, and its work group agreed by consensus that for most patients the symptoms are self-limited and resolve over a variable length of time without specific treatment. In practice the first weeks are managed with activity as pain allows, a short course of anti-inflammatory or neuropathic pain medication chosen by the doctor, and for some a collar for a short period or physiotherapy. In a Dutch randomised trial of 205 patients with radiculopathy of less than one month, a semi-hard collar with rest for three to six weeks, or physiotherapy with home exercises for six weeks, gave an extra 12 mm of arm-pain relief on a 100 mm scale at six weeks compared with waiting; by six months the groups were no different. The guideline notes that traction, ozone injections and combined programmes have shown improvement only in uncontrolled series.

For severe arm pain, a transforaminal epidural steroid injection (steroid placed next to the root under X-ray or CT guidance) may be considered, with due weight given to its complications; the guideline's review of small uncontrolled series found relief in around 60% of patients and short-term relief that avoided surgery in about 25% of those referred with surgical indications. The same review found case reports of serious harm after neck manipulation, including disc herniation, myelopathy and vertebral artery compression, a reason to avoid thrust manipulation of a neck with a compressed root. How often is this enough? In the Rochester cohort 26% had surgery over a median of 4.9 years, and 90% were symptom-free or only mildly limited at last contact.

When surgery is considered

Surgery is discussed when arm pain has not settled after 6 to 12 weeks of proper conservative care (the window commonly used in spine practice; the NASS guideline does not fix a number of weeks) and the MRI shows a lesion at the level the examination points to; sooner when a muscle is weakening or the cord is compressed. On timing, the NASS guideline suggests surgery for faster relief compared with medical and interventional treatment, and notes that in the one randomised comparison, outcomes at one year were similar for collar, physiotherapy and surgery. For pain alone, the trials do not show that waiting a few months spoils the result of a later operation, while an operation done now shortens the painful period. Progressive weakness or cord compression should not wait.

Surgical options

Endoscopic cervical foraminotomy

A posterior approach through a 7 mm incision that opens the foramen and removes the fragment pressing on the root, leaving the disc and the motion of the segment in place: the right tool for a one-sided herniation in or near the foramen. A meta-analysis of 26 studies pooled a clinical success rate of 93.6%, a complication rate of 6.1% (most often a transient nerve root palsy, a temporary weakness) and a reoperation rate of 4.8%. The same decompression can be done under a microscope through a larger opening; in the FACET randomised trial across nine Dutch hospitals, posterior foraminotomy was noninferior to ACDF (anterior cervical discectomy and fusion) for single-level arm pain, with success in 88% versus 76% at one year. See endoscopic cervical foraminotomy.

ACDF

Anterior cervical discectomy and fusion: the disc is removed from the front, root and cord are freed, and a cage is placed so the two vertebrae fuse. It is the standard choice for a central herniation pressing on the cord, for more than one level or for an unstable segment. The NASS guideline grades ACDF and posterior foraminotomy as comparable for a single-level foraminal soft disc herniation.

Cervical disc replacement

An artificial joint instead of a fusion after the anterior discectomy. NASS grades cervical disc replacement as comparable with ACDF for single-level radiculopathy in the short term; it suits a mobile segment without advanced joint wear.

Endoscopic cervical decompression

A posterior endoscopic laminotomy for the less common case where a herniation with canal narrowing presses on the cord and the anatomy allows a route from behind: see endoscopic cervical decompression.

How we treat it at spine.uz

We are Tashkent's first endoscopic spine team: five surgeons operating as one team, trained in South Korea, Japan, Germany and the USA, with 27,600+ endoscopic and spine operations between us. The first step costs nothing: send your MRI on Telegram or WhatsApp and a doctor from the team replies by voice within 48 hours. The in-person consultation and any operation are paid.

The team performs the posterior endoscopic foraminotomy described above through a 7 mm incision, with no screws or implants, as well as ACDF, cervical disc replacement and multilevel cervical operations; which one fits a given herniation follows the logic set out under surgical options. Most of our endoscopic decompressions are done under local anaesthesia with sedation, the anaesthetist and surgeon deciding per patient. Most patients walk on the day of surgery and go home within 24 hours. Across the team's operations our complication rate is well below 1%. Every patient leaves with a written team conclusion.

Recovery and outcomes

After an endoscopic foraminotomy the arm pain is usually much better once the anaesthetic wears off; tingling and numbness fade over weeks to months. The pooled success rate for full-endoscopic foraminotomy was 93.6%. Return to desk work is often possible within a few weeks of a foraminotomy and to physical work later, and a fusion adds time for the bone to knit; the timing depends on the job and is agreed with the surgeon. Without surgery the road is slower but arrives at a similar place: substantial improvement by 4 to 6 months and full recovery in about 83% by 24 to 36 months. Recurrence is real; in the Rochester cohort, in which about a quarter had surgery, 31.7% had a further episode over a median of 4.9 years. In the systematic review, a workers' compensation claim was linked to a poorer prognosis.

Living with it and prevention

No diet or device prevents a disc from tearing. A Cochrane review of 27 trials found that strengthening exercises for the neck, shoulder and shoulder-blade region help chronic neck pain and, on weaker evidence, radiculopathy, while stretching alone does little. Keep moving, change position often at a screen, and treat a new episode early and calmly rather than with weeks of bed rest.