Cervical spinal stenosis

In one minute

Cervical spinal stenosis is a narrowing of the spinal canal in the neck, the bony tunnel the spinal cord runs through, or of the side openings where the nerve roots leave it. Most of it comes from wear: bulging discs, bone spurs and thickened ligaments that grow into the space with age. Many people have it and feel nothing. It matters when it squeezes the cord, which produces cervical myelopathy (clumsy hands, unsteady walking), or a nerve root, which produces cervical radiculopathy (arm pain). It is seen on MRI (magnetic resonance imaging); the decision about treatment is made from the examination, not the picture. Narrowing that is not hurting anything is watched. Narrowing that is damaging the cord is decompressed, endoscopically or open, and that decision should not be left for years.

What it is

The cervical canal is formed by the backs of the vertebral bodies and discs in front, the bony arches behind, and ligaments in between; the cord runs through it with a cushion of fluid around it. Central stenosis is narrowing of that canal. Foraminal stenosis is narrowing of a side opening, the foramen, where a root exits. Some people are born with a narrower canal than average; the 2015 review of degenerative cervical myelopathy lists congenital spinal stenosis among the conditions that predispose to cord compression later in life. A separate form, OPLL (ossification of the posterior longitudinal ligament), is a ligament behind the vertebral bodies that turns to bone and can compress the cord over several levels. Patients meet the diagnosis as narrow canal, cord compression, or, in older reports, cervical osteochondrosis with stenosis. The word on its own does not say whether anything is being harmed.

Causes and risk factors

Age is the main factor. In a study of 1,211 volunteers aged 20 to 70 with no neck symptoms, disc bulging was present in 87.6% and increased with age in frequency, severity and number of levels; compression of the cord was found in 5.3% and signal change inside the cord in 2.3%, both rising after age 50, mostly at C5-C6 and C6-C7. In an earlier MRI study of symptom-free volunteers, foraminal stenosis was present in 4% of those under 40 and 20% of those over 40. The 2015 review adds congenital narrowing, Down syndrome and Klippel-Feil syndrome as predisposing conditions, notes occupational load such as carrying weight on the head as a possible accelerator, and describes genetic factors under study for disc degeneration and OPLL. The BMJ review puts most first diagnoses of myelopathy in the 50s and calls it uncommon before 40. Whether smoking or particular jobs raise the risk of stenosis itself has not been measured well, and we say so rather than guess.

How it develops

The disc loses height and bulges backward; the small joints and vertebral edges grow spurs; the ligamentum flavum behind the cord thickens and buckles inward when the neck extends. Each takes a little of the canal, and together they can take the fluid cushion away from the cord. The 2015 review describes three mechanisms of injury once that happens: static compression, altered tension and blood supply in a neck that has lost its alignment, and dynamic pinching with movement. The cord tolerates a surprising amount of this quietly. The BMJ review warns that the extent of compression and the signal change on MRI do not correlate well with the severity of symptoms, and that even mild compression can account for severe disease.

Symptoms

There are three states, and the scan cannot tell them apart. The first is silence: narrowing with no symptoms, the common state. In a series of randomly selected volunteers aged 40 to 80 summarised in the BMJ review, incidental cord compression was found on MRI in 59%, yet only two individuals reported related symptoms. The second is root symptoms: pain, tingling or weakness down one arm from a narrowed foramen, described on the cervical radiculopathy page. The third is cord symptoms: numb, clumsy hands, trouble with buttons or writing, stiff or weak legs, unsteady walking, falls, and sometimes bladder urgency; the BMJ review notes that pain may be absent altogether. The more consistent feature, the BMJ review says, is that the symptoms have been evolving for months.

Diagnosis

The examination looks for what the cord does when it is squeezed: brisk reflexes, a Hoffmann sign (flicking a fingertip makes the thumb twitch), clonus at the ankle, an upgoing toe, weakness in a pattern, altered sensation and a changed gait. The BMJ review notes that these signs have low sensitivity but high specificity: a normal examination does not exclude the disease, an abnormal one strongly suggests it.

For imaging, the American College of Radiology criteria are the standard. Plain radiographs are appropriate first imaging for neck pain without red flags, though spondylotic changes on them are common and can mislead in both directions; non-contrast MRI is usually appropriate for new or increasing radiculopathy; CT (computed tomography) complements radiographs after previous cervical surgery or to measure OPLL; MRI with contrast is used when infection or cancer is suspected. The BMJ review calls MRI essential when myelopathy is suspected, and urgent when the disease is progressing. The report's words have plain meanings: canal stenosis is narrowing; effacement of the CSF (cerebrospinal fluid) means the fluid cushion is gone at that level; cord compression means the cord is indented; T2 hyperintensity or myelomalacia means signal change inside the cord; foraminal stenosis is a narrowed nerve exit. When you send a scan, photograph the side-view T2 images, the cross-sections at the tightest level and the written report, and tell us whether your hands have become clumsy or your walking has changed.

Treatment without surgery

For silent stenosis the 2017 AO Spine and CSRS (Cervical Spine Research Society) guideline is clear and reassuring. It suggests not offering prophylactic surgery to non-myelopathic patients with cord compression on imaging but no signs or symptoms of radiculopathy, and suggests instead that they be counselled about the risk of progression, educated about the signs and symptoms of myelopathy, and followed clinically. Between reviews, ordinary life continues. Neck pain and arm pain from the same wear are treated as described on the cervical spondylosis and cervical radiculopathy pages. Two things do not help: the narrowing does not reverse with any tablet, injection or device, and the BMJ review states that neck manipulation is strictly contraindicated when the cord is compressed because it might cause further damage. For mild myelopathy the guideline suggests offering either surgery or a supervised trial of structured rehabilitation, with surgery if the patient deteriorates or fails to improve. For moderate and severe myelopathy it recommends surgery; there, conservative care is a delay, not a strategy.

When surgery is considered

The AO Spine and CSRS guideline of 2017 sets the indications. Surgery is recommended for moderate and severe degenerative cervical myelopathy. For mild myelopathy, surgery or supervised rehabilitation are both options, with a strong recommendation to operate if there is neurological deterioration. For cord compression without myelopathy, prophylactic surgery is not suggested. For cord compression with radiculopathy, the guideline says patients are at higher risk of developing myelopathy, should be counselled about it, and may be offered either surgery or close follow-up with structured rehabilitation.

The numbers behind that risk come from the only prospective cohort of silent compression, from Brno: of 199 patients followed for 2 to 12 years, 45 (22.6%) developed myelopathy, 16 of them within the first year, which the 2013 systematic review by Wilson and colleagues summarises as about 8% at one year and 23% at a median of 44 months. Symptomatic radiculopathy and abnormal evoked potentials (a test of conduction through the cord) predicted earlier progression; signal change in the cord on MRI predicted later progression. On timing, the guideline reports that a longer duration of symptoms and more severe myelopathy both reduce the odds of a good functional score, and advises that patients with progressive myelopathy be referred immediately for surgical consultation regardless of baseline severity.

Surgical options

Endoscopic cervical decompression

A posterior laminotomy through a 7 mm incision that thins the bony arch and removes the thickened ligament to give the cord room, for compression that comes mainly from behind at one or two levels in a neck that keeps its alignment. No screws or implants. The published evidence is still a handful of series, and we say so; see endoscopic cervical decompression.

Endoscopic cervical foraminotomy

For foraminal stenosis with root symptoms and no cord involvement: the foramen is opened through a 7 mm incision and the root freed. See endoscopic cervical foraminotomy.

ACDF and anterior corpectomy

When the compression sits in front of the cord, from a disc-spur complex or OPLL, or the neck has lost its forward curve, the disc or part of the vertebral body is removed from the front and the segment is fused with a cage or graft and a plate. ACDF (anterior cervical discectomy and fusion) is the usual choice at one to three levels.

Laminoplasty and laminectomy with fusion

Open posterior operations for narrowing over three or more levels: the arches are hinged open or removed, sometimes with screws. The guideline's pooled review of all forms of surgery for myelopathy found a cumulative complication incidence of 14.1%, the most frequent being neck pain (5.6%) and swallowing problems or laryngeal nerve injury (2.2%), with worsening of myelopathy in 1.3% and death in 0.3%.

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 the 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.

For silent stenosis the guideline's answer is a follow-up plan and a list of warning signs, not an operation. When an operation is needed, the team performs the posterior endoscopic foraminotomy and the posterior endoscopic decompression, both through a 7 mm incision without screws or implants, as well as ACDF and multilevel cervical operations; the team operates on all levels, including multilevel cervical cases, and which route fits 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

For silent stenosis that is followed, the majority stay silent: 154 of the 199 patients in the Brno cohort (77.4%) had not developed myelopathy over 2 to 12 years of follow-up. For stenosis operated on for myelopathy, the guideline's pooled review found large improvements in function at 6 to 12 months, 13 to 36 months and beyond 36 months. The BMJ review adds the honest caveats: maximal recovery occurs at around 6 to 12 months, residual symptoms beyond that are likely to be permanent, complete resolution of pain is unlikely, and recovery is most likely when treatment comes within six months of symptoms. After an endoscopic decompression most patients walk the same day; after a fusion the neck is protected for longer while the bone knits. Regular review matters, because untreated levels can degenerate further and compress the cord again.

Living with it and prevention

Learn the warning signs and act on them the week they appear, not the year. Keep moving and keep the neck and shoulder-blade muscles strong. Avoid forceful neck manipulation and extreme sustained extension of the neck, and tell any physiotherapist or masseur that you have cord compression. Nothing sold as a cure for a narrow canal has evidence behind it; spend the money on a follow-up scan instead.