Cervical Myelopathy: Spinal Cord Compression in the Neck

Cervical myelopathy is a progressive condition in which the spinal cord in the neck becomes compressed, leading to problems with hand coordination, balance, walking, and sensation. It is the most common cause of spinal cord dysfunction in adults, and it tends to get worse over time rather than resolve on its own. The compression usually comes from age-related wear on the spine, and the condition’s sneaky quality is that it can develop slowly enough for people to dismiss early symptoms as normal aging until significant damage has already occurred.

What Causes the Compression

The neck portion of the spine, the cervical spine, protects the spinal cord as it travels from the brain down through the body. With age, the structures surrounding the cord can encroach on its space. Disc degeneration and bulging, bone spur formation, thickening of the ligaments, decreased disc height, and arthritis of the facet joints can all contribute to narrowing of the spinal canal, which in turn compresses the spinal cord.¹ These changes are collectively referred to as degenerative cervical myelopathy, or DCM, and they account for the vast majority of cases.

A less common but important cause is ossification of the posterior longitudinal ligament, or OPLL, a condition where the ligament running along the back of the vertebral bodies gradually turns to bone. OPLL can be present for years without symptoms, but it can eventually cause myelopathy and also leaves people more vulnerable to spinal cord injury from trauma like falls or car accidents.² Both the degree of canal narrowing and the amount of motion at the affected spinal level play a role in determining whether someone with OPLL develops myelopathy.³

How the Spinal Cord Gets Damaged

The injury to the spinal cord in cervical myelopathy is not just a simple pinch. Researchers categorize the forces involved into static factors (the physical narrowing of the canal) and dynamic factors (repetitive movement of the neck that causes the cord to rub against the compressing structures). Together, these forces directly damage neurons and the supporting glial cells in the cord.⁴

The direct mechanical injury is only the beginning. Chronic compression also reduces blood flow to the spinal cord, creating a state of ischemia. Oligodendrocytes, the cells responsible for insulating nerve fibers so they can conduct signals efficiently, are particularly sensitive to this blood-flow reduction. When these cells die, the nerve fibers lose their insulation in a process called demyelination, which can progress even after the initial compression stabilizes.⁵ Research on human spinal cord tissue from patients with the condition has confirmed that programmed cell death of both neurons and oligodendrocytes occurs at the compression site, along with an influx of inflammatory cells.⁶ This matters because the early loss of oligodendrocytes can set people up for irreversible neurological deficits even before they notice major symptoms.⁷

Recognizing the Symptoms

Cervical myelopathy tends to announce itself subtly. People often notice clumsiness in their hands first: difficulty buttoning shirts, fumbling with keys, or changes in handwriting. Walking may feel unsteady or stiff, almost as if the legs are not quite obeying instructions. Numbness or tingling in the hands and feet is common, and some people develop a band-like sensation of tightness around the torso. Neck pain and stiffness often accompany these neurological symptoms, though the degree of pain varies widely. In more advanced cases, bladder control can be affected.

The impact of cervical myelopathy extends beyond the spinal cord itself. Brain imaging research has found that patients with the condition show thinning of the cortex in areas responsible for motor planning and hand dexterity, as well as areas involved in visual-motor coordination and gait control.⁸ In other words, the brain itself remodels in response to the disrupted signals from the compressed cord, which may partly explain why recovery after treatment is not always complete.

How Doctors Diagnose It

Diagnosing cervical myelopathy involves piecing together the clinical picture from a physical exam, the patient’s history, imaging, and sometimes electrical nerve testing. On exam, doctors look for specific neurological signs. A systematic review and meta-analysis of clinical tests found that the most sensitive individual signs were hyperreflexia and the Tromner sign, while the most specific signs were the Babinski sign, Tromner, clonus, and the inverted supinator sign.⁹ The Babinski sign, where the big toe extends upward when the sole of the foot is stroked, had the highest positive likelihood ratio among individual tests in one study evaluating diagnostic accuracy.¹⁰

One commonly performed test, the Hoffmann sign (flicking the tip of the middle finger and watching for a reflex twitch of the thumb), turns out to be less useful than many clinicians assume. A prospective study found it had low sensitivity and low specificity for cord compression, and, paradoxically, cord compression on MRI was proportionally more common in patients whose Hoffmann sign was negative.¹¹ A positive Hoffmann sign alone should not be taken as confirmation of myelopathy, and a negative one certainly does not rule it out.

MRI Findings

MRI is the cornerstone of imaging for cervical myelopathy. Increased signal intensity on T2-weighted MRI within the spinal cord generally indicates severe compression and underlying cord damage.¹² Standard MRI taken in a neutral position can sometimes miss compression that becomes apparent when the neck is bent forward or extended backward. A study using flexion-extension MRI found that positional compression at the site of T2 signal abnormality was present in about 85% of patients ultimately diagnosed with cervical spondylotic myelopathy, compared to only about 12% of patients who turned out to have a different cause for their myelopathy symptoms. The odds ratio for cervical myelopathy when positional compression was present was roughly 40 to 1.¹³ Additionally, the degree of dynamic compression change between neck positions has been identified as an independent risk factor for the T2 high signal itself.¹⁴

Electrophysiological Testing

Electrical tests of nerve and spinal cord function, including electromyography, nerve conduction studies, and evoked potentials, serve as useful supplements to imaging. These tests can detect damage to the spinal cord before symptoms become obvious, help localize the level of compression, and help distinguish myelopathy from conditions that affect the peripheral nerves instead.¹⁵ Preoperative evoked potential tests can also help predict how well a patient will recover after surgery, making them a practical tool for surgical planning.¹⁶

What Happens Without Treatment

The natural course of cervical myelopathy is generally one of decline, but the trajectory is not always a straight downhill slope. Two main patterns have been described: a slow, steady worsening over time, and a staircase pattern where function stays stable for stretches before dropping. A retrospective series found that about three-quarters of patients experienced periods of stable function interrupted by episodes of worsening, while roughly one in five had slow, continuous decline.¹⁷

People with mild myelopathy (which is defined by a modified Japanese Orthopaedic Association score, or mJOA, above 14) may do reasonably well for a while without surgery.¹⁸ In one study of conservatively managed mild cases, about 72% actually improved at three years.¹⁹ But people who have spinal cord compression on MRI without symptoms yet (a condition sometimes called non-myelopathic spinal cord compression) are at real risk of eventually developing the full condition. Roughly 8% develop myelopathy symptoms within one year, and around 20% within four years. Abnormalities on evoked potential testing and T2 signal changes on MRI are among the factors that predict who will progress.²⁰

Severity Grading

The mJOA scale is the most widely used tool for grading how much cervical myelopathy is affecting someone’s daily life. It rates motor function of the upper and lower extremities, sensation, and bladder function on a scale from 0 to 18, with lower scores indicating worse impairment. A score of 15 or above is considered mild, 12 to 14 is moderate, and 11 or below is severe.²¹ Patients in the severe category have markedly reduced quality of life and greater disability compared to those in the mild or moderate groups. The mJOA correlates strongly with the original Japanese Orthopaedic Association (JOA) score, which is still used in some Asian countries and scores on a different numerical scale.²²

When Surgery Is Needed and What It Involves

Surgery is generally recommended for moderate and severe cervical myelopathy, and for mild cases that are clearly worsening. The evidence for structured nonoperative treatment, including physical therapy and pain management, is limited. A systematic review found that most patients managed without surgery did not achieve meaningful functional gains, and between roughly a quarter and half of them eventually went on to have surgery anyway.²³ That said, physical therapy may still have a role for people with mild, stable symptoms who are not surgical candidates, or as a supportive treatment before and after surgery. A case report documented improvements in walking, pain, and function with manual therapy and exercise in a patient with mild myelopathy who was not progressing rapidly.²⁴

When surgery is pursued, the two broad categories are anterior approaches (operating through the front of the neck) and posterior approaches (operating through the back). For disease affecting three to five spinal levels, anterior and posterior fusion surgeries produce similar long-term functional outcomes, though anterior surgery tends to result in shorter hospital stays.²⁵

Anterior Procedures

The most common anterior surgery is anterior cervical discectomy and fusion (ACDF), where the damaged disc is removed and the adjacent vertebrae are fused together. For multi-level disease, an alternative is anterior cervical corpectomy and fusion (ACCF), which removes an entire vertebral body to decompress the cord over a longer segment. A meta-analysis comparing the two found both produced good clinical results, but ACDF had better radiographic outcomes and fewer overall complications.²⁶ The hardware used in ACDF has also evolved. A randomized trial comparing a zero-profile device (which sits entirely within the disc space) to a traditional plate-and-screw construct found equivalent improvements in function and alignment, but the zero-profile group had a lower rate of complications and virtually no cases of postoperative hoarseness or swallowing difficulty.²⁷

Posterior Procedures

When compression spans many levels or when the natural curve of the neck favors it, surgeons often choose a posterior approach. The two main posterior options are laminectomy with fusion (removing the back of the vertebrae and then stabilizing with instrumentation) and laminoplasty (hinging open the back of the vertebrae to widen the canal while preserving some mobility). Both produce similar improvements in clinical scores, but laminoplasty preserves more neck motion, has a shorter operating time, lower cost, and a lower rate of C5 nerve palsy.²⁸ ²⁹ A more recent study found that laminectomy with fusion produced greater spinal cord drift (the cord floating backward once the pressure is removed), and patients whose necks had a lordotic curve before surgery tended to get more cord drift and better recovery rates regardless of which posterior technique was used.³⁰

C5 Palsy and Other Surgical Complications

One complication that gets particular attention in cervical myelopathy surgery is C5 palsy, a weakness of the deltoid and biceps muscles that can appear in the days after surgery. A large multicenter review of nearly 14,000 cervical spine surgeries found an overall incidence of about 0.4%, with rates at individual centers ranging from zero to 2.5%. About half of the cases had a delayed onset, appearing more than 24 hours after the operation.³¹ A separate 21-center study reported a slightly higher incidence of about 0.6% and found that posterior surgery carried a greater risk than anterior surgery. Most symptoms appeared within the first three days, and more than half of affected patients recovered within six months.³² The most widely supported explanation is that when the spinal cord drifts backward after decompression, the C5 nerve root, being shorter than its neighbors, gets stretched.³³

Recovery After Surgery

The good news is that surgery generally improves function, pain, and quality of life. Both quality-of-life scores and functional scores improved significantly after surgery in a prospective multi-center study.³⁴ Data from the Swedish Spine Register showed that meaningful improvements in patient-reported outcomes occurred within the first year, with no additional gains after that point.³⁵ In practical terms, this means the first 12 months are the window in which recovery happens; if function has not improved by then, further spontaneous gains are unlikely.

How fast different symptoms recover varies. One retrospective analysis found that upper-extremity strength improved first, averaging about 50 days to improvement, followed by balance at roughly 60 days. Numbness was the slowest to respond, averaging about 85 days, and patients over 60 took significantly longer to regain sensation than younger patients. Smoking before surgery was associated with persistent moderate-to-severe pain in the six months afterward.³⁶

Several patient factors have been linked to worse surgical outcomes: older age, diabetes, obesity, tobacco use, and mental health conditions. From an imaging perspective, the presence of T2 signal changes on preoperative MRI and a longer duration of symptoms before surgery are also associated with poorer recovery.³⁷ One interesting and somewhat counterintuitive finding relates to neck motion after surgery: a study found that patients with greater reduction in cervical range of motion postoperatively actually had better neurological recovery. The researchers suggested that continued dynamic stress on a degenerated cord can impair its healing, even after adequate decompression.³⁸

Conditions That Mimic Cervical Myelopathy

Because cervical myelopathy shares motor symptoms with other neurological diseases, getting the diagnosis right can be tricky, especially in the early stages. The two most important mimics are multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS). All three conditions can produce weakness, stiffness, and abnormal reflexes in the limbs. Key distinguishing features include neck and shoulder pain in cervical myelopathy, visual disturbances in MS, and bulbar symptoms (difficulty speaking or swallowing) along with an absence of sensory deficits in ALS.³⁹ MRI findings help differentiate these conditions: cervical myelopathy shows compression at the stenotic level, MS shows scattered lesions in the brain and spinal cord, and ALS shows relatively normal-looking anatomy on standard imaging. Flexion-extension MRI can be particularly valuable in ambiguous cases, as described earlier.

Inequities in Diagnosis and Treatment

Not everyone with cervical myelopathy gets the same chance at a timely diagnosis and optimal treatment. Research using the US National Inpatient Sample found that insurance status and ethnicity influenced which surgical approach patients received, with private insurance and white ethnicity independently predicting a higher likelihood of receiving an anterior approach. A patient advocacy survey found that diagnostic delay was greater among Black or African American patients, with additional trends for those with lower educational attainment.⁴⁰

Geography matters too. A cohort study found that rural residence was associated with more than double the odds of presenting with worse myelopathy severity scores and significantly longer times to initial presentation. Living in a more socioeconomically disadvantaged neighborhood independently predicted worse severity at presentation as well. Unemployment was the strongest predictor of severe disease at diagnosis, with more than four-fold higher odds of presenting with worse scores, likely reflecting barriers to accessing health care.⁴¹ Given that longer symptom duration before surgery is itself a predictor of poorer outcomes, these delays in access have real consequences for neurological recovery.

Artificial Intelligence in Diagnosis and Prognosis

Researchers are increasingly exploring whether machine learning tools can improve the diagnosis and management of cervical myelopathy. A recent study using radiomics, which extracts quantitative features from MRI images that the human eye cannot easily assess, demonstrated that machine learning could distinguish patients with cervical myelopathy from healthy controls with about 88% accuracy. The same approach classified disease severity with strong performance, outperforming conventional measurements like canal diameter and compression ratios.⁴² A scoping review of AI and machine learning applications in the field found high accuracy across gait analysis, hand-motion tracking, and image-based diagnosis, with some models exceeding 90% sensitivity and specificity. Ensemble models, which combine multiple algorithms, showed particular promise for predicting surgical outcomes.⁴³ These tools are still in the research phase and not yet part of routine clinical practice, but they could eventually help with earlier detection, particularly in settings where access to specialized spine clinicians is limited.