Differentiating multiple sclerosis and cervical symptoms of spinal stenosis can be challenging and new research suggests that for patients with both conditions preoperative MRI results may not offer a clear indication of the likely success of spine surgery. Typically, people with cervical spinal stenosis can be given a pretty good idea of the benefits they could see after neck surgery, but evaluating patients with concurrent MS and cervical stenosis causing myelopathy appears to offer little indication of its usefulness.
Magnetic resonance imaging (MRI) is frequently used to assess the cervical spine as part of the decision-making process regarding neck surgery. Where cervical stenosis is causing spinal cord compression it is almost always necessary to operate in order to decompress the spine and relieve myelopathy. Symptoms of myelopathy may appear very similar in those with MS and cervical stenosis and can include paraesthesia, pain, increasing weakness and muscle atrophy.
As such, operating to decompress the cervical spine may relieve some symptoms or may have little effect if significant demyelination has occurred. Myelin is the substance which insulates nerves and facilitates nerve signalling over longer distances. The deterioration of myelin in MS means that nerve signals are weakened and tend to dissipate before reaching their target. This results in abnormal sensations and problems with mobility. Foot-drop is one symptom of both MS and spinal stenosis and differentiating the two may be difficult, even with the use of imaging.
MRI for MS and Cervical Stenosis
Patients with MS or cervical stenosis may be assessed for spinal cord and nerve lesions, nerve signal intensity, and spinal cord atrophy in order to determine the likely benefit of surgery to relieve myelopathy. When each condition occurs in isolation these factors can help a surgeon determine how successful surgery will typically be in offering symptoms relief. However, as cervical stenosis and MS can both be the cause of spinal cord lesions it may not be possible to accurately predict how effective surgery will be in treating myelopathy.
In this recent review, 48 patients with both MS and cervical stenosis were monitored for an average of 53 months after surgery and Lubelski et al found that there were no significant differences in preoperative imaging that could be connected to patient outcome. In the short-term half the patients had improvement and half did not. At long-term follow-up 37.5% of the patients had improvement and the rest had no improvement. The researchers did note that those who showed short-term improvement were significantly more likely to have high intensity lesions compared to those who did not improve.
Surgical Outcome in MS and Cervical Spinal Stenosis
In another recent paper, Lubelski et al (2014) looked at 77 patients with both MS and cervical stenosis who had symptoms of myelopathy and who underwent cervical spinal decompression surgery. Each patient was matched with a control patient of the same gender and age who did not have MS but who had cervical spondylotic myelopathy or myeloradiculopathy and who underwent the same surgical procedure in the same year.
These researchers looked at the patients’ immediate and long-term postoperative neck pain, radiculopathy, and myelopathy and scores on the Nurick Disability and modified Japanese Orthopaedic Association tests. Average follow-up was 58 months and 49 months respectively for those with MS and cervical stenosis and those with cervical stenosis only.
Preoperative neck pain was more likely in the control group (78% vs. 47%) and preoperative radiculopathy was also more likely (90% vs. 75%). Patients in the MS group were significantly less likely to have symptoms of myelopathy relieved by surgery, with 39% showing no improvement short term (vs. 23% of controls not improving). In the long-term 44% in the MS group did not improve vs. 19% in the control group.
Preoperative myelopathy scores were worse in the MS patients compared to patients with cervical stenosis only and this difference increased at the last follow-up assessment (Nurick scores were 2.4 vs. 0.9). Modified Japanese Orthopaedic Association scores for the MS patients were 16.3 versus 12.4 in the control patients.
Surgical Relief from Myelopathy Temporary and Reduced when MS and Cervical Spinal Stenosis Coincide
The authors concluded that although improvements in myelopathy symptoms do occur in some patients with co-existing MS and cervical stenosis they do so at a lower rate than for patients with cervical stenosis alone. Spine surgery does present a good option for many patients with both MS and cervical spinal stenosis, therefore, but patients should be advised that a significant reduction in symptoms is less likely than for counterparts without MS and that symptoms may only be temporarily relieved due to the progressive nature of MS.
Lubelski D, Alvin MD, Silverstein M, Senol N, Abdullah KG, Benzel EC, Mroz TE. Quality of life outcomes following surgery for patients with coexistent cervical stenosis and multiple sclerosis. Eur Spine J. 2014 May 15. [Epub ahead of print]
Lubelski D, Healy AT, Silverstein MP, Alvin MD, Abdullah KG, Benzel EC1, Mroz TE. Association of Postoperative Outcomes with Preoperative MRI for Patients with Concurrent Multiple Sclerosis and Cervical Stenosis. Spine J. 2014 Jun 18. pii: S1529-9430(14)00615-9.
Lubelski D, Abdullah KG, Alvin MD, Wang TY, Nowacki AS, Steinmetz MP, Ransohoff RM, Benzel EC, Mroz TE. Clinical outcomes following surgical management of coexistent cervical stenosis and multiple sclerosis: a cohort-controlled analysis. Spine J. 2014 Feb 1;14(2):331-7.