Myelopathy Disability Index Research Articles

Myelopathy disability index: establishing criteria for mild, moderate and severe impairment in patients with degenerative cervical myelopathy.

To find the cut-off values in the Myelopathy Disability Index (MDI) that will allow us to classify the severity of Degenerative Cervical Myelopathy (DCM) into mild, moderate and severe. Cross-sectional study with prospective data collection, with a total of 64 patients diagnosed with Degenerative Cervical Myelopathy (DCM). Anthropometric, diagnostic, neurological, functional and quality of life variables were collected. A Receiver Operating Curve (ROC) was performed. The cut-off points were validated by comparing the functional status of patients in the 3 groups and their Nurick scores. Sixty-four patients (23 women) with a mean age of 61.97 (SD 11.57) participated in this study. The majority of patients were Nurick I (28.13%) and Nurick II (32.81%). The medium MDI was 7.36 (SD 6.66) and the mJOA was 14.08 (SD 2.57). The mild-moderate cut-off value was between 4 and 5, with an Area Under the Curve (AUC) of 0.805, sensitivity of 0.853 and specificity of 0.6. For moderate-severe, the cut-off value obtained was between 7 and 8, with an AUC of 0.862, sensitivity of 0.857 and specificity of 0.684. Patients with greater severity had significantly lower functionality, with a P-value of 0.004 in the 30 Metre Walking Test and 0.005 in the Nine-Hole Peg Test. Established severity groups were also significantly related to the different categories of the Nurick score (P-value = 0.000). MDI values between 0 and 4 correspond to mild DCM, between 5 and 7 would be moderate DCM and from 8 to 30 indicate severe DCM.

Utility of Diffusion Basis Spectrum Imaging in Quantifying Baseline Disease Severity and Prognosis of Cervical Spondylotic Myelopathy.

Prospective cohort study. The aim was to assess the association between diffusion tensor imaging (DTI) and diffusion basis spectrum imaging (DBSI) measures and cervical spondylotic myelopathy (CSM) clinical assessments at baseline and two-year follow-up. Despite advancements in diffusion-weighted imaging, few studies have examined associations between diffusion magnetic resonance imaging (MRI) markers and CSM-specific clinical domains at baseline and long-term follow-up. A single-center prospective cohort study enrolled 50 CSM patients who underwent surgical decompression and 20 controls from 2018 to 2020. At initial evaluation, all patients underwent diffusion-weighted MRI acquisition, followed by DTI and DBSI analyses. Diffusion-weighted MRI metrics assessed white matter integrity by fractional anisotropy, axial diffusivity, radial diffusivity, and fiber fraction. To improve estimations of intra-axonal anisotropic diffusion, DBSI measures intra-/extra-axonal fraction and intra-axonal axial diffusivity. DBSI also evaluates extra-axonal isotropic diffusion by restricted and nonrestricted fraction. Clinical assessments were performed at baseline and two-year follow-up and included the modified Japanese Orthopedic Association (mJOA); 36-Item Short Form Survey physical component summary (SF-36 PCS); SF-36 mental component summary; neck disability index; myelopathy disability index; and disability of the arm, shoulder, and hand. Pearson correlation coefficients were computed to compare associations between DTI/DBSI and clinical measures. A False Discovery Rate correction was applied for multiple comparisons testing. At baseline presentation, of 36 correlations analyzed between DTI metrics and CSM clinical measures, only DTI fractional anisotropy showed a positive correlation with SF-36 PCS ( r =0.36, P =0.02). In comparison, there were 30/81 (37%) significant correlations among DBSI and clinical measures. Increased DBSI axial diffusivity, intra-axonal axial diffusivity, intra-axonal fraction, restricted fraction, and extra-axonal anisotropic fraction were associated with worse clinical presentation (decreased mJOA; SF-36 PCS/mental component summary; and increased neck disability index; myelopathy disability index; disability of the arm, shoulder, and hand). At latest follow-up, increased preoperative DBSI intra-axonal axial diffusivity and extra-axonal anisotropic fraction were significantly correlated with improved mJOA. This findings demonstrate that DBSI measures may reflect baseline disease burden and long-term prognosis of CSM as compared with DTI. With further validation, DBSI may serve as a noninvasive biomarker following decompressive surgery. 3.

Myelopathy disability index: Establishing criteria for mild, moderate and severe impairment in patients with degenerative cervical myelopathy

Myelopathy disability index: Establishing criteria for mild, moderate and severe impairment in patients with degenerative cervical myelopathy

Establishing mild, moderate and severe criteria for the myelopathy disability index in cervical spondylotic myelopathy

Aim Cervical Spondylotic Myelopathy (CSM) is a disabling condition arising from arthritic compression and consequent injury of the cervical spinal cord. Stratification of CSM severity has been useful to inform clinical practice and research analysis. In the UK the Myelopathy Disability Index (MDI) is a popular assessment tool and has been adopted by the British Spinal Registry. However, no categories of severity exist. Therefore, the aim of this study was to define categories of mild, moderate and severe. Method An anchor-based analysis was carried out on previously collected data from a prospective observational cohort (N = 404) of patients with CSM scheduled for surgery and assessed pre-operatively and at 3, 12, 24 and 60 months post-operatively. Outcomes collected included the SF-36 version-1 quality of life measure, visual analogue scales for neck/arm/hand pain, MDI and Neck Disability Index (NDI). A Receiver Operating Curve (ROC) analysis, using the NDI for an anchor-based approach, was performed to identify MDI thresholds. Results Complete data was available for 404 patients (219 Men, 185 Women). The majority of patients underwent anterior surgery (284, 70.3%). ROC curves plotted to identify the thresholds from mild to moderate to severe disease, selected optimal thresholds of 4–5 (AUC 0.83) and 8–9 (AUC 0.87). These MDI categories were validated against domains of the SF36 and VAS scores with expected positive linear correlations. Conclusion Categories of mild, moderate and severe CSM according to the MDI of 4–5 and 8–9 were established based on the NDI.

Outcome Measures and Variables Affecting Prognosis of Cervical Spondylotic Myelopathy: WFNS Spine Committee Recommendations.

This study is conducted to review the literature systematically to determine most reliable outcome measures, important clinical and radiological variables affecting the prognosis in cervical spondylotic myelopathy patients. A literature search was performed for articles published during the last 10 years. As functional outcome measures we recommend to use modified Japanese Orthopaedic Association scale, Nurick’s grade, and Myelopathy Disability Index. Three clinical variables that affect the outcomes are age, duration of symptoms, and severity of the myelopathy. Examination findings require more detailed study to validate their effect on the outcomes. The predictive variables affecting the outcomes are hand atrophy, leg spasticity, clonus, and Babinski’s sign. Among the radiological variables, the curvature of the cervical spine is the most important predictor of prognosis. Patients with instability are expected to have a poor surgical outcome. Spinal cord compression ratio is a critical factor for prognosis. High signal intensity on T2-weighted magnetic resonance images is a negative predictor for prognosis. The most important predictors of outcome are preoperative severity and duration of symptoms. T2 hyperintensity and cord compression ratio can also predict outcomes. New radiological tests may give promising results in the future.

Bilateral C1–C2 Transarticular Screw and C1 Laminar Hook Fixation and Bone Graft Fusion for Reducible Atlantoaxial Dislocation: A Seven-Year Analysis of Outcome

BackgroundBilateral C1-2 transarticular screw and C1 laminar hook fixation was developed on the basis of transarticular screws fixation. The modified technique has showed a better biomechanical stability than established techniques in previous study. However, long-term (minimum follow-up 7 years) outcomes of patients with reducible atlantoaxial dislocation who underwent this modified fixation technique have not still been reported.MethodsA retrospective study was conducted to evaluate the outcome of 36 patients who underwent this modified technique. Myelopathy was assessed using the Ranawat myelopathy score and Myelopathy Disability Index. Pain scores were assessed using Visual Analogue Scale. Radiological imaging was assessed and the following data were extracted: the atlantodental intervals, the space available for cord, presence of spinal cord signal change on T2 weighted image, C1–C2 angle, C2–C7 angle and fusion rates.FindingsAll patients achieved a minimum seven-year follow up. 95% patients with neck and suboccipital pain improved after surgery; in their Visual Analogue pain scores, there was a greater than 50% improvement in their VAS scores with a drop of 5 points on the VAS (P<0.05). 92% of patients improved in the Ranawat myelopathy grade; the Myelopathy Disability Index assessment showed a preoperative mean score of 35.62 with postoperative mean 12.75(P<0.05). There was not any significant atlantoaxial instability at each follow-up time. The space available for cord increased in all patients. Postoperative sagittal kyphosis of the subaxial spine was not observed. After six months after surgery, bone grafts of all patients were fused. No complications related to surgery were found in the period of follow-up.ConclusionsThe long-term outcomes of this case series demonstrate that under the condition of thorough preoperative preparations, bilateral C1–C2 transarticular screw and C1 laminar hook fixation and bone graft fusion is a reliable posterior atlantoaxial fusion technique for reducible atlantoaxial dislocation.

The surgical management of the rheumatoid spine: Has the evolution of surgical intervention changed outcomes?

Context:Surgery for the rheumatoid cervical spine has been shown to stabilize the unstable spine; arrest/improve the progression of neurological deficit, help neck pain, and possibly decelerate the degenerative disease process. Operative intervention for the rheumatoid spine has significantly changed over the last 30 years.Aims:The purpose of this study was to review all cases of cervical rheumatoid spine requiring surgical intervention in a single unit over the last 30 years.Materials and Methods:A prospectively-maintained spine database was retrospectively searched for all cases of rheumatoid spine, leading to a review of indications, imaging, Ranawat and Myelopathy Disability Index measures, surgical morbidity, and survival curve analysis.Results:A total of 224 cases were identified between 1981 and 2011. Dividing the data into three time-epochs, there has been a significant increase in the ratio of segment-saving Goel-Harms C1-C2: Occipitocervical fixation (OCF) surgery and survival has increased between 1981 and 2011 from 30% to 51%. Patients undergoing C1-C2 fixation were comparatively less myelopathic and in a better Ranawat class preoperatively, but postoperative outcome measures were well-preserved with favorable mortality rates over mean 39.6 months of follow-up. However, 11% of cases required OCF at mean 28 months post-C1-C2 fixation, largely due to instrumentation failure (80%).Conclusion:We present the largest series of surgically managed rheumatoid spines, revealing comparative data on OCF and C1-C2 fixation. Although survival has improved over the last 30 years, there have been changes in medical, surgical and perioperative management over that period of time too confounding the interpretation; however, the analysis presented suggests that rheumatoid patients presenting early in the disease process may benefit from C1 to C2 fixation, albeit with a proportion requiring OCF at a later time.

Ancillary Outcome Measures for Assessment of Individuals With Cervical Spondylotic Myelopathy

Narrative review. To identify suitable outcome measures that can be used to quantify neurological and functional impairment in the management of cervical spondylotic myelopathy (CSM). CSM is the leading cause of acquired spinal cord disability, causing varying degrees of neurological impairment which impact on independence and quality of life. Because this impairment can have a heterogeneous presentation, a single outcome measure cannot define the broad range of deficits seen in this population. Therefore, it is necessary to define outcome measures that characterize the deficits with greater validity and sensitivity. This review was conducted in 3 stages. Stage I: To evaluate the current use of outcome measures in CSM, PubMed was searched using the name of the outcome measure and the common abbreviation combined with "CSM" or "myelopathy." Stage II: Having identified a lack of appropriate outcome measures, we constructed criteria by which measures appropriate for assessing the various aspects of CSM could be identified. Stage III: A second literature search was then conducted looking at specified outcomes that met these criteria. All literature was reviewed to determine specificity and psychometric properties of outcomes for CSM. Nurick grade, modified Japanese Orthopaedic Association Scale, visual analogue scale (VAS) for pain, Short Form (36) Health Survey (SF-36), and Neck Disability Index were the most commonly cited measures. The Short-Form 36 Health Survey and Myelopathy Disability Index have been validated in the CSM population with multiple studies, whereas the modified Japanese Orthopaedic Association Scale score, Nurick grade, and European Myelopathy Scale each had only one study assessing psychometric characteristics. No validity, reliability, or responsiveness studies were found for the VAS or Neck Disability Index in the CSM population. We recommend that the modified Japanese Orthopaedic Association Scale, Nurick grade, Myelopathy Disability Index, Neck Disability Index, and 30-Meter Walk Test are most appropriate for the assessment of CSM. However, 6 additional outcome measures (QuickDASH, Berg Balance Scale, Graded Redefined Assessment of Strength Sensibility and Prehension, Grip Dynamometer, and GAITRite Analysis) were identified, which provide complementary assessments for CSM. SUMMARY STATEMENTS: There does not exist a single or composite of outcome instruments that measures myelopathy impairment, function/disability, and participation that have also demonstrated reliability, validity, and responsiveness in a CSM population. More work in the development and psychometric evaluation of new or existing measures is necessary to identify the ideal composite of measures to be used in the clinical and research settings. The mJOA, Nurick grade, NDI, MDI, and 30MWT should be adopted in any clinical practice that treats CSM both for screening and clinical follow-up. We propose that clinicians and researchers consider using the ancillary measures identified, such as the QuickDASH, Berg Balance Scale, GRASSP version 1.0, Grip Strength, and GAITRite Analysis. It is highly recommended that baseline and follow-up measurements should be performed in patients with CSM.

Measurement of long-term outcome in patients with cervical spondylotic myelopathy treated surgically

The Myelopathy Disability Index and the Neck Disability Index are widely used to assess outcome in cervical spine surgery. Short Form (SF) 36 is a generic measure of health which can be used to measure health gains across a wide variety of conditions. The aim of the current study is to assess long-term outcomes using these measures in a cohort of patients with cervical spondylotic myelopathy (CSM). Cohort study with prospective data collection. Patients with CSM being offered decompressive surgery were asked to complete a set of generic and condition-specific outcome measures. This was repeated post-operatively at 3, 12, 24 and 60 months. SF-36 was used as a generic outcome measure and the Myelopathy Index, Neck Disability Score and visual analogue scores for arm, neck and hand pain, paraesthesia and dysthaesia were used as condition-specific outcome measures. Significant improvements in all outcome measures were seen in 70% of the cohort. For SF-36, pre-operative scores were lower than age-matched controls in all domains and significant improvements were seen 3 months following surgery. This improvement in outcome was maintained at 5 years follow-up in approximately two-thirds of those with initial improvement. We have used generic and condition-specific outcome measures of health and shown that in patients with CSM treated surgically, up to 70% can expect improvement in their quality of life. These outcome measures are easy to collect and provide objective evidence of changes in quality of life and disability and can help quantify the potential health gains that can be achieved.

British spine surgery

British spine surgery

Anterior cervical corpectomy: review and comparison of results using titanium mesh cages and carbon fibre reinforced polymer cages

Different types of cages have recently become available for reconstruction following anterior cervical corpectomy. We review the results using titanium mesh cages (TMC) and stackable CFRP (carbon fibre reinforced polymer) cages. Forty-two patients who underwent anterior cervical corpectomy between November 2001 and September 2008 were retrospectively reviewed. Pathologies included cervical spondylotic myelopathy (CSM), cervical radiculopathy, OPLL (ossified posterior longitudinal ligament), metastasis/primary bone tumour, rheumatoid arthritis and deformity correction. All patients were evaluated clinically and radiologically. Outcome was assessed on the basis of the Odom's criteria, neck disability index (NDI) and myelopathy disability index (MDI). Mean age was 60 years and mean follow-up was 1½ years. Majority of the patients had single-level corpectomy. Twenty-three patients had TMC cages while 19 patients had CFRP cages. The mean subsidence noted with TMC cage was 1.91 mm, while with the stackable CFRP cage it was 0.5 mm. This difference was statistically significant (p < 0.05). However, there was no statistically significant correlation noted between subsidence and clinical outcome (p > 0.05) or between subsidence and post-operative sagittal alignment (p > 0.05) in either of the groups. Three patients had significant subsidence (>3 mm), one of whom was symptomatic. There were no hardware-related complications. On the basis of the Odom's criterion, 9 patients (21.4%) had an excellent outcome, 14 patients (33.3%) had a good outcome, 9 patients (21.4%) had a fair outcome and 5 patients (11.9%) had a poor outcome, i.e. symptoms and signs unchanged or exacerbated. Mean post-operative NDI was 26.27% and mean post-operative MDI was 19.31%. Fusion was noted in all 42 cases. Both TMC and stackable CFRP cages provide solid anterior column reconstruction with good outcome following anterior cervical corpectomy. However, more subsidence is noted with TMC cages though this might not significantly alter the clinical outcome unless the subsidence is significant (>3 mm).

C1–C2 Transarticular Screw Fixation for Atlantoaxial Instability due to Rheumatoid Arthritis

STUDY DESIGN.: Observational study. Retrospective analysis of prospectively collected data. OBJECTIVE.: The purpose of this article was to report long-term (minimum 7 years) clinical and radiologic outcome of our series of patients with Rheumatoid Arthritis who underwent transarticular screw fixation to treat atlantoaxial subluxation. SUMMARY OF BACKGROUND DATA.: The indications for intervention in patients with atlantoaxial instability are pain, myelopathy, and progressive neurologic deficit. The various treatment options available for these patients are isolated C1-C2 fusion, occipitocervical fusion with or without transoral surgery. Review of current literature suggests that C1-C2 transarticular screw fixation has significant functional benefits, although there is discrepancy in this literature regarding improvement in function following surgery. METHODS.: Myelopathy was assessed using Ranawat myelopathy score and Myelopathy Disability Index. Pain scores were assessed using Visual Analogue Scale. The radiologic imaging was assessed and the following data were extracted; atlanto-dens interval, space available for cord, presence of signal change on T2 weighted image, and fusion rates. RESULTS.: Thirty-seven patients, median age 56, were included in the study. Average duration of neck symptoms was 15.8 months. Average duration of rheumatoid arthritis before surgery was 20.6 years. Preoperative symptoms: suboccipital pain in 26 patients; neck pain, 32; myelopathy, 22; and 5 were asymptomatic. After surgery: suboccipital pain, 2; neck pain, 3; and myelopathy, 10. Ninety percent patients with neck and suboccipital pain improved after surgery in their Visual Analogue pain scores, with all of them having >50% improvement in VAS scores (6.94-2.12 [P < 0.05]).Preoperative Ranawat grade was as follows: grade 1 in 15 patients, grade 2 in 7, and grade 3a in 14, grade 3b in 1.After surgery: grade 1 in 27 patients, grade 2 in 7, grade 3a in 1, and grade 3b in 2. The mean myelopathy score improved after surgery (59.62-32.75, P < 0.05).The space available for the cord was improved in 63%, unchanged in 33%, and worse in 4%.Twenty-seven percent had T2 signal change and 18% had cervicomedullary compression; 97% had bony fusion. BILATERAL SCREWS WERE USED IN 33 PATIENTS AND UNILATERAL SCREWS IN 4 PATIENTS (ABERRANT VERTEBRAL ARTERY).: Computer image guidance was used in 73%. CONCLUSION.: C1-C2 transarticular screw fixation is a safe technique for atlantoaxial subluxation for patients with rheumatoid arthritis. This study clearly demonstrates improvement in Visual Analogue Scale, Ranawat grading and the Myelopathy Disability Index even at long-term follow up.

The Short Form 36 health survey in spine disease—validation against condition-specific measures

Health-Related Quality of Life (HRQoL) assessments in spinal disease offer the potential of outcome measures that better represent patients' disability and response to treatment. The Short Form 36 Health Survey (SF-36) is a generic HRQoL questionnaire that has been extensively used in primary and secondary care, but before it can be routinely applied in patients with spinal disease must be validated against traditional specific measures of physical and mental morbidity. Patients with lumbar disc prolapse, lumbar canal stenosis, and cervical spondylotic radiculomyelopathy were identified from a prospectively maintained database. Visual Analogue Scales (VAS) and condition-specific questionnaires including the Roland Morris Disability Score (RMDS), Myelopathy Disability Index (MDI), and Hospital Anxiety and Depression Scales (HADS), were completed alongside the SF-36 survey at baseline and following surgery. Convergent, discriminant, and predictive validity were assessed by computing correlations between the specific and generic scores. In addition, responsiveness (Standardised Response Mean, SRM) and floor and ceiling effects were examined. Data from 1623 assessments of 620 patients were available. Convergent validity was shown by strong correlations between condition-specific physical scores (MDI or RMDS) and the Physical Function and Bodily Pain domains of SF-36 (ρ = -0.52 to -0.76, all p < 0.01). VAS for leg or arm pain were also strongly correlated with Bodily Pain domain scores (ρ = -0.54 to -0.77, all p < 0.01). Discriminant validity was confirmed by non-significant partial correlations between Physical Function and Mental Health SF-36 domains when controlled for HADS scores (r = −0.01 to 0.02, p > 0.05). Predictive validity was demonstrated by similar correlations between pre- and post-operative scores for specific and generic instruments. Physical Function, Bodily Pain, and Mental Health domains were all free of significant floor or ceiling effects and showed moderate to good responsiveness (SRM 0.54-1.72). SF-36 domain scores are valid for measuring morbidity and surgical outcomes in common spinal disorders.

Measurement of outcome in patients with cervical spondylotic myelopathy treated surgically

The objective was to establish the role of the Short Form 36 (SF 36) as an objective measure of clinical outcome in cervical spondylotic myelopathy (CSM), and took the form of a prospective observational study. Seventy patients with symptomatic CSM were treated by surgical decompression. Health status was measured pre- and 3 months postoperation using objective, validated patient completed measures. These were the SF 36, neck disability index, myelopathy disability index and analogue scores for neck pain and arm symptoms. SF 36 scores were compared with age matched control data. Twelve-month postoperative data are available in a proportion of the cohort. CSM patients have lower preoperative SF 36 scores than age-matched population controls. Comparing pre- and postoperative SF36 scores for the physical functioning domain 64% of patients improve, 23% show no change and 14% of patients continue to deteriorate (Wilcoxon P< 0.0001). These changes are replicated in other domains of the SF36 and by the other measures of outcome. The SF36 is responsive, valid, and practical. Its use for determining outcome in the surgical treatment of CSM is recommended.

Measurement of outcome in patients with cervical spondylotic myelopathy treated surgically

The objective was to establish the role of the Short Form 36 (SF 36) as an objective measure of clinical outcome in cervical spondylotic myelopathy (CSM), and took the form of a prospective observational study. Seventy patients with symptomatic CSM were treated by surgical decompression. Health status was measured pre- and 3 months postoperation using objective, validated patient completed measures. These were the SF 36, neck disability index, myelopathy disability index and analogue scores for neck pain and arm symptoms. SF 36 scores were compared with age matched control data. Twelve-month postoperative data are available in a proportion of the cohort. CSM patients have lower preoperative SF 36 scores than age-matched population controls. Comparing pre- and postoperative SF36 scores for the physical functioning domain 64% of patients improve, 23% show no change and 14% of patients continue to deteriorate (Wilcoxon P< 0.0001). These changes are replicated in other domains of the SF36 and by the other measures of outcome. The SF36 is responsive, valid, and practical. Its use for determining outcome in the surgical treatment of CSM is recommended.

Clinical and radiological correlates of severity and surgery-related outcome in cervical spondylosis

The aim of this study was to determine if radiological features could be used to predict outcome in patients with cervical spondylotic myelopathy (CSM). The authors studied 69 patients consecutively referred to The National Hospital, Queen Square, for decompressive surgery. Data obtained from preoperative cervical spine magnetic resonance (MR) imaging studies were each analyzed on two separate occasions by two blinded radiologists. The parameters determined were signal change and the presence and severity of compression. Clinical outcome was determined by pre- and postoperative timed walks, as well as by evaluation of myelopathy disability index scores, Ranawat classification, and Nurick grades. There was good inter- and intraobserver reliability for determination of radiological data. A significant relationship was found between MR imaging signal change and surgery-related outcome, as reflected by improvement in walking parameters; however, this was confounded by the fact that signal change also related to preoperative walking parameters, and those patients for whom preoperative walking function was worse experienced greater functional improvement in walking postoperatively. The relationships between ambulatory-related data and severity or extent of spinal cord compression were less marked. Cervical cord compression and intrinsic MR imaging signal change correlate with clinical severity, and, in this population, the presence of signal change was correlated with better surgery-related outcome. However, confounding factors and the lack of strong correlation indicate that these radiological measurements are insufficient to be used as a reliable tool for predicting surgery-related benefits in individual patients.

Quantitative assessment of cervical spondylotic my elopathy by a simple walking test

We developed a 30 m walking test as a quantifiable measure of severity of cervical spondylotic myelopathy (CSM), which will be of use in determining the effects of decompressive surgical treatment. Preoperative measurements were made in 41 patients with CSM of 30 m walking times, number of steps taken over this distance, myelopathy disability index (MDI), and Nurick scores. The walking factors were compared with a similar number of age-matched and sex-matched controls. The individuals in the study were patients with CSM and no other relevant pathology consecutively referred for decompressive surgery to the National Hospital for Neurology and Neurosurgery. Both walking time and the number of steps taken were significantly worse in pre-operative patients than in controls. The walking data were highly reproducible over three trials. Postoperatively, there was a significant improvement in walking time (p=0.0018) and number of steps taken (p=5.87 x 10(-6)). Only two of 41 patients were worse postoperatively. There was also a significant improvement in MDI (two-tailed Wilcoxon, related samples; p<0.0001) and Nurick scores (two-tailed Wilcoxon p<0.0001) postoperatively. The preoperative and postoperative walking scores were significantly and equally correlated with the MDI and Nurick scores. Timed walks are an easily performed, quantitative, and valid means of assessing CSM and the effects of surgery.

Development of a functional scoring system for rheumatoid arthritis patients with cervical myelopathy.

To be able to measure disability objectively in rheumatoid arthritis complicated by cervical myelopathy. The responses to the Stanford health assessment questionnaire disability index were recorded from 250 consecutive patients (group 1) referred to our unit for spinal surgery. Using principal components analysis the questionnaire was reduced from 20 questions to 10 questions. In the second part of the study, the results of the questionnaire for those patients undergoing surgery from the original group of 250 patients were analysed with respect to outcome. The reduction in the number of questions results in no significant loss of information, reliability (internal consistency Cronbach's alpha = 0.968) or sensitivity. The new scale, the myelopathy disability index, measures only one dimension (Eigen value 6.97) and may be more finely tuned to the measurement of disability in these myelopathic patients. When administered to the 194 patients undergoing cervical spine (group 2) surgery the myelopathy disability index was an accurate predictor of neurological and functional outcome, as well as survival following surgery (P < 0.0001). The myelopathy disability index provides a much needed objective and reliable means of assessing disability in patients with rheumatoid involvement of the cervical spine and also in predicting outcome following surgical intervention. It also provides information for both the patient and surgeon alike, on what to realistically expect from surgery. Its adoption should facilitate comparisons between different forms of surgical intervention.