Tag: cervical spondylotic myelopathy

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The Relationship Between Preoperative Clinical Presentation and Quantitative Magnetic Resonance Imaging Features in Patients With Degenerative Cervical Myelopathy

Neurosurgery 80:121–128, 2017

Degenerative cervical myelopathy encompasses a group of conditions resulting in progressive spinal cord injury through static and dynamic compression. Although a constellation of changes can present on magnetic resonance imaging (MRI), the clinical significance of these findings remains a subject of controversy and discussion.

OBJECTIVE: To investigate the relationship between clinical presentation and quantitative MRI features in patients with degenerative cervical myelopathy.

METHODS: A secondary analysis of MRI and clinical data from 114 patients enrolled in a prospective, multicenter study was conducted. MRIs were assessed for maximum spinal cord compression (MSCC), maximum canal compromise (MCC), signal changes, and a signal change ratio (SCR). MRI features were compared between patients with and those without myelopathy symptoms with the use of t tests. Correlations between MRI features and duration of symptoms were assessed with the Spearman ρ.

RESULTS: Numb hands and Hoffmann sign were associated with greater MSCC (P < .05); broad-based, unstable gait, impairment of gait, and Hoffmann sign were associated with greaterMCC (P<.05); andnumbhands,Hoffmann sign, Babinski sign, lower limb spasticity, hyperreflexia, and T1 hypointensitywere associated with greater SCR (P<.05). Patientswith a T2 signal hyperintensity had greater MSCC and MCC (P < .001).

CONCLUSION: MSCC was associated with upper limb manifestations, and SCR was associated with upper limb, lower limb, and general neurological deficits. Hoffmann sign occurred more commonly in patients with a greater MSCC,MCC and SCR. The Lhermitte phenomenon presented more commonly in patientswith a lower SCR and may be an early indicator of mild spinal cord involvement. Research to validate these findings is required.

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Clinical and Surgical Predictors of Complications Following Surgery for the Treatment of Cervical Spondylotic Myelopathy

Clinical_and_Surgical_Predictors_of_Complications

Neurosurgery 79:33–44, 2016

Surgery for cervical spondylotic myelopathy (CSM) is generally safe and effective. Nonetheless, complications occur in 11% to 38% of patients. Knowledge of important predictors of complications will help clinicians identify high-risk patients and institute prevention and management strategies.

OBJECTIVE: To identify clinical and surgical predictors of perioperative complications in CSM patients.

METHODS: Four hundred seventy-nine surgical CSM patients were enrolled in the prospective CSM-International study at 16 sites. A panel of physicians reviewed all adverse events and classified each as related or unrelated to surgery. Univariate analyses were performed to determine differences between patients who experienced a perioperative complication and those who did not. A complication prediction rule was developed using multiple logistic regression.

RESULTS: Seventy-eight patients experienced 89 perioperative complications (16.25%). On univariate analysis, the major clinical risk factors were ossification of the posterior longitudinal ligament (OPLL) (P = .055), number of comorbidities (P = .002), comorbidity score (P = .006), diabetes mellitus (P = .001), and coexisting gastrointestinal (P = .039) and cardiovascular (P = .046) disorders. Patients undergoing a 2-stage surgery (P = .002) and those with a longer operative duration (P = .001) were at greater risk of perioperative complications. A final prediction model consisted of diabetes mellitus (odds ratio [OR] = 1.96, P = .060), number of comorbidities (OR = 1.20, P = .069), operative duration (OR = 1.07, P = .002), and OPLL (OR = 1.75, P = .040).

CONCLUSION: Surgical CSM patients have a higher risk of perioperative complications if they have a greater number of comorbidities, coexisting diabetes mellitus, OPLL, and a longer operative duration. Surgeons can use this information to discuss the risks and benefits of surgery with patients, to plan case-specific preventive strategies, and to ensure appropriate management in the perioperative period.

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Two-level corpectomy versus three-level discectomy for cervical spondylotic myelopathy

Two-level corpectomy versus three-level discectomy for cervical spondylotic myelopathy

J Neurosurg Spine 23:280–289, 2015

In the treatment of cervical spondylotic myelopathy (CSM), anterior cervical corpectomy and fusion (ACCF) and anterior cervical discectomy and fusion (ACDF) are effective decompressive techniques. It remains to be determined whether ACCF and ACDF offer equivalent outcomes for multilevel CSM. In this study, the authors compared perioperative, radiographic, and clinical outcomes between 2-level ACCF and 3-level ACDF.

Methods Between 2006 and 2012, all patients at the authors’ hospital who underwent 2-level ACCF or 3-level ACDF performed by 1 of 2 surgeons were identified. Primary outcomes of interest were sagittal Cobb angle, adjacent-segment disease (ASD) requiring surgery, neck pain measured by visual analog scale (VAS), and Nurick score. Secondary outcomes of interest included estimated blood loss (EBL), length of stay, perioperative complications, and radiographic pseudarthrosis rate. Chi-square tests and 2-tailed Student t-tests were used to compare the 2 groups. A subgroup analysis of patients without posterior spinal fusion (PSF) was also performed.

Results Twenty patients underwent 2-level ACCF, and 35 patients underwent 3-level ACDF during a 6-year period. Preoperative Nurick scores were higher in the ACCF group (2.1 vs 1.1, p = 0.014), and more patients underwent PSF in the 2-level ACCF group compared with patients in the 3-level ACDF group (60.0% vs 17.1%, p = 0.001). Otherwise there were no significant differences in demographics, comorbidities, and baseline clinical parameters between the 2 groups. Two-level ACCF was associated with significantly higher EBL compared with 3-level ACDF for the anterior stage of surgery (382.2 ml vs 117.9 ml, p < 0.001). Two-level ACCF was also associated with a longer hospital stay compared with 3-level ACDF (7.2 days vs 4.9 days, p = 0.048), but a subgroup comparison of patients without PSF showed no significant difference in length of stay (3.1 days vs 4.4 days for 2-level ACCF vs 3-level ACDF, respectively; p = 0.267). Similarly, there was a trend toward more complications in the 2-level ACCF group (20.0%) than the 3-level ACDF group (5.7%; p = 0.102), but a subgroup analysis that excluded those who had second-stage PSF no longer showed the same trend (2-level ACCF, 0.0% vs 3-level ACDF, 3.4%; p = 0.594). There were no significant differences between the ACCF group and the ACDF group in terms of postoperative sagittal Cobb angle (7.2° vs 12.1°, p = 0.173), operative ASD (6.3% vs 3.6%, p = 0.682), and radiographic pseudarthrosis rate (6.3% vs 7.1%, p = 0.909). Both groups had similar improvement in mean VAS neck pain scores (3.4 vs 3.2 for ACCF vs ACDF, respectively; p = 0.860) and Nurick scores (0.8 vs 0.7, p = 0.925).

Conclusions Two-level ACCF was associated with greater EBL and longer hospital stays when patients underwent a second-stage PSF. However, the length of stay was similar when patients underwent anterior-only decompression with either 2-level ACCF or 3-level ACDF. Furthermore, perioperative complication rates were similar in the 2 groups when patients underwent anterior decompression without PSF. Both groups obtained similar postoperative cervical lordosis, operative ASD rates, radiographic pseudarthrosis rates, neurological improvement, and pain relief.

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A clinical prediction model to assess surgical outcome in patients with cervical spondylotic myelopathy

A clinical prediction model to assess surgical outcome in patients with cervical spondylotic myelopathy

The Spine Journal 15 (2015) 388–397

Clinical prediction rules are valuable tools in a surgical setting but should not be used to guide clinical practice until validated in other populations.

PURPOSE: The objective of this study was to validate a clinical prediction rule developed to determine surgical outcome in patients with cervical spondylotic myelopathy (CSM). The study will also identify key clinical predictors of outcome at a global level.

STUDY DESIGN/SETTING: This is a prospective multicenter cohort study.

PATIENT SAMPLE: Two-hundred seventy-eight and 479 surgical CSM patients enrolled in the AOSpine CSM—North American (CSM-NA) and CSM—International (CSM-I) studies, respectively.

OUTCOME MEASURES: The outcome measure was a Modified Japanese Orthopedic Association (mJOA) Scale.

METHODS: A clinical prediction model was built using data from 272 patients enrolled in the CSM-NA study. Bootstrapping was used for internal validation. The original model was externally validated using data on 471 patients participating in the CSM-I study. The predictive performance of the model was evaluated, including its discrimination, measured by area under the receiver operating curve (AUC), and calibration, assessed by calibration slope, observed: expected ratios, and Hosmer-Lemeshow goodness-of-fit test.

RESULTS: The modified original model consisted of six covariates: age (odds ratio [OR], 0.96), duration of symptoms (0.76), baseline severity score (1.21), psychiatric comorbidities (0.44), impairment of gait (2.48), and smoking status (0.50). The AUC for the original model was 0.77 (95% confidence interval [CI]: 0.71, 0.82) and across the bootstrap replicates was 0.77 (95% CI: 0.76, 0.77), reflecting good discrimination and internal validity. The model tested on the CSM-I dataset yielded an AUC of 0.74 (95% CI: 0.69, 0.79), a calibration slope of 0.75, and an insignificant Hosmer-Lemeshow test. The ORs generated for baseline mJOA (OR, 1.26), impairment of gait (2.67), age (0.97), and smoking (0.55) were very similar to the original values of 1.28, 2.39, and 0.97, respectively. Duration of symptoms (OR, 0.94) had a significantly different odds ratio than in the original model, but the direction of its relationship with outcome was the same. Psychiatric comorbidities was not a significant predictor at an international level, likely because of underreporting: only six patients outside of North American centers were diagnosed with depression or bipolar.

CONCLUSIONS: The parameter estimates generated from the original analysis were internally valid. The original model was also externally valid. The most significant global predictors of surgical outcome were baseline myelopathy severity, age, smoking status and impaired gait.

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Anterior cervical discectomy versus corpectomy for multilevel cervical spondylotic myelopathy: a meta-analysis

Anterior cervical discectomy versus corpectomy for multilevel cervical spondylotic myelopathy

Eur Spine J (2015) 24:31–39

This is a meta-analysis to compare the results between anterior cervical discectomy fusion (ACDF) and anterior cervical corpectomy fusion (ACCF) for the patients with multilevel cervical spondylotic myelopathy (MCSM).

Methods Systematic review and meta-analysis of cohort studies between ACDF with plate fixation and ACCF with plate fixation for the treatment of MCSM. An extensive search of literature was performed in PubMed, Mediline, Embase and the Cochrane library. The following outcome measures were extracted: JOA scores, fusion rate, cervical lordosis (C2–7), complications, blood loss and operation time. Data analysis was conducted with RevMan 5.0.

Results Four cohorts (six studies) involving 258 patients were included in this study. The pooled analysis showed that there was no significant difference in the postoperative JOA score [WMD = -0.14 (-1.37, 1.10), P = 0.83], fusion rate [OR = 0.84 (0.15, 4.86), P = 0.85] between two group. However, there was significant difference in the cervical lordosis [WMD = 3.38 (2.52, 4.23), P<0.00001], surgical complication rate and instrument related complication rate (P = 0.01, 0.005 respectively), blood loss [WMD = -52.53 (-73.53, -31.52), P<0.00001], and operation time [WMD = -14.10 (-20.27, -7.93), P<0.00001].

Conclusions As compared with ACCF with plate fixation, ACDF with plate fixation showed no significant differences in terms of postoperative JOA score, fusion rate, but better improved cervical lordosis, lower complication and smaller surgical trauma. As the limitations of small sample and short follow-up in this study, it still could not be identified whether ACDF with plate fixation is more effective and safer than ACCF with plate fixation.

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Cervical Spondylotic Myelopathy Surgical Trial: Randomized, Controlled Trial Design and Rationale

Cervical Spondylotic Myelopathy Surgical Trial- Randomized, Controlled Trial Design and Rationale

Neurosurgery 75:334–346, 2014

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction in the world. There are significant practice variation and uncertainty as to the optimal surgical approach for treating CSM.

OBJECTIVE: To determine whether ventral surgery is associated with superior Short Form- 36 Physical Component Summary outcome at the 1-year follow-up compared with dorsal (laminectomy/fusion or laminoplasty) surgery for the treatment of CSM, to investigate whether postoperative sagittal balance is an independent predictor of overall outcome, and to compare health resource use for ventral and dorsal procedures.

METHODS: The study is a randomized, controlled trial with a nonrandomized arm for patients who are eligible but decline randomization. Two hundred fifty patients (159 randomized) with CSM from 11 sites will be recruited over 18 months. The primary outcome is the Short Form-36 Physical Component Summary score. Secondary outcomes include disease-specific outcomes, overall health-related quality of life (EuroQOL 5-dimension questionnaire), and health resource use.

EXPECTED OUTCOMES: This will be the first randomized, controlled trial to compare directly the health-related quality-of-life outcomes for ventral vs dorsal surgery for treating CSM.

DISCUSSION: A National Institutes of Health-funded (1R13AR065834-01) investigator meeting was held before the initiation of the trial to bring multiple stakeholders together to finalize the study protocol. Study investigators, coordinators, and major stakeholders were able to attend and discuss strengths of, limitations of, and concerns about the study. The final protocol was approved for funding by the Patient-Centered Outcomes Research Institute (CE-1304-6173). The trial began enrollment on April 1, 2014.

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Outcomes of surgical intervention for cervical spondylotic myelopathy accompanying local kyphosis

cervical kyphosis

Eur Spine J (2014) 23:341–346

The surgical strategy for cervical spondylotic myelopathy (CSM) accompanying local kyphosis is controversial. The purpose of the present study was to compare and evaluate the outcomes of two types of surgery for CSM accompanying local kyphosis: (1) laminoplasty alone (LP) and (2) posterior reconstruction surgery (PR) in which we corrected the local kyphosis using a pedicle screw or lateral mass screw.

Methods Sixty patients who presented with local kyphosis exceeding 5º were enrolled. LP and PR were each performed on a group of 30 of these patients; 30 CSM patients without local kyphosis, who had undergone LP, were used as controls. The follow-up period was 2 years or longer. Preoperative local kyphosis angles in LP and PR were 8.3 ± 4.4 and 8.8 ± 5.7, respectively. Preoperative C2–7 angles in LP, PR and controls were -1.7 ± 9.6, -0.4 ± 7.2 and -12.0 ± 5.6, respectively. The recovery rate of the JOA score, local kyphosis angle and C2–7 angle at post-op and follow-up were compared between the groups.

Results The recovery rate of the JOA score in the LP group (32.6 %) was significantly worse than that in the PR group (44.5 %) and that of controls (53.8 %). Local kyphosis angles in the PR and LP groups at follow-up were 4.0 ± 8.6 and 8.0 ± 6.0, respectively. However, although the C2–7 angle at follow-up was improved to -11.1 ± 12.7 in PR, and maintained at -11.6 ± 6.2 in controls, it deteriorated to 0.5 ± 12.7 in LP.

Conclusions The present study is the first to compare the outcomes between LP alone and PR for CSM accompanying local kyphosis. It revealed that PR resulted in a better clinical outcome than did LP alone. This result may be due to reduction of local kyphosis, stabilization of the unstable segment, and/or the maintenance of C2–7 angle until follow- up in the PR group.

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Predictors of Surgical Outcome in Cervical Spondylotic Myelopathy

Predictors of Surgical Outcome in Cervical Spondylotic Myelopathy

Spine 2013 ; 38 : 392 – 400

Study Design. Prospective study.

Objective. To determine whether magnetic resonance imaging and clinical and demographic fi ndings in patients with cervical spondylotic myelopathy (CSM) were independently associated with baseline functional scores and whether these were also predictive of postoperative functional outcomes.

Summary of Background Data. There are considerable limitations in current literature that prevent making formal recommendations regarding the use of clinical and radiological prognostic factors in patients with CSM.

Methods. This prospective study included 65 consecutive patients with CSM treated in a tertiary referral center. The modifi ed Japanese Orthopaedic Association (mJOA) scale was used to quantify disability at admission and at 12-month follow-up. Age, sex, duration of symptoms, severity of myelopathy, spinal column alignment, surgical technique, levels of compression, anteroposterior diameter and transverse area at the site of maximal cord compression, and magnetic resonance imaging signal intensity changes were assessed. Data were analyzed using Spearman rank correlation test, analysis of variance, Mann–Whitney U test, and stepwise multivariate regression.

Results. Higher baseline mJOA scores were associated with younger age ( P = 0.0002), shorter duration of symptoms ( P = 0.03), and greater transverse area ( P = 0.02). Better recovery ratio was associated with younger age ( P = 0.005) and higher baseline mJOA score ( P = 0.003). Greater changes in mJOA score were associated with higher baseline mJOA score (P < 0.0001). Using multivariate analysis, the functional outcomes after surgery were best predicted by baseline mJOA score and age of patient.

Conclusion. Age and baseline mJOA scores were highly predictive of outcome for patients undergoing surgical treatment of CSM. The degree of spinal cord compression and patterns of signal intensity changes on T1/T2 weighted images were not independently predictive of outcome, but it was found to correlate with the functional status at the time of presentation and age of the patient. The duration of symptoms correlated well with preoperative functional status but did not seem to affect the postoperative outcome.

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Complications associated with the surgical treatment of cervical spondylotic myelopathy

J Neurosurg Spine 16:425–432, 2012. (http://thejns.org/doi/abs/10.3171/ 2012.1.SPINE11467) 

Rates of complications associated with the surgical treatment of cervical spondylotic myelopathy (CSM) are not clear. Appreciating these risks is important for patient counseling and quality improvement. The authors sought to assess the rates of and risk factors associated with perioperative and delayed complications associated with the surgical treatment of CSM.

Methods. Data from the AOSpine North America Cervical Spondylotic Myelopathy Study, a prospective, multicenter study, were analyzed. Outcomes data, including adverse events, were collected in a standardized manner and externally monitored. Rates of perioperative complications (within 30 days of surgery) and delayed complications (31 days to 2 years following surgery) were tabulated and stratified based on clinical factors.

Results. The study enrolled 302 patients (mean age 57 years, range 29–86) years. Of 332 reported adverse events, 73 were classified as perioperative complications (25 major and 48 minor) in 47 patients (overall perioperative complication rate of 15.6%). The most common perioperative complications included minor cardiopulmonary events (3.0%), dysphagia (3.0%), and superficial wound infection (2.3%). Perioperative worsening of myelopathy was reported in 4 patients (1.3%). Based on 275 patients who completed 2 years of follow-up, there were 14 delayed complications (8 minor, 6 major) in 12 patients, for an overall delayed complication rate of 4.4%. Of patients treated with anterior-only (n = 176), posterior-only (n = 107), and combined anterior-posterior (n = 19) procedures, 11%, 19%, and 37%, respectively, had 1 or more perioperative complications. Compared with anterior-only approaches, posterior-only approaches had a higher rate of wound infection (0.6% vs 4.7%, p = 0.030). Dysphagia was more common with combined anterior-posterior procedures (21.1%) compared with anterior-only procedures (2.3%) or posterior-only procedures (0.9%) (p < 0.001). The incidence of C-5 radiculopathy was not associated with the surgical approach (p = 0.8). The occurrence of perioperative complications was associated with increased age (p = 0.006), combined anterior-posterior procedures (p = 0.016), increased operative time (p = 0.009), and increased operative blood loss (p = 0.005), but it was not associated with comorbidity score, body mass index, modified Japanese Orthopaedic Association score, smoking status, anterior-only versus posterior-only approach, or specific procedures. Multivariate analysis of factors associated with minor or major complications identified age (OR 1.029, 95% CI 1.002–1.057, p = 0.035) and operative time (OR 1.005, 95% CI 1.002–1.008, p = 0.001). Multivariate analysis of factors associated with major complications identified age (OR 1.054, 95% CI 1.015–1.094, p = 0.006) and combined anterior-posterior procedures (OR 5.297, 95% CI 1.626–17.256, p = 0.006).

Conclusions. For the surgical treatment of CSM, the vast majority of complications were treatable and without long-term impact. Multivariate factors associated with an increased risk of complications include greater age, increased operative time, and use of combined anterior-posterior procedures.

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Can Elderly Patients Recover Adequately After Laminoplasty?

Spine 2012 ; 37 : 667 – 671 

This was a prospective clinical comparative study of surgical outcomes for patients with cervical spondylotic myelopathy (CSM).

Objective. The purpose of this study was to compare the surgical outcomes between nonelderly and elderly patients with CSM who underwent laminoplasty.

Summary of Background Data. Age at the time of surgery influences the surgical outcome. We designed a large-scale study of the surgical outcome for CSM from a single operative procedure used exclusively in elderly patients.

Methods. A total of 520 consecutive patients with CSM (331 men; 189 women) who underwent double-door laminoplasty were included. Mean age was 62 years (range, 23–93), and mean duration of disease was 20.1 ± 32.0 months. Average postoperative followup period was 33.3 ± 15.7 months. Patients were divided into 3 groups by age: nonelderly ( < 65 years), young-old (65–74 years), and old-old ( ≥ 75 years). The number of patients in each group was 287, 143, and 90. Pre- and postoperative neurological status was evaluated using the Japanese Orthopaedic Association scoring system for cervical myelopathy (JOA score).

Results. Mean pre- and postoperative JOA scores in nonelderly, young-old, and old-old groups were 11.0 and 14.4, 10.2 and 13.2, and 8.7 and 11.8 points, respectively. The elderly group showed significantly low recovery rates of JOA scores compared with the nonelderly group ( P < 0.0001). However, mean achieved JOA scores (postoperative JOA score − preoperative JOA score) were 3.4, 3.0, and 3.1 in nonelderly, young-old, and old-old groups, respectively, with no significant difference among these groups ( P = 0.17).

Conclusion. Pre- and postoperative JOA scores were low in elderly patients. However, the achieved JOA score was almost similar among the 3 groups. Thus, elderly patients could obtain reasonable recovery after cervical laminoplasty.

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Randomized, Controlled, Multicenter, Clinical Trial Comparing BRYAN Cervical Disc Arthroplasty With Anterior Cervical Decompression and Fusion in China

Spine 2012 ; 37 : 433 – 438. DOI: 10.1097/BRS.0b013e31822699fa

Study Design. Prospective, randomized, controlled, multicenter clinical trial.

Objective. To compare outcomes of cervical disc arthroplasty with those of anterior cervical decompression and fusion (ACDF) in a Chinese population.

Summary of Background Data. Cervical disc arthroplasty has been found to be superior to ACDF for maintaining range of motion (ROM) at the index spinal segment and possibly will avoid abnormal stress to adjacent segments.

Methods. A total of 120 patients from 3 large hospitals in China were randomly assigned to treatment with cervical disc arthroplasty (n = 60) using the BRYAN prosthesis or ACDF (n = 60) and were observed postoperatively for 24 months.

Results. The 2 groups had similar preoperative demographics and baseline characteristics including ROM, neck disability index, and visual analogue scale for neck and arm pain. The total disc replacement (TDR) group had a significantly longer operation time than the ACDF group ( P < 0.001). Outcome data obtained after 24 months revealed a significant difference between the groups in mean change from baseline in ROM at the index level ( P < 0.001); ROM was maintained in the TDR group but reduced in the ACDF group. There were no signifi cant between-group differences in the baseline changes in neck disability index or visual analogue scale scores for pain. One patient in the TDR group and 4 patients in the ACDF group required reoperations.

Conclusion. At 24 months after surgery, the cervical disc prosthesis yielded good clinical results while maintaining ROM at the index level. Cervical disc arthroplasty appears to be a viable alternative to ACDF.

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Magnetic Resonance Diffusion Tensor Imaging in Patients With Cervical Spondylotic Spinal Cord Compression

Spine 2012 ; 37 : 48 – 56

Study Design. A prospective study evaluating a cohort of patients with spondylotic cervical spine compression.

Objective. To analyze the potential of diffusion tensor imaging (DTI) of the cervical spinal cord in the detection of changes associated with spondylotic myelopathy, with particular reference to clinical and electrophysiological fi ndings.

Summary of Background Data. Conventional magnetic resonance imaging (MRI) may provide confusing fi ndings because of a frequent disproportion between the degree of the spinal cord compression and clinical symptoms . The DTI is known to be more sensitive to subtle pathological changes of the spinal cord compared with conventional MRI. Methods. The DTI of the cervical spinal cord was performed within a group of 52 patients with spondylotic spinal cord compression and 13 healthy volunteers on a 1.5-T MRI scanner. All patients underwent clinical examination that differentiated between asymptomatic and symptomatic myelopathy subgroups, and 45 patients underwent electrophysiological examination. We measured the apparent diffusion coeffi cient and fractional anisotropy of the spinal cord at C2/C3 level without compression and at the maximal compression level (MCL). Sagittal spinal canal diameter, cross-sectional spinal cord area, and presence of T2 hyperintensity at the MCL were also recorded. Nonparametric statistical testing was used for comparison of controls with subgroups of patients.

Results. Significant differences in both the DTI parameters measured at the MCL, between patients with compression and control group, were found, while no difference was observed at the noncompression level. Moreover, fractional anisotropy values were lower and apparent diffusion coeffi cient values were higher at the MCL in the symptomatic patients than in the asymptomatic patients. The DTI showed higher potential to discriminate between clinical subgroups in comparison with standard MRI parameters and electrophysiological fi ndings.

Conclusion. The DTI appears to be a promising imaging modality in patients with spondylotic spinal cord compression. It refl ects the presence of symptomatic myelopathy and shows considerable potential for discriminating between symptomatic and asymptomatic patients.

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Postoperative Magnetic Resonance Imaging Can Predict Neurological Recovery After Surgery for Cervical Spondylotic Myelopathy: A Prospective Study With Blinded Assessments

Neurosurgery 69:362–368, 2011 DOI: 10.1227/NEU.0b013e31821a418

Factors that can predict the recovery of cervical spondylotic myelopathy (CSM) patients postoperatively are of significant interest to physicians and patients and their families. Magnetic resonance imaging (MRI) scans are a common method of examination after surgery, and thus of interest as a predictor of outcome.

OBJECTIVE: To investigate whether findings on MRI at 6 months postoperatively could predict recovery at 1 year in CSM patients.

METHODS: In 52 consecutive prospective patients, MRI was performed preoperatively and 6 months postoperatively. T1 and T2 signal change (area, height, and segmentation) and spinal cord re-expansion were measured. Outcome measures evaluated at 1 year postoperatively were compared with preoperative values. Univariate and stepwise multiple regressions were undertaken.

RESULTS: Using univariate analysis, patients whose cord failed to re-expand had poorer outcome according to the modified Japanese Orthopedic Association score and Nurick score (P = .014) and grip test (P = .006) postoperatively. Stepwise multivariate regression showed lack of cord re-expansion to be predictive of prognosis postoperatively in the modified Japanese Orthopedic Association score (P = .013) and Berg Balance Scale (P = .014), and walking test (P = .011). Postoperative hyperintense T2 signal change was predictive of worse outcome on the Berg Balance Scale (P = .014) and walking test (P = .020), Nurick score (P = .001), and Short Form-36 scores (P = .020). In cases in which the T2 signal intensified, there was a poorer outcome on Nurick scores (P = .013), grip test (P = .017), and Short Form-36 scores (P = .030).

CONCLUSION: Findings on postoperative MRI at 6 months is of predictive value in determining outcomes in CSM patients. The persistence and type of T2 signal change and lack of re-expansion of the cord correlate with poorer recovery and likely reflect irreversible structural changes in the spinal cord.

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Intramedullary high signal intensity and neurological status as prognostic factors in cervical spondylotic myelopathy

Acta Neurochir (2010) 152:1687–1694. DOI 10.1007/s00701-010-0692-8

The neurological outcome of cervical spondylotic myelopathy (CSM) may depend on multiple factors, including age, symptom duration, cord compression ratio, cervical curvature, canal stenosis, and factors related to magnetic resonance (MR) signal intensity (SI). Each factor may act independently or interactively with others. To clarify the factors in prognosis, we prospectively analyzed the outcomes of patients with myelopathy caused by soft disc herniation in correlation with magnetic resonance imaging (MRI) findings and other clinical parameters.

Materials and methods From June 2006 to July 2009, we performed surgical operations in 137 patients with CSM. Of these patients, 70 (51.1%), including 45 men and 25 women with ventral cord compression at one or two levels, underwent anterior cervical discectomy and fusion. The mean duration of follow-up was 32.7 months. We surveyed the cervical curvature index (CCI), canal stenosis (Torg–Pavlov ratio), cord compression ratio, the length of SI change on T2WI, and clinical outcome using the Japanese Orthopedic Association (JOA) score for cervical myelopathy. The MRI SI was evaluated by grade: grade 0, no change in signal intensity; grade 1, light signal change; and grade 2, bright signal change on the T2WI. Multifactorial effects were identified by regression analysis.

Results The mean preoperative and postoperative JOA scores were 10.5±2.9 and 14.9±2.1, respectively (p< 0.05). The mean recovery rate based on the JOA score was 70.0±20.1%. The respective preoperative JOA scores and recovery ratios(%) were 11.6±2.3 and 81.5±17.0% in 20 patients with SI grade 0; 10.8±2.3 and 70.1±17.3% in 25 patients with grade 1; and 9.2±3.6 and 60.7±20.9% in 25 patients with grade 2, respectively. Post-surgical neurological outcome showed no significant relationship to age, symptom duration, cervical alignment, stenosis, or cord compression.

Conclusions Among the variables tested, preoperative neurological status and intramedullary signal intensity were significantly related to neurological outcome. The better the preoperative neurological status was, the better the postoperative neurological outcome. The SI grade on the preoperative T2WI was negatively related to neurological outcome. Hence, the severity of SI change and preoperative neurological status emerged as significant prognostic factors in post-operative CSM.

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Cervical Laminoplasty as a Management Option for Patients With Cervical Spondylotic Myelopathy: A Series of 40 Patients

Neurosurgery 67:272-277, 2010 DOI: 10.1227/01.NEU.0000371981.83022.B1

Cervical spondylotic myelopathy (CSM) is one of the leading causes of spinal cord dysfunction in the adult population. Laminoplasty is an effective decompressive procedure for the treatment of CSM.

OBJECTIVE:We present our experience with 40 patients who underwent cervical laminoplasty using titanium miniplates for CSM.

METHODS:We performed a retrospective review of the medical records of a consecutive series of patients with CSM treated with laminoplasty at the University of Rochester Medical Center or Rochester General Hospital. We documented patient demographic data, presenting symptoms, and postoperative outcome. Data are also presented regarding the general cost of constructs for a hypothetical 3-level fusion.

RESULTS: Forty patients underwent cervical laminoplasty; all were available for follow-up. The mean number of levels was 4. All patients were myelopathic, and 17 (42.5%) had signs of radiculopathy preoperatively. Preoperatively, 62.5% of patients had a Nurick grade of 2 or worse. The average follow-up was 31.3 months. The median length of stay was 48 hours. On clinical evaluation, 36 of 40 patients demonstrated an improvement in their myelopathic symptoms; 4 were unchanged. Postoperative kyphosis did not develop in any patients.

CONCLUSION: The management of CSM for each of its etiologies remains controversial. As demonstrated in our series, laminoplasty is a cost-effective, decompressive procedure for the treatment of CSM, providing a less destabilizing alternative to laminectomy while preserving mobility. Cervical laminoplasty should be considered in the management of multilevel spondylosis because of its ease of exposure, ability to decompress, effective preservation of motion, maintenance of spinal stability, and overall cost.

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Effective lordosis: analysis of sagittal spinal canal alignment in cervical spondylotic myelopathy

J Neurosurg Spine 11:667–672, 2009. (DOI: 10.3171/2009.7.SPINE08656)

Object. Analysis of cervical sagittal deformity in patients with cervical spondylotic myelopathy (CSM) requires a thorough clinical and radiographic evaluation to select the most appropriate surgical approach. Angular radiographic measurements, which are commonly used to define sagittal deformity, may not be the most appropriate to use for surgical planning. The authors present a simple straight-line method to measure effective spinal canal lordosis and analyze its reliability. Furthermore, comparisons of this measurement to traditional angular measurements of sagittal cervical alignment are made in regards to surgical planning in patients with CSM.

Methods. Twenty preoperative lateral cervical digital radiographs of patients with CSM were analyzed by 3 independent observers on 3 separate occasions using a software measurement program. Sagittal measurements included C2–7 angles utilizing the Cobb and posterior tangent methods, as well as a straight-line method to measure effective spinal canal lordosis from the dorsal-caudal aspect of the C2–7 vertebral bodies. Analysis of variance for repeated measures or Cohen 3-way (kappa) correlation coefficient analysis was performed as appropriate to calculate the intra and interobserver reliability for each parameter. Discrepancies in angular and effective lordosis measurements were analyzed.

Results. Intra and interobserver reliability was excellent (intraclass coefficient > 0.75, kappa > 0.90) utilizing all 3 techniques. Four discrepancies between angular and effective lordotic measurements occurred in which images with a lordotic angular measurement did not have lordosis within the ventral spinal canal. These discrepancies were caused by either spondylolisthesis or dorsally projecting osteophytes in all cases.

Conclusions. Although they are reliable, traditional methods used to make angular measurements of sagittal cervical spine alignment do not take into account ventral obstructions to the spinal cord. The effective lordosis measurement method provides a simple and reliable means of determining clinically significant lordosis because it accounts for both overall alignment of the cervical spine as well as impinging structures ventral to the spinal cord. This method should be considered for use in the treatment of patients with CSM.


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Effect of spinal cord signal intensity changes on clinical outcome after surgery for cervical spondylotic myelopathy

J Neurosurg Spine 11:562–567, 2009.DOI: 10.3171/2009.6.SPINE091

The presence of intramedullary T2 high signal intensity changes in patients with cervical spondylotic myelopathy (CSM) indicates the existence of a chronic spinal cord compressive lesion. However, the prognostic significance of signal intensity changes remains controversial. The purpose of this study was to evaluate the effect of spinal cord T2 signal intensity changes on the outcome after surgery for CSM.

Method. In a prospective study, 64 patients with CSM who underwent surgical treatment between October 2006 and April 2008 using an anterior approach were included. Based on the clinical symptoms and signs present, the severity of neurological deficits of all patients was scored according to a modified Japanese Orthopaedic Association scale score for CSM just before the surgery and at 6 months follow-up. Recovery rates were calculated at 6 months.

Results. There were 22 patients who did not have spinal cord intensity changes on MR imaging and 44 who demonstrated high-intensity signal changes on T2-weighted images (focal or segmental). No statistically significant differences were found in recovery rates between cases with T2 signal intensity changes and those with no signal intensity changes. However, the postoperative modified Japanese Orthopaedic Association scale scores and the recovery rates were much lower in patients with multisegmental signal intensity changes compared with those without these changes or those with focal signal intensity change, and ANOVA demonstrated this difference to be statistically significant (p < 0.05).

Conclusion. Multisegmental spinal cord signal intensity changes on T2-weighted MR imaging are predictors of a poor outcome in terms of functional recovery rate in patients undergoing operations for CSM.

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