Magnetic resonance imaging assessment of degenerative cervical myelopathy: a review of structural changes and measurement techniques

Degenerative Cervical Myelopathy: Towards a Personalized Approach

Degenerative cervical myelopathy (DCM) is a recently coined term encompassing a variety of age-related and genetically associated pathologies, including cervical spondylotic myelopathy, degenerative disc disease, and ligamentous aberrations such as ossification of the posterior longitudinal ligament. All of these pathologies produce chronic compression of the spinal cord causing a clinical syndrome characterized by decreased hand dexterity, gait imbalance, and potential genitourinary or sensorimotor disturbances. Substantial variability in the underlying etiology of DCM and its natural history has generated heterogeneity in practice patterns. Ongoing debates in DCM management most commonly center around clinical decision-making, timing of intervention, and the ideal surgical approach. Pivotal basic science studies during the past two decades have deepened our understanding of the pathophysiologic mechanisms surrounding DCM. Growing knowledge of the key pathophysiologic processes will help us tailor personalized approaches in an increasingly heterogeneous patient population. This article focuses on summarizing the most exciting approaches in personalizing DCM patient treatments including biomarkers, factors affecting clinical decision-making, and choice of the optimal surgical approach. Throughout we provide a concise review on the conditions encompassing DCM and discuss the underlying pathophysiology of chronic spinal cord compression. We also provide an overview on clinical-radiologic diagnostic modalities as well as operative and nonoperative treatment strategies, thereby addressing knowledge gaps and controversies in the field of DCM.

Potential of intraoperative ultrasonographic assessment of the spinal cord central echo complex in predicting postoperative neurological recovery of degenerative cervical myelopathy

BACKGROUND AND PURPOSE

The spinal cord central echo complex (SCCEC) is a special ultrasonography-based intramedullary structure, but its clinical significance in degenerative cervical myelopathy (DCM) is undefined. This study aimed to explore the potential of the SCCEC in predicting postoperative neurological recovery in DCM.

METHODS

Thirty-two DCM patients who underwent intraoperative ultrasonography-guided French-door laminoplasty were prospectively enrolled. The modified Japanese Orthopaedic Association (mJOA) score was evaluated preoperatively and 12 months postoperatively. SCCEC width (SCCEC-W), and anteroposterior diameter (APD) and transverse diameter (TD) of the spinal cord were measured on transverse ultrasonographic images, while the tissue widths from anterior and posterior borders of the spinal cord to the SCCEC were measured on sagittal ultrasonographic images. The APD of the spinal cord and occupying rate of the spinal canal were measured on preoperative magnetic resonance imaging (MRI).

RESULTS

All patients achieved improvements in mJOA scores, with an average recovery rate (RR) of 68.69 ± 20.22%. Spearman correlation analysis revealed that SCCEC-W, and ratios between the SCCEC-W and APD/TD based on ultrasonography, correlated moderately with mJOA score RR, with coefficients of -0.527, -0.605 and -0.514, respectively. The ratio between SCCEC-W and ultrasonographic TD correlated moderately with preoperative APD of the spinal cord. The MRI measurements and ultrasonography-based tissue widths showed no significant correlation with mJOA score RR.

CONCLUSIONS

The SCCEC may have predictive potential as an intraoperative indicator of neurological recovery in treating DCM. SCCEC-W may be related to spinal cord compression in DCM.

Does Spondylolisthesis Affect Severity and Outcome of Degenerative Cervical Myelopathy? A Systematic Review and Meta-analysis

STUDY DESIGN

This was a systematic review and meta-analysis.

OBJECTIVES

Degenerative cervical myelopathy (DCM) with spondylolisthesis remains not well defined, poorly studied, and underreported and plays a minor role in the therapeutic decision-making. Spondylolisthesis, however, is not uncommon and may result in dynamic injury to the spinal cord. We aim to describe the impact of spondylolisthesis in DCM severity and postoperative outcomes.

METHODS

Two independent reviewers conducted a Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA 2015)-based review between 1970 and May 2020 for articles reporting outcome of DCM in patients with degenerative cervical spondylolisthesis. Patient clinical and radiological data was recorded at baseline and during postoperative follow-up (FU). A meta-analysis comparing surgical outcome between DCM patients with and without spondylolisthesis assessed by the regular/modified Japanese Orthopaedic Association Assessment Scale (mJOA) recovery ratio was completed.

RESULTS

A total of 3 studies were included (1 ambispective and 2 retrospective cohorts); 607 patients with DCM were identified, 102 (16.8%) of whom also had spondylolisthesis. DCM patients with spondylolisthesis were significantly older (P < .05), presented with worse baseline mJOA and Nurick grades (P < .05 in 2 studies), and were more commonly operated via posterior approaches (P < .05). All groups experienced a (m)JOA and/or Neck Disability Index score improvement during FU. In the pooled meta-analysis, spondylolisthesis patients showed a significantly lower functional recovery ratio at 2 years compared with other DCM patients (P = .05).

CONCLUSIONS

Spondylolisthesis is frequent in older DCM patients and may be a predictor of a more advanced degeneration and subsequent worse baseline conditions and postoperative outcome.

Spinal Cord Motion in Degenerative Cervical Myelopathy: The Level of the Stenotic Segment and Gender Cause Altered Pathodynamics

In degenerative cervical myelopathy (DCM), focally increased spinal cord motion has been observed for C5/C6, but whether stenoses at other cervical segments lead to similar pathodynamics and how severity of stenosis, age, and gender affect them is still unclear. We report a prospective matched-pair controlled trial on 65 DCM patients. A high-resolution 3D T2 sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) and a phase-contrast magnetic resonance imaging (MRI) sequence were performed and automatically segmented. Anatomical and spinal cord motion data were assessed per segment from C2/C3 to C7/T1. Spinal cord motion was focally increased at a level of stenosis among patients with stenosis at C4/C5 (n = 14), C5/C6 (n = 33), and C6/C7 (n = 10) (p < 0.033). Patients with stenosis at C2/C3 (n = 2) and C3/C4 (n = 6) presented a similar pattern, not reaching significance. Gender was a significant predictor of higher spinal cord dynamics among men with stenosis at C5/C6 (p = 0.048) and C6/C7 (p = 0.033). Age and severity of stenosis did not relate to spinal cord motion. Thus, the data demonstrates focally increased spinal cord motion depending on the specific level of stenosis. Gender-related effects lead to dynamic alterations among men with stenosis at C5/C6 and C6/C7. The missing relation of motion to severity of stenosis underlines a possible additive diagnostic value of spinal cord motion analysis in DCM.

T1 Mapping for Microstructural Assessment of the Cervical Spinal Cord in the Evaluation of Patients with Degenerative Cervical Myelopathy

BACKGROUND AND PURPOSE

Although current radiologic evaluation of degenerative cervical myelopathy by conventional MR imaging accurately demonstrates spondylosis or degenerative disc disease causing spinal cord dysfunction, conventional MR imaging still fails to provide satisfactory anatomic and clinical correlations. In this context, we assessed the potential value of quantitative cervical spinal cord T1 mapping regarding the evaluation of patients with degenerative cervical myelopathy.

MATERIALS AND METHODS

Twenty patients diagnosed with mild and moderate-to-severe degenerative cervical myelopathy and 10 healthy subjects were enrolled in a multiparametric MR imaging protocol. Cervical spinal cord T1 mapping was performed with the MP2RAGE sequence procedure. Retrieved data were processed and analyzed regarding the global spinal cord and white and anterior gray matter on the basis of the clinical severity and the spinal canal stenosis grading.

RESULTS

Noncompressed levels in healthy controls demonstrated significantly lower T1 values than noncompressed, mild, moderate, and severe stenotic levels in patients. Concerning the entire spinal cord T1 mapping, patients with moderate-to-severe degenerative cervical myelopathy had higher T1 values compared with healthy controls. Regarding the specific levels, patients with moderate-to-severe degenerative cervical myelopathy demonstrated a T1 value increase at C1, C7, and the level of maximal compression compared with healthy controls. Patients with mild degenerative cervical myelopathy had lower T1 values than those with moderate-to-severe degenerative cervical myelopathy at the level of maximal compression. Analyses of white and anterior gray matter confirmed similar results. Strong negative correlations between individual modified Japanese Orthopaedic Association scores and T1 values were also observed.

CONCLUSIONS

In this preliminary study, 3D-MP2RAGE T1 mapping demonstrated increased T1 values in the pathology tissue samples, with diffuse medullary alterations in all patients with degenerative cervical myelopathy, especially relevant at C1 (nonstenotic level) and at the maximal compression level. Encouraging correlations observed with the modified Japanese Orthopaedic Association score make this novel approach a potential quantitative biomarker related to clinical severity in degenerative cervical myelopathy. Nevertheless, patients with mild degenerative cervical myelopathy demonstrated nonsignificant results compared with healthy controls and should now be studied in multicenter studies with larger patient populations.

Fatty infiltration in cervical flexors and extensors in patients with degenerative cervical myelopathy using a multi-muscle segmentation model

Background

In patients with degenerative cervical myelopathy (DCM) that have spinal cord compression and sensorimotor deficits, surgical decompression is often performed. However, there is heterogeneity in clinical presentation and post-surgical functional recovery.

Objectives

Primary: a) to assess differences in muscle fat infiltration (MFI) in patients with DCM versus controls, b) to assess association between MFI and clinical disability. Secondary: to assess association between MFI pre-surgery and post-surgical functional recovery.

Study design

Cross-sectional case control study.

Methods

Eighteen patients with DCM (58.6 ± 14.2 years, 10 M/8F) and 25 controls (52.6 ± 11.8 years, 13M/12 F) underwent 3D Dixon fat-water imaging. A convolutional neural network (CNN) was used to segment cervical muscles (MFSS- multifidus and semispinalis cervicis, LC- longus capitis/colli) and quantify MFI. Modified Japanese Orthopedic Association (mJOA) and Nurick were collected.

Results

Patients with DCM had significantly higher MFI in MFSS (20.63 ± 5.43 vs 17.04 ± 5.24, p = 0.043) and LC (18.74 ± 6.7 vs 13.66 ± 4.91, p = 0.021) than controls. Patients with increased MFI in LC and MFSS had higher disability (LC: Nurick (Spearman’s ρ = 0.436, p = 0.003) and mJOA (ρ = -0.399, p = 0.008)). Increased MFI in LC pre-surgery was associated with post-surgical improvement in Nurick (ρ = -0.664, p = 0.026) and mJOA (ρ = -0.603, p = 0.049).

Conclusion

In DCM, increased muscle adiposity is significantly associated with sensorimotor deficits, clinical disability, and functional recovery after surgery. Accurate and time efficient evaluation of fat infiltration in cervical muscles may be conducted through implementation of CNN models.

Increased signal intensity on postoperative T2-weighted axial images in cervical spondylotic myelopathy: Patterns of changes and associated impact on outcomes

Although T2-weighted axial magnetic resonance imaging (MRI) has strength in demonstrating morphologic characteristics of the spinal cord in cervical spondylotic myelopathy (CSM), no study has investigated postoperative changes. We aimed to assess postoperative changes on T2-weighted axial MRI using the classification system based on axial imaging in cervical compressive myelopathy (Ax-CCM) and associated impact on outcome in CSM. In total, 250 patients with CSM who underwent decompressive surgery with preoperative and postoperative MRI were included. At first, we investigated the presence of increased signal intensity (SI) in cervical spinal cord on T2-weighted sagittal images. Next, the increased SI was assessed using Ax-CCM on T2weighted axial images. The classifications were type 0, no-signal abnormality; single-level type 1, diffuse; single-level type 2, fuzzy focal; single-level type 3, discrete focal; and two-level. The recovery rates (RRs) of modified Japanese Orthopaedic Association (mJOA) score were evaluated from 5 to 10 months postoperatively. Eighty-seven patients (34.8%) exhibited postoperative changes. Most of postoperative changes were in single-level type 1 and 2. Patterns of changes were resolution, reduced extent, or transition to discrete margin. The most common pattern was resolution in type 1 (23.9%) and transition to discrete margin in type 2 (46.5%). In each group, resolution showed the best RR, but insignificantly (p > 0.05).

Neurological improvement is associated with neck pain attenuation after surgery for cervical ossification of the posterior longitudinal ligament

Although favourable surgical outcomes for myelopathy caused by cervical ossification of the posterior longitudinal ligament (OPLL) have been reported, factors significantly associated with post-operative neck pain attenuation still remain unclear. The primary aim of the present study was to determine factors significantly associated with post-operative neck pain attenuation in patients with cervical OPLL using a prospective multi-centre registry of surgically treated cervical OPLL. Significant postoperative neck pain reduction (50% reduction of neck pain) was achieved in 31.3% of patients. There was no significant difference in neck pain attenuation between surgical procedures. Statistical analyses with univariate analyses followed by stepwise logistic regression revealed neurological recovery as a factor having a significant positive association with post-operative neck pain attenuation (p = 0.04, odds ratio 5.68 (95% confidence interval: 1.27-22.2)). In conclusion, neurological recovery was an independent factor having a significant positive association with post-operative neck pain attenuation in patients with cervical myelopathy caused by OPLL who underwent cervical spine surgery.

Thoracic full-endoscopic unilateral laminotomy with bilateral decompression for treating ossification of the ligamentum flavum with myelopathy

Background

The aim of the present study was to evaluate the curative effect and safety of thoracic full-endoscopic unilateral laminotomy with bilateral decompression (TE-ULBD) for treating ossification of the ligamentum flavum (OLF) with myelopathy.

Methods

Between January 2015 and December 2018, 23 consecutive patients with symptomatic thoracic OLF were treated with TE-ULBD. Of these, 21 (13 women and 8 men, aged 49-75 years) were included in the study and followed up for a minimum of 1 year. The mean blood loss was 15.48 mL (10-30 mL), operative duration was 78.86 min (55-115 min), and hospitalization was 5.05 days (3-15 days). The Japanese Orthopaedic Association (JOA) was used to evaluate spinal cord function, and the curative effect was defined by the JOA improvement rate. The area of OLF (AOLF), the maximum spinal cord compression (MSCC), and the area of spinal cord (ASC) were used to evaluate OLF clearance and spinal cord decompression status.

Results

At the final follow up,the JOA score was 8.33 points (5-11 points), which was a significant improvement from the preoperative 5.33 points (3-9 points, P<0.01). The excellent and good rate was 76.19% (16/21). The average preoperative AOLF and AOLF ratio were 85.27±23.66 mm² and 57.86%±11.86%, respectively, and the postoperative AOLF and AOLF ratio were 16.27±11.75 mm² and 8.13%±5.38%, respectively. The MSCC increased from 27.99%±13.51% preoperatively to 48.02%±6.66% postoperatively. The ASC was 42.90±10.60 mm² preoperatively and 64.54±21.36 mm² postoperatively. There were statistically significant differences in all parameters preoperatively and postoperatively (P<0.01). One case had postoperative hematoma, and the symptoms gradually eased after 3 weeks of conservative treatment. There were no other complications. No recurrence of OLF was detected during the follow-up period.

Conclusions

TE-ULBD is safe and effective for thoracic OLF with the advantages of reduced trauma and bleeding, and faster recovery.

Early Fusion Rates After Direct Lateral Lumbar Interbody Fusion With Bone-Morphogenetic Protein

BACKGROUND

Direct lateral (transpsoas) lumbar interbody fusion (LLIF) reportedly achieves union by 1 year postoperatively, but how soon fusion occurs after these minimally invasive procedures is unclear. This study investigated LLIF fusion progression at 6 months and 1 year in a large-scale cohort using bone morphogenetic protein (BMP) graft and examined risk factors associated with failed fusion.

METHODS

Patients undergoing primary LLIF with a single surgical team from 2015 through 2016 with polyetheretherketone (PEEK) iimplants and BMP graft were identified. Retrospective chart review included demographics and medical history, construct length and location, and concurrent L5-S1 fusion. Inclusion criteria included minimum 1-year follow-up and postoperative lumbar computed tomography at 6 months and 1 year, which was independently assessed for bony union at each level.

RESULTS

166 patients underwent LLIF at a total of 312 levels. Seventy-nine patients (48%) underwent 1-level fusion; 45 (27%), 2 levels; and 42 (25%), 3 or more levels. At 6 months, 160 (51%) levels showed fusion. At 1 year, 70% of the remainder were fused, and total fusion rate was 85%. Fusion rates from L1 through L4 were similar (84%-87%). Nonunion was not significantly associated with construct length (P = .19), concurrent anterior L5-S1 interbody fusion (P = .50), age (P = .70), BMI (P = .15), or comorbidities such as diabetes (P = .86) or thyroid disease (P = .46).

CONCLUSIONS

This large retrospective cohort study corroborates prior 1-year LLIF fusion rate reports (85%) independent of construct length or location or medical comorbidities. Significantly, half showed fusion by 6 months, earlier than previously described and validating the efficacy of LLIF.

LEVEL OF EVIDENCE

5.

CLINICAL RELEVANCE

This study presents a large cohort of patients to support effective lumbar fusion after LLIF with BMP-2.

MRI findings in cervical spondylotic myelopathy with gadolinium enhancement: Review of seven cases

Cervical spondylotic myelopathy (CSM) is a clinical syndrome secondary to a spinal cord compression due to cervical spondylosis. In some cases, conventional MRI typically shows an intramedullary hyperintense signal on T2W imaging and contrast enhancement on post-gadolinium T1W imaging. We report a series of seven patients with CSM who had typical clinical presentation and imaging findings on T2W and contrast-enhanced T1W sequences. The imaging findings included degenerative changes of the cervical spine, intramedullary T2-signal hyperintensity, and an intramedullary enhancement on post-gadolinium T1W images. Our results support the statement that the presence of an intramedullary gadolinium-enhancement with a flat transverse pancake-like pattern (on sagittal images) and a circumferential pattern (on axial images), located within a T2-signal abnormality, in patients with cervical spondylosis and clinical myelopathy is indicative of spondylosis as the cause of the myelopathy.

Degenerative cervical myelopathy

Degenerative cervical myelopathy (DCM) frequently leads to severe neurologic disability but is still frequently underdiagnosed. One explanation may be the variability of the symptoms presented by the patients, from paresthesia to quadriplegia, making it another great masquerader. What do we know? How can we manage better these patients? We will review the keys points concerning its challenging diagnosis (clinical and radiologic), some of the recent discoveries about DCM, notably the underlying genetic mutations identified, linked to its pathophysiology, before addressing the consensual points concerning its management and the major evolutive risk: acute decompensation.

Clinical Comparison of Selective versus Nonselective Decompression for Symptomatic Tandem Stenosis of the Cervical and Thoracic Spine: A Retrospective Cohort Study

OBJECTIVE

The aim of the present paper was to reveal the clinical differences between selective and nonselective decompression for symptomatic tandem stenosis of the cervical and thoracic spine (TSCTS).

METHODS

A total of 34 patients were eligible and included in the study. Among them, 8 patients underwent selective cervical decompression (CD), 15 patients underwent selective thoracic decompression (TD), and 11 patients underwent combined CD and TD (CTD) surgery. Age, sex, operative time, intraoperative blood loss, postoperative hospital stay, inpatient expenditure, preoperative upper Japanese Orthopaedic Association (JOA) rate, canal occupation rate, high-intensity T2-weighted image (T2WI) of the spinal cord, and preoperative and postoperative JOA scores were compared among the three groups.

RESULTS

The CD group had shorter operative time (138.8 ± 36.1 vs 229.7 ± 95.8 vs 328.6 ± 94.8, min, P < 0.001), less intraoperative blood loss (141.3 ± 116.7 vs 496.7 ± 361.8 vs 654.6 ± 320.5, mL, P = 0.004), and shorter postoperative hospital stay (4.6 ± 1.6 vs 9.0 ± 3.5 vs 10.3 ± 6.6, days, P = 0.008), as well as lower preoperative upper JOA rate (34.1 ± 5.6 vs 53.9 ± 8.4 vs 48.2 ± 15.2, %, P = 0.001) than the TD and CTD groups. The CTD group had higher inpatient expenditure than the CD and TD groups (87,850 ± 18,379 vs 55,100 ± 12,890 vs 55,772 ± 15,715, CNY, P < 0.001). The cervical canal occupation rates were similar among different groups (P > 0.05); however, the TD group showed a higher thoracic canal occupation rate than the CD group (58.3 ± 14.7 vs 43.3 ± 12.3, %, P = 0.035). All positive levels in high-intensity T2WI of the spinal cord were decompressed. The preoperative JOA scores as well as the postoperative JOA scores at 6 months and at last follow-up were comparable among the three groups (P > 0.05). Similarly, the JOA recovery rate showed no significant difference among the groups (P > 0.05).

CONCLUSION

Selective CD or TD alone demonstrated similar clinical effectiveness to nonselective and combined CTD for TSCTS. Individualized surgical decision should be made after meticulous assessments of clinical and radiological manifestations, general patient condition, and socioeconomic factors.

Focal cervical spinal stenosis causes mechanical strain on the entire cervical spinal cord tissue - A prospective controlled, matched-pair analysis based on phase-contrast MRI

BACKGROUND

Focally increased spinal cord motion at the level of cervical spinal stenosis has been revealed by phase-contrast MRI (PC-MRI).

OBJECTIVE

To investigate spinal cord motion among patients suffering of degenerative cervical myelopathy (DCM) across the entire cervical spine applying automated segmentation and standardized PC-MRI post-processing protocols.

METHODS

Prospective, matched-pair controlled trial on 29 patients with stenosis at C5/C6. MRI-protocol covering all cervical segments: 3D T2-SPACE, prospectively ECG-triggered sagittal PC-MRI. Segmentation by trained 3D hierarchical deep convolutional neural network and data processing were conducted via in-house software pipeline. Parameters per segment: maximum velocity, peak-to-peak (PTP)-amplitude, total displacement, PTP-amplitude^HB (PTP-amplitude per duration of heartbeat), and, for characterization of intraindividual alterations, the PTP-amplitude index between the cervical segments C3/C4-C7/T1 and C2/C3.

RESULTS

Spinal cord motion was increased at C4/C5, C5/C6 and C6/C7 among patients (all parameters, p < 0.001-0.025). The PTP-amplitude index revealed an increase from C3/C4 to C4/C5 (p = 0.002), C4/C5 to C5/C6 (p = 0.037) and a decrease from C5/C6 to C6/C7 and C6/C7 to C7/T1 (p < 0.001, each). This implied an up-building stretch on spinal cord tissue cranial and a mechanical compression caudal of the stenotic level. Furthermore, significant far range effects across the entire cervical spinal cord were observed (e.g. PTP-amplitude C2/C3 vs. C6/C7, p = 0.026) in contrast to controls (p = 1.00).

CONCLUSION

This study revealed the nature and extends of mechanical stress on the entire cervical spinal cord tissue due to focal stenosis. These pathophysiological alterations of spinal cord motion can be expected to be clinically relevant.

Spondylotic and Other Structural Myelopathies

PURPOSE OF REVIEW

This article highlights both common structural causes of myelopathy, such as spondylotic disease, and infrequent but treatable causes, such as syringomyelia, spinal cord herniation, arachnoid cyst, arachnoid band and web, epidural lipomatosis, Hirayama disease, and arachnoiditis.

RECENT FINDINGS

Neuroimaging improvements and availability have uncovered many structural abnormalities in the spines and spinal cords of patients who were asymptomatic or minimally symptomatic. Recent published clinical series have improved our knowledge of the natural history of structural abnormalities and the risks of intervention versus conservative management.

SUMMARY

Myelopathy from a suspected structural cause is a common reason for neurologic consultation. Correlation between the history, examination, and imaging are especially important to determine whether intervention is necessary or conservative management is the best option.

Predictive Risk Factors of Poor Preliminary Postoperative Outcome for Thoracic Ossification of the Ligamentum Flavum

Objective

The aim of the present study was to ascertain the independent risk factors of poor preliminary outcome and to reveal the value of these factors in predicting the postoperative prognosis.

Methods

A total of 165 patients diagnosed with thoracic myelopathy because of thoracic ossification of the ligamentum flavum (TOLF) were enrolled in this retrospective study. All of them underwent posterior decompressive laminectomy surgery in our hospital from May 2016 to June 2019. The postoperative improvement of symptoms was evaluated using the modified Japanese Orthopaedic Association (mJOA) scoring system. Clinical data, such as age, sex, body mass index (BMI), duration of symptoms, history of hypertension and diabetes, tobacco use, history of drinking, symptoms of incontinence, number of compressed segments, and preoperative mJOA score, were respectively recorded. Radiologic features data included sagittal maximum spinal cord compression (MSCC), axial spinal canal occupation ratio (SCOR), grades and extension of increased signal on sagittal T2‐weighted images (ISST2I), types of increased signal on axial T2‐weighted images (ISAT2I), and the classification of ossification on axial CT scan and sagittal MRI. The t‐test, the χ²‐test, Fisher's exact test, binary logistic regression analyses, receiver operating characteristic (ROC) curves, and subgroup analyses were used to evaluate the effects of individual risk predictors on surgical outcomes.

Results

A total of 76 men and 89 women were enrolled in this study. The mean age of all patients was 58.53 years. After comparison between two groups, we found some risk factors that may be associated with postoperative outcomes, such as age, preoperative mJOA score, BMI, history of hypertension, MSCC, SCOR, grade and extension of ISST2I, type of ISAT2I, axial type of ossification, and sagittal type of ossification (P < 0.05, respectively). Binary logistic regression analysis revealed that older age (odds ratio [OR] = 1.062, 95% confidence interval [CI] = 1.006–1.121, P = 0.030), number of compressed segments (OR = 1.916, 95% CI = 1.250–2.937, P = 0.003), bilateral and bridged types of ossification (OR = 4 314, 95% CI = 1.454–8.657, P = 0.019; OR = 6.630, 95% CI = 2.580–17.530, P = 0.004), and grade 1 and 2 ISST2I (OR = 8.986, 95% CI =3.056–20.294, P < 0.001; OR = 7.552, 95% CI = 3.529–16.004, P < 0.001) were independent risk factors for a poor preliminary postoperative outcome. ROC curve analysis showed that the grade of ISST2I had an excellent discriminative power (area under the curve [AUC] = 0.817). In addition, risk factors have different values for predicting the clinical outcome in each subgroup.

Conclusion

Age, duration of symptoms, number of compressed segments, SCOR, grade, and extension of ISST2I and classification of ossification were associated with the preliminary prognosis, and the intramedullary increased signal on sagittal T2‐weighted MRI was highly predictive of poor postoperative outcome.

Does Obesity Affect Outcomes of Multilevel ACDF as a Treatment for Multilevel Cervical Spondylosis?: A Retrospective Study

STUDY DESIGN

This was a retrospective study of the clinical and radiologic outcomes of multilevel anterior cervical discectomy and fusion (ACDF) surgery for multilevel cervical spondylosis patients.

OBJECTIVE

In this retrospective study, we intended to determine the relationship of neck circumference, neck length, and body mass index (BMI) with the outcomes of multilevel ACDF surgeries for patients with multilevel cervical spondylosis.

SUMMARY OF BACKGROUND DATA

Obesity has become a worldwide epidemic problem since the beginning of the 21st century. However, no study has focused on how local or whole-body obesity indexes (neck circumference, length of neck, and BMI) are related to the outcome of anterior cervical surgery.

METHODS

A total of 156 consecutive patients with multilevel cervical spondylosis who underwent anterior cervical surgery in our department from 2010 to 2016 were enrolled in our study. Preoperative parameters of patients such as the neck circumference, length of neck, height and weight were measured, and the BMI was also calculated. Neck circumference and length of neck in neutral position ratio was determined as an index for evaluated the neck situation. Preoperative and postoperative neurological functions were evaluated using the neck disability index (NDI) and Japan Orthopedic Association (JOA) scores. Postoperative complications during the follow-up period were also recorded. Correlations between the obesity indexes and the various factors were analyzed.

RESULTS

The mean follow-up duration was 3.9±1.4 years (2.0-7.3 y). Compared with the preoperative score, the NDI and JOA score had significantly improved. There were 46 patients (29.49%) developed complications after surgery. Patients in the obese group had the highest rate of complications. Neck circumference and length of neck in neutral position ratio, BMI, and number of operation levels were significant risk factors for the occurrence of dysphagia after multilevel ACDF.

CONCLUSIONS

Patients with a higher BMI, larger neck circumference, and shorter neck length may have a longer operation duration, more blood loss, and more postoperative complications. The authors recommended that the presence of obesity and neck circumference and length should be carefully considered in the perioperative risk assessment for a multilevel ACDF surgery.

Magnetic resonance imaging and dynamic X-ray's correlations with dynamic electrophysiological findings in cervical spondylotic myelopathy: a retrospective cohort study

Background

Dynamic somatosensory evoked potentials (DSSEP) can be used to disclose abnormalities of ascending sensory pathways at dynamic positions and diagnose cervical spondylotic myelopathy (CSM). However, radiographic tests including magnetic resonance imaging (MRI) and dynamic X-ray are used much more widely in the management of CSM. Our study aims to clarify the correlations between several radiographic parameters and the DSSEP results, and further determine their reliability with clinical data.

Methods

We retrospectively enrolled 38 CSM patients with surgical intervention. DSSEP tests were performed before surgery. Amplitude ratios of DSSEP N13 and N20 waves at extension and flexion were calculated and recorded as N13_E, N20_E, N13_F, N20_F, respectively. Baseline severity was evaluated with the modified Japanese Orthopedic Association (mJOA) score and the Nurick grades. Prognosis was evaluated based on the 2-year recovery rate. Sagittal diameter and transverse areas of the cord and canal were measured and the the compressive ratios at the compressed site (Compression_Ratio), central (Central_Ratio), and 1/4-lateral points (1/4-Lateral_Compression_Ratio), and spinal cord/Canal Area Ratio were calculated. The intramedullary T2 hyperintensity patterns (Ax-CCM types) were also collected from MRI axial images. Dynamic X-rays were used to test for segmental instability of the cervical spine. The correlations between radiologic findings, DSSEP data, and clinical assessments were investigated.

Results

We found that DSSEP N13_E and N13_F correlated with the Compression_Ratio, Central_Ratio, 1/4-Lateral_Compression_Ratio (Pearson, p < 0.05) and Ax-CCM types (ANOVA, p < 0.05) in MRI axial images and cervical segmental instability in dynamic X-ray (t-test, p < 0.05). Apart from the 1/4-Lateral_Compression_Ratio, these radiographic parameters above also correlated with the baseline clinical assessments (Spearman or ANOVA or t-test, p < 0.05) and postoperative recovery rate (Pearson or ANOVA or t-test, p < 0.05).

Conclusions

We found that the preoperative Compression_Ratio, Central_Ratio and 1/4-Lateral_Compression_Ratio in MRI and cervical segmental instability in dynamic X-ray could reflect the dynamic neural dysfunction of the spinal cord. Different Ax-CCM types corresponded to different DSSEP results at extension and flexion, suggesting divergent pathophysiology. These radiographic parameters could help evaluate disease severity and predict postoperative prognosis.

Compensatory brainstem functional and structural connectivity in patients with degenerative cervical myelopathy by probabilistic tractography and functional MRI

Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord impairment in adults. Previous supraspinal investigations have primarily focused on cortical changes in this patient population. As the nexus between the brain and the spinal cord, the brainstem has been understudied in patients with DCM. The current study examined the structural and functional connectivity between the brainstem and cortex in DCM patients using probabilistic tractography and resting-state functional MRI. A total of 26 study patients and 32 neurologically intact, healthy volunteers (HCs) participated in this prospective analysis. The study cohort included DCM patients (n = 18), as well as neurologically asymptomatic patients with evidence of cervical spine degenerative changes and spinal cord compression (n = 8). Results of the study demonstrated significant differences in fiber density (FD), fiber cross-section (FDC), and the functional connectivity (FC) between the study cohort and HCs. Through seeding the brainstem, the study cohort showed reductions in FD and FDC along the corticospinal tract, including regions extending through the corona radiata and internal capsule. By correlating FD and FDC with the Neck Disability Index (NDI), and the modified Japanese Orthopaedic Association (mJOA), we identified increasing total volume of projections to the thalamus, basal ganglia, and internal capsule, and increased functional connectivity to visual network and the posterior parietal cortices. These results support our hypothesis that DCM patients tend to have long-term FC reorganization not only localized to sensorimotor regions, but also to regulatory and visual processing regions, designed to ultimately preserve neurological function.

Connections between intrinsically photosensitive retinal ganglion cells and TBI symptoms

The majority of patients with traumatic brain injury (TBI) are classified as having a mild TBI. Despite being categorized as mild, these individuals report ongoing and complex symptoms, which negatively affect their ability to complete activities of daily living and overall quality of life. Some of the major symptoms include anxiety, depression, sleep problems, headaches, light sensitivity, and difficulty reading. The root cause for these symptoms is under investigation by many in the field. Of interest, several of these symptoms such as headaches, ocular pain, light sensitivity, and sleep disturbances may overlap and share underlying circuitry influenced by the intrinsically photosensitive retinal ganglion cells (ipRGCs). These cells are light sensing, but non-image forming, and they influence corneal function, pupillary constriction, and circadian rhythm. In this review, we discuss these symptoms and propose a role of the ipRGCs as at least one underlying and unifying cause for such symptoms.

NODDI in clinical research

Diffusion MRI (dMRI) has proven to be a useful imaging approach for both clinical diagnosis and research investigating the microstructures of nervous tissues, and it has helped us to better understand the neurophysiological mechanisms of many diseases. Though diffusion tensor imaging (DTI) has long been the default tool to analyze dMRI data in clinical research, acquisition with stronger diffusion weightings beyond the DTI regimen is now possible with modern clinical scanners, potentially enabling even more detailed characterization of tissue microstructures. To take advantage of such data, neurite orientation dispersion and density imaging (NODDI) has been proposed as a way to relate the dMRI signal to tissue features via biophysically inspired modeling. The number of reports demonstrating the potential clinical utility of NODDI is rapidly increasing. At the same time, the pitfalls and limitations of NODDI, and general challenges in microstructure modeling, are becoming increasingly recognized by clinicians. dMRI microstructure modeling is a rapidly evolving field with great promise, where people from different scientific backgrounds, such as physics, medicine, biology, neuroscience, and statistics, are collaborating to build novel tools that contribute to improving human healthcare. Here, we review the applications of NODDI in clinical research and discuss future perspectives for investigations toward the implementation of dMRI microstructure imaging in clinical practice.

Microstructural Changes in Compressed Cervical Spinal Cord Are Consistent With Clinical Symptoms and Symptom Duration

STUDY DESIGN

A prospective study.

OBJECTIVE

To investigate the association between microstructural changes measured by diffusion tensor imaging (DTI) and clinical symptoms and their duration in patients with cervical spondylotic myelopathy (CSM) affected by single level.

SUMMARY OF BACKGROUND DATA

No report was reported regarding the association between the microstructural changes and the symptoms and their duration at single-level spinal cord compression.

METHODS

Twenty-nine consecutive patients with CSM and 29 normal subjects were enrolled in this study. DTI with tractography was performed on the cervical spinal cord. Clinical symptoms were evaluated using modified Japanese Orthopaedic Association (mJOA) scores for each patient, and the duration of clinical symptoms was noted based on the earliest instance of limb pain or numbness or weakness or bladder dysfunction. Mean fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were calculated from tractography images.

RESULTS

The mean FA value of the cervical compressed spinal cord was significantly lower than the FA of the normal population (P < 0.001). The mean ADC value in the cervical compressed spinal cord was obviously higher than those of normal cervical spinal cord (P < 0.001). In the CSM patients, a significant positive association was observed between FA values and mJOA scores (P < 0.001). However, there were a notable negative association between mJOA scores and ADC values (P < 0.001), and between mJOA scores and symptom duration (P < 0.001).

CONCLUSION

These results illustrate DTI can measure the micostructural changes of cervical spinal cord and DTI parameters are potential biomarkers for spinal cord dysfunction in patients with CSM.

LEVEL OF EVIDENCE

3.

Multidisciplinary approach to degenerative cervical myelopathy

INTRODUCTION

Degenerative cervical myelopathy (DCM) is a prevalent condition causing significant impairment spanning several domains of health. A multidisciplinary approach to the care of DCM would be ideal in utilizing complex treatments from different disciplines to address broad patient needs.

AREAS COVERED

In this article the authors will discuss the importance of multidisciplinary care and establish a general framework for its use. The authors will then highlight the potential role of a multidisciplinary team in each aspect of DCM care including assessment, diagnosis, decision-making, surgical intervention, non-operative therapy, monitoring, and postoperative care.

EXPERT OPINION

In order to provide comprehensive personalized care to DCM patients, it is necessary to have a multidisciplinary team composed by a combination of the patient, surgeon, primary care practitioner, neurologist, anesthesiologist, radiologist, physiatrist, nurses, physiotherapist, occupational therapist, pain specialist, and social workers all functioning independently and communicating to achieve a common goal.

Diagnostic Approach to Intrinsic Abnormality of Spinal Cord Signal Intensity

Intramedullary cord hyperintensity at T2-weighted MRI is a common imaging feature of disease in the spinal cord, but it is nonspecific. Radiologists play a valuable role in helping narrow the differential diagnosis by integrating patient history and laboratory test results with key imaging characteristics. The authors present an algorithmic approach to evaluating intrinsic abnormality of spinal cord signal intensity (SI), which incorporates clinical evaluation results, time of onset (acute vs nonacute), cord expansion, and pattern of T2 SI abnormality. This diagnostic approach provides a practical framework to aid both trainees and practicing radiologists in workup of myelopathy.^©RSNA, 2019.

The Functional Relevance of Diffusion Tensor Imaging in Patients with Degenerative Cervical Myelopathy

(1) Background: In addition to conventional magnetic resonance imaging (MRI), diffusion tensor imaging (DTI) has been investigated as a potential diagnostic and predictive tool for patients with degenerative cervical myelopathy (DCM). In this preliminary study, we evaluated the use of quantitative DTI in the clinical practice as a possible measure to correlate with upper limbs function. (2) Methods: A total of 11 patients were enrolled in this prospective observational study. Fractional anisotropy (FA) values was extracted from DTI data before and after surgery using a GE Signa 1.5 T MRI scanner. The Nine-Hole Peg Test and a digital dynamometer were used to measure dexterity and hand strength, respectively. (3) Results: We found a significant increase of FA values after surgery, in particular below the most compressed level (p = 0.044) as well as an improvement in postoperative dexterity and hand strength. Postoperative FA values moderately correlate with hand dexterity (r = 0.4272, R₂ = 0.0735, p = 0.19 for the right hand; r = 0.2087, R₂ = 0.2265, p = 0.53 for the left hand). (4) Conclusion: FA may be used as a marker of myelopathy and could represent a promising diagnostic value in patients affected by DCM. Surgical decompression can improve the clinical outcome of these patients, especially in terms of the control of finger-hand coordination and dexterity.

The Influence of Cervical Spondylolisthesis on Clinical Presentation and Surgical Outcome in Patients With DCM: Analysis of a Multicenter Global Cohort of 458 Patients

STUDY DESIGN

Ambispective study with propensity matching.

OBJECTIVE

To assess the impact of cervical spondylolisthesis (CS) on clinical presentation and surgical outcome in patients with degenerative cervical myelopathy (DCM).

METHODS

A total of 458 magnetic resonance images (MRIs) from the AOSpine CSM-NA and CSM-I studies were reviewed and CS was identified. Patients with DCM were divided into 2 cohorts, those with CS and those without, and propensity matching was performed. Patient demographics, neurological and functional status at baseline and 2-year follow-up were compared.

RESULTS

Compared with nonspondylolisthesis (n = 404), CS patients (n = 54) were 8.8 years older (P < .0001), presented with worse baseline neurological and functional status (mJOA [modified Japanese Orthopaedic Association Assessment Scale], P = .008; Nurick, P = .008; SF-36-PCS [Short Form-36 Physical Component Score], P = .01), more commonly presented with ligamentum flavum enlargement (81.5% vs 53.5%, P < .0001), and were less commonly from Asia (P = .0002). Surgical approach varied between cohorts (P = .0002), with posterior approaches favored in CS (61.1% vs 37.4%). CS patients had more operated levels (4.3 ± 1.4 vs 3.6 ± 1.2, P = .0002) and tended to undergo longer operations (196.6 ± 89.2 vs 177.2 ± 75.6 minutes, P = .087). Neurological functional recovery was lower with CS (mJOA [1.5 ± 3.6 vs 2.8 ± 2.7, P = .003]; Nurick [-0.8 ± 1.4 vs -1.5 ± 1.5, P = .002]), and CS was an independent predictor of worse mJOA recovery ratio at 2 years (B = -0.190, P < .0001). After propensity matching, improvement of neurological function was still lower in CS patients (mJOA [1.5 ± 3.6 vs 3.2 ± 2.8, P < .01]; Nurick [-0.8 ± 1.4 vs -1.4 ± 1.6, P = .02]).

CONCLUSIONS

CS patients are older, present with worse neurological/functional impairment, and receive surgery on more levels and more commonly from the posterior. CS may indicate a more advanced state of DCM pathology and is more likely to result in a suboptimal surgical outcome.

Disparities in baseline neurocognitive testing for student concussion management in Massachusetts high schools

PURPOSE

There is evidence of socioeconomic disparities with respect to the implementation of student-sports concussion laws nationally. The purpose of this study was to examine school sociodemographic characteristics associated with the provision of computerised baseline neurocognitive testing (BNT) in Massachusetts (MA) high schools, and to assess whether the scope of testing is associated with the economic status of student populations in MA.

METHODS

A cross-sectional secondary analysis of surveys conducted with MA athletic directors (n=270) was employed to investigate school characteristics associated with the provision of BNT. Correlation and regression analyses were used to assess whether the scope of testing is associated with the economic status of student populations in MA.

RESULTS

The scope of BNT was independently associated with the economic disadvantage rate (EDR) of the student population (β=-0.02, p=0.01); whether or not the school employs an athletic trainer (AT) (β=0.43, p=0.03); and school size (β=-0.54, p=0.03). In a multivariable regression model, EDR was significantly associated with the scope of baseline testing, while controlling for AT and size (β=-0.01, p=0.03, adj-R2=0.1135).

CONCLUSION

Among public high schools in MA, disparities in the provision of BNT for students are associated with the economic characteristics of the student body. Schools that have a greater proportion of low-income students are less likely to provide comprehensive BNT. The clinical implications of not receiving BNT prior to concussion may include diminished quality of postconcussive care, which can have short-term and long-term social, health-related and educational impacts.

Clinical and Radiologic Features of Degenerative Cervical Myelopathy Depending on the Presence of Cord Signal Change

BACKGROUND

Cord signal change (CSC) on magnetic resonance (MR) imaging is an important radiologic feature of degenerative cervical myelopathy (DCM). Occasionally, DCMs correlate with clinical symptoms with no CSC. The aim of this study was to evaluate clinical and radiologic features, depending on the presence of CSC in DCM.

METHODS

This retrospective study included 73 patients who underwent cervical laminoplasty for DCM. They were divided into 2 groups based on the presence of CSC on static MR imaging (positive CSC in group A and negative CSC in group B). Preoperative radiologic parameters on lateral radiographs and the severity of canal stenosis on MR imaging were analyzed. The functional outcomes were evaluated using the modified Japanese Orthopedic Association score and Nurick grade.

RESULTS

Group A showed more deteriorated canal stenosis (P < 0.001) and kyphotic change than did group B. C2-7 sagittal vertical axis (P = 0.003) of group A and C2-7 range of motion (C27ROM; P < 0.001) of group B were greater than in the opposite groups, respectively. In a multivariate analysis, greater width of the cervical canal (P = 0.002) and increased C27ROM (P = 0.002) were statistically significant radiologic parameters related to negative CSC. Group B showed better functional outcomes until 6 months postoperatively, with statistical significance.

CONCLUSIONS

DCM with negative CSC can be caused by a well-preserved cervical ROM, even with less deteriorated canal stenosis and kyphosis. C27ROM may be a helpful radiologic parameter in diagnosing DCM before CSC appears.

Degenerative Cervical Myelopathy: Review of Surgical Outcome Predictors and Need for Multimodal Approach

Degenerative cervical myelopathy is the most common cause of spinal cord injury in the elderly population in the developed world, and it significantly affects the quality of life of patients and their caregivers. Surgery remains the only treatment option able to halt disease progression and provide neurological recovery for most patients. Although it has remained challenging to predict exactly who will experience improvement after surgery, increasingly it has been shown that clinical, imaging, and electrophysiological factors can predict, with relatively good capacity, those more likely to benefit. Clinically, the baseline neurological impairment appears to be strongly related to the outcome, and the magnetic resonance imaging findings of T1-weighted hypointensity and the length of T2-weighted hyperintensity appear to be the most prognostic. In this context, electrophysiology findings (both motor and sensory evoked potentials) have shown some predictive capacity. However, large studies are lacking. Although multivariate models have been conducted using clinical and magnetic resonance imaging data, no multimodal prediction models are available that encompass the predictive capacity of clinical, imaging, and electrophysiological data. In the present review, we examined the rationale for clinical, imaging, and electrophysiological usage in clinical practice and discussed a model of multimodal assessment for the management of degenerative cervical myelopathy.

Ten-Year Surgical Outcomes and Prognostic Factors for French-Door Laminoplasty in the Treatment of Multilevel Cervical Spondylotic Myelopathy

Objective

To analyze the ten-year surgical outcomes and postoperative complications of French-Door laminoplasty (FDL) in the management of multilevel cervical spondylotic myelopathy (MCSM) and analyze the prognostic factors for FDL in treating MCSM.

Methods

64 patients with MCSM, who were operated by FDL, were included in this study and followed up for at least 10 years. Clinical assessments including modified Japanese Orthopaedic Association (mJOA) score, age at surgery, preoperative symptom duration, operative time, blood loss and postoperative complications, radiological assessments including Cobb angle, cervical range of motion (ROM), intramedullary signal intensity on T2W MRI, canal narrowing ratio (CNR), and maximum spinal cord compression (MSCC). mJOA score, Cobb angle, cervical ROM, intramedullary signal intensity on T2W MRI, and CNR were assessed before surgery and at the final follow-up.

Results

The average mJOA score was significantly improved from preoperative 10.32 ± 1.63 points to 15.10 ± 0.62 points at the final follow-up (p < 0.05). The average RR of the mJOA score at the final follow-up was 69.10 ± 7.32%. The cervical Cobb angle and ROM decreased significantly at the final follow-up. Patients with high intramedullary signal intensity of T2W MRI or CNR more than 50% showed a lower RR of the mJOA score. Correlation analysis revealed that preoperative symptom duration and intramedullary signal intensity of T2W MRI, CNR, MSCC, and blood loss were significantly correlated with the RR of the mJOA score. Gender, operative method, and age at surgery were significantly correlated with the preservation rate of ROM. Operative time was significantly correlated with the incidence of axial symptoms.

Conclusions

The ten-year clinical outcomes of FDL were satisfactory. Higher intramedullary signal intensity of T2W MRI and a greater CNR predicted poorer prognoses.

Predictors of Return to Normal Neurological Function After Surgery for Moderate and Severe Degenerative Cervical Myelopathy: An Analysis of A Global AOSpine Cohort of Patients

BACKGROUND

Multiple studies have established the safety and efficacy of surgical intervention for degenerative cervical myelopathy (DCM). Although the main goal of surgery is symptom stabilization, a subset of patients achieves remarkable improvements.

OBJECTIVE

To identify predictors of return to normal neurological function after surgery for moderate or severe DCM.

METHODS

This is an analysis of 2 prospective multicenter studies (the AOSpine CSM-North America and CSM-International studies) conducted between 2005 and 2011. For patients with complete preoperative magnetic resonance imaging (MRI) and 2-yr follow-up, characteristics were compared between those who achieved a modified Japanese Orthopaedic Association (mJOA) score of 18 at 2 yr (no signs of myelopathy) vs controls. Only patients with baseline mJOA ≤ 14 (moderate and severe myelopathy) were included to minimize ceiling effects.

RESULTS

A total of 51 patients (20.3%) out of 251 with moderate or severe baseline myelopathy achieved an mJOA score of 18 at 2 yr. On stepwise multiple logistic regression analysis, T1-weighted (T1W1)-hypointensity (odds ratio [OR] 0.10; 95% confidence interval [CI], 0.01-0.79; P = .03) and longer walking time on the 30-m walking test (OR 0.95; 95% CI, 0.92-0.99; P = .03) were independent predictors of outcome, with an area under the curve of 0.71 for the model.

CONCLUSION

In this study, T1W-hypointensity on MRI and longer walking time were found to predict a less likelihood of achieving return to normal neurological function after surgery for moderate or severe DCM. These findings may provide useful information for patient counseling and perioperative expectations.

Degenerative Cervical Myelopathy: How to Identify the Best Responders to Surgery?

Surgery is the only definitive treatment for degenerative cervical myelopathy (DCM), however, the degree of neurological recovery is often unpredictable. Here, we assess the utility of a multidimensional diagnostic approach, consisting of clinical, neurophysiological, and radiological parameters, to identify patients likely to benefit most from surgery. Thirty-six consecutive patients were prospectively analyzed using the modified Japanese Orthopedic Association (mJOA) score, MEPs/SSEPs and advance and conventional MRI parameters, at baseline, and 3- and 12-month postoperatively. Patients were subdivided into “normal” and “best” responders (<50%, ≥50% improvement in mJOA), and correlation between Diffusion Tensor Imaging (DTI) parameters, mJOA, and MEP/SSEP latencies were examined. Twenty patients were “best” responders and 16 were “normal responders”, but there were no statistical differences in age, T2 hyperintensity, and midsagittal diameter between them. There was a significant inverse correlation between the MEPs central conduction time and mJOA in the preoperative period (p = 0.0004), and a positive correlation between fractional anisotropy (FA) and mJOA during all the phases of the study, and statistically significant at 1-year (r = 0.66, p = 0.0005). FA was significantly higher amongst “best responders” compared to “normal responders” preoperatively and at 1-year (p = 0.02 and p = 0.009). A preoperative FA > 0.55 was predictor of a better postoperative outcome. Overall, these results support the concept of a multidisciplinary approach in the assessment and management of DCM.

Utility and validity of neurite orientation dispersion and density imaging with diffusion tensor imaging to quantify the severity of cervical spondylotic myelopathy and assess postoperative neurological recovery

BACKGROUND CONTEXT

Predicting postoperative prognosis with preoperative diagnostic imaging has clinical importance. Recent studies have indicated the utility of diffusion tensor imaging (DTI) to quantify the severity of cervical spondylotic myelopathy (CSM) and assess the prognosis of surgical outcomes. However, how to apply DTI to evaluate CSM in a clinical setting is not fully elucidated. Neurite orientation dispersion and density imaging (NODDI) is a model-based practical diffusion-weighted magnetic resonance imaging analysis for estimating specific microstructural features related directly to neuronal morphology. In a prior study, we indicated preoperative NODDI parameters are a promising tool with which to predict neuronal recovery after decompression surgery in patients with CSM with 2 years follow-up. However, the correlation between NODDI parameters and postoperative long-term outcomes and change of parameters over time postoperatively has remained largely unknown.

STUDY DESIGN

Retrospective cohort study.

PURPOSE

To determine the change of parameters of NODDI and conventional DTI over time, and the relationship between parameters and neurological recovery 2 years after surgery.

PATIENT SAMPLE

We included 28 consecutive patients with nontraumatic cervical lesions from CSM who underwent laminoplasty and were followed up for >2 years. Patients underwent magnetic resonance imaging before and approximately 2 weeks, 6 months, and 1 year after surgery.

OUTCOME MEASURES

In addition to conventional DTI metrics, we evaluated intracellular volume fraction (ICVF) and orientation dispersion index, which are metrics derived from NODDI. The Japanese Orthopedic Association (JOA) scoring system was used before and 2 years after surgery to assess neurological outcome (JOA recovery rate).

METHODS

NODDI and conventional DTI values were measured at the C2-C3 intervertebral level (control value) and the most compressed levels (C3-C7 intervertebral levels) were measured by 3 observers. The changes of these values from preoperatively, 2 weeks after surgery, 6 months after surgery, and 1 year after surgery, were determined. The correlations between preoperative neurological severity, postoperative neuronal recovery, and preoperative DTI or NODDI metrics were determined. No financial or material support was obtained for this study. There is no conflict of interest.

RESULTS

The preoperative ICVF and fractional anisotropy at the most compressed level were significantly less than the preoperative values at the control C2-C3 intervertebral level and fractional anisotropy at the most compressed level was increased in the immediate postoperative period. By contrast, ICVF at the most compressed level was not increased in the immediate postoperative period and a significant increase was observed at 6 months after surgery. Preoperative ICVF was significantly correlated with JOA recovery rate at 2 years after surgery.

CONCLUSIONS

NODDI is a reproducible and reliable method for evaluation of CSM. ICVF improved after surgery and recovery of physical findings accompanied this change. ICVF may be applied clinically to predict postoperative recovery.

Considerations for Mean Upper Cervical Cord Area Implementation in a Longitudinal MRI Setting: Methods, Interrater Reliability, and MRI Quality Control

BACKGROUND AND PURPOSE

Spinal cord atrophy is commonly measured from cerebral MRIs, including the upper cervical cord. However, rescan intraparticipant measures have not been investigated in healthy cohorts. This study investigated technical and rescan variability in the mean upper cervical cord area calculated from T1-weighted cerebral MRIs.

MATERIALS AND METHODS

In this retrospective study, 8 healthy participants were scanned and rescanned with non-distortion- and distortion-corrected MPRAGE sequences (11-50 sessions in 6-8 months), and 50 participants were scanned once with distortion-corrected MPRAGE sequences in the Day2day daily variability study. From another real-world observational cohort, we collected non-distortion-corrected MPRAGE scans from 27 healthy participants (annually for 2-4 years) and cross-sectionally from 77 participants. Statistical analyses included coefficient of variation, smallest real difference, intraclass correlation coefficient, Bland-Altman limits of agreement, and paired t tests.

RESULTS

Distortion- versus non-distortion-corrected MPRAGE-derived mean upper cervical cord areas were similar; however, a paired t test showed incomparability (t = 11.0, P = <.001). Higher variability was found in the mean upper cervical cord areas calculated from an automatic segmentation method. Interrater analysis yielded incomparable measures in the same participant scans (t = 4.5, P = <.001). Non-distortion-corrected mean upper cervical cord area measures were shown to be robust in real-world data (t = -1.04, P = .31). The main sources of variability were found to be artifacts from movement, head/neck positioning, and/or metal implants.

CONCLUSIONS

Technical variability in cord measures decreased using non-distortion-corrected MRIs, a semiautomatic segmentation approach, and 1 rater. Rescan variability was within ±4.4% for group mean upper cervical cord area when MR imaging quality criteria were met.

Degenerative cervical myelopathy - update and future directions

Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord dysfunction in adults worldwide. DCM encompasses various acquired (age-related) and congenital pathologies related to degeneration of the cervical spinal column, including hypertrophy and/or calcification of the ligaments, intervertebral discs and osseous tissues. These pathologies narrow the spinal canal, leading to chronic spinal cord compression and disability. Owing to the ageing population, rates of DCM are increasing. Expeditious diagnosis and treatment of DCM are needed to avoid permanent disability. Over the past 10 years, advances in basic science and in translational and clinical research have improved our understanding of the pathophysiology of DCM and helped delineate evidence-based practices for diagnosis and treatment. Surgical decompression is recommended for moderate and severe DCM; the best strategy for mild myelopathy remains unclear. Next-generation quantitative microstructural MRI and neurophysiological recordings promise to enable quantification of spinal cord tissue damage and help predict clinical outcomes. Here, we provide a comprehensive, evidence-based review of DCM, including its definition, epidemiology, pathophysiology, clinical presentation, diagnosis and differential diagnosis, and non-operative and operative management. With this Review, we aim to equip physicians across broad disciplines with the knowledge necessary to make a timely diagnosis of DCM, recognize the clinical features that influence management and identify when urgent surgical intervention is warranted.

Cord compression defined by MRI is the driving factor behind the decision to operate in Degenerative Cervical Myelopathy despite poor correlation with disease severity

OBJECTIVES

The mainstay treatment for Degenerative Cervical Myelopathy (DCM) is surgical decompression. Not all cases, however, are suitable for surgery. Recent international guidelines advise surgery for moderate to severe disease as well as progressive mild disease. The goal of this study was to examine the factors in current practice that drive the decision to operate in DCM.

STUDY DESIGN

Retrospective cohort study.

METHODS

1 year of cervical spine MRI scans (N = 1123) were reviewed to identify patients with DCM with sufficient clinical documentation (N = 39). Variables at surgical assessment were recorded: age, sex, clinical signs and symptoms of DCM, disease severity, and quantitative MRI measures of cord compression. Bivariate correlations were used to compare each variable with the decision to offer the patient an operation. Subsequent multivariable analysis incorporated all significant bivariate correlations.

RESULTS

Of the 39 patients identified, 25 (64%) were offered an operation. The decision to operate was significantly associated with narrower non-pathological canal and cord diameters as well as cord compression ratio, explaining 50% of the variance. In a multivariable model, only cord compression ratio was significant (p = 0.017). Examination findings, symptoms, functional disability, disease severity, disease progression, and demographic factors were all non-significant.

CONCLUSIONS

Cord compression emerged as the main factor in surgical decision-making prior to the publication of recent guidelines. Newly identified predictors of post-operative outcome were not significantly associated with decision to operate.

The effects of simulated +Gz and microgravity on intervertebral disc degeneration in rabbits

The overall objective of this study was to test the hypothesis that +Gz (hypergravity/positive acceleration) and microgravity can both aggravate intervertebral disc degeneration (IVDD). Due to +Gz and microgravity, many pilots develop IVDD. However, the lack of animal models of IVDD under conditions of simulated +Gz and microgravity has hampered research on the onset and prevention of IVDD. Rabbits were randomly allotted to a control group, microgravity group, +Gz group, or mixed (+Gz + microgravity) group. A tail-suspension model was utilized to simulate a microgravity environment and an animal centrifuge to mimic +Gz conditions. After exposure to the above conditions for 4, 8, and 24 weeks, the body weights (BW) of animals in the control group gradually increased over time, while those of animals in the microgravity and mixed groups both decreased (p < 0.001). As compared with the control group, the proteoglycan content of animals in the other three groups was significantly reduced (F = 192.83, p < 0.001). The imageological, histopathological, and immunohistochemical changes to the L6-S1 intervertebral disc samples suggests that the effects of +Gz and microgravity can aggravate IVDD over time. The mixed effects of +Gz and microgravity had the greatest effect on degeneration and +Gz had a particularly greater effect than microgravity.

Postoperative Resolution of MR T2 Increased Signal Intensity in Cervical Spondylotic Myelopathy: The Impact of Signal Change Resolution on the Outcomes

STUDY DESIGN

A prospective comparative imaging study.

OBJECTIVE

This study investigated whether postoperative resolution of spinal cord increased signal intensity (ISI) reflected symptom improvement and surgical outcomes in cervical spondylotic myelopathy (CSM) patients.

SUMMARY OF BACKGROUND DATA

Although some CSM patients exhibit magnetic resonance imaging (MRI) ISI, its alteration and resolution have not been investigated. The association between postoperative ISI resolution and surgical outcomes in CSM patients remains controversial.

METHODS

A total of 505 consecutive CSM patients (311 males; 194 females) aged a mean of 66.6 years (range, 41-91) were enrolled. All were treated with laminoplasty and underwent MRI scans preoperatively and after an average of 26.5 months postoperatively (range 12-66 months). ISI was classified pre- and postoperatively based on sagittal T2-weighted magnetic resonance images into Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). The patients' pre- and postoperative neurological statuses were evaluated using the Japanese Orthopedic Association scoring system for cervical myelopathy [Japanese Orthopedic Association (JOA) score] and other quantifiable tests, including the 10-s grip and release (10-s G&R) test and 10-s step test.

RESULTS

A total of 337 patients showed preoperative ISI. Among these, 42 (12.5%) showed postoperative ISI resolution, associated with better postoperative JOA score and recovery rate, 10-s G&R and 10-s step test scores than those who retained it. Patients with preoperative Grade 2 ISI had no postoperative ISI resolution. Patients with ISI improvement from Grade 1 to Grade 0 had better outcomes than those with ISI worsening from Grade 1 to Grade 2.

CONCLUSION

Postoperative ISI resolution in CSM patients reflects postoperative symptoms and surgical outcomes. Patients who exhibit ISI resolution have better clinical outcomes.

LEVEL OF EVIDENCE

3.

Assessment of spinal cord motion as a new diagnostic MRI-parameter in cervical spinal canal stenosis: study protocol on a prospective longitudinal trial

Background

Increased spinal cord motion has been proven to be a relevant finding within spinal canal stenosis disclosed by phase-contrast MRI (PC-MRI). Adapted PC-MRI is a suitable and reliable method within the well deliberated setting. As the decision between conservative and operative treatment can be challenging in some cases, further diagnostic marker would facilitate the diagnostic process. We hypothesize that increased spinal cord motion will correlate to clinical course and functional impairment and will contribute as a new diagnostic marker.

Methods

A monocentric, prospective longitudinal observational trial on cervical spinal canal stenosis will be conducted at the University Medical Center Freiburg. Patients (n = 130) with relevant cervical spinal canal stenosis, being defined by at least contact to the spinal cord, will be included. Also, we will examine a control group of healthy volunteers (n = 20) as proof-of-principle. We will observe two openly assigned branches of participants undergoing conservative and surgical decompressive treatment (based on current German Guidelines) over a time course of 12 month, including a total of 4 visits. We will conduct a broad assessment of clinical parameters, standard scores and gradings, electrophysiological measurements, standard MRI, and adapted functional PC-MRI of spinal cord motion. Primary endpoint is the evaluation of an expected negative correlation of absolute spinal cord displacement to clinical impairment. Secondary endpoints are the evaluation of positive correlation of increased absolute spinal cord displacement to prolonged evoked potentials, prediction of clinical course by absolute spinal cord displacement, and demonstration of normalized spinal cord motion after decompressive surgery.

Discussion

With the use of adapted, non-invasive PC-MRI as a quantitative method for assessment of spinal cord motion, further objective diagnostic information can be gained, that might improve the therapeutic decision-making process. This study will offer the needed data in order to establish PC-MRI on spinal cord motion within the diagnostic work-up of patients suffering from spinal canal stenosis.

Trial registration

German Clinical Trials Register, ID: DRKS00012962, Register date 2018/01/17

Cervical Spondylotic Myelopathy: Natural Course and the Value of Diagnostic Techniques -WFNS Spine Committee Recommendations

Objective

This study presents the results of a systematic literature review conducted to determine most up-to-date information on the natural outcome of cervical spondylotic myelopathy (CSM) and the most reliable diagnostic techniques.

Methods

A literature search was performed for articles published during the last 10 years.

Results

The natural course of patients with cervical stenosis and signs of myelopathy is quite variable. In patients with no symptoms, but significant stenosis, the risk of developing myelopathy with cervical stenosis is approximately 3% per year. Myelopathic signs are useful for the clinical diagnosis of CSM. However, they are not highly sensitive and may be absent in approximately one-fifth of patients with myelopathy. The electrophysiological tests to be used in CSM patients are motor evoked potential (MEP), spinal cord evoked potential, somatosensory evoked potential, and electromyography (EMG). The differential diagnosis of CSM from other neurological conditions can be accomplished by those tests. MEP and EMG monitoring are useful to reduce C5 root palsy during CSM surgery. Notable spinal cord T2 hyperintensity on cervical magnetic resonance imaging (MRI) is correlated with a worse outcome, whereas lighter signal changes may predict better outcomes. T1 hypointensity should be considered a sign of more advanced disease.

Conclusion

The natural course of CSM is quite variable. Signal changes on MRI and some electrophysiological tests are valuable adjuncts to diagnosis.

Assessment of degenerative cervical stenosis on T2-weighted MR imaging: sensitivity to change and reliability of mid-sagittal and axial plane metrics

STUDY DESIGN

A retrospective cross-sectional study.

OBJECTIVE

To assess the sensitivity to change and reliability of various mid-sagittal and axial plane metrics in the assessment of patients with single-level degenerative cervical stenosis on T2-weighted MR imaging.

SETTING

A diagnostic MR imaging facility in Sydney (Australia).

METHODS

We retrospectively reviewed T2-weighted MR images of 85 consecutive patients (48 M and 37 F) with single-level degenerative cervical stenosis. Canal compromise and cord compression were evaluated using three mid-sagittal plane metrics (M₁, M₂, and M₃) and two axial plane metrics (M₄ and M₅), at the level of stenosis and nonstenotic cephalad and caudal levels (controls). Sensitivity to change (SC) for each metric was evaluated as the percentage deviation of the measured value from the estimated normal value based on cephalad and caudal controls. Reliability for each metric was evaluated using intraclass correlation coefficients.

RESULTS

Degenerative cervical stenosis showed a bimodal distribution peaking at C5-6 (n = 32) and C3-4 (n = 29) levels. The changes in the canal and cord geometry along the rostrocaudal axis were inconsistent. Across all individual subjects (reflecting a range of stenosis severity), M₃ (-32.87% ± 10.60%) was more sensitive to change compared with M₁ (16.64% ± 16.48%) and M₂ (-23.95% ± 11.12%). Similarly, M₄ (-24.62% ± 12.17%) was more sensitive to change compared with M₅ (-6.71% ± 11.08%). The level of reliability was "moderate" to "excellent" for mid-sagittal plane measurements, and "poor" to "excellent" for axial plane measurements.

CONCLUSION

Changes in canal dimensions in the mid-sagittal plane and cord shape in the axial plane are sensitive indicators of degenerative cervical stenosis on T2-weighted MR images.

[Spondylotic cervical myelopathy : Indication of surgical treatment]

BACKGROUND

The pathogenesis of cervical spondylotic myelopathy (CSM) is often multifactorial. Hence, the treatment of this disease requires a differentiated surgical approach in order to adequately address the underlying pathology.

PURPOSE

The aim of this review is to identify factors that influence the choice of treatment strategy and to summarize them in an algorithm that serves as a decision aid in choosing the optimal indication for surgical treatment. An attempt is made to define the threshold values for the indication of surgical treatment and to discuss the ideal timing for performing surgery.

MATERIALS AND METHODS

On the basis of the published data, the influencing factors on the prognosis of CSM, as well as surgical approaches are discussed.

RESULTS

Circumferential spinal cord compression, a sharply defined myelopathy signal in the T2-weighted MRI sequence, and segmental instability at the level of the myelopathy signal mean an unfavorable prognosis for the worsening of CSM. The most important factors that influence the choice of the surgical access point are the sagittal profile of the cervical spine, the extent of myelopathy, the extent of stenosis, and the location of the myelopathy-inducing pathology. Previously existing neck pain and prior cervical surgery must also be considered.

DISCUSSION

On the basis of the research carried out, we developed an algorithm that could serve as an aid in choosing the right treatment in the setting of cervical spondylotic myelopathy.

A comparison of radiological descriptions of spinal cord compression with quantitative measures, and their role in non-specialist clinical management

INTRODUCTION

Magnetic resonance imaging (MRI) is gold-standard for investigating Degenerative Cervical Myelopathy (DCM), a disabling disease triggered by compression of the spinal cord following degenerative changes of adjacent structures. Quantifiable compression correlates poorly with disease and language describing compression in radiological reports is un-standardised.

STUDY DESIGN

Retrospective chart review.

OBJECTIVES

1) Identify terminology in radiological reporting of cord compression and elucidate relationships between language and quantitative measures 2) Evaluate language's ability to distinguish myelopathic from asymptomatic compression 3) Explore correlations between quantitative or qualitative features and symptom severity 4) Investigate the influence of quantitative and qualitative measures on surgical referrals.

METHODS

From all cervical spine MRIs conducted during one year at a tertiary centre (N = 1123), 166 patients had reported cord compression. For each spinal level deemed compressed by radiologists (N = 218), four quantitative measurements were calculated: 'Maximum Canal Compromise (MCC); 'Maximum Spinal Cord Compression' (MSCC); 'Spinal Canal Occupation Ratio' (SCOR) and 'Compression Ratio' (CR). These were compared to associated radiological reporting terminology.

RESULTS

1) Terminology in radiological reports was varied. Objective measures of compromise correlated poorly with language. "Compressed" was used for more severe cord compromise as measured by MCC (p<0.001), MSCC (p<0.001), and CR (p = 0.002). 2) Greater compromise was seen in cords with a myelopathy diagnosis across MCC (p<0.001); MSCC (p = 0.002) and CR (p<0.001). "Compress" (p<0.001) and "Flatten" (p<0.001) were used more commonly for myelopathy-diagnosis levels. 3) Measurements of cord compromise (MCC: p = 0.304; MSCC: p = 0.217; SCOR: p = 0.503; CR: p = 0.256) and descriptive terms (p = 0.591) did not correlate with i-mJOA score. 4) The only variables affecting spinal surgery referral were increased MSCC (p = 0.001) and use of 'Compressed' (p = 0.045).

CONCLUSIONS

Radiological reporting in DCM is variable and language is not fully predictive of the degree of quantitative cord compression. Additionally, terminology may influence surgical referrals.

Longitudinal diffusion tensor imaging of patients with degenerative cervical myelopathy following decompression surgery

Previous studies have reported the utility of diffusion tensor imaging (DTI) as an imaging biomarker for the severity of myelopathy and subsequent surgical outcome in patients with degenerative cervical myelopathy (DCM). We hypothesized that DTI may reflect neurological recovery following surgery. The purpose of this study was to evaluate the ability of DTI to assess the post-operative alteration of neural status in patients with DCM as well as to predict post-operative recovery. We enrolled 15 patients with DCM who underwent decompression surgery. The Japanese Orthopaedic Association (JOA) score was evaluated before and 1 year after surgery. The participants were examined using DTI on a 3.0 T magnetic resonance scanner before, and 1 year after surgery. Fractional anisotropy (FA) and mean diffusivity (MD) were assessed for both time points. The correlations between the pre- and post-operative FA and MD values and the pre- and post-operative JOA scores were analyzed. Although the JOA score improved significantly after surgery from 8.9 to 12.3, there was no significant change between the pre- and post-operative FA and MD values. The post-operative outcomes after 1 year moderately correlated with the pre-operative FA values (Spearman's ρ = 0.55, p = 0.03 and Spearman's ρ = 0.56, p = 0.03 for change and recovery rate of the JOA score, respectively). However, there was no correlation between the post-operative FA and post-operative JOA scores nor between MD and clinical outcomes. DTI cannot be utilized as a biomarker for post-operative alterations of neural status of the spinal cord; however, pre-operative DTI may be useful as a predictor of surgical outcomes.

Comparison between quantitative measurements of diffusion tensor imaging and T2 signal intensity in a large series of cervical spondylotic myelopathy patients for assessment of disease severity and prognostication of recovery

OBJECTIVE

Cervical spondylotic myelopathy (CSM) is a common cause of spinal cord dysfunction. Recently, it has been shown that diffusion tensor imaging (DTI) may be a better biomarker than T2-weighted signal intensity (T2SI) on MRI for CSM. However, there is very little literature on a comparison between the quantitative measurements of DTI and T2SI in the CSM patient population to determine disease severity and recovery.

METHODS

A prospective analysis of 46 patients with both preoperative DTI and T2-weighted MRI was undertaken. Normalized T2SI (NT2SI), regardless of the presence or absence of T2SI at the level of maximum compression (LMC), was determined by calculating the T2SI at the LMC/T2SI at the level of the foramen magnum. Regression analysis was performed to determine the relationship of fractional anisotropy (FA), a quantitative measure derived from DTI, and NT2SI individually as well their combination with baseline preoperative modified Japanese Orthopaedic Association (mJOA) score and ∆mJOA score at the 3-, 6-, 12-, and 24-month follow-ups. Goodness-of-fit analysis was done using residual diagnostics. In addition, mixed-effects regression analysis was used to evaluate the impact of FA and NT2SI individually. A p value < 0.05 was selected to indicate statistical significance.

RESULTS

Regression analysis showed a significant positive correlation between FA at the LMC and preoperative mJOA score (p = 0.041) but a significant negative correlation between FA at the LMC and the ΔmJOA score at the 12-month follow-up (p = 0.010). All other relationships between FA at the LMC and the baseline preoperative mJOA score or ∆mJOA score at the 3-, 6-, and 24-month follow-ups were not statistically significant. For NT2SI and the combination of FA and NT2SI, no significant relationships with preoperative mJOA score or ∆mJOA at 3, 6, and 24 months were seen on regression analysis. However, there was a significant correlation of combined FA and NT2SI with ∆mJOA score at the 12-month follow-up. Mixed-effects regression revealed that FA measured at the LMC was the only significant predictor of ΔmJOA score (p = 0.03), whereas NT2SI and time were not. Goodness-of-fit analysis did not show any evidence of lack of fit.

CONCLUSIONS

In this large prospective study of CSM patients, FA at LMC appears to be a better biomarker for determining long-term outcomes following surgery in CSM patients than NT2SI or the combination values at LMC.

The Role of Vitamin B12 in the Management and Optimization of Treatment in Patients With Degenerative Cervical Myelopathy

STUDY DESIGN

Narrative review.

OBJECTIVES

To discuss the relationship between degenerative cervical myelopathy (DCM) and vitamin B12 deficiency. Specifically, it is the aim to outline the rational for future research into assessment and therapeutic optimization of vitamin B12 in the treatment of DCM.

METHODS

Literature review.

RESULTS

DCM is the commonest cause of spinal cord impairment, with an average age of presentation in the sixth decade. Patients at this age have also been reported to have a high prevalence of vitamin B12 deficiency, with estimates of up to 20% in the elderly. Vitamin B12 deficiency can result in subacute combined degeneration of the spinal cord (SACD), and several case reports have pointed to patients with both DCM and SACD. Both SACD and reversible compressive injury due to DCM necessitate remyelination in the spinal cord, a process that requires adequate vitamin B12 levels. Basic science research on nerve crush injuries have shown that vitamin B12 levels are altered after nerve injury and that vitamin B12 along with dexamethasone or nonsteroidal anti-inflammatory drugs can reduce Wallerian degeneration. Furthermore, it has been suggested that a combination of B-vitamins can reduce glutamate-induced neurotoxicity.

CONCLUSIONS

Given the high prevalence of clinical and subclinical vitamin B12 deficiency in the elderly, the role of vitamin B12 in myelination, and vitamin B12 deficiency as a differential diagnosis of DCM, it is important to investigate what role vitamin B12 levels play in patients with DCM in terms of baseline neurological function and whether optimization of vitamin B12 levels can improve surgical outcome. Furthermore, the routine assessment of vitamin B12 levels in patients considered for DCM surgery should be considered.

The relationship between preoperative factors and the presence of intramedullary increased signal intensity on T2-weighted magnetic resonance imaging in patients with cervical spondylotic myelopathy

OBJECTIVE

To investigate preoperative factors affecting the presence of intramedullary increased signal intensity (ISI) on T2-weighted magnetic resonance imaging (MRI) in patients with cervical spondylotic myelopathy (CSM) and the impact of ISI on clinical manifestations.

PATIENTS AND METHODS

Eighty-nine patients with CSM were retrospectively reviewed from January 2013 to December 2016 in our hospital. Based on the presence or absence of ISI on axial and sagittal T2-weighted MRI, patients were divided into ISI group (48 cases) and non-ISI group (41 cases). Factors such as age, sex, body mass index (BMI), duration of symptoms, clinical symptoms and signs, number and distribution of spinal cord compression levels, preoperative Japanese Orthopedic Association (JOA) score, preoperative C2-C7 lordotic angle, preoperative C2-C7 range of motion (ROM), maximal canal compromise (MCC) and maximal spinal cord compression (MSCC) were initially compared using univariate analysis. Factors with significant result in univariate analysis were included in multivariate logistic regression analysis. Receiver operating characteristic (ROC) curve and the area under the curve (AUC) were applied to evaluate the reliability of multivariate logistic regression model.

RESULTS

Univariate analysis showed that the number of spinal cord compression levels, preoperative JOA score, MCC and MSCC might be related to the presence of ISI (P <  0.05). Furthermore, multivariate logistic regression analysis revealed that the number of spinal cord compression levels (OR = 0.203, P <  0.05), preoperative JOA score (OR = 4.274, P <  0.05) and MSCC (OR = 0.250, P <  0.05) were independent preoperative risk factors associated with the presence of ISI, yielding an AUC of 0.9558. Patients with ISI showed a trend of increasing clinical symptoms and signs, and also exhibited statistically significantly increased frequencies of clumsy hands, lower limb spasticity, impairment of gait, broad-based, unstable gait, weakness and motor deficits (P <  0.05).

CONCLUSION

Multilevel spinal cord compression, lower preoperative JOA score and greater MSCC are independent preoperative risk factors related to the presence of ISI on T2-weighted MRI in patients with CSM. Patients with ISI tend to have more clinical symptoms and signs, especially in lower limb manifestations and motor deficits.