Does lumbar spinal stenosis increase the risk of spondylotic cervical spinal cord compression?

Investigating cervical flexion-relaxation ratio in subjects with cervical lateral spinal stenosis compared with asymptomatic controls: A case control study

INTRODUCTION

The cervical flexion-relaxation ratio (FRR) is known as a quantitative measure of the ability of the cervical extensor muscles to relax during the full flexion of the cervical spine. Compared with subjects suffering from non-specific neck pain, the changes occurring in the pattern of the neck muscles' functions in cases with cervical spinal stenosis are not yet well understood. Therefore, this study aimed to compare cervical FRR in subjects with cervical lateral spinal stenosis and asymptomatic controls.

METHODS

In total, 25 subjects with cervical lateral spinal stenosis (aged 44.7 ± 10.4) and 25 asymptomatic individuals (aged 44.3 ± 10.8) were included in this study. These participants performed full-neck flexion, and at the same time, the electrical activity of the cervical erector spinae (CES) muscles was recorded bilaterally. Cervical FRR was further calculated by analyzing the electromyographic data recorded for each muscle.

RESULTS

The mean cervical FRR was significantly lower (P = 0.015) and the FRR asymmetry (ΔFRR) was significantly higher (P = 0.003) in the patients than asymptomatic controls. In addition, the cervical FRR of the involved side was significantly lower in the subjects with cervical pain compared with that in the non-involved one (P = 0.004). There was also a significant difference in the cervical extension (CE) angle between both study groups (P < 0.001), while the cervical flexion (CF) angle was not different (P = 0.25).

CONCLUSION

According to the study results, FRR and its asymmetry in the subjects with cervical lateral spinal stenosis were significantly different from that in asymptomatic controls and the CE angle declined in these subjects.

Current understanding of tandem spinal stenosis: epidemiology, diagnosis, and surgical strategy

Tandem spinal stenosis (TSS) is defined as the concomitant occurrence of stenosis in at least two or more distinct regions (cervical, thoracic, or lumbar) of the spine and may present with a constellation of signs and symptoms. It has four subtypes, including cervico-lumbar, cervico-thoracic, thoraco-lumbar, and cervico-thoraco-lumbar TSS. The prevalence of TSS varies depending on the different subtypes and cohorts.

The main aetiologies of TSS are spinal degenerative changes and heterotopic ossification, and patients with developmental spinal stenosis, ligament ossification, and spinal stenosis at any region are at an increased risk of developing TSS.

The diagnosis of TSS is challenging. The clinical presentation of TSS could be complex, concealed, or severe, and these features may be confusing to clinicians, resulting in an incomplete or delayed diagnosis. Additionally, a consolidated diagnostic criterion for TSS is urgently required to improve consistency across studies and form a basis for establishing treatment guidelines.

The optimal treatment option for TSS is still under debate; areas of controversies include choice of the decompression range, choice between simultaneous or staged surgical patterns, and the order of the surgeries.

The present study reviews publications on TSS, consolidates current awareness on prevalence, aetiologies, potential risk factors, diagnostic dilemmas and criteria, and surgical strategies based on TSS subtypes. This is the first review to include thoracic spinal stenosis as a candidate disorder in TSS and aims at providing the readers with a comprehensive overview of TSS.

Quantitative MR Markers in Non-Myelopathic Spinal Cord Compression: A Narrative Review

Degenerative spinal cord compression is a frequent pathological condition with increasing prevalence throughout aging. Initial non-myelopathic cervical spinal cord compression (NMDC) might progress over time into potentially irreversible degenerative cervical myelopathy (DCM). While quantitative MRI (qMRI) techniques demonstrated the ability to depict intrinsic tissue properties, longitudinal in-vivo biomarkers to identify NMDC patients who will eventually develop DCM are still missing. Thus, we aim to review the ability of qMRI techniques (such as diffusion MRI, diffusion tensor imaging (DTI), magnetization transfer (MT) imaging, and magnetic resonance spectroscopy (1H-MRS)) to serve as prognostic markers in NMDC. While DTI in NMDC patients consistently detected lower fractional anisotropy and higher mean diffusivity at compressed levels, caused by demyelination and axonal injury, MT and 1H-MRS, along with advanced and tract-specific diffusion MRI, recently revealed microstructural alterations, also rostrally pointing to Wallerian degeneration. Recent studies also disclosed a significant relationship between microstructural damage and functional deficits, as assessed by qMRI and electrophysiology, respectively. Thus, tract-specific qMRI, in combination with electrophysiology, critically extends our understanding of the underlying pathophysiology of degenerative spinal cord compression and may provide predictive markers of DCM development for accurate patient management. However, the prognostic value must be validated in longitudinal studies.

Simultaneous decompression of all stenotic regions versus decompression of only the most symptomatic region in patients with tandem spinal stenosis: a systematic review and meta-analysis

PURPOSE

Selection of anatomic region of spine for decompression in patients with symptomatic tandem spinal stenosis (TSS) remains a challenge due to the confusing clinical presentation as well as uncertain evidence. A systematic review and meta-analysis of observational studies were conducted to compare the outcomes between simultaneous decompression of all stenotic regions (cervical and lumbar, Group 1) and decompression of only the most symptomatic stenotic region (cervical/lumbar, Group 2) in patients with TSS.

METHODS

A systematic review was conducted, and a comprehensive literature search with well-established inclusion and exclusion criteria with JOA score as an outcome measure was done on PubMed, Google Scholar, and EMBASE database (till January 2021). Observational studies reporting outcomes after simultaneous decompression or only the most symptomatic region were included. NIH quality assessment tool was used to check the quality of each study, and treatment effects were calculated using Dersimonian and Laird random effects model.

RESULTS

Ten studies were included in the analysis out of which all were retrospective observational studies (Level 4 evidence) except one (Level 3 evidence). Overall proportional meta-analysis showed no significant difference in change in JOA scores, operative time, blood loss, total and major complications between Group 1 and Group 2. However, minor complications were significantly increased on performing decompression of both regions simultaneously (p = 0.04). On performing subgroup analysis comparing cervical surgery cohort with lumbar surgery cohort, no difference was found in change in JOA score and requirement of second-stage surgery.

CONCLUSION

Decompression of the most symptomatic region alone irrespective of its location has equal clinical outcomes with less complication rate than simultaneous decompression in patients with TSS.

Diffusion magnetic resonance imaging reveals tract-specific microstructural correlates of electrophysiological impairments in non-myelopathic and myelopathic spinal cord compression

BACKGROUND AND PURPOSE

Non-myelopathic degenerative cervical spinal cord compression (NMDC) frequently occurs throughout aging and may progress to potentially irreversible degenerative cervical myelopathy (DCM). Whereas standard clinical magnetic resonance imaging (MRI) and electrophysiological measures assess compression severity and neurological dysfunction, respectively, underlying microstructural deficits still have to be established in NMDC and DCM patients. The study aims to establish tract-specific diffusion MRI markers of electrophysiological deficits to predict the progression of asymptomatic NMDC to symptomatic DCM.

METHODS

High-resolution 3 T diffusion MRI was acquired for 103 NMDC and 21 DCM patients compared to 60 healthy controls to reveal diffusion alterations and relationships between tract-specific diffusion metrics and corresponding electrophysiological measures and compression severity. Relationship between the degree of DCM disability, assessed by the modified Japanese Orthopaedic Association scale, and tract-specific microstructural changes in DCM patients was also explored.

RESULTS

The study identified diffusion-derived abnormalities in the gray matter, dorsal and lateral tracts congruent with trans-synaptic degeneration and demyelination in chronic degenerative spinal cord compression with more profound alterations in DCM than NMDC. Diffusion metrics were affected in the C3-6 area as well as above the compression level at C3 with more profound rostral deficits in DCM than NMDC. Alterations in lateral motor and dorsal sensory tracts correlated with motor and sensory evoked potentials, respectively, whereas electromyography outcomes corresponded with gray matter microstructure. DCM disability corresponded with microstructure alteration in lateral columns.

CONCLUSIONS

Outcomes imply the necessity of high-resolution tract-specific diffusion MRI for monitoring degenerative spinal pathology in longitudinal studies.

Prevalence and Predictive Factors of Asymptomatic Spondylotic Cervical Spinal Stenosis in Patients with Symptomatic Lumbar Spinal Stenosis

OBJECTIVE

We performed a retrospective cohort study to investigate the prevalence of and risk factors for asymptomatic spondylotic cervical spinal stenosis (ASCSS) in the setting of lumbar spinal stenosis (LSS).

METHODS

A total of 114 patients with a diagnosis of LSS without cervical myelopathy and radiculopathy were grouped into ASCSS and non-ASCSS groups. The medical data and radiological parameters, including age, sex, body mass index, Charlson comorbidity index, symptom duration, redundant nerve roots, dural sac cross-sectional area (DCSA), facet joint angle, lumbar lordosis angle (LLA), pelvic incidence (PI), Torg-Pavlov ratio, and lumbosacral transitional vertebrae, were analyzed. The lumbar stenosis index and cervical stenosis index of the 114 patients were also analyzed.

RESULTS

ASCSS occurred in 70 of the 114 patients with LSS (61.4%). The two groups showed significant differences in symptom duration, redundant nerve roots, LLA, DCSA, and PI. On multivariate logistic regression analysis, an LLA >35.85° (P < 0.001) and a DCSA <84.50 mm² (P = 0.003) were independently associated with ASCSS. The multi-index receiver operating characteristic curve showed that the area under the curve for predicted probability was 0.805 (P < 0.001). Linear regression analysis revealed that cervical stenosis index significantly and positively correlated with the lumbar stenosis index (r = 0.430; P < 0.001).

CONCLUSIONS

Our findings suggest that an LLA >35.85° and a DCSA <84.50 mm² are risk factors for the development of ASCSS. For LSS patients with an enlarged LLA and reduced DSCA, a whole spinal magnetic resonance imaging examination should be performed.

Simultaneous or Staged Decompressions for Patients with Tandem Spinal Stenosis

Objective

To compare the clinical effects of cervical decompression first, lumbar decompression first, or simultaneous decompression of both lesions in the treatment of tandem spinal stenosis (TSS).

Methods

This is a retrospective analysis. From January 2013 to December 2018, 51 TSS patients underwent our surgery and postoperative investigation. Among the 51 subjects, 27 females and 24 males, aged 49–77 years with an average age of 66.3 ± 6.8, were selected. According to the different operation sequences, all patients were divided into three groups. In simultaneous operation group, five patients underwent cervical and lumbar vertebrae surgery at the same time. In first cervical surgery group, 28 patients underwent cervical vertebra surgery first, followed by lumbar spine surgery after a period of recovery. And in first lumbar surgery group, 18 patients underwent lumbar vertebrae surgery first. The choice for neck surgery is posterior cervical single‐door vertebroplasty, the surgery of lumber is plate excision and decompression needle‐rod system internal fixation. The outcome measures are visual analogue scale (VAS), Japanese Orthopaedic Association cervical (JOA‐C) and lumbar (JOA‐L) scores, which were assessed at 3 months and 1 year after the operation by telephone interview. In addition, operative time, estimated blood loss, and hospital stay were also recorded.

Results

All the patients in the study had surgery performed successfully by the same group of orthopaedic surgeons. The preoperative VAS scores of simultaneous operation group, first cervical surgery group, and first lumbar surgery group were 8.00 ± 1.00, 8.36 ± 0.68, and 8.17 ± 0.71 (P > 0.05). The preoperative JOA‐C scores were 7.00 ± 2.35, 6.54 ± 1.53, and 7.83 ± 1.04 (P < 0.05). And the preoperative JOA‐L scores were 7.20 ± 2.17, 4.64 ± 2.36, and 5.78 ± 1.22 respectively (P < 0.05). During the final 1‐year follow‐up, the JOA‐C improvement rates of simultaneous operation group, first cervical surgery group, and first lumbar surgery group were 85.68% ± 5.44%, 84.27% ± 5.02%, and 83.34% ± 10.25%, respectively (P > 0.05), and the JOA‐L improvement rates were 80.04% ± 3.35%, 81.65% ± 3.74%, and 80.21% ± 4.76% (P > 0.05). The difference among them was not statistically significant. In addition, operation time (OP), blood loss (BL), and hospital stay (HS) in the simultaneous operation group were 245.00 ± 5.00 min, 480.00 ± 27.39 mL, and 16.60 ± 0.55 days, respectively. While those parameters in the first cervical surgery group were 342.50 ± 18.18 min, 528.21 ± 43.97 mL, and 22.75 ± 2.15 days, and in the first lumbar surgery group they were 346.11 ± 24.77 min, 519.44 ± 43.99 mL, and 22.89 ± 1.64 days. The average blood loss in simultaneous operation group was less (P > 0.05); meanwhile, the operation time and hospital stay time were significantly shorter in the simultaneous operation group than in the first cervical surgery group and first lumbar surgery group (P < 0.05). Only one case of fat liquefaction occurred in first cervical surgery group, which healed spontaneously after a regular change of dressing for 1 month.

Conclusions

Under the condition of ensuring the surgical effect, the choice of staged surgery or concurrent surgery according to the patients' own symptoms of cervical and lumbar symptoms could both obtain satisfactory results, and the damage of simultaneous surgery was less than that of staged surgery.

The Prevalence of Asymptomatic and Symptomatic Spinal Cord Compression on Magnetic Resonance Imaging: A Systematic Review and Meta-analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

Cervical spinal cord compression (SCC) due to degenerative changes of the spine is a frequent finding on magnetic resonance imaging (MRI). While most people remain asymptomatic, a proportion develop symptoms of degenerative cervical myelopathy (DCM). DCM is an often-progressive neurological disease that can cause quadriplegia. The epidemiology of SCC and DCM is poorly understood. We sought to estimate the prevalence of degenerative cervical SCC and DCM from cross-sectional cohorts undergoing MRI.

METHODS

We conducted a systematic review and meta-analysis of MRI reports on human subjects older than 16 years with degenerative SCC. A predetermined search strategy was used to identify relevant literature on MEDLINE. Title and abstract screenings were followed by full text screening. Data was extracted and analyzed by fixed or random-effects models.

RESULTS

The present search returned 1506 publications. Following our exclusion criteria, 19 studies were included. Subgroup analysis of 3786 individuals estimated the prevalence of asymptomatic SCC in a healthy population as 24.2% with a significantly higher prevalence of SCC in older populations compared with younger populations and American/European populations compared with Asian populations. Subgroup analysis of 1202 individuals estimated the prevalence of DCM in a healthy population as 2.3%.

CONCLUSIONS

We present the first estimates of the prevalence of asymptomatic SCC and DCM. Studies investigating the epidemiology of SCC are heterogeneous in methodology and results. These data indicate the need for more studies into the epidemiology of SCC and DCM performed with consistent methodologies.

Walk and Run Test in Patients with Degenerative Compression of the Cervical Spinal Cord

Impaired gait is one of the cardinal symptoms of degenerative cervical myelopathy (DCM) and frequently its initial presentation. Quantitative gait analysis is therefore a promising objective tool in the disclosure of early cervical cord impairment in patients with degenerative cervical compression. The aim of this cross-sectional observational cohort study was to verify whether an objective and easily-used walk and run test is capable of detecting early gait impairment in a practical proportion of non-myelopathic degenerative cervical cord compression (NMDCC) patients and of revealing any correlation with severity of disability in DCM. The study group consisted of 45 DCM patients (median age 58 years), 126 NMDCC subjects (59 years), and 100 healthy controls (HC) (55.5 years), all of whom performed a standardized 10-m walk and run test. Walking/running time/velocity, number of steps and cadence of walking/running were recorded; analysis disclosed abnormalities in 66.7% of NMDCC subjects. The DCM group exhibited significantly more pronounced abnormalities in all walk/run parameters when compared with the NMDCC group. These were apparent in 84.4% of the DCM group and correlated closely with disability as quantified by the modified Japanese Orthopaedic Association scale. A standardized 10-m walk/run test has the capacity to disclose locomotion abnormalities in NMDCC subjects who lack other clear myelopathic signs and may provide a means of classifying DCM patients according to their degree of disability.

Evaluation and Treatment of Tandem Spinal Stenosis

Tandem spinal stenosis (TSS) refers to simultaneous narrowing of noncontiguous regions of the spinal canal, typically the cervical and lumbar region. Symptomatic TSS may be present in more than 10% of patients presenting with spinal symptoms secondary to stenosis in any one region. Clinical presentation may present challenges because of a mixture of upper and lower motor neuron lesions that can confuse and mislead the clinician. Stenosis at another level may only be detected late, when there is failure to improve after treatment, and, if not detected, can result in either poor treatment outcomes or catastrophic complications. There is no uniform agreement in the management of TSS, and the reported surgical strategies include both simultaneous and staged approaches with each having positive and negative features. This article aims to provide the reader with details on the prevalence, evaluation, and guidance in treatment strategy for TSS.

EFFICACY OF THE CLINICAL-INSTRUMENTAL ALGORITHM IN THE TREATMENT OF SPINAL TANDEM STENOSIS

ABSTRACT Objective: To conduct a multicenter analysis of the effectiveness of surgical tactics for treating patients with symptomatic tandem stenosis of the cervical and lumbar spine, based on a differentiated clinical-instrumental algorithm. Methods: The study included 97 patients with symptomatic tandem stenosis of the cervical and lumbar spine. The patients were allocated into 2 groups. The main prospective follow-up group (Group I) consisted of patients (n=46) who had undergone staged decompression/stabilization surgery according to the surgical tactics developed based on the differential clinical-instrumental algorithm. The clinical comparison group (Group II) (n=51) consisted of retrospectively recruited patients who, depending on the prevailing clinical condition, underwent primary surgery at the cervical level (29 cases) or at the lumbar level (22 cases). Results: The comparative analysis in Group I revealed significantly better parameters in the clinical and instrumental data. The total rates of postoperative surgical complications in the cervical and lumbar spine were 15% in Group I and 68% in Group II (p=0.0014). Conclusion: The multicenter analysis of the clinical-instrumental algorithm based on differential application of decompression/stabilization techniques enabled more rational and radical surgery, with less adverse outcomes, leading to earlier start of rehabilitation in the prospective group of patients (Group I), and an objective improvement in long-term clinical and functional outcomes. Level of Evidence II; Prognostic Studies - Investigating the Effect of a Patient Characteristic on Disease Outcome.

Delayed Diagnosis of Tandem Spinal Stenosis: A Retrospective Institutional Review

Background

Tandem spinal stenosis (TSS) is defined as simultaneous spinal stenosis in the cervical, thoracic, and/or lumbar regions and may present with both upper and lower motor neuron symptoms, neurogenic claudication, and gait disturbance. Current literature has focused mainly on the prevalence of TSS and treatment methods, while the incidence of delayed TSS diagnosis is not well defined. The purpose of this study was to determine the incidence of delayed TSS diagnosis at our institution and describe the clinical characteristics commonly observed in their particular presentation.

Methods

Following institutional review board approval, an institutional billing database review was performed for patients who underwent a spinal decompression procedure between 2006 and 2016. Thirty-three patients who underwent decompression on 2 separate spinal regions within 1 year were included for review. Patients with delayed diagnosis of TSS following the first surgery were differentiated from those with preoperative diagnosis of TSS.

Results

TSS requiring surgical decompression occurred in 33 patients, with the incidence being 2.06% in this cohort. Fifteen patients received a delayed diagnosis after the first surgical decompression (45%) and were found to have a longer interval between decompressions (7.6 ± 2.1 months versus 4.01 ± 3 months, P = .0004). Patients undergoing lumbar decompression as the initial procedure were more likely to have a delayed diagnosis of TSS (8 versus 2 patients, P = .0200). The most common presentation of delayed TSS was pain and myelopathic symptoms that persisted after decompressive surgery.

Conclusion

TSS should remain within the differential diagnosis for patients at initial presentation of spinal stenosis. In addition, suspicion of TSS should be heightened if preoperative symptoms fail to expectedly improve following decompression even if overt myelopathic signs are not present.

Level of Evidence

4.

Surgical outcomes for lumbar spinal canal stenosis with coexisting cervical stenosis (tandem spinal stenosis): a retrospective analysis of 565 cases

Background

Concurrent cervical and lumbar spinal canal stenosis is known as tandem spinal stenosis (TSS). As research on TSS is limited, there is no consensus on the optimal surgical approach to this problem. We evaluated the prevalence and clinical characteristics of TSS in patients with symptomatic lumbar spinal canal stenosis (LCS).

Methods

The authors performed a retrospective analysis of the outcomes of 565 patients who underwent lumbar surgeries performed for symptomatic LCS. In all the patients, both the cervical and lumbar regions were evaluated preoperatively, and we compared TSS patients and non-TSS patients in terms of multiple clinical parameters. In the TSS patients, we investigated the ratio and clinical outcomes of additional cervical surgeries performed on TSS patients.

Results

Two hundred two cases (35.8%) were considered to be TSS. Twenty-eight patients (5.0%) underwent a cervical operation during the follow-up period. There were no differences between the radiographic TSS patients and non-TSS patients in terms of preoperative lumbar-Japanese Orthopedic Association (L-JOA) scores, postoperative L-JOA scores, and the L-JOA recovery rate (14.8 ± 4.4 points vs 14.2 ± 4.6 points, 23.9 ± 4.3 points vs 23.1 ± 4.5 points, 63.7 ± 28.2% vs 60.3 ± 27.9%, respectively), while the TSS group included a greater number of hypertension cases. The recovery rate L-JOA scores of patients who underwent additional cervical surgeries were significantly lower compared with the rate of patients who experienced treatment for only lumbar lesions (62.8 ± 25.8% vs 39.8 ± 35.5%, p = 0.0003). However, additional cervical surgery still improved both the cervical myelopathy-Japanese Orthopedic Association (C-JOA) and L-JOA scores in TSS patients with symptomatic cervical lesion (from 10.3 ± 2.8 points to 12.1 ± 3.0 points, p = 0.0302; from 14.8 ± 7.3 points to 19.9 ± 5.0 points, p = 0.0331, respectively). In these patients, there were no significant differences in the recovery rate of both C-JOA and L-JOA scores between the single-stage surgery group and the staged surgery group (40.7 ± 35.8% vs 20.7 ± 16.1%; 50.9 ± 25.1% vs 34.2 ± 39.3%, respectively).

Conclusions

Radiographic co-existing cervical stenosis did not affect surgical outcomes for LCS, although symptomatic cervical lesion affected neurological score after lumbar surgery. An additional surgery for cervical lesion significantly improved neurological findings in TSS patients.

Predictive factors of symptomatic lumbar canal stenosis in patients after surgery for cervical spondylotic myelopathy

Background

The aim of this study was to determine the incidence of coexisting symptomatic lumbar canal stenosis (LCS) in patients after surgery for cervical spondylotic myelopathy (CSM) and identify possible predictive factors associated with it.

Materials and methods

We retrospectively reviewed patients with CSM at our institution between January 2005 and December 2015. Clinical and radiographic factors including age, gender, body mass index, Japanese Orthopedic Association scores, cervical alignment, anteroposterior diameter of cervical canal, number of levels with CSM, and percentage of cervical cord compression were investigated. Symptomatic LCS was defined as leg symptoms and a narrowing of the lumbar spinal canal at one level at least, which is confirmed by magnetic resonance images of the lumbar spine. Univariate and multivariate analyses were used to identify possible predictive factors. Pearson correlation analysis was also conducted to analyze the association between cervical parameters and percentage of LCS.

Results

A total of 317 patients with CSM met the criteria for inclusion. There were 39 patients (12.3%) with LCS after cervical surgery during a mean of 7.3 years’ follow-up. In the multivariate logistic regression analysis, narrow diameter of cervical canal (OR, 3.96; 95% CI, 1.20–13.04) was identified as the only independent predictor of symptomatic LCS in CSM patients. The correlation coefficient between anteroposterior diameter of cervical canal and severity of LCS indicated a significantly positive linear relationship with 0.536 (P<0.001).

Conclusion

We found that narrow diameter of cervical canal was associated with symptomatic LCS in CSM patients. Patients with this risk factor should be informed the possibility of symptomatic LCS.