Correlations and time-dependent changes of upper arm performance tests, the Japanese Orthopaedic Association score, and a newly developed patient-based outcome measure : the Japanese Orthopaedic Cervical Myelopathy Questionnaire

Kinematic alteration in three-dimensional reaching movement in C3-4 level cervical myelopathy

OBJECT

This study aimed to compare the reaching movement between two different spinal cord compression level groups in cervical myelopathy (CM) patients.

METHODS

Nine CM patients with maximal cord compression at the C3-4 level (C3-4 group) and 15 CM patients with maximal cord compression at the C4-7 level (C4-7 group) participated in the study. We monitored three-dimensional (3D) reaching movement using an electronic-mechanical whack-a-mole-type task pre-and post-operatively. Movement time (MT) and 3D movement distance (MD) during the task were recorded. An analysis of variance for split-plot factorial design was performed to investigate the effects of compression level or surgery on MT and MD. Moreover, we investigated the relationship between these kinematic reaching parameters and conventional clinical tests.

RESULTS

The 3D reaching trajectories of the C3-4 group was unstable with higher variability. The C3-4 group showed longer MT (p < 0.05) and MD (p < 0.01) compared with the C4-7 group both before and after surgery. Moreover, MT was negatively correlated with the Japanese Orthopedic Association score only in the C3-4 group (r = - 0.48).

CONCLUSION

We found that spinal cord compression at the C3-4 level had a negative effect on 3D reaching movement and the kinematic alteration influenced the upper extremity performance. This new knowledge may increase our understanding of kinematic alteration in patients with CM.

Changes of improvement in upper limb function predict surgical outcome after laminoplasty in 1 year in patients with cervical spondylotic myelopathy: a retrospective study

BACKGROUND

Cervical spondylotic myelopathy preoperative prognostic factors include age, preoperative severity, and disease duration. However, there are no reports on the relationship between changes in physical function during hospitalization and postoperative course, and in recent years, the length of hospital stay has shortened. We aimed to investigate whether changes in physical function during hospitalization can predict the postoperative outcome.

METHODS

We recruited 104 patients who underwent laminoplasty for cervical spondylotic myelopathy by the same surgeon. Physical functions, including Simple Test for Evaluating Hand Function (STEF), grip strength, timed up and go test, 10-m walk, and time to stand on one leg, were assessed at admission and discharge. Patients with the Japanese Orthopaedic Association (JOA) score improvement rate of 50% or more were defined as the improved group. Decision tree analysis was investigated factor for identifying improvement in the JOA score. According to this analysis, we divided into two groups using age. Then, we conducted a logistic regression analysis to identify factors that improve the JOA score.

RESULTS

The improved and non-improved groups had 31 and 73 patients, respectively. The improved group was younger (p = 0.003) and had better improved Δgrip strength (p = 0.001) and ΔSTEF (p < .0007). Age was significantly positively correlated with disease duration (r = 0.4881, p =  < .001). Disease duration exhibited a significant negative correlation with the JOA score improvement rate (r = - 0.2127, p = 0.031). Based on the decision tree analysis results, age was the first branching variable, with 15% of patients ≥ 67 years showing JOA score improvement. This was followed by ΔSTEF as the second branching factor. ΔSTEF was selected as the factor associated with JOA improvement in patients ≥ 67 years (odds ratio (OR) 0.95, 95% confidence interval (CI) 0.90-0.99, p = .047); in patients < 67 years, Δgrip strength was identified (OR 0.53, CI 0.33‒0.85, p = .0086).

CONCLUSIONS

In the improved group, upper limb function improved more than lower limb function from the early postoperative period. Upper limb function changes during hospitalization were associated with outcomes one year postoperatively. Improvement factors in upper extremity function differed by age, with changes in grip strength in patients < 67 years and STEF in patients ≥ 67 years, reflecting the outcome at one year postoperatively.

Postoperative Changes in Resting State Functional Connectivity and Clinical Scores in Patients With Cervical Myelopathy

OBJECTIVE

Resting state functional magnetic resonance imaging (rs-fMRI) is a technique for the analyzing functional connectivity (FC) between anatomically distant brain regions at rest. The purpose of this study was to analyze postoperative FC changes in patients with compression cervical myelopathy, to evaluate their relationship with clinical scores, and to examine the changes in spinal cord function associated with brain networks.

METHODS

This prospective study comprised 15 patients with cervical myelopathy who underwent planned surgery. Rs-fMRI was performed preoperatively and 6 months postoperatively with the similar protocol. Clinical function was assessed by the Japanese Orthopedic Association (JOA) score, the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and the numerical rating scale (NRS). We performed a seed-based analysis, and identified the networks that changed significantly following surgery. Furthermore, we performed a correlation analysis to compare the postoperative changes in FC with clinical scores.

RESULTS

Five FCs were significantly increased postoperatively; 4 were between the sensorimotor network (SMN) and other regions. We observed a significant correlation between the FC of the right SMN and the left precentral gyrus with the JOA score, the left SMN with the JOACMEQ for upper extremity function, and the left postcentral gyrus with the NRS.

CONCLUSIONS

The reorganization of the sensorimotor cortex occurred postoperatively in patients with compression cervical myelopathy. In addition, each change in FC was significantly correlated with the clinical scores, thus indicating an association between the recovery of spinal cord function and plastic changes in the sensorimotor cortex.

Prediction of outcome following laminoplasty of cervical spondylotic myelopathy: Focus on the minimum clinically important difference

The minimum clinically important difference (MCID) of the Japanese Orthopaedic Association (JOA) score has been reported to be around 2.5 points in cervical myelopathy. This study sought to define significant predictive factors on achieving the MCID following laminoplasty in a large series of patients with cervical spondylotic myelopathy (CSM). A total of 485 consecutive patients with CSM (295 males and 190 females; mean age: 67.0 years; age range: 42-91 years) who underwent laminoplasty were prospectively enrolled. The average postoperative follow-up period was 26.6 months (range: 12-66 months). We calculated the achieved JOA score. The relationships between outcomes and various clinical and imaging predictors including comorbidity and quantitative performance tests were examined. Logistic regression analysis was conducted to identify the predictors correlated with a JOA score of 2.5 points or more. Clinically meaningful gains were exhibited in 299 patients (61.6%) with a JOA score of ≥2.5 points, whereas 186 patients (38.4%) achieved a JOA score of <2.5 points. Univariate logistic regression analysis showed the predictive factors with a shorter duration of CSM symptoms, lower preoperative JOA scores, absence of hypertension, no use of anticoagulant/antiplatelet agents, and nonsmoking status. Multivariate logistic regression analysis determined that the duration of CSM symptoms (odds ratio: 0.771, 95% confidence interval: 0.705-0.844; p < 0.01) was the only significant predictive factor for achieving JOA scores of ≥2.5 points. An important predictor of MCID achievement following laminoplasty was shorter duration of CSM symptoms.

Resting-state Amplitude of Low-frequency Fluctuation is a Potentially Useful Prognostic Functional Biomarker in Cervical Myelopathy

BACKGROUND

Cervical MRI is the standard diagnostic imaging technique for patients with cervical myelopathy. However, the utility of conventional cervical MRI as a predictive biomarker for surgical recovery remains unclear, partly because of the limited information obtained from this anatomically small area. Brain resting-state functional MRI (rs-fMRI) may help identify candidate predictive biomarkers. Two analytical methods that assess local spontaneous brain activity are widely used for rs-fMRI: functional connectivity between two brain regions and amplitude of low-frequency fluctuation (ALFF). In our previous analysis of functional connectivity, we discovered that brain functional connectivity may be a predictive biomarker for neurologic recovery in patients with cervical myelopathy; however, the functional connectivity analysis identified a correlation with only one clinical outcome (the 10-second test). To establish a comprehensive prediction measure, we need to explore other brain biomarkers that can predict recovery of other clinical outcomes in patients with cervical myelopathy.

QUESTIONS/PURPOSES

We aimed to (1) elucidate preoperative ALFF alterations in patients with cervical myelopathy and how ALFF changes after surgery, with a focus on postoperative normalization and (2) establish a predictive model using preoperative ALFF by investigating the correlation between preoperative ALFF and postoperative clinical recovery in patients with cervical myelopathy.

METHODS

Between August 2015 and June 2017, we treated 40 patients with cervical myelopathy. Thirty patients met our prespecified inclusion criteria, all were invited to participate, and 28 patients opted to do so (93%; 14 men and 14 women; mean age: 67 years). The 28 patients and 28 age- and sex-matched controls underwent rs-fMRI (twice for patients with cervical myelopathy: before and 6 months after cervical decompression surgery). We analyzed the same study population that was used in our earlier study investigating functional connectivity. Controls had none of the following abnormalities: neck or arm pain, visual or auditory disorders, cognitive disorder, structural brain disorder, a history of brain surgery, mental and neurologic disorders, and medications for the central nervous system. We performed ALFF comparisons between preoperative patients with cervical myelopathy and controls, analyzed postoperative ALFF changes in patients with cervical myelopathy, and performed a correlation analysis between preoperative ALFF and clinical recovery in these patients. Clinical outcomes in the cervical myelopathy group were assessed using the 10-second test, the Japanese Orthopaedic Association upper-extremity motor (JOA-UEM) score, JOA upper-extremity sensory score (JOA-UES), and Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire for upper-extremity function (JOACMEQ-UEF) score before and 6 months after surgery, which is when we believe these scores generally reach a plateau. A total of 93% of those enrolled (26 of 28 patients) were analyzed both preoperatively and postoperatively; the other two were lost to follow-up.

RESULTS

The cervical myelopathy group had an increase in ALFF in the bilateral primary sensorimotor cortices (right, cluster size = 850 voxels, t-value = 6.10; left, cluster size = 370 voxels, t-value = 4.84) and left visual cortex (cluster size = 556 voxels, t-value = 4.21) compared with the control group. The cervical myelopathy group had a decrease in ALFF in the bilateral posterior supramarginal gyrus (right, cluster size = 222 voxels, t-value = 5.09; left, cluster size = 436 voxels, t-value = 5.28). After surgery, the bilateral sensorimotor cortices (right, cluster size = 468 voxels, t-value = 6.74; left, cluster size = 167 voxels, t-value = 5.40) and left visual cortex (cluster size = 3748 voxels, t-value = 6.66) showed decreased ALFF compared with preoperative ALFF, indicating postoperative normalization of spontaneous brain activities in these regions. However, the bilateral posterior supramarginal gyrus did not show an increase in ALFF postoperatively, although ALFF in this region decreased preoperatively. Greater levels of ALFF at the left and right frontal pole and left pars opercularis of the inferior frontal gyrus before surgery in the cervical myelopathy group were correlated with larger improvements in the JOACMEQ-UEF score 6 months after surgery (r = 0.784; p < 0.001, r = 0.734; p < 0.001 and r = 0.770, respectively; p < 0.001). The prediction formula, based on preoperative ALFF values in the left frontal pole, was as follows: the predicted postoperative improvement in the JOACMEQ-UEF score = 34.6 × preoperative ALFF value - 7.0 (r = 0.614; p < 0.001).

CONCLUSIONS

Our findings suggest that preoperative ALFF may be a biomarker for postoperative recovery in that it predicted postoperative JOACMEQ-UEF scores. To establish a comprehensive prediction measure for neurologic recovery in patients with cervical myelopathy, a multicenter study is underway.

LEVEL OF EVIDENCE

Level II, diagnostic study.

Introduction of the Purdue Pegboard Test for fine assessment of severity of cervical myelopathy before and after surgery

[Purpose] To evaluate the severity of symptoms before and after cervical myelopathy surgery using the Simple Test for Evaluating hand Function. Because a test ceiling effect was observed in patients with less severe forms of myelopathy, we investigated the correlation between and accuracy of several different tests in order to clarify the usefulness of the Purdue Pegboard Test for evaluation of one or both hands. [Participants and Methods] Thirty-four patients (6 females and 28 males; mean age, 64.5 years) were examined, and scores were determined for each of the following tests: Purdue Pegboard Test; Simple Test for Evaluating hand Function; Japanese Orthopedic Association assessment; and Disabilities of the Arm, Shoulder, and Hand assessment. Correlations between scores of different tests were then determined. The cut-off values used for the Purdue Pegboard Test and the Simple Test for Evaluating hand Function were determined using the area under the receiver operating characteristic curve to assess the use of chopsticks. [Results] The Purdue Pegboard Test assembly task correlated moderately with the Japanese Orthopedic Association and Disabilities of the Arm, Shoulder, and Hand scores. In the receiver operating characteristic curve analyses, the Purdue Pegboard Test cut-off value was 11 and the Simple Test for Evaluating hand Function cut-off value was 90. [Conclusion] The Purdue Pegboard Test is useful for evaluating manual dexterity and coordination in both hands in patients with cervical myelopathy.

Grip force control during object manipulation in cervical myelopathy

STUDY DESIGN

Cross-sectional research.

OBJECTIVES

To objectively evaluate grip force (GF) control while holding a freely movable object in individuals with cervical myelopathy (CM).

SETTING

Harunaso Hospital, Takasaki, Japan.

METHODS

We studied 52 hands from 26 individuals with CM. Participants performed a grip-and-lift task by pulp pinch using the thumb and index finger before surgery. We monitored individual finger GF (N) during the first 3 s while lifting and holding an object. Correlations between the GF and other clinical tests were evaluated. A multiple stepwise regression analysis was used to examine the contribution of the GF to the severity of clinical symptoms.

RESULTS

Thumb GF was negatively correlated with the 10-s test (rs = -0.32), and index finger GF was positively correlated with its cutaneous pressure threshold (rs = 0.34). Multiple regression for the severity of upper extremity symptoms revealed that the model including the GF had a larger adjusted R² and a lower AIC value than that of conventionally used clinical tests.

CONCLUSIONS

These results suggested that the assessment of individual finger GF control could provide an indicator of the clinical severity of upper extremity in individuals with CM.

Impact of Cervical Sagittal Alignment on Axial Neck Pain and Health-related Quality of Life After Cervical Laminoplasty in Patients With Cervical Spondylotic Myelopathy or Ossification of the Posterior Longitudinal Ligament: A Prospective Comparative Study

STUDY DESIGN

This is prospective observational study.

OBJECTIVE

To prospectively investigate the correlation among axial neck pain; a newly developed patient-based quality of life outcome measure, the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ); and cervical sagittal alignment after open-door laminoplasty for cervical myelopathy.

SUMMARY OF BACKGROUND DATA

Many studies have focused on postoperative axial neck pain after laminoplasty. However, the correlation among cervical sagittal alignment, neck pain, and JOACMEQ has not been investigated.

MATERIALS AND METHODS

In total, 57 consecutive patients treated by open-door laminoplasty for cervical myelopathy were included (mean age, 63.7 y; 15 women and 42 men) and divided into 2 groups according to diagnosis [cervical spondylotic myelopathy (CSM) group: 35 patients, and ossification of the posterior longitudinal ligament (OPLL) group: 22 patients]. JOA score, a subdomain of cervical spine function (CSF) in the JOACMEQ, and the visual analog scale for axial neck pain were assessed preoperatively and 12 months postoperatively. Radiographic cervical sagittal parameters were measured by C2 sagittal vertical axis (C2 SVA), C2-C7 lordosis, C7 sagittal slope (C7 slope), and range of motion.

RESULTS

C2 SVA values in both groups shifted slightly anteriorly between preoperative and 12-month postoperative measurements (CSM: +19.7±10.9 mm; OPLL: +22.1±13.4 mm vs. CSM: +23.2±16.1 mm; OPLL: +28.7±15.4 mm, respectively). Postoperative axial neck pain in the OPLL group showed strong negative correlations with C2 SVA and C7 slope. Strong negative correlations were found between axial neck pain and CSF in both the preoperative CSM and OPLL groups (CSM: r=-0.45, P=0.01; OPLL: r=-0.61, P<0.01) and between axial neck pain and CSF in the postoperative OPLL group (r=-0.51, P=0.05).

CONCLUSIONS

This study demonstrated a significant negative correlation between neck pain and CSF in both the CSM and OPLL groups preoperatively and in the OPLL group postoperatively. Radiographic cervical sagittal alignment did not significantly correlate with preoperative or postoperative axial neck pain.