Analysis of gait in cervical myelopathy

The value of Clinical signs in the diagnosis of Degenerative Cervical Myelopathy - A Systematic review and Meta-analysis

STUDY DESIGN

Delayed diagnosis of degenerative cervical myelopathy (DCM) is likely due to a combination of its subtle symptoms, incomplete neurological assessments by clinicians and a lack of public and professional awareness. Diagnostic criteria for DCM will likely facilitate earlier referral for definitive management.

OBJECTIVES

This systematic review aims to determine (i) the diagnostic accuracy of various clinical signs and (ii) the association between clinical signs and disease severity in DCM?

METHODS

A search was performed to identify studies on adult patients that evaluated the diagnostic accuracy of a clinical sign used for diagnosing DCM. Studies were also included if they assessed the association between the presence of a clinical sign and disease severity. The QUADAS-2 tool was used to evaluate the risk of bias of individual studies.

RESULTS

This review identified eleven studies that used a control group to evaluate the diagnostic accuracy of various signs. An additional 61 articles reported on the frequency of clinical signs in a cohort of DCM patients. The most sensitive clinical tests for diagnosing DCM were the Tromner and hyperreflexia, whereas the most specific tests were the Babinski, Tromner, clonus and inverted supinator sign. Five studies evaluated the association between the presence of various clinical signs and disease severity. There was no definite association between Hoffmann sign, Babinski sign or hyperreflexia and disease severity.

CONCLUSION

The presence of clinical signs suggesting spinal cord compression should encourage health care professionals to pursue further investigation, such as neuroimaging to either confirm or refute a diagnosis of DCM.

The Frequency of Symptoms in Patients With a Diagnosis of Degenerative Cervical Myelopathy: Results of a Scoping Review

STUDY DESIGN

Delayed diagnosis of degenerative cervical myelopathy (DCM) is associated with reduced quality of life and greater disability. Developing diagnostic criteria for DCM has been identified as a top research priority.

OBJECTIVES

This scoping review aims to address the following questions: What is the diagnostic accuracy and frequency of clinical symptoms in patients with DCM?

METHODS

A scoping review was conducted using a database of all primary DCM studies published between 2005 and 2020. Studies were included if they (i) assessed the diagnostic accuracy of a symptom using an appropriate control group or (ii) reported the frequency of a symptom in a cohort of DCM patients.

RESULTS

This review identified three studies that discussed the diagnostic accuracy of various symptoms and included a control group. An additional 58 reported on the frequency of symptoms in a cohort of patients with DCM. The most frequent and sensitive symptoms in DCM include unspecified paresthesias (86%), hand numbness (82%) and hand paresthesias (79%). Neck and/or shoulder pain was present in 51% of patients with DCM, whereas a minority had back (19%) or lower extremity pain (10%). Bladder dysfunction was uncommon (38%) although more frequent than bowel (23%) and sexual impairment (4%). Gait impairment is also commonly seen in patients with DCM (72%).

CONCLUSION

Patients with DCM present with many different symptoms, most commonly sensorimotor impairment of the upper extremities, pain, bladder dysfunction and gait disturbance. If patients present with a combination of these symptoms, further neuroimaging is indicated to confirm the diagnosis of DCM.

Gait function assessed using 3D gait analysis in patients with cervical spinal myelopathy before and after surgical decompression: a systematic review and meta-analysis

BACKGROUND

Degenerative cervical myelopathy (DCM) is the most common cause of cervical spinal cord dysfunction in adults and the result of chronic degenerative changes of the cervical spine. The compression of the spinal cord can lead to ischemia, inflammation, and neuronal apoptosis with a consequent impairment of the neurological function. Gait impairment is one of the most frequent signs of DCM.

PURPOSE

To investigate the changes in spatio-temporal gait parameters assessed using 3D gait analysis in patients affected by DCM compared with healthy controls and the effect of surgical decompression on these parameters.

STUDY DESIGN/SETTING

Systematic review and meta-analysis.

PATIENT SAMPLE

The meta-analysis included 267 patients with DCM and 276 healthy controls.

OUTCOME MEASURES

Spatio-temporal parameters of gait were assessed. The primary outcome was gait speed; the secondary outcomes were cadence, stride length, step width, stride time, single-limb support time, and double-limb support time.

METHODS

Studies reporting spatial and/or temporal gait parameters measured using 3D gait analysis in patients with DCM were included. Data sources were Embase, Medline, and the Core Collection of Web of Science. Meta-analyses were performed to investigate the influence of surgical decompression in patients measured before and after surgery as well as to compare gait parameters of patients with DCM with controls.

RESULTS

Thirteen studies reporting on 267 patients with DCM and 276 healthy controls met the inclusion criteria. Seven studies compared patients with DCM with healthy controls, three studies compared gait in patients with DCM before and after surgical decompression, and three studies performed both comparisons. Compared with healthy controls, patients with DCM had slower gait speed (Standardized Mean Difference (SMD), -1.49; 95% confidence interval (CI) [-1.86; -1.13]; p<.001), lower cadence (SMD, -0.78; 95%CI [-1.00; -0.56]; p<.001), shorter stride length (SMD, -1.27; 95%CI [-1.53, -1.01]; p<.001), greater step width (SMD, 0.98; 95%CI [0.42, 1.54]; p=.003), longer stride time (SMD, 0.77; 95%CI [0.37, 1.16]; p=.009), single-limb support phase (SMD, -0.68; 95%CI [-1.06; -0.29]; p=.011), and double-limb support phase (SMD 0.84; 95%CI [0.35, 1.32]; p=.012). After surgical decompression, patients with DCM showed an improvement in gait speed (SMD, 0.57 (95%CI [0.29; 0.85]; p=.003) and no significant differences in other spatio-temporal parameters.

CONCLUSIONS

Patients with DCM have clearly different spatio-temporal gait parameters than healthy controls. Gait speed is the only spatio-temporal gait parameter that improves significantly after surgical decompression suggesting that gait speed may be an important clinical outcome parameter in patients with DCM.

Physical Performance Tests in Adult Neck Pain Patients with and without Clinical Myelopathic Signs: A Matched Case-Control Study

Patients with neck pain may experience cervical myelopathy, this may be detected by clinical myelopathic signs, although they did not have any symptom of myelopathy, except having neck pain. Decreasing physical performance is one symptom of cervical myelopathy that can lead to reduced quality of life in the elderly, however, in adult neck pain with clinical myelopathic signs have not been evaluated. Therefore, this research aimed to compare physical performance in two groups of adult patients with neck pain: those with and without clinical myelopathic signs. A total of 52 participants, gender, age, and body mass index (BMI) matched were allocated into 2 groups of 26 subjects with neck pain, those with, and without, clinical myelopathic signs. The grip and release test, nine-hole peg test, ten second step test and foot-tapping test were evaluated. The group of neck pain participants with clinical myelopathic signs exhibited greater impairment in all the tests than the group without clinical myelopathic signs (p < 0.001). Effect sizes (Cohen’s d) were grip and release test: 2.031, nine-hole peg test: 1.143, ten second step test: 1.329, and foot-tapping test: 0.798. Neck pain participants with clinical myelopathic signs demonstrated reduced physical performance. Physical performance tests may need to assessed in adult patients with neck pain who had clinical myelopathic signs.

Analysis of Spastic Gait in Patients With Cervical Myelopathy Using the Timed Up and Go Test With a Laser Range Sensor

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

This study aimed to objectively evaluate spastic gait and reveal its novel characteristics via analysis of gait in patients with cervical myelopathy (CM) using the Timed Up and Go (TUG) test with a laser range sensor.

SUMMARY OF BACKGROUND DATA

Among patients with CM, spastic gait is a common diagnostic symptom; thus, objective assessments of spastic gait would be useful for the diagnosis of CM and recognition of disease status. Although spastic gait has been objectively evaluated in previous studies, the methods employed in those studies are not suitable for clinical settings.

METHODS

In total, 37 and 24 participants were recruited for a control group and CM group, respectively. CM was diagnosed by spine surgeons. We developed a laser TUG test, in which the position and velocity of both the legs were captured. The parameter values for both groups were statistically compared, and odds ratios were calculated using logistic regression analyses.

RESULTS

The total TUG-test time, time to stand up, time to first step, number of steps, and trajectory error for the CM group were significantly higher than those for the control group, whereas the average velocity and average stride length for the CM group were significantly lower than those for the control group. There was a significant independent association between the total TUG-test time and CM. The optimal cutoff point of the total test time for CM risk was approximately 9 seconds.

CONCLUSION

Through the use of the laser TUG test, we were able to identify characteristics of spastic gait, which leads to difficulty in standing and taking the first step, wobbling while walking, and an increased risk of falling. We found that the risk of CM was higher if the individual took longer than 9 seconds to complete the TUG test.Level of Evidence: 4.

The Effects of Surgery on Postural Instability in Patients With Cervical Compressive Myelopathy: Evaluating Subjective Perceptions and Objective Measurements

STUDY DESIGN

A retrospective study.

OBJECTIVE

To investigate the effects of surgery on the subjective perception of bodily unsteadiness and the objective measurements of postural instability in patients with cervical compressive myelopathy (CCM).

SUMMARY OF BACKGROUND DATA

Several studies have demonstrated that CCM patients have impaired postural stability and investigated its surgical outcomes. However, these studies have only objectively measured postural stability by using a stabilometer or three-dimensional motion capture system. There have been no studies examining the subjective perception of postural instability in CCM patients.

MATERIALS AND METHODS

We retrospectively reviewed patients who underwent decompressive surgery for CCM. The Fall Efficacy Scale-International (FES-I) and a self-prepared questionnaire were used to evaluate subjective perception of bodily unsteadiness. To objectively assess postural instability, a stabilometric analysis was performed with the following parameters: sway area (SwA, cm2), sway velocity (SwV, cm/s), and sway density (SwD, /cm). The evaluations were performed preoperatively, during the early postoperative period (3-6 mo postoperatively), and at 1-year postoperatively in patients with CCM. The evaluation results were compared with age-matched, sex-matched, and body mass index-matched healthy subjects.

RESULTS

We included 70 CCM patients and 36 healthy subjects in this study. In both the FES-I and self-prepared questionnaire, CCM patients reported significantly milder postoperative bodily unsteadiness. The stabilometric parameters were significantly improved during the postoperative period when compared with preoperative values. Nevertheless, neither the self-reported outcome measures nor stabilometric parameters of CCM patients reached the levels of those in healthy controls in the postoperative period.

CONCLUSION

This was the first study to examine CCM surgical outcomes in terms of both subjective perception and objective postural instability. While both objective postural stability and subjective perception improved following decompressive surgery, they did not reach the levels seen in healthy participants.

LEVEL OF EVIDENCE

Level III.

Evaluation of Gait and Functional Stability in Preoperative Cervical Spondylotic Myelopathy Patients

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

The aim of this study was to 1) determine postural stability and spatiotemporal gait parameters and 2) characterize dynamic stability and variances in angular momentum (AM) of preoperative cervical spondylotic myelopathy (CSM) patients compared with healthy controls.

SUMMARY OF BACKGROUND DATA

CSM is the most common cause of spinal cord dysfunction in the world and can lead to significant functional deficits including proprioception and gait disturbances. Biomechanical feedback mechanisms compensating for these deficits, specifically AM regulation, have remained largely unexplored.

METHODS

Fifty-six subjects: 32 preoperative Nurick grade 2 or 3 CSM patients and 24 controls were included. Standing balance trials were performed on a single force plate, while walking trials were conducted at self-selected pace over a 15 m runway and a series of five force plates. All trials were recorded with three-dimensional motion analysis cameras and gait modeling software was utilized to calculate stability, spatiotemporal gait parameters, and joint kinematics.

RESULTS

Tilted ellipse area, a measure of center of pressure variance and postural stability, was significantly greater among CSM patients (847.54 ± 764.33 mm2vs. 258.18 ± 103.35 mm2, P < 0.001). These patients had two times as much variance medial-lateral (72.12 ± 51.83 mm vs. 29.15 ± 14.95 mm, P = 0.001) and over three times as much anterior-posterior (42.25 ± 55.01 mm vs. 9.17 ± 4.83 mm, P = 0.001) compared with controls. Spatiotemporal parameters indicated that the CSM patients tending to have slower, shorter, and wider gait compared with controls, while spending greater amount of time in double support. Compensatory AM among CSM patients was significantly increased in all three anatomic planes, where whole-body AM was approximately double that of controls (0.057 ± 0.034 vs. 0.023 ± 0.006), P < 0.001).

CONCLUSION

Preoperative CSM patients showed significant alterations in spatiotemporal gait parameters and postural stability compared with controls, consistent with prior literature. Likewise, angular momentum analysis demonstrates that these patients have globally increased body excursion to maintain dynamic balance.Level of Evidence: 3.

Improving Assessment of Disease Severity and Strategies for Monitoring Progression in Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 4]

STUDY DESIGN

Narrative Review.

OBJECTIVE

To (i) discuss why assessment and monitoring of disease progression is critical in Degenerative cervical myelopathy (DCM); (ii) outline the important features of an ideal assessment tool and (iii) discuss current and novel strategies for detecting subtle deterioration in DCM.

METHODS

Literature review.

RESULTS

Degenerative cervical myelopathy is an overarching term used to describe progressive injury to the cervical spinal cord by age-related changes of the spinal axis. Based on a study by Smith et al (2020), the prevalence of DCM is approximately 2.3% and is expected to rise as the global population ages. Given the global impact of this disease, it is essential to address important knowledge gaps and prioritize areas for future investigation. As part of the AO Spine RECODE-DCM (Research Objectives and Common Data Elements for Degenerative Cervical Myelopathy) project, a priority setting partnership was initiated to increase research efficiency by identifying the top ten research priorities for DCM. One of the top ten priorities for future DCM research was: What assessment tools can be used to evaluate functional impairment, disability and quality of life in people with DCM? What instruments, tools or methods can be used or developed to monitor people with DCM for disease progression or improvement either before or after surgical treatment?

CONCLUSIONS

With the increasing prevalence of DCM, effective surveillance of this population will require both the implementation of a monitoring framework as well as the development of new assessment tools.

Epidemiological study of cervical cord compression and its clinical symptoms in community-dwelling residents

BACKGROUND

Degenerative compressive myelopathy (DCM) is caused by cervical cord compression. The relationship between the magnitude and clinical findings of cervical cord compression has been described in the literature, but the details remain unclear. This study aimed to clarify the relationship between the magnitude and clinical symptoms of cervical cord compression in community-dwelling residents.

METHODS

The present study included 532 subjects. The subjective symptoms and the objective findings of one board-certified spine surgeon were assessed. The subjective symptoms were upper extremity pain and numbness, clumsy hand, fall in the past 1 year, and subjective gait disturbance. The objective findings were: Hoffmann, Trömner, and Wartenberg signs; Babinski's and Chaddock's signs; hyperreflexia of the patellar tendon and Achilles tendon reflexes; ankle clonus; Romberg and modified Romberg tests; grip and release test; finger escape sign; and grip strength. Using midsagittal T2-weighted magnetic resonance imaging, the anterior-posterior (AP) diameters (mm) of the spinal cord at the C2 midvertebral body level (DC2) and at each intervertebral disc level from C2/3 to C7/T1 (DC2/3-C7/T1) were measured. The spinal cord compression ratio (R) for each intervertebral disc level was defined and calculated as DC2/3-C7/T1 divided by DC2. The lowest R (LR) along C2/3 to C7/T1 of each individual was divided into 3 grades by the tertile method. The relationship between LR and clinical symptoms was investigated by trend analysis.

RESULTS

The prevalence of subjective gait disturbance increased significantly with the severity of spinal cord compression (p = 0.002812), whereas the other clinical symptoms were not significantly related with the severity of spinal cord compression.

CONCLUSIONS

The magnitude of cervical cord compression had no relationship with any of the neurologic findings. However, subjective gait disturbance might be a better indicator of the possibility of early stage cervical cord compression.

Fear-avoidance and Patients' Reported Outcomes are Strongly Correlated With Biomechanical Gait Parameters in Cervical Spondylotic Myelopathy Patients

STUDY DESIGN

This was a prospective cohort study.

OBJECTIVE

The aim was to explores whether fear-avoidance is associated with altered gait patterns in cervical spinal myelopathy (CSM) patients.

SUMMARY OF BACKGROUND DATA

Fear-avoidance is associated with activity restriction and emotional distress in chronic pain patients and with poorer spine surgery outcomes. In adults with spinal deformity, fear and avoidance correlates with gait pattern disruptions. Patients having CSM also display distorted gait.

METHODS

Ninety CSM patients completed the Tampa Scale for Kinesiophobia (TSK) questionnaire, and the Fear-avoidance Beliefs Questionnaire (FABQ). Each patient performed a series of gait trials. Pearson's product correlation analysis was used to determine the relationship between the self-reported fear of movement measures and the objective gait biomechanical data.

RESULTS

The TSK total score was correlated with walking speed ( P =0.003), cadence ( P =0.012), stride ( P =0.010) and step ( P =0.036) time, and stride ( P =0.018) and step ( P =0.035) length. The FABQ physical dimension was correlated with walking speed ( P <0.001), cadence ( P <0.001), stride ( P <0.001) and step ( P =0.006) time, stride ( P <0.001) and step ( P <0.001) length, and gait deviation index ( P <0.001). The FABQ work dimension was correlated with walking speed ( P =0.001), cadence ( P =0.001), stride ( P =0.001) and step ( P =0.008) time, and stride ( P =0.014) and step ( P =0.002) length.

CONCLUSIONS

These results provide a framework for further investigation of the relationship between psychosocial factors and objectively measured function in patients with CSM. This study demonstrates a strong correlation between fear and avoidance of movement, as measured with the TSK and FABQ and multiple biomechanical gait parameters, as measured with gait analysis. The current results may imply that fear and avoidance may compound and worsen functional deficits arising from CSM, and strongly suggest that fear and avoidance beliefs should be included as a component of presurgical diagnostic process for CSM patients.

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.

Using wearable sensors to characterize gait after spinal cord injury: evaluation of test-retest reliability and construct validity

STUDY DESIGN

Quantitative cross-sectional study.

OBJECTIVES

Evaluate the test-retest reliability and the construct validity of inertial measurement units (IMU) to characterize spatiotemporal gait parameters in individuals with SCI.

SETTING

Two SCI rehabilitation centers in Canada.

METHODS

Eighteen individuals with SCI participated in two evaluation sessions spaced 2 weeks apart. Fifteen able-bodied individuals were also recruited. Participants walked 20 m overground under five conditions that challenged balance to varying degrees. Five IMU were attached to the lower-extremities and the sacrum to collect the mean and the coefficient of variation of five gait parameters (gait cycle time, double-support percentage, cadence, stride length, stride velocity). Intra-class correlation coefficients (ICC) were used to evaluate the test-retest reliability. Linear mixed-effects models were used to compare the five walking conditions to evaluate known-group validity while Spearman's correlation coefficients were used to characterize the level of association between gait parameters and the Mini BESTest (MBT).

RESULTS

Cadence was reliable across all walking conditions. Reliability was higher for the mean (ICC = 0.55-0.98) of the parameters compared to their coefficient of variation (ICC = 0.16-0.97). Cadence collected with IMU had construct validity as their values differed across walking conditions and groups of participants. The coefficient of variation was generally better than the mean to show differences across the five walking conditions. The MBT was moderately to strongly associated with mean cadence (ρ ≥ 0.498) and its coefficient of variation (ρ ≤ -0.49) during most walking conditions.

CONCLUSIONS

IMU provide reliable and valid measurements of gait parameters in ambulatory individuals with SCI.

Kinematic, kinetic, and musculoskeletal modeling analysis of gait in patients with cervical myelopathy using a severity classification

BACKGROUND CONTEXT

Although a few reports have shown a change in gait motion in cervical myelopathy (CM) patients using a three-dimensional (3D) gait analysis system, there has been no detailed quantitative investigation of their gait including musculoskeletal modeling parameters. Also, 3D gait analysis using a classification of severity has not been substantiated.

PURPOSE

This study aimed to investigate kinematic, kinetic, and musculoskeletal modeling parameters of gait motion in CM patients using a severity classification.

STUDY DESIGN

Prospective cohort and cross-sectional study.

PATIENT SAMPLE

Forty-two patients with CM and 40 healthy, age-matched volunteers.

OUTCOME MEASURES

Lower extremity spatiotemporal, kinematic, kinetic, and musculoskeletal modeling parameters.

METHODS

Subjects were classified as to its severity using the Japan Orthopaedic Association score excluding the upper extremity items: group 1 (>10 points); group 2 (7-9 points); and group 3 (<6 points). A 3D motion analysis system and musculoskeletal modeling software were used to obtain the spatiotemporal, kinematic (the lower extremity joints angles in the sagittal plane), kinetic (the lower extremity joints moment and power in the sagittal plane), and musculoskeletal modeling parameters (the muscle-tendon length and velocity).

RESULTS

Genu recurvatum, deteriorated lower-extremity joint motion, and muscle-tendon velocity were observed in severe CM patients (group 3). Muscle-tendon velocities of the long head of the biceps femoris in controls and mild CM patients (groups 1 and 2) showed a bimodal waveform in the negative direction during the initial contact and preswing phases, whereas these characteristics were not present in severe CM patients (group 3).

CONCLUSIONS

The strategies of the knee joint moment during gait motion in severe CM patients were different from those of the normal gait pattern. The imbalance between agonist and antagonist muscle tissue during gait could be involved in the occurrence of genu recurvatum. It might be important for CM patients to consider improving the contraction or extension velocity of the biceps femoris muscle during each gait phase from the early stages of symptoms.

A Diagnostic Approach to Myelopathy Based on Prognostic Factors in Patients With Lower Extremity Symptoms

STUDY DESIGN

Case-control study.

OBJECTIVE

We aimed to identify predictors for latent myelopathy and to develop a diagnostic protocol based on these factors.

SUMMARY OF BACKGROUND DATA

There is no diagnostic protocol for latent myelopathy to avoid misdiagnosis in patients complaining only of lower extremity symptoms.

METHODS

This case-control study identified 791 patients discussed at conferences from April 2006 to August 2012. Overall, 460 patients complaining only of lower extremity symptoms and who underwent spine surgery were included as participants; 54 underwent surgery involving the cervical and thoracic vertebrae and were assigned to the cervical-thoracic group (C-T group); 406 underwent lumbar surgery and were assigned to the lumbar group (L group).

RESULTS

By univariate analysis, age ≥67 years, patellar tendon (PT) hyperreflexia, Achilles tendon (AT) hyperreflexia, spastic gait, and gait inability were more common in the C-T group than in the L group. By multivariate analysis, age ≥67 years (OR, 8; P = 0.001), AT hyperreflexia (OR, 20.5; P < 0.001), spastic gait (OR, 225; P < 0.001), and gait inability (OR, 64; P < 0.001) were significant predictive factors. In patients with age ≥67 years, PT hyperreflexia, and/or AT hyperreflexia, the sensitivity for myelopathy diagnosis was 98%. In patients with spastic gait or gait inability, the specificity of myelopathy diagnosis was 96%.

CONCLUSIONS

We analyzed factors that predict latent myelopathy in patients complaining only of lower extremity symptoms. We believe a diagnostic protocol based on the predictors shown in this study would contribute to the accurate diagnosis of latent myelopathy.

LEVEL OF EVIDENCE

4.

Upright Balance Control in Individuals with Cervical Myelopathy Following Cervical Decompression Surgery: A Prospective Cohort Study

Patients with cervical myelopathy may manifest impairments in functional activities and balance control caused by compression of the spinal cord. The objective of the current study was to determine long-term changes in the upright balance control of patients with cervical myelopathy who had undergone cervical decompression surgery. This is a prospective cohort study from the preoperative phase to 3 months, 6 months, and 1 year postsurgery. Fifty-three patients with cervical myelopathy were recruited for the cervical myelopathy group and 22 age-matched healthy controls were recruited for the control group. Functional assessments including Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire-Lower Extremity Function (JOACMEQ-LEF) and 10-second step test; as well as balance assessments including postural sway (center-of-pressure: COP) were performed for both groups. The JOACMEQ-LEF (p = 0.036) scores of the myelopathy group improved postoperatively, and a significant decrease in COP variables of postural sway was observed. The upright posture was less stable in the myelopathy group than in the control group (p < 0.05) both before and after surgery. The effect size and standard response mean of the COP variables ranged from −0.49 to 0.03 at 3 months, 6 months, and 1 year postsurgery. The upright balance control had improved significantly 6 months after decompression surgery. However, the balance control of the patients who had undergone decompression surgery remained less stable than that of the age-matched healthy controls. Balance training should be initiated before 6 months postsurgery to accelerate balance control recovery in patients with cervical myelopathy.

Muscular Activity Modulation During Post-operative Walking With Hybrid Assistive Limb (HAL) in a Patient With Thoracic Myelopathy Due to Ossification of Posterior Longitudinal Ligament: A Case Report

Disorders of the central nervous system sometimes cause severe sensory motor paralysis accompanied by gait impairment. Recently, there are several reports on the effectiveness of robot-assisted gait training for patients experiencing these issues. The purpose of this case report was to assess the neuromechanical effect of a wearable robot suit HAL (Hybrid Assistive Limb) during post-operative gait training in a patient with gait impairment due to compressive myelopathy caused by ossification of the posterior longitudinal ligament (OPLL). For this purpose, we compared lower limb muscular activities while the patient was walking with and without the robot through a course of treatment sessions by (i) gait phase-dependent muscle usage analysis, (ii) muscle synergy analysis, and (iii) muscle network analysis. The results show (i) enhanced activity of the extensor muscles for weight-bearing in the initial sessions by using HAL and reduced knee extensor and increased hip extensor activations for achieving larger steps and faster gait in the later sessions; (ii) involvement of a greater number of synergies during walking with HAL than without HAL; and (iii) modulated muscle network property during walking with HAL remaining until the next HAL session. The patient's gait was improved after completing HAL sessions, acquiring close to normal joint profile with greater range of joint movement, faster walking speed, and larger step length. We discuss that the muscular activity modulation during walking with HAL suggests altered control of the muscles by the central nervous system during post-operative walking. Activity-dependent sensorimotor augmentation by HAL is discussed in the context of recovery of gait control by the central nervous system. The relationship between the altered control and the achieved gait recovery requires further investigation.

Quantitative Assessment of Gait Characteristics in Degenerative Cervical Myelopathy: A Prospective Clinical Study

It is challenging to discriminate the early presentation of Degenerative Cervical Myelopathy (DCM) as well as sensitively and accurately distinguishing between mild, moderate, and severe levels of impairment. As gait dysfunction is one of the cardinal symptoms of DCM, we hypothesized that spatiotemporal gait parameters, including the enhanced gait variability index (eGVI), could be used to sensitively discriminate between different severities of DCM. A total of 153 patients recently diagnosed with DCM were recruited and stratified on the basis of DCM severity grades, as measured using the modified Japanese Orthopedic Association (mJOA) scale. Demographic information and neurological status were collected. Gait assessments were performed using an 8 m walkway. Spearman rank correlation was used to identify relationships between gait parameters and mJOA values as well as the mJOA lower extremity (LE) subscore. Kruskal–Wallis H test was performed to evaluate differences between severity groups, as defined by mJOA classification. A significant and relatively strong correlation was found between the mJOA score and eGVI, as well as between the LE subscore of the mJOA and eGVI. Significant differences in the eGVI (X²(2, N = 153) = 55.04, p < 0.0001, ε2 = 0.36) were found between all groups of DCM severity, with a significant increase in the eGVI as DCM progressed from mild to moderate. The eGVI was the most discriminative gait parameter, which facilitated objective differentiation between varying severities of DCM. Quantitative gait assessments show promise as an accurate and objective tool to diagnose and classify DCM, as well as to potentially evaluate the impact of therapeutic interventions.

Characterizing gait abnormalities in patients with cervical spondylotic myelopathy: a neuromuscular analysis

BACKGROUND CONTEXT

Gait impairment is a hallmark of cervical spondylotic myelopathy (CSM). It has been shown to affect quality of life but has not been well defined. Further electromyographic (EMG) characterization of the gait cycle may help elucidate the true neuromuscular pathology with implications on prognosis and rehabilitation techniques.

PURPOSE

This study compares neuromuscular activity in patients with CSM to that of healthy age-matched controls.

STUDY DESIGN

Nonrandomized, prospective, concurrent control cohort study.

METHODS

Neuromuscular activity was measured in 40 patients with symptomatic CSM during a series of over-ground gait trials at a self-selected speed before surgical intervention. External oblique, multifidus, erector spinae, rectus femoris, semitendinosus, tibialis anterior, medial gastrocnemius, and medial deltoid were assessed. Identical measurements were taken in 25 healthy control patients. Differences in time of muscle onset, peak EMG, time to peak EMG, and integrated electromyography (iEMG) were assessed using one-way ANOVA.

RESULTS

There were no significant differences between patients with CSM and healthy controls with respect to time of muscle contraction onset. Peak EMG muscle activity was significantly higher in the medial deltoid of patients with CSM (39.3% vs. 23.3% sMVC, p=.042), but no other differences were seen in the remaining muscles tested. They also demonstrated significantly longer time to peak EMG muscle activity compared with controls in 5 of the 8 muscles tested, including the multifidus (20.2 vs. 16.8 ms, p=.050), erector spinae (18.2 vs. 8.9 ms, p<.001), semitendinosis (26.3 vs. 22.4 ms, p=.037), tibialis anterior (14.7 vs. 11.0 ms, p=.050), and medial deltoid (24.2 vs. 9.2 ms, p<.001). Compared with controls, patients with CSM demonstrated significantly higher iEMG activity in the semitendinosis (586.5% vs. 272.5 sMVC, p=.047) and medial deltoid (87.62% vs. 22.5% sMVC, p=.008).

CONCLUSIONS

The onset of muscle activity is not delayed in CSM patients, but many key muscles take longer to fully contract. This produces a situation in which patients with CSM are unable to fully fire their muscles with sufficient speed to maintain a normal gait. The core and lower extremity muscles do not contract with increased peak amplitude in response, but the deltoid and hamstring muscles are more active, suggesting compensatory activity as patients attempt to maintain balance. The end result is less efficient ambulation. These findings provide a more nuanced understanding of gait in individuals suffering from CSM and may have implications on rehabilitation protocols.

Foot Tapping Test as Part of Routine Neurologic Examination in Degenerative Compression Myelopathies: A Significant Correlation between 10-sec Foot-tapping Speed and 30-m Walking Speed

Introduction

Leg spasticity in degenerative compression myelopathy causes impairment of fast and rapid repetitive movements, which tends to appear despite the disproportionate paucity of clinical weakness. As clinically useful measures used to quantify the slowness of voluntary leg movements in this pathological condition, we compared the foot tapping test (FTT) with the simple walking test, which is now considered the gold standard in this field.

Methods

We compared the FTT with the simple walking test, the grip-and-release test, and the functional scales of Nurick and the Japanese Orthopedic Association (JOA) in 77 patients with cervical compression myelopathy and 56 age-matched healthy subjects. The FTT was conducted on both sides separately, and the subject, while being seated on a chair, moved his/her toes up and down repeatedly to tap the floor as fast and as vigorously as possible for 10 sec with his/her heels planted on the floor.

Results

The number of 10-sec foot tapping in the patient group significantly correlated with the Nurick grades (r = −0.566; P < 0.0001), the JOA scores (r = 0.520; P < 0.0001), and the grip-and-release rates (r = 0.609; P < 0.0001). It also significantly correlated with the 30-m walking time (r = −0.507; P < 0.0001) and the number of steps taken (r = −0.494; P < 0.0001). Assessments of wheelchair-dependent patients and side-to-side comparison, in which the simple walking test plays no role, revealed significantly fewer FTT taps in wheelchair-bound patients than in the ambulatory patients and a significant trend for cervical compression myelopathy to dominantly affect the upper and lower limbs on the same side.

Conclusions

This study contributes to the reassessment of the currently underutilized FTT as part of a routine neurologic examination of degenerative compression myelopathy.

Gait Alteration in Cervical Spondylotic Myelopathy Elucidated by Ground Reaction Forces

STUDY DESIGN

.: Prospective cohort study.

OBJECTIVE

.: Analyze GRF parameters in cervical spondylotic myelopathy (CSM) patients to elucidate gait alterations as compared with healthy controls.

SUMMARY OF BACKGROUND DATA

.: During the human gait cycle, the magnitude and direction of the force each foot imparts on the ground varies in a controlled fashion to propel the body's center of mass forward. Alterations in GRF patterns can both point to subtle gait disturbances and explain altered gait patterns such as that seen in CSM.

METHODS

.: Thirty-two patients with symptomatic CSM who have been scheduled for surgery, along with 30 healthy controls (HC), underwent clinical gait analysis a week before surgery. Vertical GRF parameters and force magnitude and timing at various points of the gait cycle (i.e., heel contact, maximum weight acceptance, mid-stance, and push off) were analyzed and compared between groups.

RESULTS

.: Increased heel contact (CSM: 60.13% vs. HC: 27.82% of body weight, BW,P = 0.011), maximum weight acceptance (CSM: 120.13% vs. HC: 100.97% of BW, P = 0.016), and diminished push off (CSM: 91.35% vs. HC: 106.54% of BW, P = 0.001) forces were discovered in CSM patients compared with HC. Compared with controls CSM patients had delayed heel contact (CSM: 9.32% vs. HC: 5.12% of gait cycle, P = 0.050) and earlier push off (CSM: 54.96% vs. HC: 59.0% of gait cycle, P = 0.050), resulting in a shorter stance phase.

CONCLUSION

.: This study reinforces how CSM patients commonly exhibit altered gait patterns, but also uniquely demonstrates the increased heel-contract and maximum weight acceptance forces, diminished toe-off forces, and the shorter stance phase to absorb the BW load. When examined from a global perspective, these altered GRF parameters reflect the difficulty CSM patients have with catching their center of mass during heel-contact to avoid falling and with subsequently propelling themselves forward.

LEVEL OF EVIDENCE

3.

Effect of Cervical Decompression Surgery on Gait in Adult Cervical Spondylotic Myelopathy Patients

STUDY DESIGN

This is a prospective cohort study.

OBJECTIVE

To evaluate the effect of cervical decompression surgery on the biomechanics of the spine and lower extremities in cervical spondylotic myelopathy (CSM) patients and compare with asymptomatic controls.

SUMMARY OF BACKGROUND DATA

Difficulties with balance and gait are one of the most common manifestations of CSM. Patients with CSM have a slower gait speed, prolonged double support duration, and reduced cadence compared with healthy controls. Surgical decompression was found to improve clinical outcomes, but conflicting results are noted when examining function.

MATERIALS AND METHODS

In total, 25 subjects with symptomatic CSM underwent clinical gait analysis performed a week before (pre) and 3 months after the surgery (post). Clinical gait analysis was performed on 30 matched asymptomatic controls as well. Spine and lower extremity kinematics, spatiotemporal parameters, and clinical outcome were measured.

RESULTS

CSM patients demonstrated slower walking speed (P=0.006), reduced cadence (P=0.001), longer step time (P=0.013) wider step width (P=0.001), greater ankle range of motion (ROM) (P=0.019), less hip ROM (P=0.050), increased pelvis (P=0.001), and lumbar spine (P=0.049) ROM compared with controls. Postoperatively CSM patients demonstrated a faster walking speed (P=0.002), increased cadence (P=0.029), longer step length (P=0.015), narrower step width (P=0.004), greater knee (P=0.043), and hip ROM (P=0.007), less pelvis (P=0.002), lumbar spine (P=0.035), and cervical spine (P=0.044) ROM, and improved clinical outcomes (neck pain disability index questionnaire, oswestry disability index, and visual analog scale; P=0.001) compared with their preoperative values. Postsurgical CSM patients did not present with any differences compared with controls, beside pelvis ROM (P=0.019).

CONCLUSIONS

Preoperatively, CSM patients clearly showed altered gait parameters compared with controls. However, after cervical decompression surgery, CSM patients exhibited improved gait pattern, spatiotemporal parameters, spine and lower extremity ROM, as well as patient-reported outcomes. Postoperatively, CSM patients did not show major differences in gait when compared with matched asymptomatic controls.

Spine and lower extremity kinematics during gait in patients with cervical spondylotic myelopathy

BACKGROUND CONTEXT

Cervical spondylotic myelopathy (CSM) typically manifests with a slow, progressive stepwise decline in neurologic function, including hand clumsiness and balance difficulties. Gait disturbances are frequently seen in patients with CSM, with more advanced cases exhibiting a stiff, spastic gait.

PURPOSE

To evaluate the spatiotemporal parameters and spine and lower extremity kinematics during the gait cycle of adult patients with CSM before surgical intervention.

STUDY DESIGN

Prospective cohort study.

PATIENT SAMPLE

Twenty-eight subjects with symptomatic CSM who have been scheduled for surgery and 30 healthy controls (HC).

OUTCOME MEASURES

Spine and lower extremity kinematics and spatiotemporal parameters.

METHODS

Clinical gait analysis was performed for patients with CSM and HC. The data were analyzed with a one-way analysis of variance.

RESULTS

Patients with CSM have significantly more anterior pelvis tilt (CSM: 13.97°, HC: 5.56°), larger lumbar lordosis (CSM: 8.59°, HC: 2.7°), smaller cervical lordosis (CSM: 6.02°, HC: 11.35°), and less head flexion (CSM: 0.69°, HC: 8.66°) at the beginning of the gait cycle. There was a decrease in knee range of motion in patients with CSM compared with controls (CSM: 36.31°, HC: 50.17°). Furthermore, patients with CSM presented with slower walking speed (CSM: 0.81 m/s, HC: 1.05 m/s), decreased cadence (CSM: 95.57 step/m, HC: 107.64 step/m), increased double support time (CSM: 0.40 s, HC: 0.28 s) and stride time (CSM:1.28 s, HC: 1.13 s), shorter stride length (CSM: 1.04 m, HC: 1.18 m) and step length (CSM:0.51 m, HC: 0.58 m), and wider width (CSM: 0.14 m, HC:0.11 m).

CONCLUSIONS

Our study shows that patients with CSM enter the gait cycle with a larger anterior pelvic tilt and lumbar lordosis as well as less cervical lordosis and head flexion. As a consequence of these abnormal spinal parameters at the onset of the gait cycle, lower extremity biomechanics are also altered. Our study is the first to demonstrate the relationship between aberrant spinal alignment and lower extremity function. Identification of this interrelationship as well as the specific gait and biomechanical disturbances seen in myelopathic patients can both inform our understanding of the disease and tailor rehabilitation protocols.

Kinetic and kinematic follow-up gait analysis in Doberman Pinschers with cervical spondylomyelopathy treated medically and surgically

Background

The efficacy of treatment of dogs with cervical spondylomyelopathy (CSM) is commonly based on the owner's and clinician's perception of the gait, which is highly subjective and suffers from observer bias.

Hypothesis/Objectives

To compare selected kinetic and kinematic parameters before and after treatments and to correlate the findings of gait analysis to clinical outcome.

Animals

Eight Doberman Pinschers with CSM confirmed by magnetic resonsance imaging.

Methods

Patients were prospectively studied and treated with either medical management (n = 5) or surgery (n = 3). Force plate analysis and 3‐D kinematic motion capture were performed at initial presentation and approximately 8 weeks later. Force plate parameters evaluated included peak vertical force (PVF). Kinematic parameters measured included number of pelvic limb strides, stifle flexion and extension, maximum and minimum thoracic limb distance, truncal sway, and thoracic limb stride duration.

Results

Kinematic analysis showed that deviation of the spine to the right (truncal sway) was significantly smaller (P < .001) and the degree of right stifle flexion was significantly larger (P = .029) after treatment. Force plate analysis indicated that PVF was significantly different after treatment (P = .049) and the difference of the PVF also was significantly larger (P = .027). However, no correlation was found with either method of gait analysis and clinical recovery.

Conclusions and Clinical Importance

Kinetic and kinematic gait analysis were able to detect differences in dogs with CSM before and after treatment. A correlation of gait analysis to clinical improvement could not be determined.

Analysis of spastic gait in cervical myelopathy: Linking compression ratio to spatiotemporal and pedobarographic parameters

BACKGROUND

Gait dysfunction associated with spasticity and hyperreflexia is a primary symptom in patients with compression of cervical spinal cord. The objective of this study was to link maximum compression ratio (CR) to spatiotemporal/pedobarographic parameters.

METHODS

Quantitative gait analysis was performed by using a pedobarograph in 75 elderly males with a wide range of cervical compression severity. CR values were characterized on T1-weighted magnetic resonance imaging (MRI). Statistical significances in gait analysis parameters (speed, cadence, stride length, step with, and toe-out angle) were evaluated among different CR groups by the non-parametric Kruskal-Wallis test followed by the Mann-Whitney U test using Bonferroni correction. The Spearman test was performed to verify correlations between CR and gait parameters.

RESULTS

The Kruskal-Wallis test revealed significant decline in gait speed and stride length and significant increase in toe-out angle with progression of cervical compression myelopathy. The post-hoc Mann-Whitney U test showed significant differences in these parameters between the control group (0.45<CR) and the worst myelopathy group (CR≤0.25). Cadence and step width did not significantly change with CR. On the other hand, the Spearman test revealed that CR was significantly correlated with speed, cadence, stride length, and toe-out angle.

CONCLUSION

Gait speed, stride length, and toe-out angle can serve as useful indexes for evaluating progressive gait abnormality in cervical myelopathy. Our findings suggest that CR≤0.25 is associated with significantly poorer gait performance. Nevertheless, future prospective studies are needed to determine a potential benefit from decompressive surgery in such severe compression patients.

Effect of Surgery on Gait and Sensory Motor Performance in Patients With Cervical Spondylotic Myelopathy

BACKGROUND

Cervical spondylotic myelopathy (CSM) is a common disease of aging that leads to gait instability resulting from loss of leg sensory and motor functions. The results of surgical intervention have been studied using a variety of methods, but no test has been reported that objectively measures integrative leg motor sensory functions in CSM patients.

OBJECTIVE

To determine the feasibility of using a novel single leg squat (SLS) test to measure integrative motor sensory functions in patients with CSM before and after surgery.

METHODS

Fifteen patients with CSM were enrolled in this prospective study. Clinical data and scores from standard outcomes questionnaires were obtained before and after surgery. Patients also participated in experimental test protocols consisting of standard kinematic gait testing, the Purdue pegboard test, and the novel SLS test.

RESULTS

The SLS test protocol was well tolerated by CSM patients and generated objective performance data over short test periods. In patients who participated in postoperative testing, the group measures of mean SLS errors decreased following surgery. Gait velocity measures followed a similar pattern of group improvement postoperatively. Practical barriers to implementing this extensive battery of tests resulted in subject attrition over time. Compared with kinematic gait testing, the SLS protocol required less space and could be effectively implemented more efficiently.

CONCLUSIONS

The SLS test provides a practical means of obtaining objective measures of leg motor sensory functions in patients with CSM. Additional testing with a larger cohort of patients is required to use SLS data to rigorously examine group treatment effects.

ABBREVIATIONS

BW, body weightCSM, cervical spondylotic myelopathymJOA, modified Japanese Orthopedic AssociationSLS, single leg squat.

Delayed decompression exacerbates ischemia-reperfusion injury in cervical compressive myelopathy

Degenerative cervical myelopathy (DCM) is the most common progressive nontraumatic spinal cord injury. The most common recommended treatment is surgical decompression, although the optimal timing of intervention is an area of ongoing debate. The primary objective of this study was to assess whether a delay in decompression could influence the extent of ischemia-reperfusion injury and alter the trajectory of outcome in DCM. Using a DCM mouse model, we show that decompression acutely led to a 1.5- to 2-fold increase in levels of inflammatory cytokines within the spinal cord. Delayed decompression was associated with exacerbated reperfusion injury, astrogliosis, and poorer neurological recovery. Additionally, delayed decompression was associated with prolonged elevation of inflammatory cytokines and an exacerbated peripheral monocytic inflammatory response (P < 0.01 and 0.001). In contrast, early decompression led to resolution of reperfusion-mediated inflammation, neurological improvement, and reduced hyperalgesia. Similar findings were observed in subjects from the CSM AOSpine North America and International studies, where delayed decompressive surgery resulted in poorer neurological improvement compared with patients with an earlier intervention. Our data demonstrate that delayed surgical decompression for DCM exacerbates reperfusion injury and is associated with ongoing enhanced levels of cytokine expression, microglia activation, and astrogliosis, and paralleled with poorer neurological recovery.

Correlations of Japanese Orthopaedic Association Scoring Systems with Gait Parameters in Patients with Degenerative Spinal Diseases

OBJECTIVE

Japanese Orthopaedic Association (JOA) scoring systems were developed to evaluate the neurological function of patients with cervical or lumbar degeneration. As patient-based and multi-dimensional clinical evaluation tools, these systems should be capable of reflecting the walking disability of patients. The association between JOA scores and gait parameters, however, are not well characterized. The purpose of this study was to determine the correlations between JOA scores and gait parameters of patients with cervical spondylotic myelopathy (CSM) and lumbar intervertebral disc herniation (LDH).

METHODS

A total of 32 CSM and 30 LDH patients with gait dysfunction were recruited for the present study. All patients were diagnosed by two senior orthopaedic doctors and evaluated with JOA scoring systems. A body-mounted motion analyzer, the Intelligent Device for Energy Expenditure and Activity (IDEEA), was applied to measure gait parameters of patients across 30 m of flat floor in an orthopaedic ward. A linear regression model was used to determine the correlations between JOA scores and gait parameters. Multiple linear regressions were used to identify the relationships between subsections of the JOA systems and gait parameters.

RESULTS

Japanese Orthopaedic Association scores of LDH patients from the JOA lumbar scoring system are significantly correlated with gait speed (R ² = 0.557, P < 0.001) and stride length (R ² = 0.544, P < 0.001). JOA scores are also correlated with double support duration, step duration, cycle duration and cadence, and weakly correlated with single support duration. For the four subsections of the JOA lumbar scoring system, "restriction of activities of daily living" is the significant predictor of all gait parameters, especially gait speed (R ² = 0.573, P < 0.001) and stride length (R ² = 0.553, P < 0.001). However, JOA scores of CSM patients from the JOA cervical scoring system are only weakly correlated with these measures (all R ² < 0.3). For the four subsections of the JOA cervical scoring system, "motor function of the lower extremity" is a weak predictor of gait parameters (all R ² < 0.3).

CONCLUSIONS

There is a significant correlation between gait parameters and functional disability as measured by the JOA lumbar scoring system, which indicates that the JOA lumbar scoring system can reflect gait impairment. The JOA cervical scoring system, however, may need to be improved for efficiently evaluating the walking ability of CSM patients in the assessment of motor function of the lower extremity.

The Role of Gait Analysis in the Evaluation of Patients with Cervical Myelopathy: A Literature Review Study

BACKGROUND

Gait analysis represents one of the newest methodologies used in the clinical evaluation of patients with cervical myelopathy (CM).

OBJECTIVE

To describe the role of gait analysis in the clinical evaluation of patients with CM, as well as its potential role in the evaluation of the functional outcome of any surgical intervention.

METHODS

A literature review was performed in the PubMed, OVID, and Google Scholar medical databases, from January 1995 to August 2016, using the terms "analysis," "anterior," "cervical myelopathy," "gait," "posterior," and "surgery." Clinical series comparing the gait patterns of patients with CM with healthy controls, as well as series evaluating gait and walk changes before and after surgical decompression, were reviewed. Case studies were excluded.

RESULTS

Nine prospective and 3 retrospective studies were found. Most of the retrieved studies showed the presence of characteristic, abnormal gait patterns among patients with CM, consisting of decreased gait speed, cadence, step length, stride length, and single-limb support time. In addition, patients with CM routinely present increased step and stride time, double-limb support time, and step width, and they have altered knee and ankle joint range of motion, compared with healthy controls. Moreover, gait and walk analysis may provide accurate functional assessment of the functional outcome of patients with CM undergoing surgical decompression.

CONCLUSIONS

Gait analysis may well be a valuable and objective tool along with other parameters in the evaluation of functionality in patients with CM, as well as in the assessment of the outcome of any surgical intervention in these patients.

Gait disorders in adults and the elderly : A clinical guide

Human gait depends on a complex interplay of major parts of the nervous, musculoskeletal and cardiorespiratory systems. The individual gait pattern is influenced by age, personality, mood and sociocultural factors. The preferred walking speed in older adults is a sensitive marker of general health and survival. Safe walking requires intact cognition and executive control. Gait disorders lead to a loss of personal freedom, falls and injuries and result in a marked reduction in the quality of life. Acute onset of a gait disorder may indicate a cerebrovascular or other acute lesion in the nervous system but also systemic diseases or adverse effects of medication, in particular polypharmacy including sedatives. The prevalence of gait disorders increases from 10 % in people aged 60–69 years to more than 60 % in community dwelling subjects aged over 80 years. Sensory ataxia due to polyneuropathy, parkinsonism and frontal gait disorders due to subcortical vascular encephalopathy or disorders associated with dementia are among the most common neurological causes. Hip and knee osteoarthritis are common non-neurological causes of gait disorders. With advancing age the proportion of patients with multiple causes or combinations of neurological and non-neurological gait disorders increases. Thorough clinical observation of gait, taking a focused patient history and physical, neurological and orthopedic examinations are basic steps in the categorization of gait disorders and serve as a guide for ancillary investigations and therapeutic interventions. This clinically oriented review provides an overview on the phenotypic spectrum, work-up and treatment of gait disorders.

Cervical Myelopathy Doubles the Rate of Dislocation and Fracture After Total Hip Arthroplasty

BACKGROUND

Cervical spondylotic myelopathy (CSM) is a common and underdiagnosed cause of gait dysfunction, rigidity, and falls in the elderly. Given the frequent concurrency of CSM and hip osteoarthritis, this study is designed to evaluate the relative risk of CSM on perioperative and short-term outcomes after total hip arthroplasty (THA).

METHODS

The Medicare Standard Analytical Files were searched from 2005 to 2012 to identify all patients undergoing primary THA and the subset of patients with preexisting CSM. Risk ratios with 95% confidence intervals were calculated for 90-day, 1-year, and overall follow-up for common postoperative complications: periprosthetic dislocation, fracture, infection, revision THA, and wound complications.

RESULTS

The risk ratios of all surgical complications, including dislocation, periprosthetic fractures, and prosthetic joint infection, were increased approximately 2-fold at all postoperative time points for patients.

CONCLUSION

Preexisting CSM is a significant risk factor for primary THA complications including dislocation, periprosthetic fractures, and prosthetic joint infection.

Effects of brain derived neurotrophic factor Val66Met polymorphism in patients with cervical spondylotic myelopathy

Cervical spondylotic myelopathy (CSM) is the leading cause of spinal cord related disability in the elderly. It results from degenerative narrowing of the spinal canal, which causes spinal cord compression. This leads to gait instability, loss of dexterity, weakness, numbness and urinary dysfunction. There has been indirect data that implicates a genetic component to CSM. Such a finding may contribute to the variety in presentation and outcome in this patient population. The Val66Met polymorphism, a mutation in the brain derived neurotrophic factor (BDNF) gene, has been implicated in a number of brain and psychological conditions, and here we investigate its role in CSM. Ten subjects diagnosed with CSM were enrolled in this prospective study. Baseline clinical evaluation using the modified Japanese Orthopaedic Association (mJOA) scale, Nurick and 36-Item Short Form Health Survey (SF-36) were collected. Each subject underwent objective testing with gait kinematics, as well as hand functioning using the Purdue Peg Board. Blood samples were analyzed for the BDNF Val66Met mutation. The prevalence of the Val66Met mutation in this study was 60% amongst CSM patients compared to 32% in the general population. Individuals with abnormal Met allele had worse baseline mJOA and Nurick scores. Moreover, baseline gait kinematics and hand functioning testing were worse compared to their wild type counterpart. BDNF Val66Met mutation has a higher prevalence in CSM compared to the general population. Those with BDNF mutation have a worse clinical presentation compared to the wild type counterpart. These findings suggest implication of the BDNF mutation in the development and severity of CSM.

Three-dimensional gait analysis outcomes at 1 year following decompressive surgery for cervical spondylotic myelopathy

PURPOSE

Gait impairment is an important feature of cervical sponydylotic myelopathy (CSM) as it can have a detrimental effect on function and quality of life. The aim of this study was to measure changes in gait in people with CSM following surgical decompression.

METHODS

Thirteen participants with clinical and radiological evidence of CSM underwent three-dimensional gait analysis, using a full lower limb kinematic, kinetic and electromyography protocol, before and 12 months after decompressive surgery.

RESULTS

No significant post-operative changes were detected in temporal-spatial or kinematic parameters. Kinetic data showed significant improvements in knee power absorption [mean improvement, 0.42 watts per kilogram (W/kg)], ankle plantarflexor moment (0.1 Nm/kg) and ankle power generation (0.55 W/kg). Electromyography showed a 4.7 % increase in tibialis anterior activation time.

CONCLUSIONS

These findings indicate that improvement in locomotor function can be achieved after surgery. Future studies should explore the potential for further recovery of gait through targeted neuro-rehabilitation.

A summary of assessment tools for patients suffering from cervical spondylotic myelopathy: a systematic review on validity, reliability and responsiveness

PURPOSE

One of the objectives of this review is to summarize the important features of a good scale. A second aim is to conduct a systematic review to identify scales that can detect the presence of cervical myelopathy and to determine their psychometric properties including validity, reliability and responsiveness.

METHODS

A thorough literature search was performed using MEDLINE, MEDLINE in process, EMBASE, and Cochrane Central Register of Controlled Trials. Articles were included in this study if they compared scale measurements between a control and a myelopathic patient population or if they discussed any psychometric property of a scale.

RESULTS

An ideal scale should be one that is quantifiable, valid, sensitive, responsive and easy to perform, has high inter/intra-rater reliability, internal consistency and a suitable distribution, and is one-dimensional and relevant. In the context of cervical spondylotic myelopathy, it is essential that the scale also addresses the pathophysiology, its key signs and symptoms as well as its natural history. For the systematic review, the search yielded 5,745 citations. Of these, 37 met inclusion criteria, 10 explored the ability of a scale to detect myelopathy, 23 examined validity by assessing correlation between scales, 10 reported reliability, 8 analyzed responsiveness, and 6 discussed internal consistency. The most frequently reported scale was short form-36 (n = 16) followed by Nurick grade (n = 14), Japanese Orthopaedic Association (n = 13), (modified) Japanese Orthopaedic Association (n = 7) and grip and release test (n = 6). Four studies each presented results on the Cooper, Harsh and 30-m walking test.

CONCLUSION

This review summarizes outcome measures used to assess the presence and severity of cervical myelopathy. It includes several validation studies as well as those that have reported the responsiveness and reliability of various measures.

A novel experimental model of cervical spondylotic myelopathy (CSM) to facilitate translational research

Cervical spondylotic myelopathy (CSM) is the most common form of spinal cord impairment in adults. However critical gaps in our knowledge of the pathobiology of this disease have limited therapeutic advances. To facilitate progress in the field of regenerative medicine for CSM, we have developed a unique, clinically relevant model of CSM in rats. To model CSM, a piece of synthetic aromatic polyether, to promote local calcification, was implanted microsurgically under the C6 lamina in rats. We included a sham group in which the material was removed 30s after the implantation. MRI confirmed postero-anterior cervical spinal cord compression at the C6 level. Rats modeling CSM demonstrated insidious development of a broad-based, ataxic, spastic gait, forelimb weakness and sensory changes. No neurological deficits were noted in the sham group during the course of the study. Spasticity of the lower extremities was confirmed by a significantly greater H/M ratio in CSM rats in H reflex recordings compared to sham. Rats in the compression group experienced significant gray and white matter loss, astrogliosis, anterior horn cell loss and degeneration of the corticospinal tract. Moreover, chronic progressive posterior compression of the cervical spinal cord resulted in compromise of the spinal cord microvasculature, blood-spinal cord barrier disruption, inflammation and activation of apoptotic signaling pathways in neurons and oligodendrocytes. Finally, CSM rats were successfully subjected to decompressive surgery as confirmed by MRI. In summary, this novel rat CSM model reproduces the chronic and progressive nature of human CSM, produces neurological deficits and neuropathological features accurately mimicking the human condition, is MRI compatible and importantly, allows for surgical decompression.

Effect of the number of involved spinal cord segments on gait function in patients with cervical spondylotic myelopathy

Study Design

Retrospective.

Purpose

To determine the effect of severity of cervical spondylotic myelopathy (CSM) on gait parameters according to the number of involved spinal cord segments.

Overview of Literature

Although there are a large number of studies on CSM, almost all studies have focused on hand function and only a few studies have examined the gait function in patients with CSM.

Methods

Twenty-three patients with CSM underwent magnetic resonance imaging and gait analysis. The subjects were divided into 2 groups; group I consisted of 9 patients with a single-level stenotic lesion and group II comprised 14 patients with multi-level stenotic lesions. Gait parameters were compared between the 2 groups and the normal control group.

Results

There was no significant difference in the Japanese Orthopaedic Association score between the 2 groups. Cadence, walking speed, stride length, and step length were decreased in group II compared to group I and normal control group. Peak ankle plantar flexion moments during the stance phase and peak knee flexion angle during the swing phase were decreased in group II. Peak ankle, knee, and hi p power generation during the stance phase were decreased in group II; in addition, the peak ankle power generation was decreased in group II than in the normal control group.

Conclusions

Patients with multi-level stenotic lesions had decreased gait ability compared to that in patients with a single-level stenotic lesion. The number of involved spinal cord segments can be one cause of gait deterioration in patients with CSM. Performing a gait analysis is useful for accurate evaluation of the patient.

Prevalence of cervical cord compression and its association with physical performance in a population-based cohort in Japan: the Wakayama Spine Study

STUDY DESIGN

A population-based magnetic resonance imaging (MRI) study of the cervical spine.

OBJECTIVE

This study was undertaken in order to investigate the prevalence of cervical cord compression (CCC) and to examine the association between CCC and physical performance measures in a population-based cohort established in Japan.

SUMMARY OF BACKGROUND DATA

Population-based cohort studies of the prevalence of CCC, although essential for clarification of the prevalence of slowly progressive disease and specification of the time of incidence of CCC, are not available.

METHODS

This cross-sectional study was performed as a part of the Research on Osteoarthritis/osteoporosis Against Disability study, a large-scale population-based cohort study in Japan. From 1011 inhabitants who underwent MRI examinations, images of the cervical spine of 977 subjects (324 men and 653 women, mean age of 66.4 yr) were evaluated. CCC was assessed by sagittal T2-weighted MRI and was defined as spinal cord compression. The prevalence of CCC and its association with myelopathic signs (hyper-reflexia of the patellar tendon and Hoffmann and Babinski reflexes) were examined. In addition, physical performance measures (grip and release test, grip strength, 6-m walking time, step length, chair-stand time, and one-leg standing time) were tested.

RESULTS

The prevalence of CCC was 24.4% and was significantly higher in men (29.3% in men and 21.9% in women, P = 0.011). The prevalence of CCC was higher with increasing age in both sexes. CCC was not significantly associated with any myelopathic signs but was significantly associated with grip and release test, 6-m walking time, step length, and chair-stand time.

CONCLUSION

In this MRI study, the prevalence of CCC was examined. The present results indicate that CCC correlates with physical performance measures from an early stage of the disease before myelopathic signs appear.

Gait impairment in cervical spondylotic myelopathy: comparison with age- and gender-matched healthy controls

INTRODUCTION

Gait impairment is a primary symptom of cervical spondylotic myelopathy (CSM); however, little is known about specific kinetic and kinematic gait parameters. The objectives of the study were: (1) to compare gait patterns of people with untreated CSM to those of age- and gender-matched healthy controls; (2) to examine the effect of gait speed on kinematic and kinetic parameters.

MATERIALS AND METHODS

Sixteen patients with CSM were recruited consecutively from a neurosurgery clinic, and 16 healthy controls, matched to age (± 5 years) and gender, were recruited for comparison. Patients and controls underwent three-dimensional gait analysis using a Vicon(®) motion analysis system, at self-selected speed over a 10-m track. Controls were also assessed at the speed of their CSM match.

RESULTS

At self-selected speed, the CSM group walked significantly more slowly, with shorter stride lengths and longer double support duration. They showed significant decreases in several kinematic and kinetic parameters, including sagittal range of motion at the hip and knee, ankle plantarflexion, anteroposterior ground reaction force (GRF) at toe-off, power absorption at the knee in loading response and terminal stance, and power generation at the ankle. At matched speed, the CSM group showed significant decreases in knee flexion during swing, total sagittal knee range of motion, peak ankle plantarflexion and anteroposterior GRF.

CONCLUSION AND IMPLICATIONS

The findings suggested that people with CSM have significant gait abnormalities that have not been previously reported. In particular, there are key differences in the motor strategies used in the terminal stance phase of gait that cannot be explained by speed alone.

Simple foot tapping test as a quantitative objective assessment of cervical myelopathy

STUDY DESIGN

A clinical and cohort study.

OBJECTIVE

The first purpose of this study was to investigate the standard value of a simple foot tapping test (FTT) in a large healthy population. The second purpose was to elucidate the validity of FTT as a quantitative assessment of lower extremity motor function for cervical compressive myelopathy.

SUMMARY OF BACKGROUND DATA

Several clinical performance tests have been reported as objective assessments for the severity of cervical myelopathy. The FTT is the simplest and easiest method for a quantitative analysis of lower limb motor dysfunction in the upper motor neuron diseases. However, there were few studies about the FTT in cervical myelopathy.

METHODS

We recruited 252 patients who were diagnosed with cervical myelopathy and 792 healthy volunteers who participated in a health promotion project. Among the patients, 126 who underwent surgery were evaluated both before and 1 year after surgery. We performed the FTT and grip and release test and evaluated the modified Japanese Orthopaedic Association (JOA) score for cervical myelopathy.

RESULTS

The mean value of FTT was 23.8 ± 7.2 in myelopathic patients, which was significantly lower than 31.7 ± 6.4 in healthy controls and decreased with age. The value of FTT significantly correlated with the lower extremity motor function of modified JOA score and the value of grip and release test. Among the patients who underwent surgery, the average value of FTT was 22.4 ± 7.0 preoperatively and improved to 28.4 ± 8.1 at 1 year postoperatively. Postoperative gain of FTT significantly correlated with the gain of JOA score.

CONCLUSION

The FTT results correlated with those of other tests for cervical myelopathy, and the FTT scores were improved by surgery. The FTT is an easy and useful quantitative assessment method for lower extremity motor function in patients with cervical myelopathy, especially those who cannot walk.

Gait kinematic analysis in patients with a mild form of central cord syndrome

BACKGROUND

Central cord syndrome (CCS) is considered the most common incomplete spinal cord injury (SCI). Independent ambulation was achieved in 87-97% in young patients with CCS but no gait analysis studies have been reported before in such pathology. The aim of this study was to analyze the gait characteristics of subjects with CCS and to compare the findings with a healthy age, sex and anthropomorphically matched control group (CG), walking both at a self-selected speed and at the same speed.

METHODS

Twelve CCS patients and a CG of twenty subjects were analyzed. Kinematic data were obtained using a three-dimensional motion analysis system with two scanner units. The CG were asked to walk at two different speeds, at a self-selected speed and at a slower one, similar to the mean gait speed previously registered in the CCS patient group. Temporal, spatial variables and kinematic variables (maximum and minimum lower limb joint angles throughout the gait cycle in each plane, along with the gait cycle instants of occurrence and the joint range of motion - ROM) were compared between the two groups walking at similar speeds.

RESULTS

The kinematic parameters were compared when both groups walked at a similar speed, given that there was a significant difference in the self-selected speeds (p < 0.05). Hip abduction and knee flexion at initial contact, as well as minimal knee flexion at stance, were larger in the CCS group (p < 0.05). However, the range of knee and ankle motion in the sagittal plane was greater in the CG group (p < 0.05). The maximal ankle plantar-flexion values in stance phase and at toe off were larger in the CG (p < 0.05).

CONCLUSIONS

The gait pattern of CCS patients showed a decrease of knee and ankle sagittal ROM during level walking and an increase in hip abduction to increase base of support. The findings of this study help to improve the understanding how CCS affects gait changes in the lower limbs.

Gait analysis for evaluating the relationship between increased signal intensity on t2-weighted magnetic resonance imaging and gait function in cervical spondylotic myelopathy

OBJECTIVE

To determine relationships between increased signal intensity (ISI) on T2-weighted cervical spine magnetic resonance imaging (MRI) and parameters of gait analysis in patients with cervical spondylotic myelopathy (CSM).

DESIGN

Retrospective comparative study.

SETTING

Gait analysis laboratory.

PARTICIPANTS

Patients (N=36) who undertook cervical laminectomy or laminoplasty because of CSM.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Subjects were evaluated by using the modified Japanese Orthopaedic Association (JOA) scale, the Nurick scale, cervical spine MRI, and gait analysis. Two radiologists classified patients into 3 groups: intense, faint, and no ISI.

RESULTS

Relative to patients without ISI, those with ISI showed significantly slower gait speed, longer step time, decreased single-limb support time, increased double-limb support time, and limited range of motion of knee and ankle (P<.05). Increased intensity tended to correlate with poor gait function including slower gait speed, longer step time, decreased single-limb support time, and increased double-limb support time. The modified JOA and Nurick scale did not correlate with ISI.

CONCLUSIONS

In patients with CSM who received surgical treatment, more intense ISI on T2-weighted MRI correlated preoperatively with increased difficulties in gait function. Gait analysis may be a useful tool for evaluating gait functions in cervical myelopathy.

Functional outcomes assessment for cervical degenerative disease

Object

The objective of this systematic review was to use evidence-based medicine to identify valid, reliable, and responsive measures of functional outcome after treatment for cervical degenerative disease.

Methods

The National Library of Medicine and Cochrane Database were queried using MeSH headings and key words relevant to functional outcomes. Abstracts were reviewed after which studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.

Results

Myelopathy Disability Index, Japanese Orthopaedic Association scale, 36-Item Short Form Health Survey, and gait analysis were found to be valid and reliable measures (Class II) for assessing cervical spondylotic myelopathy. The Patient-Specific Functional Scale, the North American Spine Society scale, and the Neck Disability Index were found to be reliable, valid, and responsive (Class II) for assessing radiculopathy for nonoperative therapy. The Cervical Spine Outcomes Questionnaire was a reliable and valid method (Class II) to assess operative therapy for cervical radiculopathy.

Conclusions

Several functional outcome measures are available to assess cervical spondylotic myelopathy and cervical radiculopathy.

Evaluation of the elderly patient with an abnormal gait

Distinguishing between the normal gait of the elderly and pathologic gaits is often difficult. Pathologic gaits with neurologic causes include frontal gait, spastic hemiparetic gait, parkinsonian gait, cerebellar ataxic gait, and sensory ataxic gait. Pathologic gaits with combined neurologic and musculoskeletal causes include myelopathic gait, stooped gait of lumbar spinal stenosis, and steppage gait. Pathologic gaits with musculoskeletal causes include antalgic gait, coxalgic gait, Trendelenburg gait, knee hyperextension gait, and other gaits caused by inadequate joint mobility. A working knowledge of the characteristics of these gaits and a systematic approach to observational gait examination can help identify the causes of abnormal gait. Patients with abnormal gait can benefit from the treatment of the primary cause of the disorder as well as by general fall-prevention interventions. Treatable causes of gait disturbance are found in a substantial proportion of patients and include normal-pressure hydrocephalus, vitamin B(12) deficiency, Parkinson's disease, alcoholism, medication toxicity, cervical spondylotic myelopathy, lumbar spinal stenosis, joint contractures, and painful disorders of the lower extremity.

Knee joint position sense in compressive myelopathy

STUDY DESIGN

The knee joint position sense (JPS) and kinesthesia were measured in patients with compressive myelopathy.

OBJECTIVES

To find out how the knee JPS and kinesthesia are useful to evaluate lower limb function in patients with compressive myelopathy.

SUMMARY OF BACKGROUND DATA

No previous reports have been written on the quantitative analysis of knee joint proprioception in myelopathy patients.

METHODS

Twenty-one compressive myelopathy patients with a mean age of 64 years were studied. The measured values of JPS and kinesthesia were examined in relation to the following: lower limb function and central motor conduction time (CMCT).

RESULTS

Inaccurate angles of the knee JPS in patients with severe walking disability were significantly larger than those in patients with mild disability. Inaccurate angles of the knee JPS in patients with severe sensory disturbance were significantly larger than those in patients with mild disturbance. CMCT showed a significant correlation to the knee JPS.

CONCLUSIONS

The knee JPS was useful to evaluate lower limb function in patients with compressive myelopathy.

Quantitative changes in gait parameters after central corpectomy for cervical spondylotic myelopathy

OBJECT

In this study, quantitative gait analysis is used to describe the changes in the kinematic and kinetic parameters of gait after central corpectomy in patients with cervical spondylotic myelopathy (CSM).

METHODS

Six men with CSM that was categorized preoperatively as Nurick Grade 3 or 4 were assessed using quantitative gait analysis. The values of various kinematic and kinetic parameters, physiological cost index, and range of motion (ROM) in the lower-limb joints were computed preoperatively as well as at follow-up review 12 months or more postoperatively. Patients also received scores based on the Nurick and Japanese Orthopaedic Association (JOA) lower-limb functional scales pre- and postoperatively. The mean Nurick grade improved from 3.3 to 2 (p = 0.02) and the mean JOA lower-limb score improved from 4.2 to 6 (p = 0.02). The forward ground reaction force showed a statistically significant increase from 10.8+/-4.1% body weight to 12.1+/-3.6% body weight (p = 0.04). There was a significant improvement in the ROM at the knees, from 48.6+/-7.7 degrees to 54.2+/-5.2 degrees (p = 0.03). There was an increase in the mean walking speed, stride length, percentage of single-limb support time, vertical and backward ground reaction forces, and ROM at the hips in the postoperative gait analysis. These results indicate an improved stability of gait as well as greater flexibility in the knee after decompression of the spinal cord. These changes correlated with an improvement in the functional status of patients with CSM after central corpectomy.

CONCLUSIONS

Gait analysis can be used as a quantitative tool in the pre- and postoperative evaluation of patients with CSM.

Proprioceptive recovery of patients with cervical myelopathy after surgical decompression

STUDY DESIGN

A prospective observational study.

OBJECTIVES

To determine whether proprioceptive deficit recovers after surgery and whether proprioceptive evaluation can predict functional outcome in cervical myelopathy patients.

SUMMARY OF BACKGROUND DATA

Proprioceptive sensation plays an important role in smooth, coordinated movement of the limbs. Information about proprioception ascends through the dorsal columns in the spinal cord. In severe compressive myelopathy, proprioceptive ability would be reduced and could be improved after surgical decompression. However, there have been few studies concerning proprioceptive impairment in cervical myelopathy.

MATERIALS AND METHODS

The study group included 26 cervical myelopathy patients who underwent posterior surgical decompression. Knee proprioception was assessed by joint position sense, which was evaluated by measuring the error angle when the subjects tried to reproduce the predetermined angle by extension and by flexion. Proprioceptive deficit in the study group was evaluated, compared with age-matched normal subjects. Postoperative recovery and correlation to functional status was analyzed in the study group. The Japanese Orthopedic Association (JOA) scores were used for functional evaluation.

RESULTS

The error angles were significantly higher in the study group than those in the control group before surgery. All patients in the study group finally had improvement of the error angles by a year after surgery. The average of error angles in the study group was improved 2 weeks after surgery; however, no changes were observed later. There was significant correlation between the improvement rate of the error angles 2 weeks after surgery and that of the JOA scores 2 years after surgery. There were 9 patients who had worsened proprioception 2 weeks after surgery either by extension or by flexion, all of whom had poor functional outcome.

CONCLUSIONS

Knee proprioception was impaired in cervical myelopathy and recovered after surgical posterior decompression. Proprioceptive improvement at 2 weeks correlates with the degree of improvement in JOA scores at 2 years after surgery.

Treatment options and results in cervical myelopathy

Cervical myelopathy is a clinical entity resulting from external compression of the cervical medulla. The clinical course can be divided into the acute form (secondary to trauma) versus subacute (progression within weeks to months) and chronic cervical myelopathy (months to years). The clinical picture of myelopathy is that of unsteady gait with long-tract signs, such as hyperreflexia, spasticity and extensor plantar responses. Between 1997 and 2000, 359 consecutive patients have been operated on in our department presenting with a variety of symptoms related to compression of the cervical medulla. Beside of standard MRI for all patients we applied SSEPs, gait analysis and dynamic MRI studies as additional helpful tools in evaluating selected patients pre- and postoperatively. We prefer the anterior approach as first-line approach because in the majority of patients the osteophytic spurs are more dominant anteriorly, and after anterior decompression and stabilization the posterior approach appears safer. We also favor the more extended approach of spondylectomy versus multilevel decompression in patients with bisegmental or multisegmental spinal canal stenosis. However it seems to be that radicular decompression is better achieved through multilevel decompression than through spondylectomy.

Quantification of human motion: gait analysis-benefits and limitations to its application to clinical problems

The technology supporting the analysis of human motion has advanced dramatically. Past decades of locomotion research have provided us with significant knowledge about the accuracy of tests performed, the understanding of the process of human locomotion, and how clinical testing can be used to evaluate medical disorders and affect their treatment. Gait analysis is now recognized as clinically useful and financially reimbursable for some medical conditions. Yet, the routine clinical use of gait analysis has seen very limited growth. The issue of its clinical value is related to many factors, including the applicability of existing technology to addressing clinical problems; the limited use of such tests to address a wide variety of medical disorders; the manner in which gait laboratories are organized, tests are performed, and reports generated; and the clinical understanding and expectations of laboratory results. Clinical use is most hampered by the length of time and costs required for performing a study and interpreting it. A "gait" report is lengthy, its data are not well understood, and it includes a clinical interpretation, all of which do not occur with other clinical tests. Current biotechnology research is seeking to address these problems by creating techniques to capture data rapidly, accurately, and efficiently, and to interpret such data by an assortment of modeling, statistical, wave interpretation, and artificial intelligence methodologies. The success of such efforts rests on both our technical abilities and communication between engineers and clinicians.

Analysis of the spastic gait caused by cervical compression myelopathy

We evaluated the spastic gait of patients with cervical myelopathy with a three-dimensional gait analysis system. Fifteen patients with cervical myelopathy (S group) were investigated. The results obtained were compared with those of normal volunteers (N group). The S group exhibited significant reduction of gait velocity and step length (p < 0.01). In the knee flexion-extension curve, two peaks were observed in the N group. In the S1 group (symptomatic period <1 year), the anterior peak was not smooth, whereas in the S2 group (symptomatic period >1 year), no peak was observed. The pelvis tilted to the side of the standing leg in the N group. However, in the S1 group, this tilting was much less pronounced, and in some patients tilting toward the nonsupporting leg was observed. In the S2 group, the pelvis again tilting toward the supporting side was observed.

Gait analysis of spastic walking in patients with cervical compressive myelopathy

To assess neurological status and to evaluate the effect of surgical decompression in patients with cervical myelopathy, we performed computerized gait analysis in 24 patients with cervical compressive myelopathy who showed spastic walking. Gait analysis was repeated during neurological follow-up that averaged 32.4 months. The gait pattern in patients with severe myelopathy was characterized by hyperextension of the knee in the stance phase without plantar flexion of the ankle in the swing phase, significantly reduced walking speed and step length, prolonged stance phase duration and decreased single-stance phase duration, and increased step width. The angle of flexion of the knee joint in the stance phase was significantly correlated with the Japanese Orthopaedic Association (JOA) score. Postoperative neurological improvement was associated with increased walking speed and decreased extension angle of the knee joint (single-stance phase and swing phase). Postoperatively, 12 patients had normalized extension of the knee in stance phase and their walking speed, cadence, stance phase duration, and single-stance phase duration, as well as step length and width, showed nonsignificant differences from these parameters in healthy controls. Our results show that kinesiological gait analysis is clinically useful for the functional assessment of the severity of spastic walking in cervical myelopathy.

Subsystems contributing to the decline in ability to walk: bridging the gap between epidemiology and geriatric practice in the InCHIANTI study

BACKGROUND

Older patients are often referred to geriatricians because of complaints of progressive difficulties in walking. The diagnostic and therapeutic approach to these patients is complex. Multiple physiologic subsystems may influence the ability to walk, and no standard criteria are currently available to establish whether these subsystems are functioning within the normal range. To address this lack of knowledge we conducted the InCHIANTI study.

OBJECTIVE

To identify measures that clinicians can use to understand the causes of walking difficulties in older persons.

DESIGN

A population-based study of persons living in the Chianti geographic area (Tuscany, Italy).

PARTICIPANTS

1,453 persons (age-range 20-102 years; 91.6% of the eligible) selected from city registry of Greve in Chianti and Bagno a Ripoli (Tuscany, Italy), using a multistage sampling method.

MEASUREMENTS

Factors that influence walking ability were classified into six main physiologic subsystems: central nervous system, perceptual system, peripheral nervous system, muscles, bone/joints, and energy production/delivery. Measures of the integrity and functioning of each of these proposed subsystems were identified and administered to all participants.

CONCLUSIONS

Data collected in InCHIANTI will be used to identify the main risk factors that influence loss of the ability to walk in older persons, to define physiologic subsystems that are critical for walking, to select the best measures of their integrity, and to establish critical ranges in these measures that are compatible with "normal" walking ability. The final goal is to translate epidemiological research into a geriatric clinical tool that makes possible more precise diagnosis and more effective treatment in patients with walking dysfunction.