Browsing by Author "Brown, Christopher"

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    Clustered clinical findings for diagnosis of cervical spine myelopathy.
    (The Journal of manual & manipulative therapy, 2010-12) Cook, Chad; Brown, Christopher; Isaacs, Robert; Roman, Matthew; Davis, Samuel; Richardson, William
    Cervical spine myelopathy (CSM) is a clinical diagnosis made with imaging confirmation. At present, most clinical tests used to identify CSM are specific and no clusters of tests have proven more beneficial than stand alone tests in guiding treatment decision making. This study endeavored to produce a cluster of predictive clinical findings for a sample of patients using a clinical diagnosis/imaging confirmation as the reference standard for cervical spine myelopathy. Data from 249 patients with various conditions associated with cervical spine dysfunction were analyzed to determine which clinical tests and measures, when clustered together, were most diagnostic for CSM. Using multivariate regression analyses and calculations for sensitivity, specificity, and positive and negative likelihood ratios, a definitive cluster was identified. Thirteen clinical findings were investigated for capacity to diagnosis CSM. Five clinical: (1) gait deviation; (2) +Hoffmann's test; (3) inverted supinator sign; (4) +Babinski test; and (5) age >45 years, were demonstrated the capacity when clustered into one of five positive tests to rule out CSM (negative likelihood ratio = 0.18; 95% CI = 0.12-0.42), and when clustered into three of five positive findings to rule in CSM (positive likelihood ratio = 30.9; 95% CI = 5.5-181.8). This study found clustered combinations of clinical findings that could rule in and rule out CSM. These clusters may be useful in identifying patients with this complex diagnosis in similar patient populations.
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    Differences in comorbidities on low back pain and low back related leg pain.
    (Pain practice : the official journal of World Institute of Pain, 2011-01) Goode, Adam; Cook, Chad; Brown, Christopher; Isaacs, Robert; Roman, Matthew; Richardson, William

    Objective

    Investigate the influence of external factors such as depression and BMI among subjects with primary severe low back pain (LBP) and low back related leg pain (LBLP).

    Background

    The report of disability in patients with LBP may be significantly influenced by confounding and moderating variables. No similar studies have examined the influence of these factors on LBLP.

    Methods

    This study included 1,448 consecutive subjects referred to a tertiary spine clinic. Unconditional binary logistic regression was used to determine the influence of comorbidities on the relationship between self-reported back and leg pain. A change in estimate formula was used to quantify this relationship.

    Results

    Among those subjects with primary LBP the unadjusted odds ratio was 8.58 (95% CI 4.87, 15.10) and when adjusting for BMI, depression and smoking was 5.94 (95% CI 3.04, 11.60) resulting in a 36.7% change due to confounding by these comorbidities. Among those with primary LBLP, the unadjusted odds ratio was 4.49 (95% CI 2.78, 7.27) and when adjusting for BMI and depression was 4.60 (95% CI 2.58, 8.19) resulting in a 1.7% change due to confounding by these comorbidities.

    Conclusion

    The disability statuses of the patients with primary LBP in this study were more significantly affected by comorbidities of BMI, depression and smoking than patients with report of LBLP. However, these comorbidities contribute little to the relationship of primary low back related leg pain and Oswestry scores ≥ 40.
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    Proinflammatory cytokine expression profile in degenerated and herniated human intervertebral disc tissues.
    (Arthritis and rheumatism, 2010-07) Shamji, Mohammed F; Setton, Lori A; Jarvis, Wingrove; So, Stephen; Chen, Jun; Jing, Liufang; Bullock, Robert; Isaacs, Robert E; Brown, Christopher; Richardson, William J

    Objective

    Prior reports document macrophage and lymphocyte infiltration with proinflammatory cytokine expression in pathologic intervertebral disc (IVD) tissues. Nevertheless, the role of the Th17 lymphocyte lineage in mediating disc disease remains uninvestigated. We undertook this study to evaluate the immunophenotype of pathologic IVD specimens, including interleukin-17 (IL-17) expression, from surgically obtained IVD tissue and from nondegenerated autopsy control tissue.

    Methods

    Surgical IVD tissues were procured from patients with degenerative disc disease (n = 25) or herniated IVDs (n = 12); nondegenerated autopsy control tissue was also obtained (n = 8) from the anulus fibrosus and nucleus pulposus regions. Immunohistochemistry was performed for cell surface antigens (CD68 for macrophages, CD4 for lymphocytes) and various cytokines, with differences in cellularity and target immunoreactivity scores analyzed between surgical tissue groups and between autopsy control tissue regions.

    Results

    Immunoreactivity for IL-4, IL-6, IL-12, and interferon-gamma (IFNgamma) was modest in surgical IVD tissue, although expression was higher in herniated IVD samples and virtually nonexistent in control samples. The Th17 lymphocyte product IL-17 was present in >70% of surgical tissue fields, and among control samples was detected rarely in anulus fibrosus regions and modestly in nucleus pulposus regions. Macrophages were prevalent in surgical tissues, particularly herniated IVD samples, and lymphocytes were expectedly scarce. Control tissue revealed lesser infiltration by macrophages and a near absence of lymphocytes.

    Conclusion

    Greater IFNgamma positivity, macrophage presence, and cellularity in herniated IVDs suggests a pattern of Th1 lymphocyte activation in this pathology. Remarkable pathologic IVD tissue expression of IL-17 is a novel finding that contrasts markedly with low levels of IL-17 in autopsy control tissue. These findings suggest involvement of Th17 lymphocytes in the pathomechanism of disc degeneration.
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    Psychological Predictors of Outcomes with Lumbar Spinal Fusion: A Systematic Literature Review.
    (Physiotherapy research international : the journal for researchers and clinicians in physical therapy, 2017-04) Wilhelm, Mark; Reiman, Michael; Goode, Adam; Richardson, William; Brown, Christopher; Vaughn, Daniel; Cook, Chad

    Purpose

    To review the predictive/risk psychological factors at baseline that are associated with a favourable (or non-favourable) outcome following lumbar spinal fusion (LSF).

    Methods

    A computer-assisted literature search of PubMed, CINAHL complete and EMBASE for studies published between January 1, 1990 and October 1, 2014 with controlled vocabulary and key words related to LSF, degenerative lumbar spine diagnoses and appropriate terms for predictive variables. Each study was required to be a retrospective or prospective design that involved LSF (all forms). Quality assessment was conducted with the Quality In Prognosis Studies tool. A study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO# CRD42014008728).

    Results

    The majority of the eight accepted studies were observational, prospective cohorts (n = 6). High levels of baseline depression and lower SF-36 Mental Component Scores (MCS) lower quality of life were associated with non-favourable outcomes. Two studies were rated as high quality, five were moderate and one study had low quality.

    Conclusions

    At present, there are a number of psychological variables that are associated with a poorer outcome with LSF. Higher levels of depression and lower scores on the SF-36 MCS are the most commonly implicated. However, based on the results of the studies using single arm designs there is not enough evidence to determine which psychological variables are influential in predicting outcomes for LSF. Copyright © 2015 John Wiley & Sons, Ltd.
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    The clinical value of a cluster of patient history and observational findings as a diagnostic support tool for lumbar spine stenosis.
    (Physiotherapy research international : the journal for researchers and clinicians in physical therapy, 2011-09) Cook, Chad; Brown, Christopher; Michael, Keith; Isaacs, Robert; Howes, Cameron; Richardson, William; Roman, Matthew; Hegedus, Eric

    Objective

    The study aims to create a diagnostic support tool to indicate the likelihood of the presence of lumbar spinal stenosis (LSS) using a cluster of elements from the patient history and observational findings.

    Design

    The study is case based and case controlled.

    Setting

    The study was performed in the tertiary care of a medical center.

    Subjects

    There were a total of 1,448 patients who presented with a primary complaint of back pain with or without leg pain.

    Methods

    All patients underwent a standardized clinical examination. The diagnosis of LSS was made by one of two experienced orthopaedic surgeons based on clinical findings and imaging. Data from the patient history and observational findings were then statistically analysed using bivariate analysis and contingency tables.

    Results

    The most diagnostic combination included a cluster of: 1) bilateral symptoms; 2) leg pain more than back pain; 3) pain during walking/standing; 4) pain relief upon sitting; and 5) age>48 years. Failure to meet the condition of any one of five positive examination findings demonstrated a high sensitivity of 0.96 (95% CI=0.94-0.97) and a low negative likelihood ratio (LR-) of 0.19 (95% CI=0.12-0.29). Meeting the condition of four of five examination findings yielded a LR+ of 4.6 (95% CI=2.4-8.9) and a post-test probability of 76%.

    Conclusion

    The high sensitivity of the diagnostic support tool provides the potential to reduce the incidence of unnecessary imaging when the diagnosis of LSS is statistically unlikely. In patients where the condition of four of the five findings was present, the post-test probability of 76% suggests that imaging and further workup are indicated. This is an inexpensive but powerful tool, with a potential to increase diagnostic efficiency and reduce cost by narrowing the indications for imaging.
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    The risk of risk-adjustment measures for perioperative spine infection after spinal surgery.
    (Spine, 2011-04) Goode, Adam P; Cook, Chad; Gill, J Brian; Tackett, Sean; Brown, Christopher; Richardson, William

    Study design

    Cross-sectional data analysis of the Nationwide Inpatient Sample (NIS).

    Objective

    To develop a risk-adjustment index specific for perioperative spine infection and compare this specific index to the Deyo Comorbidity Index. Assess specific mortality and morbidity adjustments between teaching and nonteaching facilities.

    Summary of background data

    Risk-adjustment measures have been developed specifically for mortality and may not be sensitive enough to adjust for morbidity across all diagnosis.

    Methods

    This condition-specific index was developed by using the NIS in a two-step process to determine confounders and weighting. Crude and adjusted point estimates for the Deyo and condition-specific index were compared for routine discharge, death, length of stay, and total hospital charges and then stratified by teaching hospital status.

    Results

    A total of 23,846 perioperative spinal infection events occurred in the NIS database between 1988 and 2007 of 1,212,241 procedures. Twenty-three diagnoses made up this condition-specific index. Significant differences between the Deyo and the condition-specific index were seen among total charges and length of stay at nonteaching hospitals (P < 0.001) and death, length of stay, and total charges (P < 0.001) for teaching hospitals.

    Conclusion

    This study demonstrates several key points. One, condition-specific measures may be useful when morbidity is of question. Two, a condition-specific perioperative spine infection adjustment index appears to be more sensitive at adjusting for comorbidities. Finally, there are inherent differences in hospital disposition characteristics for perioperative spine infection across teaching and nonteaching hospitals even after adjustment.