Ma Agnes Ith

ISSLS PRIZE IN BASIC SCIENCE 2017: Intervertebral disc/bone marrow cross-talk with Modic changes

Study designCross-sectional cohort analysis of patients with Modic Changes (MC).ObjectiveOur goal was to characterize the molecular and cellular features of MC bone marrow and adjacent discs. We hypothesized that MC associate with biologic cross-talk between discs and bone marrow, the presence of which may have both diagnostic and therapeutic implications.Background dataMC are vertebral bone marrow lesions that can be a diagnostic indicator for discogenic low back pain. Yet, the pathobiology of MC is largely unknown.MethodsPatients with Modic type 1 or 2 changes (MC1, MC2) undergoing at least 2-level lumbar interbody fusion with one surgical level having MC and one without MC (control level). Two discs (MC, control) and two bone marrow aspirates (MC, control) were collected per patient. Marrow cellularity was analyzed using flow cytometry. Myelopoietic differentiation potential of bone marrow cells was quantified to gauge marrow function, as was the relative gene expression profiles of the marrow and disc cells. Disc/bone marrow cross-talk was assessed by comparing MC disc/bone marrow features relative to unaffected levels.ResultsThirteen MC1 and eleven MC2 patients were included. We observed pro-osteoclastic changes in MC2 discs, an inflammatory dysmyelopoiesis with fibrogenic changes in MC1 and MC2 marrow, and up-regulation of neurotrophic receptors in MC1 and MC2 bone marrow and discs.ConclusionOur data reveal a fibrogenic and pro-inflammatory cross-talk between MC bone marrow and adjacent discs. This provides insight into the pain generator at MC levels and informs novel therapeutic targets for treatment of MC-associated LBP.

Physical performance analysis: A new approach to assessing free-living physical activity in musculoskeletal pain and mobility-limited populations

Background Accurate measurement of physical performance in individuals with musculoskeletal pain is essential. Accelerometry is a powerful tool for this purpose, yet the current methods designed to evaluate energy expenditure are not optimized for this population. The goal of this study is to empirically derive a method of accelerometry analysis specifically for musculoskeletal pain populations. Methods We extracted data from 6,796 participants in the 2003–4 National Health and Nutrition Examination Survey (NHANES) including: 7-day accelerometry, health and pain questionnaires, and anthropomorphics. Custom macros were used for data processing, complex survey regression analyses, model selection, and statistical adjustment. After controlling for a multitude of variables that influence physical activity, we investigated whether distinct accelerometry profiles accompany pain in different locations of the body; and we identified the intensity intervals that best characterized these profiles. Results Unique accelerometry profiles were observed for pain in different body regions, logically clustering together based on proximity. Based on this, the following novel intervals (counts/minute) were identified and defined: Performance Sedentary (PSE) = 1–100, Performance Light 1 (PL1) = 101–350, Performance Light 2 (PL2) = 351–800, Performance Light 3 (PL3) = 801–2500, and Performance Moderate/Vigorous (PMV) = 2501–30000. The refinement of accelerometry signals into these new intervals, including 3 distinct ranges that fit inside the established light activity range, best captures alterations in real-life physical performance as a result of regional pain. Discussion and conclusions These new accelerometry intervals provide a model for objective measurement of real-life physical performance in people with pain and musculoskeletal disorders, with many potential uses. They may be used to better evaluate the relationship between pain and daily physical function, monitor musculoskeletal disease progression, gauge disease severity, inform exercise prescription, and quantify the functional impact of treatments. Based on these findings, we recommend that future studies of pain and musculoskeletal disorders analyze accelerometry output based on these new “physical performance” intervals.

Differential Rates of Inadvertent Intravascular Injection during Lumbar Transforaminal Epidural Injections Using Blunt-Tip, Pencil-Point, and Catheter-Extension Needles

OBJECTIVE To quantify the incidence of inadvertent vascular penetration during lumbosacral transforaminal epidural injections using blunt-tip, pencil-point, and catheter-extension needles. STUDY DESIGN/SETTING This is a prospective, observational, consecutive cohort study. SUBJECTS Two hundred consecutive patients undergoing lumbosacral transforaminal epidural injections at an academic outpatient spine center. METHODS Four hundred seventy-five fluoroscopically guided lumbosacral transforaminal epidural injections were performed on consecutively consenting patients by one interventional spine physician, using three different needle types. The presence or absence of vascular uptake was determined during contrast injection under live fluoroscopy. RESULTS Vascular uptake of contrast was observed in 58 of the total 475 injections, for an overall incidence of 12.2%. By needle type, the incidence of inadvertent vascular uptake was 16.6% (26/157) in the pencil-point group, 15.6% (24/154) in the blunt-tip group, and 4.9% (8/164) in the catheter-extension group. The difference in rates is statistically significant between the catheter-extension needle group and both the pencil-point group (P = 0.0009) and blunt-tip group (P = 0.0024). A secondary analysis was performed to quantify the incidence of functional pitfalls between needle groups, with a significantly lower incidence in the pencil-point group compared to both the catheter-extension (P = 0.0148) and blunt-tip needle (P = 0.0288) groups. CONCLUSIONS Blunt-tip and pencil-point needles have comparable risk of inadvertent vascular injection during lumbosacral transforaminal injections. Catheter-extension needles demonstrated a reduce incidence of vascular uptake, but also result in a significantly higher rate of functional pitfalls that limits their usefulness in routine practice.

[18F]FDG PET/MRI of patients with chronic pain alters management: early experience

The chronic pain sufferer is currently faced with a lack of objective tools to identify the source of their pain. The overarching goal is to develop clinical [18F]FDG PET/MRI methods to more accurately localize sites of increased neuronal and muscular metabolism or inflammation as it relates to neurogenic sources of pain and to ultimately improve outcomes of chronic pain sufferers. The aims are to 1) correlate imaging findings with location of pain symptomology, 2) predict location of symptoms based on imaging findings alone and 3) to determine whether the imaging results affect current management decisions. Six patients suffering from chronic lower extremity neuropathic pain (4 complex regional pain syndrome, 1 chronic sciatica and 1 neuropathic pain) have been imaged with a PET/MRI system (time-of-flight PET; 3.0T bore) from mid thorax through the feet. All patients underwent PET/MR imaging one hour after a injection of 10mCi [18F]FDG. Two radiologists evaluated PET/MR images (one blinded and the other unblinded to patient exam/history). ROI analysis showed focal increased [18F]FDG uptake in affected nerves and muscle (approx 2-4 times more) over background tissue in various regions of the body in 5 of 6 patients at the site of greatest pain symptoms and other areas of the body (SUVmax of Target 0.9-4.2 vs. Background 0.2-1.2). The radiologist blind to the patient history/exam was able to correctly identify side/location of the symptoms in 5 out of 6 patients. Imaging results were reviewed with the referring physician, who then determined whether a modification in the management plan was needed: 1/6 no change, 2/6 mild modification (e.g., additional diagnostic test ordered) and 3/6 significant modification.

Poster 87 Activity Changes Following Treatment of Lumbar Spinal Stenosis

were found in any variable between males and females (all P .05), and hence males and females were combined for the analysis. There were far fewer significant correlations in the s/e pain severity group, even though there was a larger number of them in the sample. RMQ was not correlated with any measure in the s/e group, but was correlated with several measures in the m/m group: PDQ-Total (r .529, P .024); MODQ (r .590, P .010); PF (r .579, P .012); and, PI (r .628, P .005). MODQ was not correlated with any measure in the s/e group, but was correlated in m/m with both PI (r .546, P .019) and RMQ (r .590, P .010). PDQ-Total scores were correlated with PI and PF in the mild/moderate group, but not in the s/e group. Conclusions: Disability was driven primarily by measures of pain and global health and not by their multi-morbidity burden. Because the PDQ is a simple and useful clinical tool, we suggest that physicians should make a routine attempt to characterize the functional status of patients due to LBP-related impairments. We believe that identifying potentially modifiable disability determinants in LBP patients provides an opportunity to broaden strategies to reduce its socioeconomic burden.

Gait Symmetry Assessment with a Low Back 3D Accelerometer in Post-Stroke Patients

Gait asymmetry is an important marker of mobility impairment post stroke. This study proposes a new gait symmetry index (GSI) to quantify gait symmetry with one 3D accelerometer at L3 (GSIL3). GSIL3 was evaluated with 16 post stroke patients and nine healthy controls in the Six-Minute-Walk-Test (6-MWT). Discriminative power was evaluated with Wilcoxon test and the effect size (ES) was computed with Cliff’s Delta. GSIL3 estimated during the entire 6-MWT and during a short segment straight walk (GSIL3straight) have comparable effect size to one another (ES = 0.89, p < 0.001) and to the symmetry indices derived from feet sensors (|ES| = [0.22, 0.89]). Furthermore, while none of the indices derived from feet sensors showed significant differences between post stroke patients walking with a cane compared to those able to walk without, GSIL3 was able to discriminate between these two groups with a significantly lower value in the group using a cane (ES = 0.70, p = 0.02). In addition, GSIL3 was strongly associated with several symmetry indices measured by feet sensors during the straight walking cycles (Spearman correlation: |ρ| = [0.82, 0.88], p < 0.05). The proposed index can be a reliable and cost-efficient post stroke gait symmetry assessment with implications for research and clinical practice.

Poster 381: Gait Symmetry is More Sensitive Than Walking Speed to Assess Function and Recovery After Stroke

being “very relevant”. They indicated a relevance of 46 in spending clinical time with a rehabilitation specialist. Trainees who had rotated with PM&R during medical school were more likely to report a higher level of knowledge (P 1⁄4 .003) in addition to those with awareness of a PM&R department at their institution (P 1⁄4 .04). There was no significant difference in responses between oncology subspecialties. Conclusions: Physician trainees in oncologic subspecialties perceived rehabilitation as a highly relevant service; however, they expressed a low level of knowledge in defining services to patients. Despite the high prevalenceof rehabilitationat their institutions, 19%had receivededucationby a rehabilitation specialist. These findings highlight a need to increase education about rehabilitation among oncology physician trainees. Level of Evidence: Level III

Poster 383: Identification of Novel Wearable-Sensor Derived Gait Features Associated with Physical Activity and Function in Knee Osteoarthritis and Lumbar Stenosis

Disclosures: Charles Odonkor: I Have No Relevant Financial Relationships To Disclose Objective: To objectively measure physical activity using body worn sensors and to establish new gait features which differentiate knee osteoarthritis (OA) and lumbar stenosis (LSS) from healthy controls. Design: Cross-sectional cohort study. Setting: Academic Medical Center. Participants: 30 participants enrolled in the study. Interventions: Not Applicable Main Outcome Measures: Gait features derived from dual feet-sensors and ability to discriminate functional capacity, reported physical activity intensity and mobility limitations in patients with knee OA and LSS vs. healthy controls. Results: Compared to healthy controls, the best novel gait features were: minimum toe clearance, effect size (ES) 1⁄4 0.61, P < .0001 for knee OA; and lift off angle at toe off, ES1⁄4 0.67, P 1⁄4 .006 for LSS. Adjusting for pain localization, the last minute of 6-min walk and self-paced walking tests were more sensitive to functional differences between healthy vs. disease states than the first minute of measured gait cycles, P < .0001. Peak angular velocity, heel-strike angle, respective time ratio of stance, double-support, foot load, push and flat phases were each identified as sensitive markers with ES>0.2, P < .05 for both knee OA and LSS vs. healthy controls. Push-ratio discriminated reported light vs. moderate activity (ES1⁄40.46, P 1⁄4 .0009) while strike-length discriminated reported moderate vs. no activity (ES1⁄40.33, P 1⁄4 .002) on the Stanford brief physical activity score-survey. Adjusting for age, gender, BMI and ethnicity, mean push-ratios were 27.5 (95% CI: 24.4-30.7) and 33.8 (95% CI: 30.6-36.9) for those with reported light vs. moderate activity intensity scores, respectively. With a mean Oswestry-Disability-Index score of 39.6 19.8, ten unique sensor gait features each significantly distinguished LSS patients with zero to minimum disability from those with moderate disability, ES>0.2, P < .05. Conclusions: Sensor-derived spatio-temporal gait-features provide objective markers for discriminating functional status in healthy vs. disease states and hold much promise towards more precise and accurate characterization of physical activity and mobility limitations in people with LSS vs. knee OA. Level of Evidence: Level I

18F-FDG PET/MRI in Chronic Sciatica: Early Results Revealing Spinal and Non-spinal Abnormalities

Chronic sciatica is a major cause of disability worldwide, but accurate diagnosis of the causative pathology remains challenging. In this report, the feasibility of an 18F-FDG PET/MRI approach for improved diagnosis of chronic sciatica is presented. Methods: 18F-FDG PET/MRI was performed on 9 chronic sciatica patients and 5 healthy volunteers (healthy controls). Region-of-interest analysis using SUVmax was performed, and 18F-FDG uptake in lesions was compared with that in the corresponding areas in healthy controls. Results: Significantly increased 18F-FDG uptake was observed in detected lesions in all patients and was correlated with pain symptoms. 18F-FDG–avid lesions not only were found in impinged spinal nerves but also were associated with nonspinal causes of pain, such as facet joint degeneration, pars defect, or presumed scar neuroma. Conclusion: The feasibility of 18F-FDG PET/MRI for diagnosing pain generators in chronic sciatica was demonstrated, revealing various possible etiologies.

App Development for Therapeutic Exercise

With 77% of U.S. adults now owning smartphones [1], and an increasing number of mobile phone health applications (mHealth apps) available to download, a mobile transformation of health care is anticipated in the near future [2]. Exercise promotion is a common feature in the mHealth app landscape. As physicians who rely on therapeutic home exercises for rehabilitation of their patients, physiatrists are familiar with engaging patients to make lifestyle changes for health. As such, physiatrists are particularly poised to lead the development, validation, and widespread and continued adoption of these apps. Both Apple’s app store and the Google Play app store have numerous apps promoting exercise therapies to treat a host of ailments, spanning from knee osteoarthritis to stroke [3,4]. mHealth apps are well suited to facilitate therapeutic exercise and other aspects of rehabilitation care as the result of 3 unique featuresdinteractivity through bidirectional communication between patients and providers; personalization by adapting interventions to each of our patients’ unique needs; and accessibility with capability for continuous contact and assessments instead of the traditional sporadic point-of-care approach. Creating our own app was important to provide full access to the user data, something not available from existing commercial apps. We assembled a multidisciplinary team of experts (physiatrists, physical therapists, computer scientists, and app developers) to design and deploy an mHealth app to improve and record adherence to home exercise therapy for patients with low back pain as they began treatment in physical therapy. Our app allows the treating physical therapist to select the patient’s specific home exercises and frequency; reminds patients to do their exercises at the recommended frequency; provides an interactive guide through the exercises as prescribed by the physical therapist; and includes supplementary pictures, videos, and patient-specific written notes