Racial Disparities in Access to DBS: Results of a Real-World U.S. Claims Data Analysis

INTRODUCTION: Deep brain stimulation (DBS) is an effective and standard-of-care therapy for Parkinson\u27s Disease and other movement disorders when symptoms are inadequately controlled with conventional medications. It requires expert care for patient selection, surgical targeting, and therapy titration. Despite the known benefits, racial/ethnic disparities in access have been reported. Technological advancements with smartphone-enabled devices may influence racial disparities. Real-world evidence investigations can shed further light on barriers to access and demographic disparities for DBS patients. METHODS: A retrospective cross-sectional study was performed using Medicare claims linked with manufacturer patient data tracking to analyze 3,869 patients who received DBS. Patients were divided into two categories: traditional omnidirectional DBS systems with dedicated proprietary controllers ( traditional ; RESULTS: A significant disparity in DBS utilization was evident. White individuals comprised 91.4 and 89.9% of traditional and smartphone-enabled DBS groups, respectively. Non-White patients were significantly more likely to live closer to implanting facilities compared with White patients. CONCLUSION: There is great racial disparity in utilization of DBS therapy. Smartphone-enabled systems did not significantly impact racial disparities in receiving DBS. Minoritized patients were more likely to live closer to their implanting facility than White patients. Further research is warranted to identify barriers to access for minoritized patients to receive DBS. Technological advancements should consider the racial discrepancy of DBS utilization in future developments

Racial disparities in access to DBS: results of a real-world U.S. claims data analysis

IntroductionDeep brain stimulation (DBS) is an effective and standard-of-care therapy for Parkinson’s Disease and other movement disorders when symptoms are inadequately controlled with conventional medications. It requires expert care for patient selection, surgical targeting, and therapy titration. Despite the known benefits, racial/ethnic disparities in access have been reported. Technological advancements with smartphone-enabled devices may influence racial disparities. Real-world evidence investigations can shed further light on barriers to access and demographic disparities for DBS patients.MethodsA retrospective cross-sectional study was performed using Medicare claims linked with manufacturer patient data tracking to analyze 3,869 patients who received DBS. Patients were divided into two categories: traditional omnidirectional DBS systems with dedicated proprietary controllers (“traditional”; n = 3,256) and directional DBS systems with smart controllers (“smartphone-enabled”; n = 613). Demographics including age, sex, and self-identified race/ethnicity were compared. Categorical demographics, including race/ethnicity and distance from implanting facility, were analyzed for the entire population.ResultsA significant disparity in DBS utilization was evident. White individuals comprised 91.4 and 89.9% of traditional and smartphone-enabled DBS groups, respectively. Non-White patients were significantly more likely to live closer to implanting facilities compared with White patients.ConclusionThere is great racial disparity in utilization of DBS therapy. Smartphone-enabled systems did not significantly impact racial disparities in receiving DBS. Minoritized patients were more likely to live closer to their implanting facility than White patients. Further research is warranted to identify barriers to access for minoritized patients to receive DBS. Technological advancements should consider the racial discrepancy of DBS utilization in future developments

Templated Hybrid Hydrogels for Osteochondral Repair

A synthetic materials-guided approach, wherein the scaffold’s chemical and physical properties alone instruct cellular behavior for tissue regeneration, has the potential to repair clinically pervasive osteochondral defects (OCDs) without the use of exogenous growth factors. Poly(ethylene glycol) diacrylate (PEG-DA) hydrogels are widely utilized in tissue regeneration, but lacks macroporosity for osteoconduction and are also not strongly bioactive (i.e. inducing mineralization for bone bonding) or osteoinductive (i.e. inducing mesenchymal stem cell [MSC] differentiation toward an osteoblastic-lineage). Previously, work by Grunlan and coworkers established that inclusion of star poly(dimethyl siloxane) methacrylate (PDMSstar-MA) with PEG-DA produced hydrogels with enhanced bioactivity and osteoinductivity. Furthermore, fabrication with solvent-induced phase separation and a salt template (“SIPS/salt”) yielded interconnected, macroporous scaffolds with excellent distribution of the siloxane macromer. Towards achieving osteochondral regeneration, this work sought to prepare macroporous PEG-based hydrogel scaffolds that included siloxane or phosphonated-siloxane macromers, ultimately prepared as monolithic scaffolds with spatial control of chemical and physical properties. In a first study, SIPS/salt scaffolds were prepared with PDMSstar-MA of two number average molecular weights (Mn’s) (2k and 7k) with varying PDMSstar-MA:PEG-DA ratios and template salt sizes. Interconnected macropore size was tuned by the salt size, and a more uniform distribution was achieved with a lower Mn PDMSstar-MA. All PDMSstar-PEG hydrogels were confirmed to be bioactive upon exposure to 1X simulated body fluid (SBF) and, when cultured with human bone marrow derived MSCs (hBMSCs) for 14 days, displayed a PDMSstar-MA dose-dependent increase in osteogenesis. In a second study, to further increase bioactivity and osteoinductivity, a siloxane macromer with pendant phosphonate groups, poly(diethyl(2-(propylthio)ethyl) phosphonate methylsiloxane) diacrylate (PPMS-DA), was synthetized. SIPS/salt PPMS:PEG scaffolds showed an enhanced osteogenic potential versus PDMS:PEG scaffolds when cultured with hBMSCs for 14 and 28 days. Finally, to afford spatial control of chemical and physical properties, a method was developed to prepare monolithic scaffolds from such individual scaffolds, termed ‘hydrogel scaffolds with spatially tunable chemistries and arrangements’ (SSTACs). Demonstrated with several SSTAC designs, the desired spatial distribution of chemistry and pore size was confirmed. Moreover, the interfaces of SSTACs were shown to lack a hard boundary and achieved good mechanical integrity

Diffusion-weighted MR Imaging for Characterizing Musculoskeletal Lesions

Diffusion-weighted (DW) imaging is a functional magnetic resonance (MR) imaging technique that can readily be incorporated into a routine non–contrast material–enhanced MR imaging protocol with little additional scanning time. DW imaging is based on changes in the Brownian motion of water molecules caused by tissue microstructure. The apparent diffusion coefficient (ADC) is a quantitative measure of Brownian movement: Low ADC values typically reflect highly cellular microenvironments in which diffusion is restricted by the presence of cell membranes, whereas acellular regions allow free diffusion and result in elevated ADC values. Thus, with ADC mapping, one may derive useful quantitative information regarding the cellularity of a musculoskeletal lesion using a nonenhanced technique. The role of localized DW imaging in differentiating malignant from benign osseous and soft-tissue lesions is still evolving; when carefully applied, however, this modality has proved helpful in a subset of tumor types, such as nonmyxoid soft-tissue tumors. Studies of the use of DW imaging in assessing the treatment response of both osseous and soft-tissue tumors have shown that higher ADC values correlate with better response to cytotoxic therapy. Successful application of DW imaging in the evaluation of musculoskeletal lesions requires familiarity with potential diagnostic pitfalls that stem from technical artifacts and confounding factors unrelated to lesion cellularity. Further investigation is needed to evaluate the impact of DW imaging–ADC mapping on management and outcome in patients with musculoskeletal lesions. ©RSNA, 201

Matrix IGF-1 maintains bone mass by activation of mTOR in mesenchymal stem cells

Insulin-like growth factor 1 (IGF-1), the most abundant growth factor in the bone matrix, maintains bone mass in adulthood. We now report that IGF-1 released from the bone matrix during bone remodeling stimulates osteoblastic differentiation of recruited mesenchymal stem cells (MSCs) by activation of mammalian target of rapamycin (mTOR), thus maintaining proper bone microarchitecture and mass. Mice with knockout of the IGF-1 receptor (Igf1r) in their pre-osteoblastic cells showed lower bone mass and mineral deposition rates than wild-type mice. Further, MSCs from Igf1r flox/flox mice with Igf1r deleted by a Cre adenovirus in vitro, although recruited to the bone surface after implantation, were unable to differentiate into osteoblasts. We also found that the concentrations of IGF-1 in the bone matrix and marrow of aged rats were lower than in those of young rats and directly correlated with the age-related decrease in bone mass. Likewise, in age-related osteoporosis in humans, we foun