Neural processing stages during object-substitution masking and their relationship to perceptual awareness

The extent of visual perceptual processing that occurs in the absence of awareness is as yet unclear. Here we examined event-related-potential (ERP) indices of visual and cognitive processes as awareness was manipulated through object-substitution masking (OSM), an awareness-disrupting effect that has been hypothesized to result from the disruption of reentrant signaling to low-level visual cortical areas. In OSM, a visual stimulus array is briefly presented that includes a parafoveal visual target denoted by a cue, typically consisting of several surrounding dots. When the offset of the target-surrounding cue dots is delayed relative to the rest of the array, a striking reduction in the perception of the target image surrounded by the dots is observed. Using faces and houses as the target stimuli, we found that successful OSM reduced or eliminated all the measured electrophysiological indices of visual processing stages after 130 ms post-stimulus. More specifically, when targets were missed within the masked condition (i.e., on trials with effective OSM that disrupted awareness), we observed fully intact early feed-forward processing up through the visual extrastriate P1 ERP component peaking at 100 ms, followed by reduced low-level activity over the occipital pole 130–170 ms post-stimulus, reduced ERP indices of lateralized shifts of attention toward the parafoveal target, reduced object-generic visual processing, abolished object-category-specific (face-specific) processing, and reduced late visual short-term-memory processing activity. The results provide a comprehensive electrophysiological account of the neurocognitive underpinnings of effective OSM of visual-object images, including evidence for central roles of early reentrant signal disruption and insufficient visual attentional deployment.     

Financial analysis of acetaminophen suicide in a teen girl

There is no doubt that prevention and primary care treatment is less costly than emergency room efforts and tertiary care to save someone's life. Preventive health care is the cornerstone of any health care system designed to reduce costs and human suffering (American Nurses Association, 1997). Unfortunately, emergency room and intensive care nurses frequently care for critically ill children and adults who suffer from conditions that might have been prevented. This case study presents the financial breakdown of the costs at each level of care for an 18-year-old college student who suffers terrible consequences of an acetaminophen overdose.     

Cortical Bone Porosity in Rabbit Models of Osteoporosis

Cortical bone porosity is intimately linked with remodeling, is of growing clinical interest, and is increasingly accessible by imaging. Thus, the potential of animal models of osteoporosis (OP) to provide a platform for studying how porosity develops and responds to interventions is tremendous. To date, rabbit models of OP have largely focused on trabecular microarchitecture or bone density; some such as ovariectomy (OVX) have uncertain efficacy and cortical porosity has not been extensively reported. Our primary objective was to characterize tibial cortical porosity in rabbit-based models of OP, including OVX, glucocorticoids (GC), and OVX + GC relative to controls (SHAM). We sought to: (i) test the hypothesis that intracortical remodeling is elevated in these models; (ii) contrast cortical remodeling and porosity in these models with that induced by parathyroid hormone (1–34; PTH); and (iii) contrast trabecular morphology in the proximal tibia across all groups. Evidence that an increase in cortical porosity occurred in all groups was observed, although this was the least robust for GC. Histomorphometric measures supported the hypothesis that remodeling rate was elevated in all groups and also revealed evidence of uncoupling of bone resorption and formation in the GC and OVX + GC groups. For trabecular bone, a pattern of loss was observed for OVX, GC, and OVX + GC groups, whereas the opposite was observed for PTH. Change in trabecular number best explained these patterns. Taken together, the findings indicated rabbit models provide a viable and varied platform for the study of OP and associated changes in cortical remodeling and porosity. Intriguingly, the evidence revealed differing effects on the cortical and trabecular envelopes for the PTH model. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR)..     

Inflammatory pain pattern and pain with lumbar extension associated with Modic 1 changes on MRI: a prospective case–control study of 120 patients

Purpose

To compare, in a case–control study, clinical characteristics of patients with low back pain (LBP) with and without Modic 1 signal changes on MRI.

Methods

Patients with chronic non-specific LBP and a recent (<6 months) MRI were prospectively screened and included in Modic 1 group or control group. Patients in control group were age- and gender-matched with patients with Modic 1 group. Pain characteristics, including night pain and worse pain on waking and morning stiffness, were recorded. The presence of at least one of these three characteristics indicated an inflammatory pain pattern. Patients were evaluated by questionnaires and physical examination (including lumbar range of motion). Data were analyzed by univariate and multivariate analyses.

Results

120 patients were included (60 in each group). The groups did not differ in sedentary work (p = 0.25), morning stiffness for >60 min (p = 0.19), waking at night (p = 0.08), worse pain on waking (p = 0.09), back stiffness (p = 0.12), or pain with flexion (p = 0.87). Modic 1 patients more frequently exhibited an inflammatory pain pattern (p = 0.006), worse pain with lumbar extension (p < 0.005) and responded better to oral steroids (p = 0.004) than did controls. On multivariate analysis, Modic 1 changes were associated with sedentary work [odds ratio 0.22 (95 % confidence interval 0.05–0.93)], pain with lumbar extension [11.2 (3.1–40.4)] and an inflammatory pain pattern [4.5 (1.2–16.9)].

Conclusions

Characteristics of patients with LBP and Modic 1 changes on MRI consist of an inflammatory pain pattern and pain with lumbar extension. Level of evidence 3b.