Trends in Diagnostic Imaging Medicare Reimbursements: 2007 to 2019.

PURPOSE: The aim of this study was to evaluate recent trends in Medicare reimbursement rates for various imaging studies. METHODS: Common diagnostic radiologic studies were selected across multiple imaging modalities: bone densitometry, CT, CT angiography, mammography, MR angiography, MRI, nuclear medicine, radiography, and ultrasound. The Physician Fee Schedule Look-Up Tool from CMS was queried for Current Procedural Terminology codes to extract reimbursement data. All monetary data were adjusted for inflation to 2019 US dollars. The compound annual growth rate, average annual change, and total percentage change in reimbursement were calculated on the basis of these adjusted trends. RESULTS: Inflation-adjusted Medicare reimbursement for all imaging modalities decreased between 2007 and 2019. The greatest mean decrease in reimbursement rates was observed for MRI (-$52.08), and the largest decrease in total percentage change was seen for bone densitometry (-70.5%). Nuclear medicine demonstrated the smallest mean decreases in both annual change (-$0.32) and total percentage change (-4.28%). CONCLUSIONS: This study examined Medicare reimbursements for radiologic studies from 2007 to 2019. After accounting for inflation, reimbursement rates were shown to decline for all studies across all imaging modalities except for individual studies in nuclear medicine, radiography, and ultrasound. Further investigation is encouraged to properly model future trends in reimbursement rates.

Pain-Related Drug Use Among Older Adults With Activity Limiting Pain Who Received Home Care Services.

Pain is a common problem for patients receiving home care, often limiting mobility and contributing to functional decline. Pharmacological pain management is common, but all drugs bring some risk of side effects and adverse reactions. The opioid epidemic has brought into question analgesic prescribing patterns across all care settings. This study, which used data collected between 2012 and 2014, examines the pain medications used by older adults with activity-limiting pain receiving home care physical therapy in a large metropolitan home care agency. Eighty-five percent of subjects took at least one analgesic medication on admission to home care, and of these, 51.3% were using an opioid, 33.1% used acetaminophen, and 23.2% used nonsteroidal anti-inflammatory drugs (NSAIDs). At the 60-day follow-up, the most common medication classes taken by participants included acetaminophen (38%), opioids (35.9%), and NSAIDs (31.6%). We found racial/ethnic differences in analgesic use at baseline but not at follow-up. At baseline, analgesic use differed by pain type, but there were no differences at follow-up. The high use of medications to control pain by patients receiving home care, particularly opioid use, underscores the importance of providers being alert to potential adverse drug reactions.

Cholinergic modulation of hippocampal calcium activity across the sleep-wake cycle.

Calcium is a critical second messenger in neurons that contributes to learning and memory, but how the coordination of action potentials of neuronal ensembles with the hippocampal local field potential (LFP) is reflected in dynamic calcium activity remains unclear. Here, we recorded hippocampal calcium activity with endoscopic imaging of the genetically encoded fluorophore GCaMP6 with concomitant LFP in freely behaving mice. Dynamic calcium activity was greater in exploratory behavior and REM sleep than in quiet wakefulness and slow wave sleep, behavioral states that differ with respect to theta and septal cholinergic activity, and modulated at sharp wave ripples (SWRs). Chemogenetic activation of septal cholinergic neurons expressing the excitatory hM3Dq DREADD increased calcium activity and reduced SWRs. Furthermore, inhibition of muscarinic acetylcholine receptors (mAChRs) reduced calcium activity while increasing SWRs. These results demonstrate that hippocampal dynamic calcium activity depends on behavioral and theta state as well as endogenous mAChR activation.

Nonsurgically induced disuse muscle atrophy and neuromuscular dysfunction upregulates alpha7 acetylcholine receptors.

Previous models of muscle disuse have invariably used surgical methods that require the repetitive application of plaster casts. A method of disuse atrophy that does not require such repetitive applications is described herein. Modified plastic pipette tubing was applied to a single hindlimb (mouse), from thigh to foot, resulting in immobilization of the knee in the extension position, and the ankle in the plantar flexion position. This method resulted in the loss of soleus muscle to 11%, 22%, 39%, and 45% of its original mass at 3, 7, 14, and 21 days, respectively, in association with a significant decrease of tibialis twitch (25%) and tetanic tensions (26%) at 21 days, compared with the contralateral side and (or) sham-immobilized controls. Immunohistochemical analysis of the soleus using fluorescent α-bungarotoxin revealed a significant increase in the number of synapses per unit area (818 + 31 compared with 433 + 16/mm(2)) and an increase in muscle fibers per unit area (117 compared with 83/mm(2)), most likely related to the atrophy of muscle fibers bringing synapses closer. A 3-fold increase in alpha7 acetylcholine receptor (α7AChR) protein expression, along with increased expression of α1AChR subunit in the immobilized side compared with the contralateral side was observed. The physiology and pharmacology of the novel finding of upregulation of α7AChRs with disuse requires further study.

Beta and gamma oscillations in the olfactory system of the urethane-anesthetized rat.

Fast oscillations in the beta (15-40 Hz in awake rats) and gamma (50-100 Hz) frequency ranges are prominent in field potentials induced by odorants in the mammalian olfactory bulb (OB) and piriform cortex (PC). Whereas the gamma oscillation has been studied for >50 yr, the beta oscillation has attracted attention only recently, and its origin, mechanism, and relationship to gamma are unknown. To address these questions, we have examined responses induced by odorants in the urethane-anesthetized rat-a preparation well-suited for the analysis of mechanisms. We found that both oscillations could be induced by odorants in a concentration-dependent manner. Analysis with a concentration series and spectral methods revealed that the beta and gamma oscillations were distinct and not harmonically related, indicating generation by independent mechanisms. The beta oscillation was synchronous at sites < or =4 mm apart in the OB, the greatest distance tested. In contrast, the gamma oscillation was synchronous in some experiments and asynchronous in others (frequency differed slightly at different sites, resulting in progressive phase shifts). Current source-density analysis indicated that, for both oscillations, the field potentials in the OB were generated by synaptic currents in granule cells. The two oscillations were differently affected by surgical interruption of the lateral olfactory tract. This lesion abolished the beta oscillation, whereas the gamma oscillation was still induced in the OB. Our results confirm previous reports that the gamma oscillation is generated within the OB but indicate that the beta oscillation requires the participation of PC.