The use of auricular acupuncture in opioid use disorder: A systematic literature review.

BACKGROUND AND OBJECTIVES: Opioid use disorder (OUD) is a chronic disease with significant personal, societal, and public health consequences. Even for the minority who receive the most effective evidence-based treatments, morbidity, and mortality remain significant. These facts, along with the recovery movement calling for individualized, holistic, culturally sensitive care, have led to the exploration of adjunctive interventions including acupuncture. Despite hundreds of international trials, however, there is a lack of consensus regarding its efficacy in OUD due in large part to methodological issues of trials to date. In response to these issues, the National Acupuncture Detoxification Association (NADA) developed an operationalized manual auricular acupuncture protocol that has since become the most widely used in the US. This systematic review is the first to focus explicitly on randomized trials utilizing the NADA protocol as a complementary intervention to address OUD. METHODS: The methods utilized to identify studies for inclusion are based on a 2009 protocol developed by the Cochrane Collaboration. RESULTS: Four trials met inclusion criteria. Despite methodological issues, results indicate that while the NADA protocol may not be effective in reducing acute opiate craving or withdrawal, it may be effectively utilized as an adjunctive treatment to increase treatment retention and decrease methadone detoxification and maintenance dosages in OUD. CONCLUSION AND SCIENTIFIC SIGNIFICANCE: Incorporation of the NADA protocol into existing evidence-based treatment approaches may facilitate recovery and, through its impact on treatment retention and completion, indirectly impact morbidity, and mortality in individuals with OUD. Given the limitations of the current review, conclusions are tentative and directions for future research are discussed. (Am J Addict 2016;25:592-602).

Interactions between core and matrix thalamocortical projections in human sleep spindle synchronization.

Sleep spindles are bursts of 11-15 Hz that occur during non-rapid eye movement sleep. Spindles are highly synchronous across the scalp in the electroencephalogram (EEG) but have low spatial coherence and exhibit low correlation with the EEG when simultaneously measured in the magnetoencephalogram (MEG). We developed a computational model to explore the hypothesis that the spatial coherence spindles in the EEG is a consequence of diffuse matrix projections of the thalamus to layer 1 compared with the focal projections of the core pathway to layer 4 recorded in the MEG. Increasing the fanout of thalamocortical connectivity in the matrix pathway while keeping the core pathway fixed led to increased synchrony of the spindle activity in the superficial cortical layers in the model. In agreement with cortical recordings, the latency for spindles to spread from the core to the matrix was independent of the thalamocortical fanout but highly dependent on the probability of connections between cortical areas.

Corticothalamic feedback controls sleep spindle duration in vivo.

Spindle oscillations are commonly observed during stage 2 of non-rapid eye movement sleep. During sleep spindles, the cerebral cortex and thalamus interact through feedback connections. Both initiation and termination of spindle oscillations are thought to originate in the thalamus based on thalamic recordings and computational models, although some in vivo results suggest otherwise. Here, we have used computer modeling and in vivo multisite recordings from the cortex and the thalamus in cats to examine the involvement of the cortex in spindle oscillations. We found that although the propagation of spindles depended on synaptic interaction within the thalamus, the initiation and termination of spindle sequences critically involved corticothalamic influences.

Randomised controlled trial of high concentration versus titrated oxygen therapy in severe exacerbations of asthma.

BACKGROUND: The effect on Paco2 of high concentration oxygen therapy when administered to patients with severe exacerbations of asthma is uncertain. METHODS: 106 patients with severe exacerbations of asthma presenting to the Emergency Department were randomised to high concentration oxygen (8 l/min via medium concentration mask) or titrated oxygen (to achieve oxygen saturations between 93% and 95%) for 60 min. Patients with chronic obstructive pulmonary disease or disorders associated with hypercapnic respiratory failure were excluded. The transcutaneous partial pressure of carbon dioxide (Ptco2) was measured at 0, 20, 40 and 60 min. The primary outcome variable was the proportion of patients with a rise in Ptco2 ≥4 mm Hg at 60 min. RESULTS: The proportion of patients with a rise in Ptco2 ≥4 mm Hg at 60 min was significantly higher in the high concentration oxygen group, 22/50 (44%) vs. 10/53 (19%), RR 2.3 (95% CI 1.2 to 4.4, p<0.006). The high concentration group had a higher proportion of patients with a rise in Ptco2 ≥8 mm Hg, 11/50 (22%) vs. 3/53 (6%), RR 3.9 (95% CI 1.2 to 13.1, p=0.016). All 10 patients with a final Ptco2 ≥45 mm Hg received high concentration oxygen therapy, and in five there was an increase in Ptco2 ≥10 mm Hg. CONCLUSION: High concentration oxygen therapy causes a clinically significant increase in Ptco2 in patients presenting with severe exacerbations of asthma. A titrated oxygen regime is recommended in the treatment of severe asthma, in which oxygen is administered only to patients with hypoxaemia, in a dose that relieves hypoxaemia without causing hyperoxaemia. Clinical trial number ACTRN12607000131459.

Spontaneous pattern formation and pinning in the primary visual cortex.

A mean field approach to the population activity of cortical neurons is used to provide a possible mechanism for the generation of geometric visual hallucinations. As was previously investigated, competition between short-range excitation and longer-range inhibition in the connectivity profile of neurons provides the difference of length scales necessary for spontaneous symmetry breaking in the form of the Turing mechanism to generate patterns of activity. This approach is expanded in order to be able to incorporate additional details of the cortical circuitry, namely that neurons are also weakly connected at long ranges to other neurons sharing a particular preference for a stimulus feature such as orientation, spatial frequency, motion, color or disparity. Since the layout of cortical feature maps is approximately crystalline, one can apply a study of nonlinear dynamics similar to the analysis of wave propagation in a crystalline lattice to demonstrate how the spatial pattern formed through the Turing instability can be pinned to the geometric layout of various feature preferences. The specific feature map used in the study presented here is that of orientation preference, although the model can be extended to include additional features. The perturbation analysis is analogous to solving the Schrödinger equation in a weak periodic potential. Competition between the local isotropic connections which produce patterns of activity via the Turing mechanism and the weaker patchy lateral connections that depend on a neuron's particular set of feature preferences create long wavelength affects analogous to commensurate-incommensurate transitions found in fluid systems under a spatially periodic driving force. Using the retinocortical map, spontaneously formed activity patterns generated by the model can then be overlayed on the feature maps to construct the corresponding image in the visual field. We thus describe a new approach that allows the incorporation of some of the above features into a comprehensive account of the origins of hallucinations.

Cortical maps of separable tuning properties predict population responses to complex visual stimuli.

In the earliest cortical stages of visual processing, a scene is represented in different functional domains selective for specific features. Maps of orientation and spatial frequency preference have been described in the primary visual cortex using simple sinusoidal grating stimuli. However, recent imaging experiments suggest that the maps of these two spatial parameters are not sufficient to describe patterns of activity in different orientation domains generated in response to complex, moving stimuli. A model of cortical organization is presented in which cortical temporal frequency tuning is superimposed on the maps of orientation and spatial frequency tuning. The maps of these three tuning properties are sufficient to describe the activity in orientation domains that have been measured in response to drifting complex images. The model also makes specific predictions about how moving images are represented in different spatial frequency domains. These results suggest that the tangential organization of primary visual cortex can be described by a set of maps of separable neuronal receptive field features including maps of orientation, spatial frequency, and temporal frequency tuning properties.