Influence of Experimental Pain on the Perception of Action Capabilities and Performance of a Maximal Single-Leg Hop

Changes in an individual's state—for example, anxiety/chronic pain—can modify the perception of action capabilities and physical task requirements. In parallel, considerable literature supports altered motor performance during both acute and chronic pain. This study aimed to determine the effect of experimental pain on perception of action capabilities and performance of a dynamic motor task. Performance estimates and actual performance of maximal single-leg hops were recorded for both legs in 13 healthy participants before, during, and after an episode of acute pain induced by a single bolus injection of hypertonic saline into vastus lateralis of 1 leg, with the side counterbalanced among participants. Both estimation of performance and actual performance were smaller (P < .01) during pain than before and after pain. This decrease in estimation and performance during pain was apparent for hops using either leg, but it was greater (P < .01) for the painful leg (−10.8 ± 12.1 cm) than for the control leg (−5.5 ± 7.9 cm). Participants accurately estimated their performance in all conditions for both legs. The results provide evidence that healthy participants have the ability to update the action-scaled relationship between perception and ability during acute pain.PerspectiveThis study demonstrates that the relationship between perceived physical ability and actual performance is effectively updated during acute muscle pain. This match between perceived ability and performance could be relevant during clinical pain assessment, with the potential to be a biomarker of transition from acute to chronic pain state.     

Reducing Variability of Radiation Dose in CT: The New Frontier in Patient Safety

PurposeAlthough reducing radiation dose in CT examinations is an important goal, also important in the management of radiation dose is ensuring consistency of dose administered for a given type of examination. We have implemented an approach to reducing variance in CT radiation dose by standardizing protocols and implementing software that decreases variance.MethodsA multifaceted approach to reducing variance in CT radiation dose was utilized: (1) establishment of the Radiation Dose Optimization Committee, (2) standardization of protocols, and (3) implementation of scanner software. Two periods of data were collected: pre-intervention (January 1, 2013, to July 31, 2014) and postintervention (January 1, 2016, to December 31, 2016). The period from August 1, 2014, to December 31, 2015, represented the time the major interventions were performed.ResultsThe average radiation dose for all CT exams performed during the pre-intervention period (n = 39,314) was 22.3 CTDIvol with an SD of 17.0. The average radiation dose for all CT exams performed during the postintervention period (n = 49,863) was 13.6 CTDIvol with an SD of 9.01. The postintervention variance was significantly decreased (P < .0001).ConclusionsA significant decrease in the variability of our network CT radiation dose was achieved as a result of a combination of standardizing protocols across the network and implementation of advanced software that effectively managed radiation dose, all overseen by the Radiation Dose Optimization Committee.     

Motor Cortical Excitability Assessed by Transcranial Magnetic Stimulation in Psychiatric Disorders: A Systematic Review

BackgroundTranscranial magnetic stimulation (TMS) is a popular neurostimulation technique suitable for the investigation of inhibitory and facilitatory networks in the human motor system. In the last 20 years, several studies have used TMS to investigate cortical excitability in various psychiatric disorders, leading to a consequent improvement in pathophysiological understanding. However, little is known about the overlap and specificity of these findings across these conditions.ObjectiveTo provide a systematic review of TMS studies (1985–2013) focusing on motor cortical excitability in dementia, schizophrenia, affective disorders (major depression and bipolar), attention deficit hyperactivity disorder (ADHD), obsessive compulsive disorder (OCD), Tourette Syndrome (TS), substance abuse (alcohol, cocaine, cannabis, nicotine) and other disorders (borderline personality disorder, posttraumatic stress disorder (PTSD)).MethodsSystematic literature-based review.ResultsAcross disorders, patients displayed a general pattern of cortical disinhibition, while the most consistent results of reduced short-interval intracortical inhibition could be found in schizophrenia, OCD and Tourette Syndrome. In dementia, the most frequently reported finding was reduced short-latency afferent inhibition as a marker of cholinergic dysfunction.ConclusionsThe results of this systematic review indicate a general alteration in motor cortical inhibition in mental illness, rather than disease-specific changes. Changes in motor cortical excitability provide insight that can advance understanding of the pathophysiology underlying various psychiatric disorders. Further investigations are needed to improve the diagnostic application of these parameters.     

Compliance with a law to reduce alcoholic beverage sales and service in Zacatecas,Mexico

BackgroundResearch on the effects of restricting bar opening hours and alcohol sales in middle-income countries is very limited. We assessed compliance with and possible effects of a law enacted in Zacatecas, Mexico on December 30, 2017 and implemented in 2018 and 2019 that established a 2 AM bar closing time and 10 PM cut-off for alcohol sales by off-premises stores.MethodsMonthly observations of bars and off-premises stores and alcohol mystery shopping visits from 2018 to early 2020 were conducted to assess compliance with the law. Breath tests were conducted in 2018 and 2019 with samples of pedestrians in the nighttime entertainment districts of Zacatecas and a comparison city (Aguascalientes). Surveys of bar owners/managers and staff, emergency medical personnel (EMP), and police officers were conducted in Zacatecas in 2018 and 2019 to assess awareness and support of the law and possible effects of the law on alcohol-related problems such as violence and injuries.ResultsMonthly observations indicated that a substantial percentage of bars and off-premises package stores did not comply with the law. Pedestrian breath tests in 2018 and 2019 indicated significant reductions in blood alcohol concentration and heavy drinking among pedestrians in Zacatecas from 11 PM to 2 AM compared to Aguascalientes, but not after 2 AM. Surveys of bar owners/managers indicated that most were aware and supportive of the law. EMP surveys indicated reductions in incidents of physical fighting and drunk or injured customers during the annual September fair in Zacatecas.ConclusionsThis study suggests that restricting bar opening hours and alcohol sales may not result in full compliance by bars and off-premises stores, but may help to reduce excessive alcohol use and related harms in a middle-income country. A more rigorous evaluation with pre-intervention data is needed, however, to fully address this latter question.