1,036 research outputs found

    Defining the border of the subthalamic nucleus for deep brain stimulation: A proposed model using the symmetrical sigmoid curve function

    Get PDF
    Background: The subthalamic nucleus (STN) is an important target during deep brain stimulation (DBS). Accurate lead placement is integral to achieving satisfactory clinical outcomes; however, the STN remains a structure whose visualization is highly variable with borders often difficult to define. We aimed to develop an objective method of evaluating the visibility of the STN on preoperative magnetic resonance imaging (MRI) to standardize future comparative assessments between imaging protocols and patient-specific parameters. Methods: An imaging study of 64 prospectively collected patients undergoing bilateral DBS of the STN for various movement disorders was performed with institutional approval. MRI scans were acquired using a uniform protocol involving general anesthesia, cranial fixation in a Leksell stereotactic frame, and long acquisition times using a 3T MRI scanner. The images were analyzed using the iPlan Stereotaxy, version 2.6, workstation. High-resolution T2-weighted axial sections were evaluated, and the voxel values in the region of the presumed posterior border of the STN (as defined by the operating neurosurgeon) were obtained. A 4-parameter logistic symmetrical sigmoid curve was used to map the voxel values as they progressed from within to outside the region of the STN border. The inflection point and Hill coefficient of this symmetrical curve was calculated to provide objective information on the location and clarity of the STN border, respectively. These findings were compared with the surgeon\u27s judgment of the STN border. To demonstrate the use of the sigmoid curve, the patients\u27 head volumes were also calculated and evaluated to assess whether larger head volumes adversely affected STN visibility. Results: The symmetrical sigmoid curve model provided objective information on the visibility of the STN on T2-weighted MRI scans and could be generated in 86% of the patients. The other 14% of patients had MRI scans that generated linear graphs, indicating the poorest scoring for STN image quality. No correlation between head volume and STN visibility was identified. Conclusions: Our proposed statistical model allows for standardized examination of the visibility of the STN border for DBS and has potential for both clinical and academic applications

    Upper back pain in postmenopausal women and associated physical characteristics

    Get PDF
    The physical characteristics of postmenopausal women that are associated with upper back pain are not well-understood. The aim of this cross-sectional study was to identify the physical characteristics associated with presence and severity of upper back pain in healthy postmenopausal women. Self-reported upper back pain presence (within the previous month) and severity (numerical rating scale) were examined against the physical characteristics: height; weight; body mass index; breast size; breast ptosis; upper back extensor muscle endurance (isometric chest raise test); head, shoulder and upper back posture (photogrammetry); thoracic extension mobility (photogrammetry); bone mineral density (dual-energy x-ray absorptiometry (DXA)); body composition (DXA); and thoracic kyphosis, thoracic osteoarthritis and thoracic vertebral fracture (all radiography). A multivariable logistic regression model, adjusted for age, was built using physical characteristics with a significant univariate association with upper back pain. Censored Tobit regression, adjusted for age, was used to examine each physical characteristic against upper back pain severity. Postmenopausal women (n = 119) with a mean (SD) age of 61.4 (7.0) years participated in the study. After adjusting for age, the physical characteristics independently associated with upper back pain were: height (OR: 0.50, 95% CI: 0.31–0.79); and upper back extensor muscle endurance (OR: 0.46, 95%CI: 0.28–0.75). This model explained 31% of the variance in upper back pain (p<0.001). After adjusting for age, being taller and having better upper back extensor muscle endurance were associated with lower odds for upper back pain. After adjusting for age, differences in upper back pain severity were explained by upper back extensor muscle endurance (p = <0.001) and lean mass (p = 0.01). Conclusion: As a modifiable physical characteristic of postmenopausal women with upper back pain, upper back extensor muscle endurance is worth considering clinically

    Guy Time: The Effects Of Men\u27s Male Friends On Their Heavy Drinking, Consensual Sexual Behaviors, And Sexual Assault Perpetration

    Get PDF
    Risky, reckless, and potentially harmful behaviors reach their peak during the adolescent and emerging adulthood years. Past research demonstrates that a variety of social influences, including descriptive and injunctive norms, overt pressure, and modeling affect adolescents\u27 and college students\u27 heavy drinking, consensual sexual experiences, and sexual assaults. The construct of peer influence has been measured in many different ways, and little research has simultaneously considered peer influence on even two of the three outcomes in the current study. Further, much of the research with emerging adults is conducted with college students. To address these gaps in the literature, this study had two interrelated goals. First, to demonstrate how men\u27s male friends influence their past-year frequency of heavy drinking, number of consensual sexual partners, and number of sexual assaults perpetrated. Second, to develop three new measures: Male Friends\u27 Pressure to Drink Heavily, Have Numerous Sexual Partners, and Have Sex by Any Means; Comfort with Sexist and Nonsexist Statements; and a qualitative assessment of how men and their friends discuss women. Participants were 423 single, heterosexual men aged 18 to 35 from the Detroit metropolitan area who completed two audio-computer-assisted self-interviews, one year apart. The three new measures demonstrated excellent internal reliability coefficients, although the factor analyses did not fully support the hypothesized factor structure. Responses to the single item assessing how men and their friends talk about women were coded by three research assistants, who counted the number of objectifying and egalitarian phrases with a high level of interrater reliability. As hypothesized, male friends\u27 pressures were significantly related to participants\u27 past-year frequency of heavy drinking, number of consensual sexual partners, and number of sexual assaults perpetrated. There were also several interactions with individual difference measures, satisfaction with male friends, and age. Sexual assault perpetration was also associated with the types of discussions men had with their male friends about women and comfort in these situations. This study demonstrates that friends influence young men\u27s drinking and sexual behaviors. Suggestions are made for involving peer groups in sexual assault prevention programs

    Non-aromatic hydrocarbons in recent sediments of Sepetiba and Ilha Grande Bays, Brazil

    Full text link
    An investigation was conducted in Ilha Grande and Sepetiba Bays aiming at identifying the nature of non-aromatic hydrocarbons (NAH) in surface sediments. NAH concentrations ranged from 2.5 ”g g-1 to 193.8 ”g g-1 of which the major fraction (53 to 93%) was composed by unresolved complex mixture (UMC). In most samples n-alkane distribution was dominated by compounds of odd carbon number showing maxima in nC29 and nC31. Mono-olefins were at low concentrations and the polyolefins including highly branched isoprenoids and squalene varied from 0.099 ”g g-1 to 1.387 ”g g-1 with lower values relative to NAH appearing in areas of strong terrestrial and anthropogenic influence. Hopanes between C27 and C33 were observed in all samples with the predominant configuration 17a(H),21b(H), characteristic of a petrogenic origin

    Standing desks in a grade 4 classroom over the full school year

    Get PDF
    © 2019 by the authors. Licensee MDPI, Basel, Switzerland. School-aged children are spending increasingly long periods of time engaged in sedentary activities such as sitting. Recent school-based studies have examined the intervention effects of introducing standing desks into the classroom in the short and medium term. The aim of this repeated-measures crossover design study was to assess the sit-stand behaviour, waking sedentary time and physical activity, and musculoskeletal discomfort at the start and the end of a full school year following the provision of standing desks into a Grade 4 classroom. Accelerometry and musculoskeletal discomfort were measured in both standing and traditional desk conditions at the start and at the end of the school year. At both time points, when students used a standing desk, there was an increase in standing time (17-26 min/school day) and a reduction in sitting time (17-40 min/school day). There was no significant difference in sit-stand behaviour during school hours or sedentary time and physical activity during waking hours between the start and the end of the school year. Students were less likely to report discomfort in the neck and shoulders when using a standing desk and this finding was consistent over the full school year. The beneficial effects of using a standing desk were maintained over the full school year, after the novelty of using a standing desk had worn off

    Effectiveness of mouth rinsing versus ingesting pickle juice for alleviating electrically induced cramp in physically active adults

    Get PDF
    (1) Background: Stimulating oropharyngeal transient receptor potential (TRP) channels in-hibits muscle cramping by triggering a supraspinal reflex to reduce α-motor neuron hyperexcitability. This study investigated whether the longer stimulation of the TRP channels via mouth rinsing with PJ is more effective than drinking PJ at inhibiting an electrically induced muscle cramp (EIMC). Both conditions were compared to the control (water). (2) Methods: The tibial nerves in 11 cramp-prone adults were percutaneously stimulated to elicit an EIMC of the flexor hallucis brevis in three trials that took place one week apart from each other. At cramp onset, the participants received mouth rinsing and expelling PJ (25 mL), ingesting PJ (1 mL·kg−1 body-mass (BM)), or ingesting water (1 mL·kg−1 BM). Cramp onset and offset were induced by electromyography, and the severity of discomfort was recorded using a visual analogue scale (VAS). (3) Results: The median time to cramp cessation as a percentage of water was 82.8 ± 14.63% and 68.6 ± 47.78% for PJ ingestion and PJ mouth rinsing, respectively. These results had large variability, and no statistically significant differences were observed. There were also no differences in perceived cramp discomfort between conditions, despite the hazard ratios for the time taken to reach VAS = 0, which was higher than water (control) for PJ ingestion (22%) and mouth rinsing (35%) (p = 0.66 and 0.51, respectively). (4) Conclusions: The data suggest no difference in cramp duration and perceived discomfort between PJ and water. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Andrew Lavender” is provided in this record*

    The influence of a positive empathetic interaction on conditioned pain modulation and manipulation induced analgesia in people with lateral epicondylalgia

    Get PDF
    Objective: Conditioned pain modulation (CPM) and manipulation induced analgesia (MIA) are two forms of endogenous analgesia. Many forms of analgesia can be influenced by the nature of the patient clinician interaction. The aim of this study was to evaluate the influence of an empathetic and supportive interaction on CPM and MIA in people with Lateral Epicondylalgia (LE). Methods: In a double-blind, randomised, controlled trial, 68 participants with LE were assigned to two groups: the empathetic and neutral interaction groups. The interactions were carried out by a trained, professional role play actor, playing the part of a research assistant (RA). The RA actor spent 15min prior to CPM and MIA assessment interacting with the participants in an empathetic or neutral manner. Immediately after the interaction, a blinded assessor measured pressure pain threshold (PPT) at the symptomatic elbow and ipsilateral wrist during CPM and MIA testing. Linear mixed models were used to evaluate differences in CPM and MIA responses between the interaction groups. Results: There was a significant difference in CARE scores between the groups (p\u3c0.001), indicating that the intervention group experienced a more empathic interaction. Both groups showed a significant increase in PPT measures, indicative of a CPM and MIA analgesic response (p\u3c0.001), however the analgesic responses were greater in the group that had experienced a supportive, empathetic interaction (post CPM, wrist: p\u3c0.001; elbow: p=0.001), (post MIA wrist: p=\u3c0.001; elbow: p=0.001). Discussion: A single session of empathetic interaction positively influenced both CPM and MIA responses in people with LE
    • 

    corecore