Rod and frame alignment times increase when the frame is tilted.

The Rod and Frame test measures an individual’s subjective assessment of visual vertical and horizontal in the presence of a surrounding tilted frame. Attention has focused upon the effects of the surrounding frame upon spatial accuracy (Spatial Frame Effect). We have investigated if the tilted frame also affects the time that subjects take to make the alignment (Temporal Frame Effect). Results: 125 subjects performed a computerised Rod and Frame test to investigate the effects of a tilted frame on subjective visual vertical and horizontal. In addition the program recorded the time taken to make each alignment. For most subjects the mean Spatial Frame Effect was small (vertical 1.62, SD 0.93; horizontal 1.9, SD 1.43). The mean time taken to make alignments in the presence of a tilted frame was longer than when the frame was not tilted (vertical, +3.4s, SD 4.4; horizontal, +3.2s, SD 4.5). Differences in the times taken when the rod and frame were presented congruently and incongruently could be fully accounted for by the differences in steps needed to move the rod to its final alignment. No relationship was found between the spatial accuracy and the time to make the alignment and there was no relationship between the Spatial and Temporal Frame Effects. Conclusions: This study suggests that the Spatial, and Temporal, Frame Effects provide information about different aspects of the process of resolving conflicting visual information when making judgments on alignment. In everyday functions such as the maintenance of balance or susceptibility to motion sickness, the increased time taken may be as important as spatial accuracy

Addressing prescription discrepancies in renal patients: a prospective audit

Background Management of chronic renal failure requires complex medication regimens to manage hypertension, hyperlipidaemia, diabetes, phosphate, anaemia and acidosis. Patient engagement in medicine management is essential to avoid potential harm. Methods We prospectively audited the rate of discrepancies between our hospital record of patient medications and their current prescription. We investigated whether changes to appointment letters reduced the number of discrepancies. Results The proportion of patients attending renal outpatient clinics failing to bring a list or unable to recall their medications fell over a 3-year period following changes to appointment letters (median proportion: 0.45 in 2014, 0.36 in 2015, 0.30 in 2016, Chi-sq = 46.94, p < 0.001); percentage of patients forgetting to bring a list with significant prescription discrepancies fell from 10.9% in 2014 to 3.9% in 2016). Conclusion Changes to appointment letters can potentially improve prescribing safety in an outpatient setting

Tactile acuity, body schema and motor control and clinical outcome measures – A comparison study of adults with chronic low back pain and matched controls.

Tactile acuity, body schema and motor control and clinical outcome measures – A comparison study of adults with chronic low back pain and matched controls Chronic low back pain (CLBP) is common, often lacks discernible aetiology and contributes to morbidity and low quality of life. Treatments often focus on pain relief and improving motor function but outcomes remain moderate and many experience ongoing pain. In Complex Regional Pain Syndrome and Phantom Limb Pain, the cortical neurophysiology and specific sensory outputs are altered. Interventions to reverse these impairments coincide with a reduction in pain intensity. Sharing similar neurophysiological characteristics, it’s plausible that similar approaches may improve CLBP outcomes so identification of similar features in this group is needed. We conducted a systematic review regarding the questions: Are two-point discrimination threshold (TPDT) and body schema (BS) altered in adults with CLBP and do they relate to impaired lumbopelvic motor control (LMC)? This review initiated stage two; data collection to investigate TPDT, BS, LMC, back-perception, disability, kinesiophobia and clinical outcome measures in adults with CLBP and matched controls. Following a systematic review to guide our study, we aimed to identify differences in tactile acuity, body schema, lumbopelvic motor function and association with clinical outcome measures when measured in adults with chronic low back pain and matched controls. Using a systematic search strategy, a literature search of 12 bibliographic databases, grey literature, Google Scholar and the reference lists of included articles was undertaken over 5 months to Feb 2016. Studies involving adults aged 18 or older with CLBP longer than 3 months duration were included. Pregnancy, 6 months post-partum, central neurological conditions and nerve root pathologies were exclusion criteria. Two independent reviewers’ assessed for quality using an adapted Downs and Black Quality Index Score. Studies of high (≥70%) or medium (60-69%) quality involving adults with CLBP ≥3 month’s duration were included. Varied research designs led to a narrative data synthesis. In stage two, data collection was undertaken in two matched groups (CLBP and control) using established measures of TPDT and tactile threshold on the low back and finger-tip of dominant hand, low back laterality discrimination, lumbopelvic motor control and outcome measures such as disability, kinesiophobia, back-perception and pain. The review identified 335 studies. Following inclusion and exclusion screening, nine met the selection criteria and were included in the data extraction process. Assessment revealed similar quality strengths with eight of high and one of medium quality. Only one reported power. Sample sizes ranged from six to 51 with a total of 398 participants. All included male and female participants with a mean age of 44.2 years. The studies utilised different techniques and populations to explore tactile discrimination, body schema and motor function but critically; none explored all three. Stage two data collection has been completed in 62 adults (31 per group) and data analysis is underway. Preliminary results reveal significant between group differences for TPDT, disability, kinesiophobia, back-perception and motor-function. Lateral discrimination and associations have yet to be analysed and results will be presented in the final poster as; a) differences between groups and b) relationships to outcome measures. Our systematic review revealed TPDT to be altered in those with CLBP and is related to altered LMC. Body schema tasks may also be altered but the evidence is limited. The relationship between BS and LMC remains unknown and the relationships to other clinical measures are unclear. Data analysis is underway and some of our results correspond with the systematic review (TPDT, LMC) but others do not (BS). Association analysis continue and further results and conclusions will be presented on the poster once complete

Is spatial orientation affected by Ramadan fasting?

Purpose: Ramadan intermittent fasting (RIF) has produced heterogeneous and domain-specific effects on cognitive function. This study aims to investigate the effect of RIF on verticality perception or estimation of subjective visual vertical (SVV) in young adults. The significance of SVV is that it is essential for spatial orientation, upon which many daily activities depend. Methodology Verticality perception was assessed with a computerized rod and frame test (CRFT) in two visual conditions: without a surrounding frame and with a distracting tilted frame. The tilted frame condition measures level of visual dependence or reliance of visual cues for posture and orientation. In total, 39 young adult men were recruited at different stages of Ramadan fasting: 21 were tested at the end of the first week (Week 1) and 18 others at the end of the third week (Week 3) of Ramadan. Also, 39 participants were recruited to serve as a non-fasting control group. Factorial ANOVA analyses were conducted to identify the main effects of fasting status, time-of-day and the interaction between them on blood glucose levels, nocturnal sleep duration and vertical alignment errors. Findings The main effect of fasting status on glucose level was significant (p = 0.03). There was a significant time-of-day main effect on glucose levels (p = 0.007) and sleep duration (p = 0.004) only in fasting participants. Neither the main effects of fasting status nor time-of-day were significant for rod alignment errors in both visual conditions. The interaction of fasting status and time-of-day was not significant either. This may indicate that any negative effect of Ramadan fasting on activities that are critically dependent on verticality perception and spatial orientation, such as sports and driving, may not be due to verticality misperception. Originality The present study was the first to investigate the effect of Ramadan fasting on spatial orientation. It demonstrated robustness of verticality perception to fasting status and the point of fasting during Ramadan. Verticality perception was also unaffected by time-of-day effects in non-fasting and fasting groups at two different points of Ramadan. This study corroborates others reporting heterogeneous effects of Ramadan fasting on cognitive function

A preliminary study on whether HbA1c levels can predict visual dependence for spatial orientation in asymptomatic Type 2 diabetic patients

Introduction: Diabetes-induced vestibular dysfunction has been commonly reported, and asymptomatic patients with type 2 diabetes display higher degrees of perceptual visual dependence for spatial orientation than healthy controls. This study aims to assess whether HbA1c can predict such visual dependence in the diabetic patients. Methods and Materials: Diabetic patients were divided into 2 groups: 22 subjects with “good” (HbA1c < 7%) and 25 with “poor” (HbA1c ≥ 7%) glycemic control. Otolithic vestibular function was tested using the computerized rod-and-frame test (CRFT) and results for the two diabetic groups were compared to 29 healthy controls. Results: When the frame was tilted, the diabetic group with “good” glycemic control had largest positioning errors, with a significant difference only in comparison to the control group. The “good” glycemic group exhibited larger degree of asymmetry under titled frame condition. Although HbA1c was not associated with vestibular asymmetry in any diabetic group, it was significantly associated with visual dependence in the “good” glycemic group. During frame tilts, 10 diabetic patients had positioning errors above the reference range of 3.3°, 8 of which belonged to the “good” glycemic diabetic group. Conclusions: Diabetes disease processes may affect vestibular symmetry during visuo-vestibular conflicts, even in asymptomatic diabetics within the recommended glycemic range. The weak correlations between HbA1c and CRFT parameters may indicate that HbA1c cannot fully predict visual dependence or asymmetry on the CRFT in patients with diabetes, and different glycemic disorders may affect vestibular dependent spatial orientation in diabetic patients

From line to dots: an improved computerised rod and frame system for testing subjective visual vertical and horizontal

Background Perception of subjective visual vertical (SVV) and horizontal (SVH) has traditionally been measured by rotating a mechanical rod either with or without a frame present. The computerised rod and frame (CRAF) system has previously only been used to measure SVV. We have expanded the use of this system by testing its feasibility to measure SVH. This was done by comparing two groups of subjects (n = 103) randomly assigned to be tested for SVV or SVH. Findings Preliminary results showed a higher than expected percentage of individuals with SVH errors < 0.5°. This was attributed to additional visual cues provided by the changing appearance of the rod as it approached the horizontal. A solution to this problem was sought by replacing the rod by two dots to mark its ends. In a second investigation 30 subjects were tested using both the "rod as line" and "rod as dots" presentation. Bland and Altman analysis showed no difference between the rod and dots presentations in the measurement of SVV, but confirmed a fixed error of -0.93° between rods and dots for SVH. Changing the rod from a line to dots in the computer system resulted in errors for both SVV and SVH that were comparable to previous studies using manual systems. Conclusions The computerized rod and frame system may be improved by replacement of the line with two dots. This reduces clues provided to the subject by the appearance of the rod on the screen

Changes in rod and frame test scores recorded in schoolchildren during development--a longitudinal study.

The Rod and Frame Test has been used to assess the degree to which subjects rely on the visual frame of reference to perceive vertical (visual field dependence-independence perceptual style). Early investigations found children exhibited a wide range of alignment errors, which reduced as they matured. These studies used a mechanical Rod and Frame system, and presented only mean values of grouped data. The current study also considered changes in individual performance. Changes in rod alignment accuracy in 419 school children were measured using a computer-based Rod and Frame test. Each child was tested at school Grade 2 and retested in Grades 4 and 6. The results confirmed that children displayed a wide range of alignment errors, which decreased with age but did not reach the expected adult values. Although most children showed a decrease in frame dependency over the 4 years of the study, almost 20% had increased alignment errors suggesting that they were becoming more frame-dependent. Plots of individual variation (SD) against mean error allowed the sample to be divided into 4 groups; the majority with small errors and SDs; a group with small SDs, but alignments clustering around the frame angle of 18°; a group showing large errors in the opposite direction to the frame tilt; and a small number with large SDs whose alignment appeared to be random. The errors in the last 3 groups could largely be explained by alignment of the rod to different aspects of the frame. At corresponding ages females exhibited larger alignment errors than males although this did not reach statistical significance. This study confirms that children rely more heavily on the visual frame of reference for processing spatial orientation cues. Most become less frame-dependent as they mature, but there are considerable individual differences

Young and Older Adults Differ in Integration of Sensory Cues for Vertical Perception.

Introduction: The subjective visual vertical (SVV) measures the perception of a person's spatial orientation relative to gravity. Weighted central integration of vestibular, visual, and proprioceptive inputs is essential for SVV perception. Without any visual references and minimal proprioceptive contribution, the static SVV reflects balance of the otolith organs. Normal aging is associated with bilateral and progressive decline in otolith organ function, but age-dependent effects on SVV are inconclusive. Studies on sensory reweighting for visual vertical and multisensory integration strategies reveal age-dependent differences, but most studies have included elderly participants in comparison to younger adults. The aim of this study was to compare young adults with older adults, an age group younger than the elderly. Methods: Thirty-three young and 28 older adults (50-65 years old) adjusted a tilted line accurately to their perceived vertical. The rod's final position from true vertical was recorded as tilt error in degrees. For otolithic balance, visual vertical was recorded in the dark without any visual references. The rod and frame task (RFT) with tilted disorienting visual frames was used for creating visuovestibular conflict. We adopted Nyborg's analysis method to derive the rod and frame effect (RFE) and trial-to-trial variability measures. Rod alignment times were also analyzed. Results: There was no age difference in signed tilts of SVV without visual reference. There was an age effect on RFE and on overall trial-to-trial variability of rod tilt, with older adults displaying larger frame effects and greater variability in rod tilts. Alignment times were longer in the tilted-frame conditions for both groups and in the older adults compared to their younger counterparts. The association between tilt accuracy and tilt precision was significant for older adults only during visuovestibular conflict, revealing an increase in RFE with an increase in tilt variability. Correlation of σSVV, which represents vestibular input precision, with RFE yielded exactly the same contribution of σSVV to the variance in RFE for both age groups. Conclusions: Older adults have balanced otolithic input in an upright position. Increased reliance on visual cues may begin at ages younger than what is considered elderly. Increased alignment times for older adults may create a broader time window for integration of relevant and irrelevant sensory information, thus enhancing their multisensory integration. In parallel with the elderly, older adults may differ from young adults in their integration of sensory cues for visual vertical perception

Association studies of up to 1.2 million individuals yield new insights into the genetic etiology of tobacco and alcohol use.

Tobacco and alcohol use are leading causes of mortality that influence risk for many complex diseases and disorders1. They are heritable2,3 and etiologically related4,5 behaviors that have been resistant to gene discovery efforts6-11. In sample sizes up to 1.2 million individuals, we discovered 566 genetic variants in 406 loci associated with multiple stages of tobacco use (initiation, cessation, and heaviness) as well as alcohol use, with 150 loci evidencing pleiotropic association. Smoking phenotypes were positively genetically correlated with many health conditions, whereas alcohol use was negatively correlated with these conditions, such that increased genetic risk for alcohol use is associated with lower disease risk. We report evidence for the involvement of many systems in tobacco and alcohol use, including genes involved in nicotinic, dopaminergic, and glutamatergic neurotransmission. The results provide a solid starting point to evaluate the effects of these loci in model organisms and more precise substance use measures