Effects of alcohol ingestion on vestibular function in postural control

Sensory processing and alcohol use in adults with autism spectrum disorder

The association between substance use and autism spectrum disorder (ASD) is complex. Although sensory processing difficulties are highly prevalent in individuals with ASD, data on the association between sensory processing and substance use in ASD are limited. This study aimed to investigate the association between sensory processing patterns and alcohol use in adults with ASD. Kruskal-Wallis tests were performed on questionnaire data (Adolescent/Adult Sensory Profile and Alcohol Use Disorders Identification Test - Consumption) of 101 adults with ASD. Sensory processing difficulties are associated with alcohol use in adults with ASD. Differences in sensory processing between alcohol-based subgroups vary per specific sensory processing pattern: drinkers reported 6.5 to 8 points higher levels of low registration [χ2(2) = 12.408, p = .002, 99 % CI (.002.002)], non-hazardous drinkers reported 9 points higher levels of sensory sensitivity [χ2(2) = 6.868, p = .031, 99 % CI (.031, .032)], and hazardous drinkers reported 7.5 points higher levels of sensory seeking [χ2(2) = 6.698, p = .034, 99 % CI (.034, .035)], all in comparison with non-drinkers on scales ranging from 15 to 75. Our proof-of-concept study indicates that vulnerability in some individuals with ASD for substance use disorders might be explained by sensory processing difficulties. Whether alcohol is used as 'self-medication' or is associated with other neurobiological vulnerabilities needs further investigation in larger follow-up studies.

Acute Alcohol Intake Impairs the Velocity Storage Mechanism and Affects Both High-Frequency Vestibular-Ocular Reflex and Postural Control

Background: Acute alcohol intake is known to cause gait instability, dizziness, and lack of psychomotor coordination. Previous studies demonstrated the positive effects of alcohol on the oculomotor system and the low-frequency vestibulo-ocular reflex (VOR). However, the low-frequency VORs is a rather un-physiologic stimulation, and the reported explanations regarding the relations between the alcohol-induced VOR changes and posture control are inconsistent. OBJECTIVE: The present study evaluates how acute alcohol intake affects more physiologic mid- to high-frequency VORs, postural control, and elucidates the connection between the VOR and posture control after alcohol intake. Methods: A total of 31 healthy volunteers participated. Each participant received calculated amounts of alcohol drinks according to their body weight and genders with the targeted blood alcohol content (BAC) level of 0.05% using the Widmark formula. A vestibular test battery composed of posturography, video head impulse test, rotatory chair test (slow harmonic acceleration (SHA) and step velocity), and subjective visual vertical/horizontal tests (SVV/SVH) were conducted twice in alcohol-free condition (no alcohol intake within 24 h) and acute alcohol condition. Results: Acute alcohol intake decreased stability scores in all NS/EO (normal stability-eyes open), NS/EC (normal stability- eyes closed), PS/EO (perturbed stability-eyes open), and PS/EC (perturbed stability-eyes closed) conditions. High-frequency VOR gains decreased, but mid-frequency VOR gains were not significantly affected by alcohol intake. In addition, time constants were reduced significantly after alcohol ingestion in both clockwise and counter-clockwise rotation. Phase lead in SHA test and SVV/SVH was not affected by alcohol intake. Conclusion: Acute alcohol intake affected postural stability, high-acceleration head impulses, and the velocity storage mechanism.

The effects of breath alcohol concentration on postural control

BACKGROUND

Two of the 3 standardized field sobriety tests that U.S. law enforcement uses at roadside checks have a postural equilibrium component to them. Those tests have been validated to detect impairment caused by blood alcohol concentrations (BACs) of 0.08 g/dL or above. Many medical and traffic safety associations support a lower limit, and one state, Utah, has passed a law to lower the limit to 0.05 g/dL. Many studies have examined the effects of alcohol on postural control (of which postural equilibrium is a component), with a consensus emerging that impairment is usually found at BACs greater than 0.06 g/dL. Most of these studies, however, had a relatively small number of subjects, usually between 10 and 30. The current study collected data from a much larger sample.

OBJECTIVE

The objective of this study was to provide additional evidence that posture control is negatively affected at BACs greater than 0.06 g/dL or breath alcohol concentrations (BrACs) of 0.06 g/210 L.

METHOD

This was a between-subjects study, with BrAC group as the independent variable (5 levels: 0.00, 0.04, 0.06, 0.08, and 0.10 g/210 L); 4 measures of postural control as the dependent variables; and age, height, and weight as the covariates. Posture control was measured with a force-sensing platform connected to a computer. The feet's center of pressure (CoP) on the platform was recorded and the corresponding movement of the body in the anterior-posterior and lateral planes was derived. Participants (N = 96) were randomly assigned to one of the BrAC groups. Positive BrAC groups were compared to the zero BrAC group. Data were examined with hierarchical multiple regression.

RESULTS

Adjusted for age, height, and weight, the main effect of lateral CoP with eyes open was not statistically significant. There was a statistically significant main effect of alcohol on anterior-posterior CoP excursion with eyes open and with eyes closed and lateral CoP excursion with eyes closed. For all 3 of those variables, only BrACs of 0.08 and 0.10 g/210 L produced differences against zero BrAC. Although the main effect of alcohol on Lateral CoP Excursion with eyes open was not statistically significant, the contrasts between 0 and 0.08 and 0 and 0.10 g/210L BrAC were in the hypothesized direction.

CONCLUSION

The current study did not directly address the issue of whether the sobriety tests are sensitive to BrACs of 0.05 g/210 L or above; rather, it provides additional evidence that postural control, one of the components of those tests, is relatively unaffected by BrACs lower than 0.08 g/210 L. Additional research is needed on the diagnostic characteristics of the sobriety tests at BrACs lower than 0.08 g/210 L.

Association between Suicide Ideation and Attempts and Being an Immigrant among Adolescents, and the Role of Socioeconomic Factors and School, Behavior, and Health-Related Difficulties

The risk of suicide behaviors in immigrant adolescents varies across countries and remains partly understood. We conducted a study in France to examine immigrant adolescents' likelihood of experiencing suicide ideation in the last 12 months (SI) and lifetime suicide attempts (SA) compared with their native counterparts, and the contribution of socioeconomic factors and school, behavior, and health-related difficulties. Questionnaires were completed by 1559 middle-school adolescents from north-eastern France including various risk factors, SI, SA, and their first occurrence over adolescent's life course (except SI). Data were analyzed using logistic regression models for SI and Cox regression models for SA (retaining only school, behavior, and health-related difficulties that started before SA). Immigrant adolescents had a two-time higher risk of SI and SA than their native counterparts. Using nested models, the excess SI risk was highly explained by socioeconomic factors (27%) and additional school, behavior, and health-related difficulties (24%) but remained significant. The excess SA risk was more highly explained by these issues (40% and 85%, respectively) and became non-significant. These findings demonstrate the risk patterns of SI and SA and the prominent confounding roles of socioeconomic factors and school, behavior, and health-related difficulties. They may be provided to policy makers, schools, carers, and various organizations interested in immigrant, adolescent, and suicide-behavior problems.

Effectuation of adaptive stability and postural alignment strategies are decreased by alcohol intoxication

Human stability control is a complex process comprising contributions from several partly independent mechanisms such as coordination, feedback and feed-forward control, and adaptation. Acute alcohol intoxication impairs these functions and is recognized as a major contributor to fall traumas. The study aimed to investigate how alcohol intoxication at .06% and .10% blood alcohol concentration (BAC) affected the movement spans and control of posture alignment. The angular positions of the head, shoulder, hip and knees relative to the ankles were measured with a 3D motion analysis system in 25 healthy adults during standing with eyes open or closed and with or without vibratory balance perturbations. Alcohol intoxication significantly increased the movement spans of the head, shoulders, hip and knees in anteroposterior and lateral directions during quiet stance (p < or = .047 and p < or = .003) and balance perturbations (p<.001, both directions). Alcohol intoxication also decreased the ability to reduce the movement spans through adaptation in both anteroposterior (p < or = .011) and lateral (p < or = .004) directions. When sober and submitted to balance perturbations, the subjects aligned the head, shoulders, hip and knees more forward relative to the ankle joint (p < .001), hence adopting a more resilient posture increasing the safety margin for backward falls. Alcohol intoxication significantly delayed this forward realignment (p < or = .022). Alcohol intoxication did not cause any significant posture realignment in the lateral direction. Thus, initiation of adaptive posture realignments to alcohol or other disruptions might be context dependent and associated with reaching a certain level of stability threats.

Association between health-related quality of life and being an immigrant among adolescents, and the role of socioeconomic and health-related difficulties

To develop satisfactorily, adolescents require good health-related quality of life (QOL, including physical health, psychological health, social relationships and living environment). However, for poorly understood reasons, it is often lacking, especially among immigrants with lower family and socioeconomic resources. This study assessed health-related QOL of European and non-European immigrant adolescents and the contributions of socioeconomic difficulties, unhealthy behaviors, and violence. It included 1,559 middle-school adolescents from north-eastern France (mean age 13.5, SD 1.3; 1,451 French adolescents, 54 European immigrants and 54 non-European immigrants), who completed a self-administered questionnaire including sex, age, socioeconomic characteristics (family structure, parents’ education, occupation, and income), unhealthy behaviors (uses of tobacco/alcohol/cannabis/hard drugs, obesity, and involvement in violence), having sustained violence, sexual abuse, and the four QOL domains measured with the World Health Organization’s WHOQOL-BREF (poor: score < 25th percentile). Data were analyzed using logistic regression models. Poor physical health, psychological health, social relationships, and living environment affected more European immigrants (26% to 35%) and non-European immigrants (43% to 54%) than French adolescents (21% to 26%). European immigrants had a higher risk of poor physical health and living environment (gender-age-adjusted odds ratio 2.00 and 1.88, respectively) while non-European immigrants had a higher risk for all poor physical health, psychological health, social relationships, and living environment (3.41, 2.07, 3.25, and 3.79, respectively). Between 20% and 58% of these risks were explained by socioeconomic difficulties, parts of which overlapped with unhealthy behaviors and violence. The associations between the two sets of covariates greatly differed among French adolescents and immigrants. Poor QOL was more common among European and non-European immigrants due to socioeconomic difficulties and associated unhealthy behaviors and violence. The different risk patterns observed between French adolescents and immigrants may help prevention.

The effect of alcohol on cervical and ocular vestibular evoked myogenic potentials in healthy volunteers

OBJECTIVE

We investigated the effect of alcohol on the cervical and ocular vestibular evoked myogenic potentials (cVEMPs and oVEMPs). As alcohol produces gaze-evoked nystagmus (GEN), we also tested the effect of nystagmus independent of alcohol by recording oVEMPs during optokinetic stimulation (OKS).

METHODS

The effect of alcohol was tested in 14 subjects over multiple rounds of alcohol consumption up to a maximum breath alcohol concentration (BrAC) of 1.5‰ (mean 0.97‰). The effect of OKS was tested in 11 subjects at 5, 10 and 15deg/sec.

RESULTS

oVEMP amplitude decreased from baseline to the highest BrAC level by 27% (range 5-50%, P<0.001), but there was no significant effect on oVEMP latency or cVEMP amplitude or latency. There was a significant negative effect of OKS on oVEMP amplitude (16%, P=0.006).

CONCLUSIONS

We found a selective effect of alcohol on oVEMP amplitude, but no effect on the cVEMP. Vertical nystagmus elicited by OKS reduced oVEMP amplitude.

SIGNIFICANCE

Alcohol selectively affects oVEMP amplitude. Despite the effects of alcohol and nystagmus, both reflexes were reliably recorded in all subjects and conditions. An absent response in a patient affected by alcohol or nystagmus indicates a vestibular deficit.

Static posturography in addicted to illicit drugs and alcohol

The use of illicit drugs and alcohol can affect body balance.

AIM

To evaluate balance control with static posturography in individuals addicted to illicit drugs, with or without alcohol abuse.

STUDY DESIGN

Case-control, prospective.

METHODS

47 users of illicit drugs, with or without alcohol abuse, and a homogeneous control group consisting of 47 healthy individuals were submitted to a neurotological evaluation including Balance Rehabilitation Unit posturography.

RESULTS

The stability threshold mean values were significantly lower (p < 0.0001) in users of illicit drugs, with or without alcohol abuse when compared to the control group; the mean values for sway velocity and ellipse area in all evaluated conditions were significantly higher (p <0.05) in the experimental group when compared to the control group, except for the ellipse area in static force surface and opened eyes (p = 0.168).

CONCLUSION

The balance control of individuals addicted to illicit drugs with or without alcohol abuse could present stability threshold, sway velocity and ellipse area abnormalities in static posturography.

School difficulties in immigrant adolescent students and roles of socioeconomic factors, unhealthy behaviours, and physical and mental health

BACKGROUND

School is a multi-cultural setting where students need social, material, physical, and mental resources to attain school achievement. But they are often lacking, especially for immigrant students. In an early adolescence context, this study assessed risk for school difficulties among European and non-European immigrants and the roles of socioeconomic characteristics, physical health, psychological health, social relationships, living environment, and unhealthy behaviours.

METHODS

This cross-sectional study included 1,559 middle-school adolescents from north-eastern France, who completed a self-administered questionnaire including socioeconomic characteristics (gender, age, family structure, father's occupation, and family income), WHO-Quality of life (measuring the four dimensions physical health, psychological health, social relationships, and living environment), unhealthy behaviours (last-30-day uses of tobacco, alcohol, cannabis, and other illicit drugs and no regular sports/physical activities), grade repetition, low school performance (<10/20), and school dropout ideation at 16 years. Data were analyzed using logistic models.

RESULTS

Grade repetition affected 14.8% of students, low school performance 8.2%, and school dropout ideation 3.9%. European immigrants had a higher risk for grade repetition only with a gender-age-adjusted odds ratio (OR) of 2.44, vs. French students. This odds ratio decreased to 1.76 (contribution 47%) with further adjustment for all confounders (family structure, father's occupation, family income, physical health, psychological health, social relationships, living environment, and unhealthy behaviours). Non-European immigrants had a statistically higher risk for all grade repetition, low school performance, and school dropout ideation with ORs of 3.29, 3.02, and 3.42, respectively vs. French students. These odds ratios decreased to 1.76, 1.54, and 1.54, respectively (contributions 66%, 73%, and 78%) with further adjustment for all confounders.

CONCLUSIONS

Compared with French students, European immigrant students were more affected only by grade repetition while non-European immigrant students by all grade repetition, low school performance, and school dropout ideation. The contribution of socioeconomic characteristics, physical health, psychological health, social relationships, living environment, and unhealthy behaviours was very high and much higher for non-European than for European immigrant students. Public policy should focus on these factors and services to reduce school difficulties.

Study I: effects of 0.06% and 0.10% blood alcohol concentration on human postural control

Alcohol intoxication causes many accidental falls presented at emergency departments, with the injury severity often related to level of blood alcohol concentration (BAC). One way to evaluate the decline in postural control and the fall risk is to assess standing stability when challenged. The study objective was to comprehensively investigate alcohol-related impairments on postural control and adaptive motor learning at specific BAC levels. Effects of alcohol intoxication at 0.06% and 0.10% BAC were examined with posturography when unperturbed or perturbed by calf vibration. Twenty-five participants (mean age 25.1 years) were investigated standing with either eyes open or closed. Our results revealed several significant findings: (1) stability declined much faster from alcohol intoxication between 0.06% and 0.10% BAC (60-140%) compared with between 0.0% and 0.06% BAC (30%); (2) sustained exposure to repeated balance perturbations augmented the alcohol-related destabilization; (3) there were stronger effects of alcohol intoxication on stability in lateral direction than in anteroposterior direction; and (4) there was a gradual degradation of postural control particularly in lateral direction when the balance perturbations were repeated at 0.06% and 0.10% BAC, indicating adaptation deficits when intoxicated. To summarize, alcohol has profound deteriorating effects on human postural control, which are dose dependent, time dependent and direction specific. The maximal effects of alcohol intoxication on physiological performance might not be evident initially, but may be revealed first when under sustained sensory-motor challenges.

Blood alcohol concentration at 0.06 and 0.10% causes a complex multifaceted deterioration of body movement control

Alcohol-related falls are recognized as a major contributor to the occurrence of traumatic brain injury. The control of upright standing balance is complex and composes of contributions from several partly independent mechanisms such as appropriate information from multiple sensory systems and correct feedback and feed forward movement control. Analysis of multisegmented body movement offers a rarely used option for detecting the fine motor problems associated with alcohol intoxication. The study aims were to investigate whether (1) alcohol intoxication at 0.06 and 0.10% blood alcohol concentration (BAC) affected the body movements under unperturbed and perturbed standing; and (2) alcohol affected the ability for sensorimotor adaptation. Body movements were recorded in 25 participants (13 women and 12 men, mean age 25.1 years) at five locations (ankle, knee, hip, shoulder, and head) during quiet standing and during balance perturbations from pseudorandom pulses of calf muscle vibration over 200s with eyes closed or open. Tests were performed at 0.00, 0.06, and 0.10% BAC. The study revealed several significant findings: (1) an alcohol dose-specific effect; (2) a direction-specific stability decrease from alcohol intoxication; (3) a movement pattern change related to the level of alcohol intoxication during unperturbed standing and perturbed standing; (4) a sensorimotor adaptation deterioration with increased alcohol intoxication; and (5) that vision provided a weaker contribution to postural control during alcohol intoxication. Hence, alcohol intoxication at 0.06 and 0.10% BAC causes a complex multifaceted deterioration of human postural control.

Postural control in patients with liver cirrhosis: a posturographic study

BACKGROUND

Ataxia has been suggested in the literature to be a symptom of hepatic encephalopathy (HE), but so far has not been objectively quantified. In this study, we wanted to objectively quantify ataxia in patients with liver cirrhosis.

METHODS

One hundred and seven patients with liver cirrhosis were tested for postural control using posturography and compared with 25 controls. For quantification of HE, we used the number connection tests A and B, ammonia levels (NH3), and the partial pressure of ammonia in the arterial blood (pNH3).

RESULTS

Patients showed an impaired postural control compared with controls. Patients with Child C cirrhosis had lower scores in the posturography than those with Child A or B cirrhosis. Patients with alcohol-induced (AIC) Child B cirrhosis achieved lower scores in the posturography than those with non-alcohol-induced (NAIC) Child B cirrhosis. Patients with AIC Child C had lower scores than the corresponding NAIC patients, although this did not reach statistical significance. In the NAIC group Child C patients, in the AIC group Child B and C patients had lower scores than the controls. Patients with abnormal results in the number connection tests, as well as those with high NH3 and pNH3 levels showed worse postural control than those with normal results.

CONCLUSION

Patients with cirrhosis have an impaired postural control compared with controls and this impairment deteriorates with progression of liver disease. HE as well as past alcohol abuse contribute to the pathogenesis of ataxia in liver cirrhosis and past alcohol abuse leads to an earlier and more pronounced manifestation of ataxia in the affected patients.

Relationships of job hazards, lack of knowledge, alcohol use, health status and risk taking behavior to work injury of coal miners: a case-control study in India

Objective is to assess the relationships of job hazards, individual characteristics, and risk taking behavior to occupational injuries of coal miners. This case-control study compared 245 male underground coal miners with injury during the previous two-year period with 330 matched controls without injury during the previous five years. Data were collected via face-to-face interview and analyzed using the conditional logistic model. Handling material, poor environmental/working conditions, and geological/strata control- related hazards were the main risk factors: adjusted ORs 5.15 (95% CI 2.42-10.9), 2.40 (95% CI 1.29-4.47), and 2.25 (95% CI 1.24-4.07) respectively. Their roles were higher among the face-workers than among the non-face-workers. No formal education, alcohol consumption, disease, big-family, and risk-taking behavior were associated with injuries (2.36</=ORs</=10.35), and the findings were similar for both face and non-face workers. Prevention should focus on handling material, poor environmental condition, especially addressing workers with no formal education, alcohol consumption, disease, big family size, and risk-taking behavior.

Association of physical job demands, smoking and alcohol abuse with subsequent premature mortality: a 9-year follow-up population-based study

This study assessed the relationships of physical job demands (PJD), smoking, and alcohol abuse, with premature mortality before age 70 (PM-70) among the working or inactive population. The sample included 4,268 subjects aged 15 or more randomly selected in north-eastern France. They completed a mailed questionnaire (birth date, sex, weight, height, job, PJD, smoking habit, alcohol abuse (Deta questionnaire)) in 1996 and were followed for mortality until 2004 (9 yr). PJD score was defined by the cumulative number of the following high job demands at work: hammer, vibrating platform, pneumatic tools, other vibrating hand tools, screwdriver, handling objects, awkward posture, tasks at heights, machine tools, pace, working on a production line, standing about and walking. The data were analyzed using the Poisson regression model. Those with PM-70 were 126 (3.81 per 1,000 person-years). The leading causes of death were cancers (46.4% in men, 57.1% in women), cardiovascular diseases (20.2% and 11.9%), suicide (9.5% and 7.1%), respiratory diseases (6.0% and 4.8%), and digestive diseases (2.4% and 4.8%). PJD3, smoker, and alcohol abuse had adjusted risk ratios of 1.71 (95% CI 1.02-2.88), 1.76 (1.08-2.88), and 2.07 (1.31-3.26) respectively for all-cause mortality. Manual workers had a risk ratio of 1.84 (1.00-3.37) compared to the higher socio-economic classes. The men had a two-fold higher mortality rate than the women; this difference became non-significant when controlling for job, PJD, smoker and alcohol abuse. For cancer mortality the factors PJD3, smoker, and alcohol abuse had adjusted risk ratios of 2.00 (1.00-3.99), 2.34 (1.19-4.63), and 2.22 (1.17-4.20), respectively. Health promotion efforts should be directed at structural measures of task redesign and they should also concern lifestyle.

Associations of social and material deprivation with tobacco, alcohol, and psychotropic drug use, and gender: a population-based study

BACKGROUND

The aim was to assess the relationships between social and material deprivation and the use of tobacco, excessive alcohol and psychotropic drugs by both sexes and in various age groups. Greater knowledge concerning these issues may help public health policy-makers design more effective means of preventing substance abuse.

METHODS

The sample comprised 6,216 people aged > or 15 years randomly selected from the population in north-eastern France. Subjects completed a post-mailed questionnaire covering socio-demographic characteristics, occupation, employment, income, smoking habit, alcohol abuse and "psychotropic" drug intake (for headache, tiredness, nervousness, anxiety, insomnia). A deprivation score (D) was defined by the cumulative number of: low educational level, manual worker, unemployed, living alone, nationality other than western European, low income, and non-home-ownership. Data were analysed using adjusted odds ratios (ORa) computed with logistic models.

RESULTS

Deprivation was common: 37.4% of respondents fell into category D = 1, 21.2% into D = 2, and 10.0% into D > or 3a re men than women reported tobacco use (30.2% vs. 21.9%) and alcohol abuse (12.5% vs. 3.3%), whereas psychotropic drug use was more common among women (23.8% vs. 41.0%). Increasing levels of deprivation were associated with a greater likelihood of tobacco use (ORa vs. D = 0: 1.16 in D = 1, 1.49 in D = 2, and 1.93 in D > or = 3), alcohol abuse (1.19 in D = 1, 1.32 in D = 2, and 1.80 in D > or = 3) and frequent psychotropic drug intake (1.26 in D = 1, 1.51 in D = 2, and 1.91 in D > or = 3). These patterns were observed in working/other non-retired men and women (except for alcohol abuse in women). Among retired people, deprivation was associated with tobacco and psychotropic drug use only in men.

CONCLUSION

Preventive measures should be designed to improve work conditions, reduce deprivation, and help deprived populations to be more aware of risk and to find remedial measures.

Associations of job, living conditions and lifestyle with occupational injury in working population: a population-based study

OBJECTIVES

To assess the roles of job demands, living conditions and lifestyle in occupational injury.

METHODS

The sample included 2,888 workers, aged > or =15 years, randomly selected from the north-eastern France. The subjects completed a mailed questionnaire. Data were analyzed with adjusted odds ratios (ORa) computed with the logistic model.

RESULTS

In total, 9.2% of workers had an injury during the previous 2 years. The high job demands: tasks at height, handling objects, pneumatic tools, other vibrating hand tools, work in adverse climate, physical workload, vibrating platform, machine tools, cold, heat, awkward posture, noise, hammer, and pace had crude odds ratios between 1.81 and 5.25 for injury. A strong exposure-response relationship was found between the cumulated job demands (CJD, defined by their number) and injury: OR 1.88 (95% CI 1.23-2.87) for CJD1, 4.39 (2.98-4.46) for CJD2-3, and 9.93 (6.70-14.7) for CJD > or = 4, versus CJD0. These ORs decreased to 1.68, 3.70, and 7.15 respectively, when adjusted for sex, age, and living conditions/lifestyle confounders; and to 1.54, 2.99, and 5.45 respectively when also adjusted for job category. The following factors had significant ORa: age <30 years (1.54, 1.12-2.12), male (1.64, 1.18-2.30), smoking (1.60, 1.22-2.10), musculoskeletal disorders (1.54, 1.17-2.04), and frequent drug use for fatigue (2.03, 1.17-3.53). The workmen, farmers/craftsmen/tradesmen, and foremen had a 5.7-8.7-fold while the clerks and technicians a 2.7-3.6-fold higher risk compared with upper class. The risk associated with CJD was twofold higher among the workers aged > or =40 or with frequent drug use for fatigue compared with the others. Obesity had ORa 2.05 (1.11-3.78) among the subjects aged > or =40, and excess alcohol use had ORa 2.44 (1.26-4.72) among those free of disease.

CONCLUSIONS

This study identified a wide range of job demands and living conditions/lifestyle which predicted injury. Preventive measures should be conducted to reduce job demands and to help workers to be aware of the risk and to improve their living conditions/lifestyle.

Effect of Ethanol on Visual-Vestibular Interactions During Vertical Linear Body Acceleration

BACKGROUND

Ethanol led to disturbed dynamic visual acuity (DVA) during vertical linear acceleration (VLA; amplitude, 5 cm; frequency, 1.2 Hz). The aim of this study was to analyze whether suppression of visual-oculomotor or vestibular pathway is responsible for the disturbance of DVA.

METHODS

Twenty volunteers were investigated before and after ethanol consumption (mean breath alcohol concentration, 0.32 mg/liter). Vertical eye movements and linear head acceleration were recorded. Tested stimuli were vestibular (VLA in the dark), visual (smooth pursuit), and combined (VLA plus fixation on an earth-fixed target) stimulation; visual suppression (VLA plus fixation of a head-fixed target); static visual acuity; and DVA. Parameters of analysis were gain, sensitivity, eye velocity and amplitude, latency between onset of head acceleration and start of eye movement, correct and wrong answers during static visual acuity and DVA testing, feeling of drunkenness (FOD), and breath alcohol concentration.

RESULTS

Both during isolated visual and during combined visual-vestibular stimulation, alcohol induced a significant latency increase. Furthermore, DVA was disturbed after ethanol consumption. Test subjects with a strong alcohol-induced disturbance of DVA presented during isolated visual stimulation a significantly higher latency change than volunteers with a minor alcohol-induced disturbance of DVA. On the basis of the FOD, two groups were formed (one with a slight and one with a strong FOD). The two groups differed significantly concerning the alcohol-induced latency increase during isolated visual stimulation and the alcohol-induced disturbance of DVA.

CONCLUSIONS

Ethanol leads to a disturbance of the visual-oculomotor system and, thus, even during combined visual-vestibular stimulation, to a latency increase. This "delay" is responsible for the disturbance of DVA. This alcohol-induced suppression of the visual-oculomotor system and the disturbance of DVA show a significantly positive correlation with the subjective FOD.

Individual characteristics in occupational accidents due to imbalance: a case-control study of the employees of a railway company

BACKGROUND

Falls are frequent occupational accidents, and are responsible for a significant amount of lost working time and, more importantly, for a high mortality. The factors involved in falling mechanisms can be of external or individual origin, the latter being less well identified.

AIMS

To assess the relations between certain individual characteristics and occupational accidents due to imbalance.

METHODS

A total of 427 male employees, who had been victims of at least one occupational accident with sick leave due to imbalance (cases) and 427 controls were recruited among the employees of a large French railway company. A standardised questionnaire on life conditions and professional factors, and a description of the accidents was filled in by an occupational physician for each subject.

RESULTS

Some job categories were more affected by a specific release mechanism of work related falls. Certain individual characteristics such as smoking, alcohol consumption, inactivity, sleep disorders, and request for a job change were correlated with the occurrence of occupational accidents. Sick leaves of eight days or over were more frequent in older and overweight injured workers. Some lesions were linked with the specific fall released mechanisms.

CONCLUSIONS

Individual characteristics can increase the risk of occupational accidents, especially falling. This study identified subjects most at risk on whom prevention related to working conditions and falls could be focused.

Computerised dynamic posturography to assess recovery comparing general anaesthesia with sedation and local anaesthesia for day case nasal surgery

Computerised dynamic posturography (CDP) can be used as an early marker of recovery to street fitness in patients undergoing ambulatory surgery. We studied three groups of patients undergoing nasal surgery. The goal of this study was to determine whether recovery, as assessed by CDP, is more rapid in patients having nasal surgery under sedation coupled with local anaesthesia or those having surgery under general anaesthesia. We further assessed the acceptability of sedation accompanied by local anaesthesia. A control group was included to determine if there is a learning curve to posturography. There was no difference between the two study groups in terms of balance. Balance was not significantly impaired at 3 h postoperative testing.

Ataxia from lithium toxicity successfully treated with high-dose buspirone: a single-case experimental design

Injury to the cerebellum commonly results in clumsiness or uncoordinated movement, which is referred to as ataxia. The severity of ataxia varies according to the extent of the lesion. Severe ataxia usually restricts activities of daily living, impairs mobility, and increases level of disability. Recent studies investigating use of serotonin agonists in the treatment of ataxia have produced mixed results; however, buspirone with an affinity specific to the 5-hydroxytryptamine(1A) subreceptors has shown promise. In this brief report, we use a prospective, open, single-case experimental design to describe substantial subjective and objective dose-dependent improvement of ataxia after unusually high doses of buspirone taken by a patient whose severe ataxia was due to lithium toxicity.

Alcohol and injuries in elderly people

Injuries are a common cause of morbidity and mortality among elderly people. Falls are the most common type of accident, accounting for around 40% of injuries. There is substantial evidence that heavy alcohol use is an important risk factor for injuries in younger people, but results of the few studies of alcohol and injuries among elderly people have been inconsistent. In this paper, we review the literature on the effects of alcohol on gait and balance and present reasons that a causal relationship between alcohol and injuries is biologically plausible. We review the epidemiological studies of the relationship between alcohol and falls, hip fractures and other injuries in the elderly population and discuss sources of error in these studies. Selection bias, small sample sizes, measurement error and potential confounders such as age, gender, health status and medications may have played a substantial role in negative results from several studies. Further research that will help clarify the relationship between alcohol and injuries in elderly people is sorely needed.