Chronic solvent-induced encephalopathy: course and prognostic factors of neuropsychological functioning.

PURPOSE: Working in conditions with daily exposure to organic solvents for many years can result in a disease known as chronic solvent-induced encephalopathy (CSE). The aims for this study were to describe the neuropsychological course of CSE after first diagnosis and to detect prognostic factors for neuropsychological impairment after diagnosis. METHODS: This prospective study follows a Dutch cohort of CSE patients who were first diagnosed between 2001 and 2011 and underwent a second neuropsychological assessment 1.5-2 years later. Cognitive subdomains were assessed and an overall cognitive impairment score was calculated. Paired t tests and multivariate linear regression analyses were performed to describe the neuropsychological course and to obtain prognostic factors for the neuropsychological functioning at follow-up. RESULTS: There was a significant improvement on neuropsychological subdomains at follow-up, with effect sizes between small and medium (Cohen's d 0.27-0.54) and a significant overall improvement of neuropsychological impairment with a medium effect size (Cohen's d 0.56). Prognostic variables for more neuropsychological impairment at follow-up were a higher level of neuropsychological impairment at diagnosis and having a comorbid diagnosis of a psychiatric disorder at diagnosis. CONCLUSIONS: Results are in line with previous research on the course of CSE, stating that CSE is a non-progressive disease after cessation of exposure. However, during follow-up the percentage patients with permanent work disability pension increased from 14 to 37%. Preventive action is needed in countries where exposure to organic solvents is still high to prevent new cases of CSE.

The Coping with Attention and Memory Complaints Questionnaire (CAMQ): psychometric evaluation of an instrument in suspected chronic solvent-induced encephalopathy (CSE).

Long-term occupational exposure to organic solvents may induce chronic solvent-induced encephalopathy (CSE), leading to neuropsychological impairments. We developed the Coping with Attention and Memory Complaints Questionnaire (CAMQ), an instrument for the assessment of coping strategies in patients suspected of CSE with neuropsychological complaints. Items for the CAMQ were based on existing coping dimensions and constructed by experts. The psychometric properties of the CAMQ were evaluated in a sample of 307 workers suspected of CSE. Factor analysis revealed four coping subscales: active coping, avoidance, acceptance, and seeking social support, all with good internal consistency (alphas .71-.78) and good test-retest reliability (ICCs .67-.82). The subscales demonstrated moderate correlations with related external constructs such as anxiety and depression, locus of control, meta-memory, mastery and generic coping styles. In conclusion, this study: (1) shows that the newly developed CAMQ is a reliable instrument, and (2) provides evidence for its validity in assessing coping with complaints of memory and attention in CSE-suspected patients. These results may serve for further study on coping with complaints of memory and attention, psychological adjustment and well-being in CSE patients.

Cerebral impairment in chronic solvent-induced encephalopathy.

OBJECTIVE: Worldwide, many workers experience occupational exposure to organic solvents, which may induce chronic solvent-induced encephalopathy (CSE). Disturbances within the frontostriatothalamic (FST) circuitry might explain the symptomatology of CSE. We tested the hypothesis of FST circuitry abnormalities in CSE, as well as associations with performance of psychomotor speed, attention, and solvent exposure. To detect preclinical, solvent-related effects, we also studied the FST circuitry in solvent-exposed, but asymptomatic workers. METHODS: Ten CSE patients, 10 asymptomatic but solvent-exposed house painters (EC), and 11 nonexposed asymptomatic carpenters were included. Dopamine D(2) receptor (D2R) binding, central nervous system tissue metabolites, and fractional anisotropy were measured within the FST circuitry, using single-photon emission computed tomography, magnetic resonance spectroscopy, and diffusion tensor imaging. Performance of psychomotor speed and attention, and severity of solvent exposure were assessed. RESULTS: Striatal D2R binding was reduced in CSE. In the solvent-exposed asymptomatic patients, striatal D2R binding and levels of N-acetylaspartate + N-acetylaspartyl-glutamate in frontal gray matter were reduced. In both exposed groups, a trend was seen for reduced choline in frontal gray matter. In CSE, the fractional anisotropy in the thalamus, caudate nucleus, and striatal D2R binding significantly predicted reduced performance of attention and psychomotor speed. In CSE, striatal D2R binding showed a negative correlation with solvent exposure. INTERPRETATION: This is the first study in CSE showing pronounced disturbances within the FST circuitry that are related to the clinical findings and to exposure severity to solvents. The comparable, but milder, abnormalities within the FST circuitry in the exposed asymptomatic workers may imply a presymptomatic phase of CSE.

Development and Evaluation of a Training Program on Occupational Health Research and Surveillance in Turkey.

OBJECTIVES: The aim of this study was to increase knowledge and skills regarding occupational health surveillance and research in professionals. METHODS: Following the Analysis, Design, Development, Implementation, and Evaluation model, several training modules have been designed and implemented in the course of 2016. Evaluation forms were distributed to 42 participants before the start and after each training module to measure changes in knowledge, skills, and self-efficacy. RESULTS: The majority of the participants were satisfied and found the training relevant and interesting for adult learners. The level of self-efficacy increased after the trainings. Females and occupational physicians displayed higher scores than men and other disciplines. After 1 year, the self-efficacy level decreased, but the level was still substantially higher than before the training. CONCLUSIONS: Feedback on the implemented training program was favorable. Participants were able to acquire and apply competencies in the subject matter at short and long term.

Prevention of Occupational Diseases in Turkey: Deriving Lessons From Journey of Surveillance.

INTRODUCTION: To prevent and manage the societal and economic burden of occupational diseases (ODs), countries should develop strong prevention policies, health surveillance and registry systems. This study aims to contribute to the improvement of OD surveillance at national level as well as to identify priority actions in Turkey. METHODS: The history and current status of occupational health studies were considered from the perspective of OD surveillance. Interpretative research was done through literature review on occupational health at national, regional and international level. Analyses were focused on countries' experiences in policy development and practice, roles and responsibilities of institutions, multidisciplinary and intersectoral collaboration. OD surveillance models of Turkey, Belgium and the Netherlands were examined through exchange visits. Face-to-face interviews were conducted to explore the peculiarities of legislative and institutional structures, the best and worst practices, and approach principles. RESULTS: Some countries are more focused on exploring OD trends through effective and cost-efficient researches, with particular attention to new and emerging ODs. Other countries try to reach every single case of OD for compensation and rehabilitation. Each practice has advantages and shortcomings, but they are not mutually exclusive, and thus an effective combination is possible. CONCLUSION: Effective surveillance and registry approaches play a key role in the prevention of ODs. A well-designed system enables monitoring and assessment of OD prevalence and trends, and adoption of preventive measures while improving the effectiveness of redressing and compensation. A robust surveillance does not only provide protection of workers' health but also advances prevention of economic losses.

Education and Training: Key Factors in Global Occupational and Environmental Health.

INTRODUCTION: Education and training in Occupational and Environmental Health (OEH) play an important role in building global capacity and contribute to safer working conditions. The shortage of occupational health professionals, the lack of knowledge and a high number of occupational accidents and diseases stress the demand for providing further education and training in OEH. This need is especially urgent in low and middle-income countries. Three international courses on OEH provide valuable insights on how to develop successful trainings in the field and how to contribute to the creation of healthy and safe workplaces. METHODOLOGY AND RESULTS: The courses "Global Occupational and Environmental Determinants of Diseases: a multidisciplinary and multicultural approach for prevention" (University of Brescia, Italy), "Advanced International Training Course in OEH" (Chulabhorn Research Institute, Bangkok, Thailand) and "Teaching interventions crossing borders" (Ludwig-Maximillians-Universität, Munich, Germany) offer a unique networking opportunity for health professionals from low-, middle- and high-income countries. Three main characteristics of learning were identified as successful for adult learning in OEH: Interdisciplinary learning allows exchanging skills and knowledge and therefore closes gaps between the several disciplines within OEH. Experiential learning enables participants to reflect on their personal experiences, e.g. through workplace visits. Finally, active learning empowers the learner to take the leading role in the learning process using e.g. problem- or project-based learning approaches. CONCLUSION: Training and education in OEH should become a higher priority by including it in the standard public health and medical curricula. For this, train the trainer approaches are essential in many countries. Any OEH training should follow the interdisciplinary, experiential and interactive learning approach and should be accessible to participants from all regions.

The Mersin Greenhouse Workers Study. Surveillance of Work-related Skin, Respiratory, and Musculoskeletal Diseases.

BACKGROUND: Skin, respiratory, and musculoskeletal diseases in greenhouse workers are frequently observed due to exposure to plant products and pesticides in enclosed conditions and ergonomic risks. Current studies on occupational health risks of greenhouse workers in Turkey are insufficient. OBJECTIVES: The aim of the present study was to assess work-related skin, respiratory, and musculoskeletal diseases in greenhouse workers in the Erdemli province, Mersin, an area with a workforce predominantly active as greenhouse workers. METHODS: The study population consists of adult greenhouse workers, who visited their family physician between June 12-14, 2017 and were diagnosed with dermatological, respiratory, and musculoskeletal diseases. Immediately after this consultation, occupational physicians conducted face-to-face interviews, asking questions about sociodemographic features and occupational factors including current and previous work, current exposures and relation of current symptoms with work. RESULTS: In total, 423 workers with 555 diagnoses were included in the study. Percentages of diagnoses were 30.1%, 21.6% and 48.3%, for skin, respiratory and musculoskeletal diseases respectively. Nearly half of participants had taken an absence from work due to those diseases. Mean age of onset for greenhouse working was 15.5 years. Almost all participants (96.2%) reported contact with chemicals, and usage of respiratory protection was low (17.3%). Pesticides were regarded as a risk factor by nearly two-thirds of workers with skin or respiratory system disorders. Participants' answers to questions regarding the relationship between their diseases and their work was positive for more than half of patients and patients with skin and respiratory diseases. Nearly half of the patients with musculoskeletal diseases attributed their complaints to physical overload at work. CONCLUSIONS: We found evidence of work-relatedness in almost half of the 555 greenhouse workers with dermatological, respiratory and musculoskeletal diseases. These findings are helpful in creating an awareness program. There is a need for a more detailed assessment of the cases and the related working conditions to start a tailored prevention program.

[Brain damage caused by exposure to organic solvents; diagnostics and disease course of chronic solvent-induced encephalopathy]. / Hersenschade door blootstelling aan oplosmiddelen; diagnostiek en beloop van chronische toxische encefalopathie.

Since 1997 more than 3,000 patients have been referred to one of the two Dutch Solvent Teams with health problems that may have been caused by long-term occupational exposure to organic solvents. A diagnosis of 'chronic solvent-induced encephalopathy' was made in approximately 500 patients. The diagnostics of this disease is based on five elements: (a) symptoms in line with the diagnosis; (b) relevant exposure to an organic solvent with neurotoxic effects; (c) a clear temporal relationship between the onset of symptoms and exposure to a solvent with neurotoxic effects; (d) exclusion of other causes for the symptoms; and (e) impairment on neuropsychological assessment. Exposure to organic solvents can cause chronic health effects, which may even persist years after exposure has ceased. In general, no more serious deterioration of health is observed after exposure has ceased.

A screening programme on chronic solvent-induced encephalopathy among Dutch painters.

BACKGROUND: Long-term exposure to organic solvents may lead to chronic solvent induced encephalopathy (CSE) in painters. In combination with reduction of exposure, a workers' health surveillance programme was developed, resulting in a three-stage CSE screening procedure for early neurobehavioural changes possibly predicting chronic health effects. The screening consists of a questionnaire (Neurosymptom Screening Checklist 60, NSC-60), computerised neurobehavioural functioning testing (Neurobehavioural Evaluation System; NES2) and multidisciplinary differential diagnostic evaluation by experts (called 'Solvent Team'). Results from the screening were compared with the results of the 'care as usual' (CAU), in which symptomatic patients were referred directly to the Solvent Team by occupational physicians, general practitioners or medical specialists. Parallel to the screening programme, a legal ban on indoor use of solvent-based paints resulted in lower exposure to solvents. OBJECTIVE: To investigate the usefulness of the NSC-60 questionnaire as a screening tool for CSE among painters and to investigate the course of the number of CSE cases over the years as a potential consequence of improved prevention and control. RESULTS: From 1998 to 2004, more than 40,000 painters were invited to participate in a health surveillance programme including a periodical occupational health examination (PHE) and 50% did participate. Four percent (N=794) of these had a positive score on the NSC-60. The Solvent Team assessed 101 of these for CSE, which resulted in 27 CSE cases diagnosed. CAU during the same period of the surveillance (1998-2004) yielded 619 painters and 75 of these had the diagnosis CSE. After 2002 the number of CSE diagnosed cases dropped considerably and in 2004 only one case of CSE could be diagnosed. The substantially lower prevalence of CSE diagnosed cases in painters after 2002 might partly be explained as a result of a successful participation in the screening procedure of most prevalent CSE cases during the years 1998-2002. A second reason for the reduction of new diagnosed cases of CSE can be the effectiveness of the ban on indoor use of solvent-based paints resulting in lower exposure levels at work. CONCLUSION: The screening procedure is useful to screen for CSE among people taking part in the PHE programme. Control of CSE can be achieved by an integrated preventive approach with reduction of exposure and screening on early health effects.

Chronic solvent-induced encephalopathy: European consensus of neuropsychological characteristics, assessment, and guidelines for diagnostics.

INTRODUCTION: The presence of neuropsychological impairment is a hallmark of chronic solvent-induced encephalopathy (CSE), and using clinical neuropsychological procedures to generate a valid assessment of the condition is crucial for its diagnosis. The goals of this consensus document are to provide updated knowledge of the neuropsychological characteristics of CSE and to provide internationally acceptable guidelines for using neuropsychological assessments in the process of diagnosing patients who are suspected of having CSE. MATERIALS AND METHODS: A European working group that was composed of experts in the field of the clinical diagnosis of CSE met at several round-table meetings and prepared this report. The first section of the consensus paper addresses a review of the relevant literature that was published between 1985 and March 2012. The second section addresses recommendations for the clinical neuropsychological assessment of patients who are suspected of having CSE. RESULTS: The literature review indicates that the most common neuropsychological impairments in CSE patients are within the domains of attention, particularly the speed of information processing, memory, and motor performance. It appears that the influence of CSE on memory processes mainly involves immediate recall and generally involves verbal, visual and visuospatial material. In the second section, six recommendations are presented regarding important functional domains for the neuropsychological diagnostic process of CSE that relate to the evaluation of neuropsychological impairment, the assessment and evaluation of symptoms, differential diagnostic considerations, the reliability and validity of neuropsychological test results, and the retesting of patients. DISCUSSION AND CONCLUSIONS: These recommendations will contribute to the improvement of the process for accurately diagnosing CSE, better counselling for CSE patients, the comparability of epidemiological data between countries, and finally, by raising awareness, these recommendations will contribute to combating the adverse health effects of occupational exposure to solvents.

Decision rules for assessment of chronic solvent-induced encephalopathy: Results in 2370 patients.

For the diagnosis of patients suspected of chronic solvent-induced encephalopathy (CSE), it would be helpful if the applied cognitive tests show a characteristic profile of impairment in this disease. We investigated the existence of such a profile. In 1997-2006 two expert teams in The Netherlands systematically examined 2370 patients referred for evaluation of suspected CSE. The procedure included two selection steps: (1) intake interview, using criteria of exposure, development of symptoms and absence of non-solvent causes, and (2) seven tests of the computerized Neurobehavioural Evaluation System (NES). Patients showing negligible impairments were considered free from CSE and were not further examined. The third step comprised a neuropsychological, neurological and exposure evaluation. Explicit decision rules for the diagnosis of CSE were developed, including a minimum score for cognitive impairment summarizing 25 cognitive tests. These rules were retroactively applied to 563 patients, comprising 513 patients who had regularly completed all diagnostic steps and a sample of 50 out of the approximately 450 patients with negligible impairments on the NES, who were fully examined. The data from this sample were extrapolated to the original number of 450. In the combined population of 963 patients, a calculated 301 patients were given the diagnosis 'Solely CSE', 242 'CSE and other disease', 158 'Other Disease' and 262 'No (known) disease'. In the Solely CSE patients, the most impaired tests regarded Verbal Fluency & -Similarities, Motor Speed and Simple Attention. A profile of test results that might support the identification of patients with CSE amongst the other referred patients, was not found. The diverging results of related cognitive tests indicate that the use of a core test battery is needed to improve comparability. We consider the decision rules as a step towards a more objective assessment of CSE.

Tracing new occupational diseases in nano-workers.

Identifying new risks due to new technologies like nanotechnology is a process that involves many uncertainties in which a balance must be found between a dynamic and a careful approach. The challenge is to prevent any occupational damage to health without creating unnecessary concern.

Prevalence of psychiatric disorders in patients with chronic solvent induced encephalopathy (CSE).

INTRODUCTION: Long term occupational exposure to organic solvents may induce chronic solvent-induced encephalopathy (CSE), characterized by mild to severe cognitive impairment, generally seen as the key diagnostic feature. Psychiatric disorders are often diagnosed in subjects with CSE, but were never studied in more detail. This study was designed to establish the prevalence rates of DSM IV mood, anxiety, and alcohol and substance related disorders in patients with CSE. MATERIALS AND METHODS: In CSE, n=203 (consecutively recruited between 2002 and 2005), defined according to the criteria of the World Health Organisation (WHO), one month prevalence rates of DSM IV mood, anxiety, and life time alcohol/substance related disorders were assessed using the Structured Clinical Interview for DSM IV disorders (SCID). These prevalences were compared with those from an age and gender matched community sample (n=3212) while controlling for insufficient neuropsychological test effort. RESULTS: In CSE, prevalence rates for major depressive disorder (n=36, relative risk (RR)=7.4), dysthymia (n=15, RR=6.0), panic disorders (n=18, RR=7.1), agoraphobia (n=7, RR=5.5) and generalized anxiety disorder (n=19, RR=15.8) were increased. Reduced prevalence rates were found for alcohol related disorders (n=21, RR=0.3). Insufficient neuropsychological test effort was not associated with increased prevalence rates of DSM IV disorders in subjects suspected of CSE. DISCUSSION AND CONCLUSIONS: In conclusion, in this first large scale study in patients with CSE, prevalence rates of DSM IV mood and anxiety disorders were elevated as compared with those in the general community, while the prevalence rates of alcohol related disorders were reduced. Further study must determine whether CSE, and mood and anxiety disorders, share a same, solvent induced, neurobiological pathway, supporting the use of a more inclusive diagnostic approach. Additionally, randomised controlled trials are needed for the urgent issue of how to treat mood and anxiety disorders in CSE patients effectively.

NanoLINEN: nanotoxicology link between India and European Nations.

Nanotoxicology link between India and European Nations (NanoLINEN) is a consortium of 7 European laboratories and Indian Institute of Toxicology Research (CSIR Laboratory) from India to strengthen the research ties in the area of Nanomaterial Toxicology. The goal of this project is to develop robust risk assessment methodologies that will be useful for the community manufacturing and using nano-products.

The course of chronic solvent induced encephalopathy: a systematic review.

BACKGROUND: Worldwide millions of workers are exposed to organic solvents. Long term exposure leads in some workers to the development of Chronic Solvent induced Encephalopathy (CSE). The first reports about CSE came from the European Nordic countries in the 1970s. In spite of decades of experience with this disease, little is known about the course and prognostic factors of CSE. OBJECTIVE: To provide an overview of the evidence about the course and prognostic factors of CSE. METHODS: A systematic review was conducted. Databases PubMed, PsycINFO (1970-2008) and EMBASE (1980-2008) were searched with the search strategy: solvent AND follow up AND (encephalopathy OR chronic intoxication). Inclusion criteria were: written in English, study population of CSE patients, follow-up time of at least 1 year. Included articles were assessed on methodological quality. RESULTS: Sixty unique articles were retrieved of which sixteen met the inclusion criteria. Data extraction provided information about domains of neurology, neuropsychology, physical and mental health perceptions, and social consequences. In a number of studies no significant changes, and in other studies improvement of functioning could be measured. Prognostic factors resulting from included studies were summarized for each domain indicating a potential positive influence of younger age and lower exposure variables. DISCUSSION: Due to the large heterogeneity of methodology no levels of evidence could be obtained. This review shows that there is a need for future research that addresses a variety of domains of functioning, hopefully resulting in an overall prognostic model for CSE. CONCLUSION: Studies in this review are in agreement about CSE being a non-progressive disease in which no severe deterioration of functioning occurs after diagnosis. In a number of studies no significant changes, and in other studies improvement of functioning could be measured. Presumably cessation of exposure might be one of the causal factors for the non-progressive character of the disease as has been found. Future studies are needed to clarify the role of various prognostic factors on the course of CSE.