Moniek van Hout

Suboptimal performance on neuropsychological tests in patients with suspected chronic toxic encephalopathy.

Suboptimal performance during neuropsychological testing can seriously complicate assessment in behavioral neurotoxicology. We present data on the prevalence of suboptimal performance in a group of Dutch patients with suspected chronic toxic encephalopathy (CTE) after long-term occupational exposure to solvents. One hundred and forty-five subjects referred to one of two Dutch national assessment centers for CTE were administered the Amsterdam Short-Term Memory Test (ASTM) and the Test of Memory Malingering (TOMM), two tests specifically developed for the detection of suboptimal performance. For both tests, very cautious cut-off scores were chosen with a specificity of 99%. Results indicated that suboptimal performance appears to be a substantial problem in this group of patients with suspected CTE after long-term exposure to organic solvents. Only 54% of our subjects obtained normal scores on both tests of malingering, i.e. at or above cut-off score. The two tests seemed to measure the same concept in that nearly all the subjects with low TOMM scores also had low ASTM scores. However, a higher proportion of subjects scored below the cut-off on the ASTM than on the TOMM.

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.

Psychosocial and cognitive rehabilitation of patients with solvent-induced chronic toxic encephalopathy: A randomised controlled study

Background: There is little experience with the (neuro) psychological treatment of patients with solvent-induced chronic toxic encephalopathy (CSE). In this randomised controlled trial (RCT), a treatment programme was evaluated based on previous outcome studies of patients with chronic fatigue, whiplash and traumatic brain damage. Methods: The treatment consisted of 8 group sessions based on cognitive behavioural principles focusing on inadequate illness behaviours, and 8 sessions of cognitive strategy training to compensate memory problems. The research design was an RCT with follow-up, comparing the cumulative effect of the 2 interventions allocated in random order with a waiting-list control group. Outcome measures were treatment satisfaction, self-ratings of psychosocial and cognitive changes, psychosocial and memory questionnaires and neuropsychological tests. Multiple linear regression analyses were performed with baseline scores, treatment versus control condition, effort status, and litigation or financial compensation status as predictors. Results: Ninety-five patients started treatment, 84 patients had complete data. Treatment satisfaction was high. After the treatment, only the treatment group had improved on objective memory tests and on complaints related to CSE, but not on other questionnaires. Treatment effects diminished at follow-up. Insufficient effort and litigation were negatively associated with treatment outcome. Conclusions: The positive treatment effects on the cognitive tests were only temporary. It might be important to study the effect of booster sessions to update practiced cognitive strategies. Effort was an important predictor of success, more important than involvement in a litigation procedure. This finding should have implications for the selection of patients.

Psychological treatment of patients with chronic toxic encephalopathy: Lessons from studies of chronic fatigue and whiplash

Background: Chronic toxic encephalopathy (CTE), which can result from long-term exposure to organic solvents, is characterized by problems of attention and memory, fatigue and affective symptoms. There is little experience with (neuro)psychological treatment in this patient group. We reviewed treatment outcome studies of CTE and comparable syndromes, namely, chronic whiplash-associated disorder (WAD) and chronic fatigue syndrome (CFS), with a view to providing recommendations for the psychological treatment of patients with CTE. Methods: PubMed and PsychLIT were systematically searched and reference lists of retrieved articles were studied. The articles were classified according to study design and level of evidence. Results: The studies of CFS provided high-level evidence for the effectiveness of cognitive-behavior therapy (CBT) in challenging dysfunctional cognitions regarding the effectiveness of rest and in stimulating graded activity. The studies of WAD were methodologically weaker, and most evaluated a combination of CBT and graded activity training. There was some evidence that changing fatigue- or pain-related behaviors may result in cognitive improvement. Two uncontrolled studies of CTE evaluated cognitive rehabilitation techniques but yielded inconsistent findings. Conclusions: CBT techniques focusing on changing illness attributions and on stimulating graded activity might be useful for patients with CTE, diminishing fatigue-related problems of concentration and memory. Future studies should evaluate whether cognitive deficits of CTE patients as a result of neurotoxic effects of exposure should be treated by cognitive rehabilitation.

Pitfalls in clinical assessment of neurotoxic diseases: negative effects of repeated diagnostic evaluation, illustrated by a clinical case.

Exposure to different toxic substances can have acute and chronic neurological and neuropsychiatric health effects on humans. Patients often report impaired concentration and memory, irritability, fatigue, instability of affect and difficulties in impulse control. The diagnostic process for neurotoxic diseases is complex and relies heavily on the exclusion of differential diagnosis and substantiating the cognitive complaints by neuropsychological assessment. Diagnostic evaluations have the purpose to help the patient by finding an explanation for the symptoms to guide treatment strategy or prevent further deterioration. But what if the diagnostic process in itself leads to problems that can be quite persistent and difficult to manage? The iatrogenic, or sick-making, side effects of the diagnostic process are the main focus of this case study.

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.