Differentiating Prodromal Dementia with Lewy Bodies from Prodromal Alzheimer's Disease: A Pragmatic Review for Clinicians.

This pragmatic review synthesises the current understanding of prodromal dementia with Lewy bodies (pDLB) and prodromal Alzheimer's disease (pAD), including clinical presentations, neuropsychological profiles, neuropsychiatric symptoms, biomarkers, and indications for disease management. The core clinical features of dementia with Lewy bodies (DLB)-parkinsonism, complex visual hallucinations, cognitive fluctuations, and REM sleep behaviour disorder are common prodromal symptoms. Supportive clinical features of pDLB include severe neuroleptic sensitivity, as well as autonomic and neuropsychiatric symptoms. The neuropsychological profile in mild cognitive impairment attributable to Lewy body pathology (MCI-LB) tends to include impairment in visuospatial skills and executive functioning, distinguishing it from MCI due to AD, which typically presents with impairment in memory. pDLB may present with cognitive impairment, psychiatric symptoms, and/or recurrent episodes of delirium, indicating that it is not necessarily synonymous with MCI-LB. Imaging, fluid and other biomarkers may play a crucial role in differentiating pDLB from pAD. The current MCI-LB criteria recognise low dopamine transporter uptake using positron emission tomography or single photon emission computed tomography (SPECT), loss of REM atonia on polysomnography, and sympathetic cardiac denervation using meta-iodobenzylguanidine SPECT as indicative biomarkers with slowing of dominant frequency on EEG among others as supportive biomarkers. This review also highlights the emergence of fluid and skin-based biomarkers. There is little research evidence for the treatment of pDLB, but pharmacological and non-pharmacological treatments for DLB may be discussed with patients. Non-pharmacological interventions such as diet, exercise, and cognitive stimulation may provide benefit, while evaluation and management of contributing factors like medications and sleep disturbances are vital. There is a need to expand research across diverse patient populations to address existing disparities in clinical trial participation. In conclusion, an early and accurate diagnosis of pDLB or pAD presents an opportunity for tailored interventions, improved healthcare outcomes, and enhanced quality of life for patients and care partners.

Dementia with Lewy bodies: Impact of co-pathologies and implications for clinical trial design.

Dementia with Lewy bodies (DLB) is clinically defined by the presence of visual hallucinations, fluctuations, rapid eye movement (REM) sleep behavioral disorder, and parkinsonism. Neuropathologically, it is characterized by the presence of Lewy pathology. However, neuropathological studies have demonstrated the high prevalence of coexistent Alzheimer's disease, TAR DNA-binding protein 43 (TDP-43), and cerebrovascular pathologic cases. Due to their high prevalence and clinical impact on DLB individuals, clinical trials should account for these co-pathologies in their design and selection and the interpretation of biomarkers values and outcomes. Here we discuss the frequency of the different co-pathologies in DLB and their cross-sectional and longitudinal clinical impact. We then evaluate the utility and possible applications of disease-specific and disease-nonspecific biomarkers and how co-pathologies can impact these biomarkers. We propose a framework for integrating multi-modal biomarker fingerprints and step-wise selection and assessment of DLB individuals for clinical trials, monitoring target engagement, and interpreting outcomes in the setting of co-pathologies.

Plasma metabolites distinguish dementia with Lewy bodies from Alzheimer's disease: a cross-sectional metabolomic analysis.

Background: In multifactorial diseases, alterations in the concentration of metabolites can identify novel pathological mechanisms at the intersection between genetic and environmental influences. This study aimed to profile the plasma metabolome of patients with dementia with Lewy bodies (DLB) and Alzheimer's disease (AD), two neurodegenerative disorders for which our understanding of the pathophysiology is incomplete. In the clinical setting, DLB is often mistaken for AD, highlighting a need for accurate diagnostic biomarkers. We therefore also aimed to determine the overlapping and differentiating metabolite patterns associated with each and establish whether identification of these patterns could be leveraged as biomarkers to support clinical diagnosis. Methods: A panel of 630 metabolites (Biocrates MxP Quant 500) and a further 232 metabolism indicators (biologically informative sums and ratios calculated from measured metabolites, each indicative for a specific pathway or synthesis; MetaboINDICATOR) were analyzed in plasma from patients with probable DLB (n = 15; age 77.6 ± 8.2 years), probable AD (n = 15; 76.1 ± 6.4 years), and age-matched cognitively healthy controls (HC; n = 15; 75.2 ± 6.9 years). Metabolites were quantified using a reversed-phase ultra-performance liquid chromatography column and triple-quadrupole mass spectrometer in multiple reaction monitoring (MRM) mode, or by using flow injection analysis in MRM mode. Data underwent multivariate (PCA analysis), univariate and receiving operator characteristic (ROC) analysis. Metabolite data were also correlated (Spearman r) with the collected clinical neuroimaging and protein biomarker data. Results: The PCA plot separated DLB, AD and HC groups (R2 = 0.518, Q2 = 0.348). Significant alterations in 17 detected metabolite parameters were identified (q ≤ 0.05), including neurotransmitters, amino acids and glycerophospholipids. Glutamine (Glu; q = 0.045) concentrations and indicators of sphingomyelin hydroxylation (q = 0.039) distinguished AD and DLB, and these significantly correlated with semi-quantitative measurement of cardiac sympathetic denervation. The most promising biomarker differentiating AD from DLB was Glu:lysophosphatidylcholine (lysoPC a 24:0) ratio (AUC = 0.92; 95%CI 0.809-0.996; sensitivity = 0.90; specificity = 0.90). Discussion: Several plasma metabolomic aberrations are shared by both DLB and AD, but a rise in plasma glutamine was specific to DLB. When measured against plasma lysoPC a C24:0, glutamine could differentiate DLB from AD, and the reproducibility of this biomarker should be investigated in larger cohorts.

Distinguishing Lewy Body Dementia from Alzheimer's Disease using Machine Learning on Heterogeneous Data: A Feasibility Study.

Dementia with Lewy Bodies (DLB) is the second most common form of dementia, but diagnostic markers for DLB can be expensive and inaccessible, and many cases of DLB are undiagnosed. This work applies machine learning techniques to determine the feasibility of distinguishing DLB from Alzheimer's Disease (AD) using heterogeneous data features. The Repeated Incremental Pruning to Produce Error Reduction (RIPPER) algorithm was first applied using a Leave-One-Out Cross-Validation protocol to a dataset comprising DLB and AD cases. Then, interpretable association rule-based diagnostic classifiers were obtained for distinguishing DLB from AD. The various diagnostic classifiers generated by this process had high accuracy over the whole dataset (mean accuracy of 94%). The mean accuracy in classifying their out-of-sample case was 80.5%. Every classifier generated consisted of very simple structure, each using 1-2 classification rules and 1-3 data features. As a group, the classifiers were heterogeneous and used several different data features. In particular, some of the classifiers used very simple and inexpensive diagnostic features, yet with high diagnostic accuracy. This work suggests that opportunities may exist for incorporating accessible diagnostic assessments while improving diagnostic rate for DLB. Clinical Relevance- Simple and interpretable high-performing machine learning algorithms identified a variety of readily available clinical assessments for differential diagnosis of dementia offering the opportunities to incorporate various simple and inexpensive screening tests for DLB and addressing the problem of DLB underdiagnosis.

Can early phase cardiac [123I]mIBG images be used to diagnose Lewy body disease?

PURPOSE: Some studies have suggested that cardiac [123I]metaiodobenzylguanidine images obtained 15-20 min after tracer administration are as accurate for dementia with Lewy bodies (DLB) diagnosis as standard images acquired after a delay of 3-4 h; some suggest delayed imaging is preferable. We compare early and delayed heart-to-mediastinum ratios (HMR) in a well-characterised research dataset and make recommendations for clinical practice. METHODS: Images were acquired using a Siemens gamma camera with medium energy collimators. Early images were obtained at 20 min and delayed at 4 h (± 30) min. In total 167 pairs of images were reviewed: 30 controls, 39 people with dementia and 98 with mild cognitive impairment. HMR normal cutoff values derived from control data were ≥2.10 for early imaging and ≥1.85 for delayed. RESULTS: HMR tended to drop between early and delayed for abnormal images, but increase for normal images. Histograms of early and delayed HMR showed a slightly better separation of results into two groups for delayed imaging. Accuracy results were slightly higher for delayed imaging than early imaging (73 vs. 77%), sensitivity 63 vs. 65% and specificity 82 vs. 88%. However, this was not statistically significant - in total only 8/167 (5%) of scans changed designation between early and delayed imaging. CONCLUSION: We suggest that a delayed image could be acquired only if the early result is borderline. This removes the need for delayed imaging in about 70% of patients. Adopting this protocol in clinical practice would reduce the time most patients have to wait and could free up scanner time.

Implementation of personalised medicine policies in mental healthcare: results from a stated preference study in the UK.

BACKGROUND: Public support for the implementation of personalised medicine policies (PMPs) within routine care is important owing to the high financial costs involved and the potential for redirection of resources from other services. AIMS: We aimed to determine the attributes of a PMP most likely to elicit public support for implementation. We also aimed to determine whether such support differed between a depression PMP and one for cystic fibrosis. METHOD: In a discrete-choice experiment, paired vignettes illustrating both the current model of care (CMoC) and a hypothetical PMP for either depression or cystic fibrosis were presented to a representative sample of the UK public (n = 2804). Each vignette integrated varying attributes, including anticipated therapeutic benefit over CMoC, and the annual cost to the taxpayer. Respondents were invited to express their preference for either the PMP or CMoC within each pair. RESULTS: The financial cost was the most important attribute influencing public support for PMPs. Respondents favoured PMP implementation where it benefited a higher proportion of patients or was anticipated to be more effective than CMoC. A reduction in services for non-eligible patients reduced the likelihood of support for PMPs. Respondents were more willing to fund PMPs for cystic fibrosis than for depression. CONCLUSIONS: Cost is a significant factor in the public's support for PMPs, but essential caveats, such as protection for services available to PMP-ineligible patients, may also apply. Further research should explore the factors contributing to condition-specific nuances in public support for PMPs.

Dementia with Lewy bodies research consortia: A global perspective from the ISTAART Lewy Body Dementias Professional Interest Area working group.

Dementia with Lewy bodies (DLB) research has seen a significant growth in international collaboration over the last three decades. However, researchers face a challenge in identifying large and diverse samples capable of powering longitudinal studies and clinical trials. The DLB research community has begun to focus efforts on supporting the development and harmonization of consortia, while also continuing to forge networks within which data and findings can be shared. This article describes the current state of DLB research collaborations on each continent. We discuss several established DLB cohorts, many of whom have adopted a common framework, and identify emerging collaborative initiatives that hold the potential to expand DLB networks and diversify research cohorts. Our findings identify geographical areas into which the global DLB networks should seek to expand, and we propose strategies, such as the creation of data-sharing platforms and the harmonization of protocols, which may further potentiate international collaboration.

Progression of Clinical Features in Lewy Body Dementia Can Be Detected Over 6 Months.

OBJECTIVE: This study aimed to quantify the trajectory and magnitude of change of the key clinical features and corresponding symptom domains of dementia with Lewy bodies (DLB) and Parkinson disease dementia (PDD), including global cognition, parkinsonism, recurrent visual hallucinations, cognitive fluctuations, and sleep disturbance. METHODS: One hundred sixteen patients with Lewy body dementia (DLB = 72, PDD = 44) underwent assessment at baseline and 3 and 6 months as part of a prospective multicenter randomized controlled trial. Linear mixed models were constructed for core outcome measures using the Mini-Mental State Examination (MMSE), motor section of the Unified Parkinson's Disease Rating Scale (UPDRS-III), Dementia Cognitive Fluctuations Scale (DCFS), and Neuropsychiatric Inventory (NPI). RESULTS: Within the time frame of our study (6 months), we were able to identify a significant cognitive decline of 1.3 points on the MMSE (p = 0.002) and significant worsening of motor parkinsonism with an increase in UPDRS-III score of 3.2 points (p = 0.018). Fluctuation severity also increased using the DCFS with a 6-month change in score of 1.3 points (p = 0.001). Uniquely, a signal for increased severity of sleep symptoms of 1.2 points (NPI-sleep) was also detectable (p = 0.04). Significant changes in neuropsychiatric symptoms were not detected. There was no difference in rates of change of scores between DLB and PDD. DISCUSSION: Clinically significant rates of change in core clinical features can be detected and quantified in Lewy body dementia over a relatively short period (6 months) using common clinical instruments and thus may be useful as clinical endpoints for therapeutic trials of disease-modifying and symptomatic agents.

Cognitive impairment and development of dementia in very late-onset schizophrenia-like psychosis: a systematic review.

OBJECTIVES: This study aimed to review the evidence base regarding cognitive impairment and the development of dementia in patients with very late-onset schizophrenia-like psychosis (VLOSLP). METHODS: We conducted a systematic literature search of PubMed, PsycINFO and Web of Science according to Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. Two reviewers independently screened records first by title and abstract and then by full text, resolving differences after each stage. Selected studies were assessed for quality using the GRADE system, and data on study design, participants, cognitive ability and rates of developing dementia were extracted and synthesised. RESULTS: Seventeen publications were identified for review. They were generally poor in quality and heterogenous in design. VLOSLP patients were found to have impaired global cognition compared to non-psychotic controls, but no difference was found between VLOSLP patients and aged early-onset schizophrenia (EOS) patients. No single cognitive domain was consistently affected. Patients with VLOSLP demonstrated significantly higher rates of dementia diagnosis (ranging from 4.4% over 3 years to 44.4% over 15 years) than controls, but no difference was found between VLOSLP patients and aged EOS patients. CONCLUSIONS: VLOSLP may not necessarily predict cognitive decline, but few studies have adequately investigated cohorts on a longitudinal basis. Heterogeneity between and within cohorts and varying selection criteria compromise the clinical generalisability of studies investigating the association between VLOSLP and neurodegenerative disease. Further studies on the clinical presentation, cognitive profile and neuropathology of VLOSLP with comparison to EOS/late-onset schizophrenia (LOS) and neurodegenerative disease are needed to better inform the diagnosis and management of VLOSLP.

Uniformity of cardiac 123I-MIBG uptake on SPECT images in older adults with normal cognition and patients with dementia.

INTRODUCTION: Some studies report that assessing regional 123I-cardiac MIBG uptake can aid in the diagnosis of Lewy body disease, but others report heterogeneity in healthy controls. We aimed to evaluate regional cardiac MIBG uptake patterns in healthy older adults and patients with dementia. METHODS: 31 older adults with normal cognition, 15 Alzheimer's disease (AD), and 17 Dementia with Lewy bodies (DLB) patients were recruited. 5 individuals had previous myocardial infarction. Participants with sufficient cardiac uptake for regional SPECT analysis (29/31 controls, 15/15 AD, 5/17 DLB) had relative uptake pattern recorded. Controls were assessed for risk of future cardiovascular events using QRISK2, a validated online tool. RESULTS: In controls uptake was reduced in the inferior wall (85%), apex (23%), septum (15%), and lateral wall (8%). AD and DLB showed similar patterns to controls. Lung or liver interference was present in 61% of cases. Myocardial infarction cases showed regional reductions in uptake, but normal/borderline planar uptake. In controls, there was no relationship between cardiovascular risk score and uptake pattern. CONCLUSIONS: Significant variability of regional cardiac 123I-MIBG uptake is common in cases with normal planar cardiac uptake. Heterogeneity of regional uptake appears non-specific and unlikely to aid in the diagnosis of Lewy body disease.

Introduction of a Management Toolkit for Lewy Body Dementia: A Pilot Cluster-Randomized Trial.

BACKGROUND: Lewy body dementia, comprising both dementia with Lewy bodies and Parkinson's disease dementia, is challenging to manage because of a complex symptom profile and lack of clear evidence-based management guidelines. OBJECTIVES: We assessed the feasibility of undertaking a cluster randomized study of the introduction of an evidence-based management toolkit for Lewy body dementia, assessing the outcomes for patients and carers as secondary measures. METHODS: We randomized 23 memory/dementia, movement disorder, or nonspecialist secondary care services to the management toolkit or usual care. People with dementia with Lewy bodies or Parkinson's disease dementia underwent assessments of cognition, motor and neuropsychiatric symptoms, and global outcome at baseline and 3 and 6 months. Healthcare, personal and social care costs, and carer-related outcomes of carer stress, depression, and anxiety were also examined. RESULTS: A total of 131 participants were recruited (target 120), for whom 6-month data were available on 108 (83%). There was a benefit of being in the intervention arm for carers (reduced Zarit Burden Scale [P < 0.01], reduced depressive symptoms [P < 0.05]), who also reported less marked patient deterioration on the global outcome measure (P < 0.05). There were no significant differences in other outcomes or in costs between groups. CONCLUSIONS: The introduction of an evidence-based management toolkit for Lewy body dementia was feasible and associated with some benefits, especially for carers. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Clinical diagnosis of Lewy body dementia.

BACKGROUND: Lewy body dementia, consisting of both dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD), is considerably under-recognised clinically compared with its frequency in autopsy series. AIMS: This study investigated the clinical diagnostic pathways of patients with Lewy body dementia to assess if difficulties in diagnosis may be contributing to these differences. METHOD: We reviewed the medical notes of 74 people with DLB and 72 with non-DLB dementia matched for age, gender and cognitive performance, together with 38 people with PDD and 35 with Parkinson's disease, matched for age and gender, from two geographically distinct UK regions. RESULTS: The cases of individuals with DLB took longer to reach a final diagnosis (1.2 v. 0.6 years, P = 0.017), underwent more scans (1.7 v. 1.2, P = 0.002) and had more alternative prior diagnoses (0.8 v. 0.4, P = 0.002), than the cases of those with non-DLB dementia. Individuals diagnosed in one region of the UK had significantly more core features (2.1 v. 1.5, P = 0.007) than those in the other region, and were less likely to have dopamine transporter imaging (P < 0.001). For patients with PDD, more than 1.4 years prior to receiving a dementia diagnosis: 46% (12 of 26) had documented impaired activities of daily living because of cognitive impairment, 57% (16 of 28) had cognitive impairment in multiple domains, with 38% (6 of 16) having both, and 39% (9 of 23) already receiving anti-dementia drugs. CONCLUSIONS: Our results show the pathway to diagnosis of DLB is longer and more complex than for non-DLB dementia. There were also marked differences between regions in the thresholds clinicians adopt for diagnosing DLB and also in the use of dopamine transporter imaging. For PDD, a diagnosis of dementia was delayed well beyond symptom onset and even treatment.

A comparison of visual and semiquantitative analysis methods for planar cardiac 123I-MIBG scintigraphy in dementia with Lewy bodies.

OBJECTIVES: Cardiac I-MIBG imaging is an established technique for the diagnosis of dementia with Lewy bodies but various analysis methods are reported in the literature. We assessed different methods in the same cohort of patients to inform best practice. PATIENTS AND METHODS: Seventeen patients with dementia with Lewy bodies, 15 with Alzheimer's disease and 16 controls were included. Planar images were acquired 20 min and 4 h after injection. Nine operators produced heart-to-mediastinum ratios (HMRs) using freehand and 6, 7 and 8 cm diameter circular cardiac regions. Interoperator variation was measured using the coefficient of variation. HMR differences between methods were assessed using analysis of variance. Seven raters assessed the images visually. Accuracy was compared using receiver operating characteristic analysis. RESULTS: There were significant differences in HMR between region methods (P=0.006). However, with optimised cut-offs there was no significant difference in accuracy (P=0.2-1.0). The sensitivity was 65-71% and specificity 100% for all HMR methods. Variation was lower with fixed regions than freehand (P<0.001). Visual rating sensitivity and specificity were 65 and 77% on early images and 76 and 71% on delayed images. There was no significant difference in HMR between early and delayed images (P=0.4-0.7) although a greater separation between means was seen on delayed images (0.73 vs. 0.95). CONCLUSION: HMR analysis using a suitable cut-off is more accurate than visual rating. Accuracy is similar for all methods, but freehand regions are more variable and 6 cm circles easiest to place. We recommend calculating HMR using a 6 cm circular cardiac region of interest on delayed images.

123I-FP-CIT striatal binding ratios do not decrease significantly with age in older adults.

OBJECTIVE: I-123-2ß-Carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl)nortropane (FP-CIT) imaging is an established biomarker used in the diagnosis of Lewy body disease. Images are often reported with the aid of striatal binding ratios (SBRs), comparing uptake to a normal database via Z scores. It is well known that SBRs are age dependent. However, previous studies cover wide age ranges between 20 and 80 years, rather than focusing on older adults. Typically a linear relationship is reported, but some authors have suggested that SBRs do not decline as rapidly in old age. Commercial software packages usually adjust the SBR Z score to attempt to compensate for age-related decline, but the model used varies. Ensuring age correction is appropriate for older adults is important, given that the majority of patients referred for FP-CIT scans are aged over 60 years. We examined the relationship of SBR with age in older adults and the effect of age correction using research scans from 123 adults over 60 years of age. METHODS: Twenty-nine healthy older adults and twenty-three with MCI due to Alzheimer's disease were included as controls, i.e. individuals with no evidence of Lewy body disease. Their ages ranged from 60 to 92 years (mean 76; SD 7.9). SBRs and Z scores were calculated using BRASS (Hermes Medical) and DaTQUANT (GE Healthcare). SBRs were plotted against age and linear mixed effect models applied. We tested the effect of removing age correction in BRASS using an independent dataset of 71 older adults with dementia or mild cognitive impairment. RESULTS: The slopes of the linear fits between SBR and age per year were - 0.007 (p = 0.30) with BRASS and - 0.004 (p = 0.35) with DaTQUANT. The slopes are smaller than reported in the literature and show no statistically significant difference from zero. Switching age correction off in BRASS in the test subjects reduced Z scores by approximately 1 standard deviation at 80 years of age. CONCLUSION: We found no statistically significant age-related decline in SBR in adults over 60 years of age without Lewy body disease. Commercial software packages that apply a fixed rate of age correction may be overcorrecting for age in older adults, which could contribute to misdiagnosis.

Physician-Specific Maximum Acceptable Risk in Personalized Medicine: Implications for Medical Decision Making.

BACKGROUND: In discrete-choice experiments (DCEs), respondents are presented with a series of scenarios and asked to select their preferred choice. In clinical decision making, DCEs allow one to calculate the maximum acceptable risk (MAR) that a respondent is willing to accept for a one-unit increase in treatment efficacy. Most published studies report the average MAR for the whole sample, without conveying any information about heterogeneity. For a sample of psychiatrists prescribing drugs for a series of hypothetical patients with schizophrenia, this article demonstrates how heterogeneity accounted for in the DCE modeling can be incorporated in the derivation of the MAR. METHODS: Psychiatrists were given information about a group of patients' responses to treatment on the Positive and Negative Syndrome Scale (PANSS) and the weight gain associated with the treatment observed in a series of 26 vignettes. We estimated a random parameters logit (RPL) model with treatment choice as the dependent variable. RESULTS: Results from the RPL were used to compute the MAR for the overall sample. This was found to be equal to 4%, implying that, overall, psychiatrists were willing to accept a 4% increase in the risk of an adverse event to obtain a one-unit improvement of symptoms - measured on the PANSS. Heterogeneity was then incorporated in the MAR calculation, finding that MARs ranged between 0.5 and 9.5 across the sample of psychiatrists. LIMITATIONS: We provided psychiatrists with hypothetical scenarios, and their MAR may change when making decisions for actual patients. CONCLUSIONS: This analysis aimed to show how it is possible to calculate physician-specific MARs and to discuss how MAR heterogeneity could have implications for medical practice.

Clinical prevalence of Lewy body dementia.

BACKGROUND: The prevalence of dementia with Lewy bodies (DLB) and dementia in Parkinson's disease (PDD) in routine clinical practice is unclear. Prevalence rates observed in clinical and population-based cohorts and neuropathological studies vary greatly. Small sample sizes and methodological factors in these studies limit generalisability to clinical practice. METHODS: We investigated prevalence in a case series across nine secondary care services over an 18-month period, to determine how commonly DLB and PDD cases are diagnosed and reviewed within two regions of the UK. RESULTS: Patients with DLB comprised 4.6% (95% CI 4.0-5.2%) of all dementia cases. DLB was represented in a significantly higher proportion of dementia cases in services in the North East (5.6%) than those in East Anglia (3.3%; χ2 = 13.6, p < 0.01). DLB prevalence in individual services ranged from 2.4 to 5.9%. PDD comprised 9.7% (95% CI 8.3-11.1%) of Parkinson's disease cases. No significant variation in PDD prevalence was observed between regions or between services. CONCLUSIONS: We found that the frequency of clinical diagnosis of DLB varied between geographical regions in the UK, and that the prevalence of both DLB and PDD was much lower than would be expected in this case series, suggesting considerable under-diagnosis of both disorders. The significant variation in DLB diagnostic rates between these two regions may reflect true differences in disease prevalence, but more likely differences in diagnostic practice. The systematic introduction of more standardised diagnostic practice could improve the rates of diagnosis of both conditions.

How Do Psychiatrists Apply the Minimum Clinically Important Difference to Assess Patient Responses to Treatment?

Symptom report scales are used in clinical practice to monitor patient outcomes. Using them permits the definition of a minimum clinically important difference (MCID) beyond which a patient may be judged as having responded to treatment. Despite recommendations that clinicians routinely use MCIDs in clinical practice, statisticians disagree about how MCIDs should be used to evaluate individual patient outcomes and responses to treatment. To address this issue, we asked how clinicians actually use MCIDs to evaluate patient outcomes in response to treatment. Sixty-eight psychiatrists made judgments about whether hypothetical patients had responded to treatment based on their pre- and posttreatment change scores on the widely used Positive and Negative Syndrome Scale. Psychiatrists were provided with the scale's MCID on which to base their judgments. Our secondary objective was to assess whether knowledge of the patient's genotype influenced psychiatrists' responder judgments. Thus, psychiatrists were also informed of whether patients possessed a genotype indicating hyperresponsiveness to treatment. While many psychiatrists appropriately used the MCID, others accepted a far lower posttreatment change as indicative of a response to treatment. When psychiatrists accepted a lower posttreatment change than the MCID, they were less confident in such judgments compared to when a patient's posttreatment change exceeded the scale's MCID. Psychiatrists were also less likely to identify patients as responders to treatment if they possessed a hyperresponsiveness genotype. Clinicians should recognize that when judging patient responses to treatment, they often tolerate lower response thresholds than warranted. At least some conflate their judgments with information, such as the patient's genotype, that is irrelevant to a post hoc response-to-treatment assessment. Consequently, clinicians may be at risk of persisting with treatments that have failed to demonstrate patient benefits.

Clozapine-induced liver injury and pleural effusion.

Clozapine, whilst associated commonly with a transient and benign increase in liver enzymes, has also been associated with varying presentations of hepatitis in existing case reports. This report describes what we believe to be the first documented case of acute liver injury and pleural effusion associated with clozapine, resolving after cessation of the agent. The case supports existing literature in advocating a high index of suspicion, particularly in the 4-5 weeks following clozapine initiation, when considering nonspecific clinical symptoms and signs.