Neuroimaging is increasingly used to supplement the clinical diagnosis of dementia with Lewy bodies (DLB) by showing reduced occipital metabolism and perfusion and reduced striatal dopaminergic innervation. We aimed to optimize the interpretation of 18 F-FDG PET images for differentiating DLB from Alzheimer disease (AD) and to compare the results with dopamine transporter imaging using 123 I-b-carbomethoxy-3ß-(4-iodophenyl)-tropane ( 123 I-b-CIT) SPECT. Methods: Fourteen subjects with a clinical diagnosis of DLB and 10 with AD underwent both 18 F-FDG PET and 123 I-b-CIT SPECT. Four DLB and 1 AD diagnoses were subsequently confirmed at autopsy. Diagnostic accuracy was calculated for visual interpretation by 3 readers of standard 3-plane and stereotactic surface projection 18 F-FDG PET images, receiver-operating-characteristic analysis of regional 18 F-FDG uptake, and a cutoff value for the striatal-to-occipital binding ratio of b-CIT defined by receiver-operating-characteristic analysis. Results: Visual interpretation of 3-plane 18 F-FDG PET images had a sensitivity of 83% and specificity of 93% for DLB, slightly higher than the results with the stereotactic surface projection images. Regionally, hypometabolism in the lateral occipital cortex had the highest sensitivity (88%), but relative preservation of the mid or posterior cingulate gyrus (cingulate island sign) had the highest specificity (100%). Region-of-interest analysis revealed that occipital hypometabolism and relative preservation of the posterior cingulate both had a sensitivity of 77% and specificity of 80%. b-CIT achieved 100% accuracy and greater effect size than did 18 F-FDG PET (Cohen d 5 4.1 vs. 1.9). Conclusion: Both 18 F-FDG PET and 123 I-b-CIT SPECT appear useful for the diagnosis of DLB, although the latter provides more robust results. The cingulate island sign may enhance the specificity of 18 F-FDG PET.

A large sample of 7-year-old children (n = 940) was rated by teachers using the Rutter Child Scale B, a 26-item questionnaire covering a variety of behavioural problems. A factor analysis of the data revealed three main factors of interest, identified as aggressiveness, hyperactivity and anxiety-fearfulness. Measures based upon these factors had a reasonably high level of reliability and were moderately stable over a 2-year interval. An analysis of the relationship between these three behavioural measures and some cognitive measures indicated that only hyperactivity was negatively associated with cognitive ability. However, both hyperactivity and aggressiveness were related to adversity in the child's family background. The findings suggest the usefulness of distinguishing between aggressive and hyperactive dimensions of behaviour.

Objectives: To document and illustrate qualitative features of fluctuating cognition as described by care givers of patients with probable dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). To determine whether the quality of the fluctuations differs between DLB and AD. To examine the clinical utility of two recently developed rating scales. Methods: Care givers of 13 patients with early probable DLB and 12 patients with early probable AD were interviewed using the Clinician Assessment of Fluctuation and the One Day Fluctuation Assessment Scale, both developed recently. Descriptions of fluctuating cognition were recorded verbatim, analysed, and rated. Results: Descriptions of fluctuating cognition in DLB had a spontaneous, periodic, transient quality, which appeared to reflect an interruption in the ongoing flow of awareness or attention that impacted on functional abilities. Descriptions of fluctuations in AD frequently highlighted episodes of memory failure, or a more enduring state shift in the form of ''good'' and ''bad'' days, typically occurring in response to the cognitive demands of the immediate environment. These qualitative differences could be detected reliably by independent raters, but were not always captured in standard severity scores. Conclusion: Fluctuations occuring in DLB have particular characteristics that are distinguishable from fluctuations occurring in AD. Interpretation and application of the fluctuation criterion continues to limit the diagnostic sensitivity of the consensus criteria for DLB. Findings suggest that explicit documentation and a wider appreciation of these distinctions could improve the reliability with which less experienced clinicians identify this core diagnostic feature in the clinical setting.

Magnetic resonance imaging markers of structural brain aging and performance on neuropsychological tests are powerful predictors of dementia. We need to understand the trajectory of regional brain volume change and cognitive decline in patients after stroke. This will allow future risk stratification for prognostic counseling, service planning, and early therapeutic intervention.

Background: Attentional dysfunction is believed to be a prominent and distinguishing neuropsychological feature of dementia with Lewy bodies (DLB); yet, the specific nature of the attentional deficit and factors that can potentially influence attentional processing in DLB have not been fully defined. Aims: To clarify the nature of the attentional deficit in early-stage DLB relative to patients with early-stage dementia of the Alzheimer's type (DAT) and elderly controls, and examine the effect of task complexity and type of cognitive load on attentional processing in DLB. Methods: Attentional impairment and fluctuating attention were investigated in three groups of subjectspatients with clinical features of early probable DLB (n = 20), a group with early probable DAT (n = 19) and healthy elderly controls (n = 20)-using an experimental computerised reaction time paradigm. Results: Patients with DLB showed greater attentional impairment and fluctuations in attention relative to patients with DAT and elderly controls. The attentional deficit was generalised in nature but increased in magnitude as greater demands were placed on attentional selectivity. Attentional deficits in DLB were most pronounced under task conditions that required more active recruitment of executive control and visuospatial cognitive processes. Conclusions: Attentional deficits in DLB are widespread and encompass all aspects of attentional function. Deficits in higher cortical function influence the degree of attentional impairment and fluctuating attention, suggesting that attentional processing in DLB is mediated by interacting cortical and subcortical mechanisms. These findings serve to clarify the nature of the attentional deficit in DLB and have potentially important ramifications for our understanding of the neurocognitive underpinnings of fluctuations.