Clinicopathologic correlates in temporal cortex in dementia with Lewy bodies

OBJECTIVE: To address the relationship between dementia and neuropathologic findings in dementia with Lewy bodies (DLB) in comparison with AD. METHODS: We evaluated the clinical presentation of autopsy-confirmed DLB in comparison with AD according to new Consortium on DLB criteria and compared the two conditions using quantitative neuropathologic techniques. This clinicopathologic series included 81 individuals with AD, 20 with DLB (7 "pure" DLB and 13 "DLB/AD"), and 33 controls. We counted number of LB, neurons, senile plaques (SP), and neurofibrillary tangles (NFT) in a high order association cortex, the superior temporal sulcus (STS), using stereologic counting techniques. RESULTS: The sensitivity and specificity of Consortium on DLB clinical criteria in this series for dementia, hallucinations, and parkinsonism are 53% and 83%, respectively, at the patient's initial visit and 90% and 68%, respectively, if data from all clinic visits are considered. In pathologically confirmed DLB brains, LB formation in an association cortical area does not significantly correlate with duration of illness, neuronal loss, or concomitant AD-type pathology. Unlike AD, there is no significant neuronal loss in the STS of DLB brains unless there is concomitant AD pathology (neuritic SP and NFT). CONCLUSIONS: The evaluation of new Consortium on DLB criteria in this series highlights their utility and applicability in clinicopathologic studies but suggests that sensitivity and specificity, especially at the time of the first clinical evaluation, are modest. The lack of a relationship of LB formation to the amount of Alzheimer-type changes in this series suggests that DLB is a distinct pathology rather than a variant of AD.     

The influence of vascular risk factors on the survival rate of patients with dementia with Lewy bodies and Alzheimer disease

Background and purposeThe aim of this study was to determine whether dementia with Lewy bodies (DLB) progresses more rapidly than Alzheimer disease (AD) and to compare survival after dementia onset and mortality in both dementia groups.Material and methodsA medical records analysis of AD (n = 183) and DLB (n = 51) patients was performed to determine age at onset of symptoms, the date of first presentation to the psychiatric services, dementia severity at diagnosis (MMSE score), and mean disease duration before diagnosis. Categorical data regarding vascular risk factors were collected. Projected decline rate (MMSE/year), survival rate after the diagnosis of dementia, mean survival time after diagnosis and mortality rate were calculated and compared between DLB and AD groups.ResultsThe comparison of clinical and demographic parameters revealed no significant differences between groups, apart from a more pronounced decline rate in the DLB group. Diabetes, and to a lesser extent hypertension, influenced survival in AD, but not in DLB subjects. Overall, however, the difference in mortality rates and survival time between DLB and AD subjects cannot be attributed to the presence of any vascular risk factor analysed. DLB, independently of the presence of vascular risk factors, seems to be a more aggressive disorder than AD, when mortality and survival time are taken into account.ConclusionsMore rapid progression of cognitive decline and shorter duration of dementia were found in DLB in this naturalistic study. The findings may have important implications for the management and treatment of DLB and should be confirmed in prospective studies.     

Three years survival in patients with a clinical diagnosis of dementia with Lewy bodies

The majority of information available on the prognosis of dementia with Lewy bodies (DLB) is based on retrospective data from autopsy series, which are subject to selection bias due to the specific reasons patients are referred for post-mortem studies. The earlier studies comparing DLB patients with patients with Alzheimer's disease (AD) suggest that the mean duration of illness is shorter in DLB patients than in patients with AD. However, more recent studies have not observed significant differences between DLB and AD in age of onset, age at death or duration of illness. We report a 3 year follow-up of a cohort of 114 consecutive patients with dementia, referred to an old age psychiatric service and diagnosed using ICD 10 criteria and the McKeith and Byrne DLB criteria. The case notes of all patients were reviewed to determine the date of onset of symptoms and the date of first presentation to the psychiatric services. Information about outcome was gathered from case notes, hospital files and general practitioner (GP) records. Of the original sample of 114 patients, 106 could be traced. Sixty-four had died and 42 were still alive at the time of the follow-up. Thirty-two patients had originally been assigned the diagnosis of DLB, 43 the diagnosis of AD, 31 vascular dementia and other diagnoses. There were no differences between the AD and DLB group in age at onset, age at death or survival. We have not found any evidence that the prognosis of clinically diagnosed DLB patients is worse than that of patients with a clinical diagnosis of AD.     

The progression of cognition, psychiatric symptoms, and functional abilities in dementia with Lewy bodies and Alzheimer disease

BACKGROUND: Although dementia with Lewy bodies (DLB) may be one of most common forms of dementia, relatively little is known about its cognitive and functional course. OBJECTIVE: To compare change over time in general cognitive status, memory test performance, psychiatric symptoms, neurological signs, and functional abilities in patients with probable DLB and probable Alzheimer disease (AD). DESIGN: Twenty-eight patients who met diagnostic criteria for DLB were recruited into the study from 3 sites. Patients with AD (n = 55) were selected from a larger cohort and matched 2 to 1 to the patients with DLB on age and baseline global cognitive status. Patients were followed up at 6-month intervals for an average of 6.2 visits and assessed at each visit with tests of global cognitive functioning and verbal learning and memory and measures of psychiatric, neurological, and functional status. RESULTS: At the baseline evaluation, patients with DLB performed more poorly on a measure of constructional praxis and all measures of functional status. They also had more severe psychiatric symptoms and neurological signs than the AD group. Despite these initial differences, generalized estimating equations applied to regression analyses with repeated measures determined that the only difference between the 2 groups in change in cognitive test performance was on a measure of recognition memory; patients with AD declined, while patients with DLB remained relatively stable. Patients with DLB had relatively stable behavioral symptoms and visual illusions, whereas patients with AD had a significant increase in these symptoms over time. Neurological and functional changes over time were similar in the 2 groups. CONCLUSIONS: Both baseline and longitudinal differences between patients with DLB and patients with AD were noted; these have implications for clinical diagnosis and treatment.     

The medial temporal lobe in dementia with lewy bodies: A comparative study with Alzheimer's disease

The usefulness of determining medial temporal lobe (MTL) size in differentiating Alzheimer's disease (AD) from other dementia subtypes is unknown. We compared the cross-sectional areas of the MTLs in histological sections from the brains of 18 patients with dementia with Lewy bodies (DLB) but lacking AD changes, 24 DLB patients with concurrent AD pathology, 20 pure AD cases, and 18 age-matched control cases. Duration and severity of disease were comparable between groups. When data for cross-sectional area were expressed as percentages of the average control area, DLB MTLs were significantly larger than either AD or DLB/AD MTLs at rostral levels (86 ± 16%, 54 ± 17%, and 66 ± 23% of control areas, respectively). At caudal levels, DLB MTLs were larger than AD MTLs (80 ± 20%, 59 ± 21%, and 77 ± 26% of control areas in DLB, AD, and DLB/AD, respectively). MTL cross-sectional area often approaches normal in pure DLB, even when disease duration is prolonged and symptoms are end stage. In contrast, a greatly reduced MTL area mitigates against the diagnosis of DLB, unless there are concurrent AD changes.     

Patients with Alzheimer's disease and dementia with Lewy bodies mistaken for Creutzfeldt-Jakob disease.

OBJECTIVES: To describe the clinical presentation of patients with Alzheimer's disease (AD) or dementia with Lewy bodies (DLB) who were suspected of having Creutzfeldt-Jakob disease (CJD) and to investigate whether current clinical diagnostic criteria cover these atypical forms of AD and DLB. METHODS: Brains from necropsy were examined for the diagnosis of CJD at the German reference centre for spongiform encephalopathies. Symptoms and signs in patients with suspected CJD in whom necropsy showed AD (n=19) or DLB (n=12) were analysed. Their data were compared with a group of patients with CJD (n=25) to determine overlapping and discriminating clinical features. All patients were classified according to clinical diagnostic criteria for CJD, AD, and DLB. RESULTS: Demented patients were suspected of having CJD if disease was rapidly progressing and/or focal neurological signs appeared and/or an EEG showed sharp wave complexes. Myoclonus and limb rigidity were the most common neurological signs in all three dementias. DLB was not suspected in any patient, although patients with DLB showed parkinsonism (58%) and fluctuations (58%). Periodic sharp wave complexes (PSWCs) in EEG typical of CJD were found in five patients with AD and one patient with DLB. 14-3-3 Protein in CSF was detected in 20 patients with CJD, in two patients with AD, but not in any patient with DLB. Although most patients with DLB or AD met the clinical criteria for their respective diagnosis (74% and 90%), they also fulfilled criteria for CJD (42% and 58%). CONCLUSIONS: In patients with rapidly progressive dementia and focal neurological signs, CJD should be the first line diagnosis. Facing the triad dementia, myoclonus, and rigidity, AD should be considered if the disease course is longer and DLB is the differential diagnosis if parkinsonism or fluctuations are present. Findings on EEG or CSF typical of CJD do not exclude AD or DLB.     

Qualitative performance characteristics differentiate dementia with Lewy bodies and Alzheimer's disease

OBJECTIVES: To determine whether dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) can be differentiated on the basis of qualitative performance characteristics during neuropsychological evaluation. METHODS: Forty one patients with clinically defined DLB were matched with 26 patients with AD for age, illness duration, nature and severity of cognitive deficits, and regional blood flow distribution on SPECT. The presence or absence of a set of qualitative performance characteristics, observed and recorded during the patients' initial cognitive evaluation, was identified by retrospective analysis of patients' records and the groups compared. RESULTS: Inattention, visual distractibility, impairments in establishing and shifting mental set, incoherence, confabulatory responses, perseveration, and intrusions were significantly more common in DLB than AD. Intrusions were particularly common in DLB, occurring in 78% of the group. They included externally cued intrusions arising from the visual environment, a feature never seen in AD. In a stepwise logistic regression analysis impaired mental set shifting, perseveration, and the presence of intrusions correctly classified 79% of patients. CONCLUSION: It is possible to differentiate DLB and AD on the basis of qualitative features of performance. As many features are amenable to detection at clinical interview, they ought to contribute to clinicians' diagnostic armoury, leading to improved clinical recognition of DLB.     

Severity of cognitive impairment and the clinical diagnosis of AD with Lewy bodies

OBJECTIVE: 1) To examine the clinical differences between AD and AD with Lewy bodies (AD+LB); and 2) to determine the accuracy of Consensus guidelines for the clinical diagnosis of dementia with Lewy bodies (DLB) at different levels of dementia severity. METHODS: The authors examined the clinical characteristics of 185 patients with pathologically diagnosed AD alone and 60 with AD+LB. The relationship between clinical symptoms and AD+LB was determined by multivariate analyses, controlled by age, duration of symptoms, presence of cerebrovascular disease, and dementia severity. RESULTS: Mild dementia syndrome: No specific clinical symptom was associated with the presence of AD+LB. The sensitivity of the diagnosis of DLB was 62% and specificity was 54%. Moderate dementia syndrome: Extrapyramidal signs (EPS), especially cogwheel rigidity, and major depression were associated with AD+LB. The sensitivity for DLB was 82% and specificity was 31%. Severe dementia syndrome: Cogwheel rigidity and diurnal hypersomnia were associated with AD+LB. The sensitivity for DLB was 93% and specificity was 16%. CONCLUSIONS: The presence of EPS is not useful in differentiating AD+LB from AD in patients with mild dementia. However, as the disease progressed, they emerge as defining features, especially cogwheel rigidity. The accuracy of AD+LB diagnosis varies according the severity of the dementia syndrome. The low sensitivity and specificity in AD+LB patients with mild dementia suggest that in early stages AD+LB patients do not present the clinical characteristics of DLB. By contrast, the high sensitivity and low specificity for the diagnosis of DLB in moderate/severe dementia stages suggests that AD patients can also have characteristic symptoms of DLB. These results indicate that the antemortem diagnosis of AD+LB is difficult in all dementia stages, and better clinical and biologic differentiations of these entities are needed.     

Attention and fluctuating attention in patients with dementia with Lewy bodies and Alzheimer disease

BACKGROUND: Attentional deficits are described in the consensus clinical criteria for the operationalized diagnosis of dementia with Lewy bodies (DLB) as characteristic of the condition. In addition, preliminary studies have indicated that both attentional impairments and fluctuation of attentional impairments are more marked in patients with DLB than in patients with Alzheimer disease (AD), although neuropsychological function has not previously been examined in a large prospective cohort with confirmed diagnostic accuracy against postmortem diagnosis. METHODS: A detailed evaluation of attention and fluctuating attention was undertaken in 155 patients with dementia (85 with DLB and 80 with AD) from a representative hospital dementia case register and 35 elderly controls using the Cognitive Drug Research Computerized Assessment System for Dementia Patients computerized neuropsychological battery. Operationalized clinical diagnosis was made using the consensus criteria for DLB and the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for AD. High levels of sensitivity and specificity have been achieved for the first 50 cases undergoing postmortem examination. RESULTS: The groups were well matched for severity of cognitive impairments, but the AD patients were older (mean age, 80 vs 78 years) and more likely to be female (55% vs 40%). Patients with DLB were significantly more impaired than patients with AD on all measures of attention and fluctuating attention (for all comparisons, t > or = 2.5, P<.001), and patients from both dementia groups were significantly more impaired than elderly controls for all comparisons other than cognitive reaction time, which was significantly more impaired in DLB patients than controls but was comparable in controls and AD patients. There were, however, significant associations between the severity of cognitive impairment and the severity of both attentional deficits and fluctuations in attention. CONCLUSIONS: This large prospective study confirms that slowing of cognitive processing, attention, and fluctuations of attention are significantly more pronounced in DLB and AD patients, although fluctuating attention is common in patients with moderate-to-severe AD. Deficits of cognitive reaction time appear to be specific to DLB, except in severe dementia. A detailed evaluation of attentional performance could make an important contribution to differential diagnosis, although the results need to be interpreted within the context of the overall severity of cognitive deficits.     

Dementia with Lewy bodies may present as dementia and REM sleep behavior disorder without parkinsonism or hallucinations.

Rapid eye movement (REM) sleep behavior disorder (RBD) is a sleep disturbance that commonly occurs in Dementia with Lewy bodies (DLB). Retrospective examination of DLB course has shown that RBD and cognitive decline may precede the onset of parkinsonism and visual hallucinations. Therefore, some patients with DLB may initially present with dementia and RBD, but would not meet current formal criteria for probable DLB at that time. The purpose of this study is to determine whether patients with dementia and RBD, who do not have parkinsonism or visual hallucinations, have cognitive profiles that can be distinguished from autopsy-confirmed definite AD, but not from clinically probable DLB. If so, this would support the hypothesis that the presence of RBD and dementia, as the only presenting symptoms, reflects the early manifestation of DLB. Results show that early dementia in probable DLB and dementia with RBD are neuropsychologically indistinguishable. Both groups differ from definite AD of a similar early stage with significantly worse visual perceptual organization, sequencing and letter fluency but significantly better confrontation naming and verbal memory. In addition, follow-up data from a subset of patients with dementia and RBD reveal the subsequent development of parkinsonism or hallucinations 1 to 6 years later. Results indicate that the presentation of dementia and RBD is suggestive of underlying Lewy body disease and not Alzheimer's disease. This provides further evidence in support of including RBD as one of the core diagnostic features of DLB.     

Diagnostic accuracy of dementia with Lewy bodies

BACKGROUND: Diagnostic criteria for dementia with Lewy bodies (DLB) are still evolving. No data exist on prospective differentiation of DLB and Alzheimer disease (AD). OBJECTIVE: To examine the clinician's diagnostic accuracy for DLB and analyze factors contributing to false-positive DLB diagnoses. METHODS: A prospective series of 10 patients with clinically diagnosed DLB who came to autopsy was compared with 32 autopsy-confirmed cases of DLB (27 Lewy body variant, 5 diffuse Lewy body disease) and 20 autopsy-confirmed cases of AD (matched on age, sex, education, and initial Mini-Mental State Examination score) with regard to distinguishing and/or confounding clinical features. RESULTS: The clinical diagnostic accuracy for DLB was 50%, with 5 of the 10 patients clinically presumed to have DLB confirmed at autopsy. Of the 5 misdiagnosed cases, 4 had AD and 1 had progressive supranuclear palsy. The misdiagnosed DLB cases who had pure AD had fewer hallucinations (25%) than those with Lewy body variant (63%) or diffuse Lewy body disease (100%) (P = .048); however, an equal amount of spontaneous (in the absence of neuroleptics) extrapyramidal signs was found. There were no differences among groups with regard to daily fluctuations in cognition or falls. Compared with the AD control group, the misdiagnosed DLB cases with pure AD showed significantly more spontaneous extrapyramidal signs (P< or =.02). CONCLUSIONS: The clinician's diagnostic accuracy for DLB was poor. Early spontaneous extrapyramidal signs in AD were associated with false-positive clinical diagnoses of DLB. The distinction between DLB and AD may be improved by greater emphasis on hallucinations.     

Clinical profiles of autopsy-confirmed dementia with Lewy bodies at institutionalization: Comparison with Alzheimer's disease

Background: It has been reported that Alzheimer’s disease (AD) patients with Lewy pathology have a shorter time from a given baseline to institutionalization than those with AD alone. Taking the clinical distinction between dementia with Lewy bodies (DLB) and AD into consideration, the previous findings may indicate the possibility that the clinical characteristics of DLB patients have an influence on early institutionalization. This study was carried out to clarify whether there are any differences in the symptoms that required institutionalization between patients with DLB and those with AD. Methods: Hospital records and standardized data forms completed at admission to a residential care facility were reviewed to assess the profiles in all cases with autopsy‐confirmed diagnoses for correct differential diagnosis. We examined functional, cognitive and symptomatic conditions at admission to a residential care facility of 18 DLB and 35 AD patients whose diagnoses were confirmed by autopsy. The examinations were conducted using the Gottfries‐Bråne‐Steen (GBS) scale and cognitive tests, and the results were compared between the two groups of patients. Results: Hallucinations, impaired wakefulness, disturbance of ADL and emotional disturbance, common clinical features compatible with DLB, were more frequently observed in DLB patients than in AD patients (P < 0.05). Moreover, DLB patients had higher scores on cognitive tests than did AD patients at admission to a residential care facility (P < 0.05). Conclusion: The distinctive clinical features at admission to a residential care facility may indicate that the reasons for the necessity of institutionalization are different between DLB and AD, and that the interventions specific to DLB patients and their families would be necessary to prevent or postpone institutionalization.     

The Alzheimer variant of lewy body disease: a pathologically confirmed case-control study

The objective of the study was to identify clinical features that distinguish patients with dementia with Lewy bodies (DLB), who were classified as Alzheimer's disease (AD) patients, from patients with AD. We examined a group of 27 patients from our memory clinic, originally diagnosed with AD, of whom 6 were postmortem found to have DLB. For the present study, we compared cognitive, noncognitive and neurological symptoms between the two groups. We found that there were no differences on ratings of dementia and scales for activities of daily living. Patients with DLB performed better on the MMSE and the memory subtest of the CAMCOG, but there was no difference in any other cognitive domain. Furthermore, genetic risk factors, including family history of dementia or allele frequency of the apolipoprotein epsilon4, did not discriminate between the two groups, and there were no differences on CCT scans. Taken together, our findings suggest that Lewy body pathology may be present in patients who do not show the typical clinical features which distinguish DLB from AD.     

Validity of clinical criteria for the diagnosis of dementia with Lewy bodies

OBJECTIVE: To assess the clinical validity of clinical diagnostic criteria for dementia with Lewy bodies (DLB). METHODS: We assessed the sensitivity, specificity, and positive and negative predictive values of the clinical criteria of the Consortium on dementia with Lewy Bodies (CDLB) in 18 patients with autopsy-proven DLB and in 76 patients with dementia not associated with Lewy bodies, using postmortem diagnosis as a gold standard. RESULTS: CDLB criteria had either high sensitivity or high specificity, but no set of criteria simultaneously provided both high sensitivity and high specificity. Clinical criteria had higher predictive validity in patients with pure DLB than in patients with DLB and AD. Seventy-eight percent of patients with pure DLB had two or more major criteria, compared with 44% of patients with DLB and AD (p<0.02). If the nine patients with DLB and AD were excluded from the DLB group, the CDLB criteria for probable DLB had sensitivity of 78% and specificity of 85%. CDLB criteria for probable DLB (two or more major criteria) distinguished DLB from AD with a sensitivity of 78% and a specificity of 64%. CONCLUSIONS: The proposed CDLB criteria have high negative predictive value and thus do well at excluding patients with DLB. Positive predictive value of 75% can be achieved by a combination of any three major or minor criteria, providing the analysis is confined to patients with mild to moderate dementia. Criteria were most accurate if confined to patients with pure DLB who had mild to moderate dementia.     

Comparison of dementia with Lewy bodies to Alzheimer's disease and Parkinson's disease with dementia.

We compared the clinical and neuropsychological pattern of dementia with Lewy bodies (DLB) to Alzheimer's disease (AD) and Parkinson's disease with dementia (PD-d). Sixteen patients clinically diagnosed with DLB were compared with two groups of patients with PD-d (n = 15) and AD (n = 16) matched for level of dementia. Isolated cognitive impairment was the most common form of presentation in AD (93.8%) and DLB (31.3%) groups, while parkinsonism was in 100% of PD-d subjects. Psychoses associated with cognitive impairment at the beginning of the disease were more frequent in DLB patients (31.3%) than in AD (6.3%) and PD-d (0%) groups. There were no significant differences in Unified Parkinson Disease Rating Scale motor-subscale scores between DLB and PD-d patients. DLB and PD-d patients performed significantly worse on attentional functions and better on memory tests than AD. DLB patients also showed lower scores than AD subjects on visual memory, visuoperceptive, and visuoconstructive tests. No significant differences were found between PD-d group and DLB subjects on any neuropsychological test. We were unable to find any differences in cognitive tasks between PD-d and DLB subjects. Clinical features and neuropsychological deficiencies of DLB (attentional, visuoperceptive, and visuoconstructive deficits) and PD (attentional deficits) compared to AD (amnesic syndrome) can contribute to accurate identification of these entities and to the understanding of the neuropathological and neurochemical substrate underlying these diseases.     

A comparison of episodic memory deficits in neuropathologically-confirmed Dementia with Lewy bodies and Alzheimer's disease.

Little is known about possible differences in the memory deficits that occur in Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). We compared 24 autopsy-confirmed DLB and 24 age-, education-, and MMSE-matched autopsy-confirmed AD patients on the California Verbal Learning Test (CVLT) and the Wechsler Memory Scale-Revised Logical Memory subtest. The DLB and AD groups were similarly impaired on CVLT Total Learning (Trials 15) and Long Delayed Free Recall, but the DLB group demonstrated relative improvement in Savings scores and on recognition testing compared to the AD group. Likewise, the patient groups were equally impaired on Logical Memory immediate and delayed recall, but the DLB group's Saving scores were significantly better than those of the AD patients. These results indicate that while both DLB and AD patients exhibit significant memory impairment, the ability to consolidate information may be less severely impaired in DLB patients than in AD patients.     

Dementia with Lewy Bodies is associated with higher scores on the Geriatric Depression Scale than is Alzheimer's disease

Background: Several reports suggest a higher morbidity of depression in patients with dementia with Lewy bodies (DLB) than in patients with Alzheimer's disease (AD). However, these results have not been duplicated consistently. The psychiatric symptoms of dementia, including depression, are important for its diagnosis and management. Thus, the aim of the present study was to clarify the characteristics of the depressive symptoms in DLB compared with AD using the Geriatric Depression Scale (GDS). Methods: We examined the GDS score for 86 patients with probable DLB (based on the Consensus Criteria for the clinical diagnosis of DLB) and 86 patients with probable AD (based on criteria of the National Institute for Neurological and Communicative Disorders and Stroke‐Alzheimer's Disease and Related Disorders Association), who were matched according to age, sex, education, and Mini‐Mental State Examination (MMSE) scores. We also examined correlations between GDS scores and age, sex, or MMSE scores in both groups. Correlations between GDS scores and metaiodobenzylguanidine (MIBG) scintigraphy were examined in patients with DLB. To characterize the GDS in DLB, its profile was examined using factor structures. Results: Scores for DLB patients were twice as high on the GDS as those for AD patients. There was no correlation between GDS score and age, sex, or MMSE scores in either group. Furthermore, there was no correlation between the results of MIBG scintigraphy and GDS scores in the DLB group. Using factor structures, the depression symptom profile of these diseases suggested that depression‐specific symptoms, such as mood, worry, or future outlook, were more frequent in the DLB group than non‐specific symptoms, such as lack of energy, decreased concentration, or apathy. Conclusions: The data suggest that depressive symptoms are highly specific symptoms of DLB, independent of other features of this disorder. The GDS could be used as a subsidiary tool in differentiating DLB from AD and is more useful than clinical observations of depression.     

White matter changes in dementia with Lewy bodies and Alzheimer's disease: a tractography-based study

Dementia with Lewy bodies (DLB) and Alzheimer’s disease (AD) are different types of dementia. However, their clinical symptoms partially overlap and differential diagnosis is occasionally difficult. There is need for additional diagnostic criteria to reliably differentiate between these two conditions. Meanwhile, several imaging studies have showed inconsistent results between DLB and AD. The aim of this study was to use a tractography-based analysis to elucidate white matter alterations in subjects with DLB compared to those with AD and to controls. An understanding of the white matter connectivity differences between AD, DLB and controls will be helpful for differential diagnosis and an understanding of the pathophysiology. Twenty-six subjects with DLB, 26 with AD and 26 controls underwent magnetic resonance diffusion tensor imaging and neuropsychological assessment. Diffusion tensors were computed and fiber-tract maps were created using “dTV II” software. We measured mean fractional anisotropy (FA) values along the uncinate fasciculus (UNC), the inferior occipitofrontal fasciculus (IOFF) and the inferior longitudinal fasciculus (ILF). Both subjects with DLB and AD had lower FA values for the bilateral UNC than controls. Subjects with DLB exhibited significantly lower FA values on both sides of the IOFF and the left side of the ILF than those of controls. Although there were no significant differences between subjects with DLB and AD for any measurements, those with DLB exhibited lower FA values especially in visual-related white matter. These different changes in white matter tracts among groups could be helpful for differential diagnosis and an understanding of the pathophysiology.     

Familial dementia with Lewy bodies with an atypical clinical presentation

The authors report a case of a 64-year-old male with Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) pathology at autopsy who did not manifest the core symptoms of DLB until very late in his clinical course. His initial presentation of early executive and language dysfunction suggested a cortical dementia similar to frontotemporal lobar degeneration (FTLD). Core symptoms of DLB including dementia, hallucination, and parkinsonian symptoms were not apparent until late in the course of his illness. Autopsy revealed both brainstem and cortical Lewy bodies and AD pathology. Family history revealed 7 relatives with a history of dementia including 4 with possible or probable DLB. This case is unique because of the FTLD-like presentation, positive family history of dementia, and autopsy confirmation of DLB.     

The prevalence, assessment and associations of falls in dementia with Lewy bodies and Alzheimer's disease

Falls were assessed for 3 months using a daily fall diary in 65 (30 dementia with Lewy bodies, DLB; 35 Alzheimer's disease, AD) dementia patients from a case register, diagnosed using operationalised clinical criteria, with established accuracy against post-mortem. Multiple falls (>5) occurred in 37% of DLB patients and 6% of those with AD, often resulting in injury. None of the standard risk assessment tools identified fallers, but they did identify multiple fallers. More detailed evaluation methods examining gait patterns, sway and neurovascular instability were not helpful. Multiple falls were associated with DLB, parkinsonism, previous falls, greater impairment of activities of daily living and older age. Falls are particularly common in DLB sufferers and may aid diagnosis. Treatment studies evaluating fall reduction strategies are a priority.