Core Clinical Features Of Dementia With Lewy Bodies Research Articles

Neuropsychological and clinical indicators of Lewy body and Alzheimer's pathology

Background Clinical distinction between Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) poses significant challenges due to pathological comorbidity. Similar ages of onset and overlapping cognitive and psychiatric symptoms can lead to diagnostic inaccuracy and inappropriate treatment recommendations. Objective Identify the best combination of clinical and neuropsychological predictors of AD, DLB, and mixed DLB/AD neuropathology in dementia patients. Methods Using the National Alzheimer's Coordinating Center dataset, we selected either pure AD ( n = 189), DLB ( n = 21), or mixed DLB/AD ( n = 42) patients on autopsy. Neuropsychological and clinical predictors, including core clinical features of DLB, were entered into multivariable logistic regressions. Results Gait disturbances (odds ratio (OR) = 19.32; p = 0.01), visual-spatial complaints (OR = 6.06; p = 0.03), and visual hallucinations (OR = 31.06; p = 0.002) predicted DLB compared to AD, along with better memory (OR = 3.42; p = 0.003), naming (OR = 3.35; p = 0.002), and worse processing speed (OR = 0.51; p = 0.01). When comparing DLB to DLB/AD, gait disturbances (OR = 6.33; p = 0.01), increased depressive symptoms (OR = 1.44; p = 0.03), and better memory (OR = 3.01; p = 0.004) predicted DLB. Finally, rapid eye movement sleep behavior disorder (RBD) (OR = 6.44; p = 0.004), parkinsonism severity (OR = 1.07; p = 0.02), and lower depressive symptoms (OR = 0.70; p = 0.006) and memory impairment (OR = 0.57; p = 0.02) distinguished DLB/AD from AD. Conclusions Our study converges with prior research suggesting specific neuropsychological and clinical features can help distinguish DLB from AD. Neuropsychological differentiation becomes more challenging among mixed pathologies and in advanced cognitive impairment, although the presence of RBD and parkinsonism distinguished DLB. Earlier clinical assessment and incorporation of in vivo and postmortem biomarkers should enhance diagnostic accuracy and understanding of disease characteristics, offering significant relevance for disease-modifying treatments.

Clinical correlates of Dopamine transporter imaging and EEG biomarkers in Dementia with Lewy bodies

AbstractBackgroundDiagnostic value of dopamine transporter (DAT) imaging and electroencephalography (EEG) biomarkers in Dementia with Lewy bodies (DLB) is well studied, but their relationships with clinical symptoms in DLB are not elusive. We investigated the association between DAT imaging and EEG biomarkers and clinical characteristics of DLB.MethodWe evaluated the 120 patients with DLB retrospectively. Quantitative analysis of DAT imaging was performed and uptakes for caudate, putamen, and ventral striatum (VST) were assessed. Frequency of posterior dominant rhythm and theta/beta ratio (TBR) were used as EEG biomarkers. Four core clinical features of DLB were assessed. Firstly, correlation analysis between biomarkers and clinical symptoms were assessed. Regression analyses with significantly correlated biomarkers as model variable were performed to investigate the association between clinical characteristics and biomarkers. Age, sex, and education were used as covariates.ResultParietal TBR (B = 0.498, P = 0.023) and putaminal DAT uptake (B = ‐0.609, P = 0.010) were related to the presence of fluctuation. The severity of visual hallucination was associated with the higher parietal TBR (B = 0.391, P = 0.045) and lower DAT uptake in putamen (B = ‐0.520, P = 0.010) and. Putaminal DAT uptake was related to the presence of REM sleep behavior disorder (B = ‐0.646, P = 0.010). Severity of parkinsonism was associated with the frontal TBR (B = 3.353, P < 0.001).ConclusionDAT imaging and EEG biomarkers were related to the clinical symptoms in DLB differently. In addition, TBR reflects characteristics of DLB better than posterior slow activity.

White matter hyperintensities in dementia with Lewy bodies are associated with poorer cognitive function and higher dementia stages.

PurposeWhite matter hyperintensities (WMHs) are frequently found in elderly individuals with or without dementia. However, the association between WMHs and clinical presentations of dementia with Lewy bodies (DLB) has rarely been studied.MethodsWe conducted a retrospective analysis of patients with DLB registered in a dementia database. WMHs were rated visually using the Fazekas scale, and its associated factors including dementia severity, cognitive functions, neuropsychiatric symptoms, and core clinical features were compared among different Fazekas scores. Domains in the Clinical Dementia Rating (CDR), Cognitive abilities Screening Instruments (CASI), and Neuropsychiatric Inventory (NPI) were compared among different Fazekas groups after adjusting for age, sex, education, and disease duration.ResultsAmong the 449 patients, 76, 207, 110, and 56 had Fazekas score of 0, 1, 2, and 3, respectively. There was a positive association between dementia severity and WMHs severity, and the mean sums of boxes of the Clinical Dementia Rating (CDR-SB) were 5.9, 7.8, 9.5, and 11.2 (f = 16.84, p < 0.001) for the Fazekas scale scores 0, 1, 2, and 3, respectively. There was a negative association between cognitive performance and WMHs severity, and the mean CASI were 57.7, 45.4, 4.06, and 33.4 (f = 14.22, p < 0.001) for the Fazekas scale scores 0, 1, 2, and 3, respectively. However, WMHs were not associated with the core clinical features of DLB. After adjustment, all cognitive domains in CDR increased as the Fazekas score increased. In addition, performance on all cognitive domains in CASI decreased as the Fazekas score increased (all p < 0.001). Among neuropsychiatric symptoms, delusions, euphoria, apathy, aberrant motor behavior, and sleep disorders were significantly worse in the higher Fazekas groups compared to those in the group with Fazekas score of 0 after adjustment.ConclusionWMHs in DLB might contribute to deterioration of cognitive function, neuropsychiatric symptoms, and dementia stages. However, core clinical features were not significantly influenced by WMHs in DLB.

Prodromal characteristics of dementia with Lewy bodies: baseline results of the MEMENTO memory clinics nationwide cohort

BackgroundIsolated subjective cognitive impairment (SCI) and mild cognitive impairment (MCI) are the prodromal phases of dementia with Lewy bodies (DLB). MEMENTO is a nationwide study of patients with SCI and MCI with clinic, neuropsychology, biology, and brain imaging data. We aimed to compare SCI and MCI patients with symptoms of prodromal DLB to others in this study at baseline.MethodsParticipants of the French MEMENTO cohort study were recruited for either SCI or MCI. Among them, 892 were included in the Lewy sub-study, designed to search specifically for symptoms of DLB. Probable prodromal DLB diagnosis (pro-DLB group) was done using a two-criteria cutoff score among the four core clinical features of DLB. This Pro-DLB group was compared to two other groups at baseline: one without any core symptoms (NS group) and the one with one core symptom (1S group). A comprehensive cognitive battery, questionnaires on behavior, neurovegetative and neurosensory symptoms, brain 3D volumetric MRI, CSF, FDG PET, and amyloid PET were done.ResultsThe pro-DLB group comprised 148 patients (16.6%). This group showed more multidomain (59.8%) MCI with slower processing speed and a higher proportion of patients with depression, anxiety, apathy, constipation, rhinorrhea, sicca syndrome, and photophobia, compared to the NS group. The pro-DLB group had isolated lower P-Tau in the CSF (not significant after adjustments for confounders) and on brain MRI widening of sulci including fronto-insular, occipital, and olfactory sulci (FDR corrected), when compared to the NS group. Evolution to dementia was not different between the three groups over a median follow-up of 2.6 years.ConclusionsPatients with symptoms of prodromal DLB are cognitively slower, with more behavioral disorders, autonomic symptoms, and photophobia. The occipital, fronto-insular, and olfactory bulb involvement on brain MRI was consistent with symptoms and known neuropathology. The next step will be to study the clinical, biological, and imaging evolution of these patients.Trial registrationClinicaltrials.gov, NCT01926249

Synuclein Motor Dysfunction Composite Scale for the Discrimination of Dementia With Lewy Bodies From Alzheimer's Disease.

BackgroundAn abnormal increase of α-synuclein in the brain is the hallmark of dementia with Lewy bodies (DLB). However, the diagnostic power of plasma α-synuclein in DLB is not yet confirmed. Parkinsonism is highly associated with and is one of the core clinical features of DLB. We studied plasma α-synuclein and developed a novel tool that combined plasma α-synuclein level and Motor Dysfunction Questionnaire (MDQ), namely Synuclein Motor Dysfunction Composite Scale (SMDCS), for the clinical discrimination of DLB from Alzheimer’s disease (AD).MethodsThis cross-sectional study analyzed participants’ demographical data, plasma α-synuclein level, MDQ, structured clinical history questionnaire, neuropsychological and motor function tests, and neuroimaging studies. The power of plasma α-synuclein level, MDQ, and SMDCS for discriminating DLB from non-demented controls (NC) or AD were compared.ResultsOverall, 121 participants diagnosed as 58 DLB, 31 AD, and 31 NC were enrolled. Patients with DLB had significantly higher mean plasma α-synuclein level (0.24 ± 0.32 pg/ml) compared to the NC group (0.08 ± 0.05 pg/ml) and the AD group (0.08 ± 0.05 pg/ml). The DLB group demonstrated higher MDQ (2.95 ± 1.60) compared to the NC (0.42 ± 0.98) or AD (0.44 ± 0.99) groups. The sensitivity/specificity of plasma α-synuclein level, MDQ, and SMDCS for differentiating DLB from non-DLB were 0.80/0.64, 0.83/0.89, and 0.88/0.93, respectively.ConclusionBoth plasma α-synuclein and MDQ were significantly higher in patients with DLB compared to the NC or AD groups. The novel SMDCS, significantly improved accuracy for the clinical differentiation of DLB from AD or NC.

Prodromal Dementia With Lewy Bodies: Evolution of Symptoms and Predictors of Dementia Onset.

Research criteria for prodromal dementia with Lewy bodies (DLB) were published in 2020, but little is known regarding prodromal DLB in clinical settings. We identified non-demented participants without neurodegenerative disease from the National Alzheimer's Coordinating Center Uniform Data Set who converted to DLB at a subsequent visit. Prevalence of neuropsychiatric and motor symptoms were examined up to 5 years prior to DLB diagnosis. The sample included 116 participants clinically diagnosed with DLB and 348 age and sex-matched (1:3) Healthy Controls. Motor slowing was present in approximately 70% of participants 3 years prior to DLB diagnosis. In the prodromal phase, 50% of DLB participants demonstrated gait disorder, 70% had rigidity, 20% endorsed visual hallucinations, and over 50% of participants endorsed REM sleep behavior disorder. Apathy, depression, and anxiety were common prodromal neuropsychiatric symptoms. The presence of 1+ core clinical features of DLB in combination with apathy, depression, or anxiety resulted in the greatest AUC (0.815; 95% CI: 0.767, 0.865) for distinguishing HC from prodromal DLB 1 year prior to diagnosis. The presence of 2+ core clinical features was also accurate in differentiating between groups (AUC = 0.806; 95% CI: 0.756, 0.855). A wide range of motor, neuropsychiatric and other core clinical symptoms are common in prodromal DLB. A combination of core clinical features, neuropsychiatric symptoms and cognitive impairment can accurately differentiate DLB from normal aging prior to dementia onset.

Prevalence and severity of neuropsychiatric symptoms in the prodromal stages of dementia with Lewy bodies and Alzheimer’s disease

AbstractBackgroundThere has been minimal investigation into the prodromal features dementia with Lewy bodies (DLB) and how they may differ from prodromal features of Alzheimer’s disease (AD).MethodThe data analyzed for this investigation were collected as part of a large, prospective longitudinal study conducted by the National Alzheimer’s Coordinating Center (NACC database is funded by NIA/NIH Grant U01 AG016976). We identified 110 non‐demented participants who converted to DLB at a subsequent visit. Participants were age and sex matched to 220 non‐demented participants who later converted to AD. We examined between group differences in the prevalence of symptoms on the Neuropsychiatric Inventory Questionnaire (NPI‐Q) at time of dementia diagnosis and in the 1‐3 years preceding conversion to dementia using Chi‐Square or Fisher Exact Test analyses.ResultsFor the DLB and AD groups, 82% were male and the average age at the time of dementia diagnosis was 75.4 years (SD=7.9). There was no significant difference in education between the two groups. The DLB group was significantly less culturally diverse than the AD group (See Table 1). Nighttime behaviors and hallucinations were significantly more common in the DLB group compared to the AD group at all time points during the prodromal phase and at the time of dementia diagnosis. There was no significant difference in the informant’s report of motor symptoms in the prodromal phases between the two groups (See Table 2).ConclusionThe DLB group demonstrated a significantly higher prevalence of nighttime behaviors and hallucinations than the AD group in both the prodromal phase and at the time of dementia diagnosis. These findings support the occurrence of core clinical features of DLB during the prodromal phase of the disease [1]; however, there was no significant difference in the informant’s report of motor symptoms within the prodromal phases, which warrants a comparison utilizing more objective motor data. Reference: 1. McKeith IG, Boeve BF, Dickson DW, et al.; Dementia with Lewy Bodies Consortium. Diagnosis and management of Dementia with Lewy Bodies: Fourth consensus report of the DLB Consortium. Neurol. 2017;89:1‐13.

Anxiety symptoms are quantitatively and qualitatively different in dementia with Lewy bodies than in Alzheimer's disease in the years preceding clinical diagnosis.

Dementia with Lewy bodies (DLB) is a common but underdiagnosed type of cognitive impairment and dementia. The current diagnostic criteria for research purposes have a high specificity but lack sensitivity. Moreover, patients who live alone are not always aware that they have core clinical features such as cognitive fluctuations, visual hallucinations, and parasomnia. Anxiety is a common and early manifestation in DLB. We matched 41 DLB patients with 41 patients with Alzheimer's disease (AD) according to gender, age, and cognitive status and retrospectively analyzed their files for the presence of anxiety, depression, constipation, and the core clinical features of DLB in the documented period before diagnosis. Anxiety, but not depression, occurred significantly more frequently in DLB than in AD (63.4% vs 26.8%). It appears up to 4-5 years before the diagnosis of DLB and is associated with depression and living at home. Anxiety in DLB was often described as intermittent panic attacks without reason or during states of delirium; it was also severe enough to require medical treatment and inpatient or outpatient psychiatric care. It was often mistaken for a psychiatric illness or a manifestation of other common forms of dementia. Anxiety in AD seemed much milder, was often related to the patient's coping with cognitive dysfunction, and was never cited as a specific reason for medical help. The concomitant presence of anxiety with at least one core clinical criterion of DLB enabled us to differentiate it from AD in our study, with a sensitivity of 63.4% but a specificity of 100%. In all patients over 50 who present with cognitive problems and anxiety, DLB should be considered. Patients and informants should be carefully questioned regarding the presence of other typical signs and symptoms of DLB.

Molecular Imaging of Dementia With Lewy Bodies.

Dementia with Lewy bodies (DLB) is the second most common cause of neurodegenerative dementia. The core clinical features of DLB include fluctuating cognition, visual hallucinations, rapid eye movement sleep behavior disorder, and parkinsonism. Molecular imaging is a powerful tool to assess the brain function in vivo. In this chapter, we reviewed the positron emission tomography, single-photon emission computed tomography, and [123I]-metaiodobenzylguanidine scintigraphy studies evaluating the pathological processes underlying DLB, including altered brain metabolism and neurotransmitter pathways, abnormal protein aggregation, and neuroinflammation. These techniques can aid in the differential diagnosis of DLB (versus Alzheimer's disease and related dementia) and in the monitoring disease progression and treatment efficacy of disease-modifying drugs. Furthermore, we explored the limitations of current imaging biomarkers and future directions, particularly focusing on the vital need for tracers that have high affinity for alpha-synuclein.

Clinical and neuroimaging characteristics of Chinese dementia with Lewy bodies

Dementia with Lewy bodies (DLB) is the second most common subtype of degenerative dementia. To our knowledge, available information about the clinical features of DLB in China remains limited. Our study therefore aimed to address this issue. Thirty-seven Chinese patients with probable DLB were recruited for this study. All subjects underwent neuropsychological assessment by trained neurologists, as well as undergoing MRI, 11C-PIB PET scans for Aβ deposition and 18F-FDG PET scans for regional cerebral glucose metabolism. Our results showed that the gender ratio of patients was 16:21 (F:M). The mean age of onset was 69.5 ± 9.0 years and the mean age at diagnosis was 71.8 ± 9.1 years. At diagnosis, the prevalence of three core clinical features of DLB was: 64.9% for fluctuating cognition, 73.0% for visual hallucinations and 62.2% for parkinsonism. The result from 11C-PiB PET and 18F-FDG PET scans confirmed Aβ deposition in the cortex and demonstrated hypometabolism in the bilateral temporoparietooccipital region, the frontal lobe, the insular lobe, and the posterior cingulate, precuneus and caudate nuclei. Our study elucidated the clinical features of Chinese DLB patients, and will improve the understanding and the early diagnosis of DLB in Chinese patients.

Delirium prior to dementia as a clinical phenotype of Lewy body disease: an autopsied case report

Although delirium shares clinical characteristics with dementia with Lewy bodies (DLB), there is limited information regarding the relationship between delirium and Lewy body pathology. Here, we report an 89-year-old Japanese woman with an episode of delirium who was pathologically confirmed to have limbic-type Lewy body disease (LBD). Although she exhibited transient visual hallucinations during the delirium, she had no overt dementia. She developed no core clinical features of DLB and died of pneumonia at the age of 90 years. This autopsied case suggests that delirium may be one of the clinical phenotypes of LBD prior to the onset of dementia.

Prediction of later clinical course by a specific glucose metabolic pattern in non-demented patients with probable REM sleep behavior disorder admitted to a memory clinic: A case study

The present study is a follow-up study of 11 non-demented patients with probable rapid eye movement (REM) sleep behavior disorder (RBD) at our memory clinic. During the follow-up period (mean±SD of 46.7±6.4 months), all 11 patients exhibited cognitive decline: four (Group A) exhibited core clinical features of dementia with Lewy bodies (DLB), along with severe cognitive decline, and were subsequently diagnosed as having probable DLB; four (Group B) did not exhibit core clinical features of DLB; and the remaining three (Group C) were diagnosed as having Parkinson's disease with dementia (PDD). Positron emission tomography with fluorodeoxyglucose-F18 at baseline revealed that Groups A and B exhibited glucose hypometabolism in the occipital lobe, especially in the primary visual cortex, and Group A tended to present hypometabolism in the parieto-temporal area as well. Group C tended to present hypometabolism in the medial prefrontal area and anterior cingulate gyrus. Neuropsychological examinations indicated poor performance in verbal memory and visuoperception in all groups. This case study suggests that patterns of hypometabolism and neuropsychological examinations at baseline may be indicators of the later clinical course of probable RBD patients.

Clinicians' ability to diagnose dementia with Lewy bodies is not affected by β-amyloid load.

To investigate whether an increasing load of β-amyloid and/or neuritic plaques influences the phenotype, and thus the clinical diagnostic accuracy, of dementia with Lewy bodies (DLB). A series of 64 subjects with autopsy-proven DLB was studied. Last diagnosis before death was used to determine the clinical diagnostic accuracy of DLB in relation to Lewy body distribution and extent of Alzheimer β-amyloid and/or neuritic pathology. DLB pathologic diagnosis was made according to consensus criteria, using α-synuclein immunostaining for Lewy body identification. β-Amyloid immunostaining was used for quantifying β-amyloid deposits. The Consortium to Establish a Registry for Alzheimer's Disease criteria and Braak stage were applied for semiquantitative grading of neuritic plaque and neurofibrillary tangle pathology. Overall clinical diagnostic accuracy for the entire DLB cohort was high (80%), reflecting the high prevalence of core clinical features (fluctuations [81%], parkinsonism [77%], visual hallucinations [70%]). Lower frequencies of core clinical features of DLB, resulting in lower accuracy of its clinical diagnosis, were associated with decreasing Lewy body distribution (p < 0.0001) and with increasing neuritic plaque pathology (p = 0.035), but not with the number of β-amyloid plaque deposits. The likelihood of occurrence of the DLB clinical syndrome is positively related to the extent of Lewy body pathology and negatively related to the severity of Alzheimer neuritic pathology, while β-amyloid load has no effect.

Early detection of dementia with Lewy bodies in patients with amnestic mild cognitive impairment using 123I-MIBG cardiac scintigraphy

Increasing clinical attention has been focused on cardiac sympathetic denervation for the differential diagnosis of dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) with the development of [123I] metaiodobenzylguanidine (MIBG) scintigraphy. Decreased MIBG uptake, which reflects cardiac sympathetic denervation, has been detected in DLB, but not in AD. However, the time course of detected cardiac sympathetic degeneration is poorly understood in DLB. Herein, the authors report two patients with a clinical diagnosis of amnestic mild cognitive impairment (MCI) who had cardiac sympathetic denervation, detected by cardiac 123I-MIBG scintigraphy, without the core clinical features of DLB. One amnestic MCI patient had nocturnal dream enactment behavior, consistent with clinically probable REM sleep behavior disorder (RBD), and converted to probable DLB with the development of recurrent visual hallucination and spontaneous parkinsonism two years after MCI is diagnosed. The other amnestic MCI patient exhibited occipital metabolic reduction on [18F]-fluoro-d-glucose (FDG) positron emission tomography (PET) scan, which is the preferentially affected region in DLB patients, although she had no core or suggestive clinical features of DLB. Both patients had abnormal findings on electrocardiogram at annual health checkups despite having no cardiac-related symptoms. Detailed clinical examinations, including angiography and echocardiogram, revealed no overt etiology, supporting the idea that cardiac sympathetic denervation is due to underlying Lewy body disease. The clinical courses of these patients suggest that 123I-MIBG cardiac scintigraphy is useful for the detection of DLB in the predementia phase, even before core clinical features appear.

Focal atrophy in dementia with Lewy bodies on MRI: a distinct pattern from Alzheimer's disease

Dementia with Lewy bodies (DLB) is the second most common cause of degenerative dementia after Alzheimer's disease. However, unlike the latter, the patterns of cerebral atrophy associated with DLB have not been well established. The aim of this study was to identify a signature pattern of cerebral atrophy in DLB and to compare it with the pattern found in Alzheimer's disease. Seventy-two patients that fulfilled clinical criteria for probable DLB were age- and gender-matched to 72 patients with probable Alzheimer's disease and 72 controls. Voxel-based morphometry (VBM) was used to assess patterns of grey matter (GM) atrophy in the two patient groups, relative to controls, after correction for multiple comparisons (P < 0.05). Study-specific templates and prior probability maps were used to avoid normalization and segmentation bias. Region-of-interest (ROI) analyses were also performed comparing loss of the midbrain, substantia innominata (SI), temporoparietal cortex and hippocampus between the groups. The DLB group showed very little cortical involvement on VBM with regional GM loss observed primarily in the dorsal midbrain, SI and hypothalamus. In comparison, the Alzheimer's disease group showed a widespread pattern of GM loss involving the temporoparietal association cortices and the medial temporal lobes. The SI and dorsal midbrain were involved in Alzheimer's disease; however, they were not identified as a cluster of loss discrete from uninvolved surrounding areas, as observed in the DLB group. On direct comparison between the two groups, the Alzheimer's disease group showed greater loss in the medial temporal lobe and inferior temporal regions than the DLB group. The ROI analysis showed reduced SI and midbrain GM in both patient groups, with a trend for more reduction of SI GM in Alzheimer's disease than DLB, and more reduction of midbrain in DLB than Alzheimer's disease. Significantly greater loss in the hippocampus and temporo-parietal cortex was observed in the Alzheimer's disease patients when the two patient groups were compared. A pattern of relatively focused atrophy of the midbrain, hypothalamus and SI, with a relative sparing of the hippocampus and temporoparietal cortex is, therefore, suggestive of DLB and this may aid in the differentiation of DLB from Alzheimer's disease. These findings support recent pathological studies showing an ascending pattern of Lewy body progression from brainstem to basal areas of the brain. Damage to this network of structures in DLB may affect a number of different neurotransmitter systems which in turn may contribute to a number of the core clinical features of DLB.

Dementia with Lewy Bodies

Synucleinopathies, with and without dementia, encompass a wide range of diseases including Parkinson's disease, multiple system atrophy, rapid eye movement (REM) sleep behavior disorder, and dementia with Lewy bodies (DLB). DLB is a neurodegenerative disorder resulting in slowly progressive and unrelenting dementia until death. Prevalence studies suggest that it is the second most common dementing illness in the elderly. The neuropathologic findings of DLB show a wide anatomic range. Lewy bodies and Lewy-related pathology are found from the brain stem to the cortex and, in many cases, associated with concurrent Alzheimer's disease pathology. A recent international consortium on DLB has resulted in revised criteria for the clinical and pathological diagnosis of DLB incorporating new information about the core clinical features and improved methods for their assessment. The presentation of DLB is typically one of cortical and subcortical cognitive impairments, with worse visuospatial and executive dysfunction than Alzheimer's disease. There may be relative sparing of memory especially in the early stages. Core clinical features of DLB include fluctuating attention, recurrent visual hallucinations, and parkinsonism. Suggestive features include REM sleep behavior disorder, severe neuroleptic sensitivity, and low dopamine transporter uptake in the basal ganglia on functional neuroimaging. Additional supportive features that commonly occur in DLB, but with lower specificity, include repeated falls and syncope, transient, unexplained loss of consciousness, severe autonomic dysfunction, hallucinations in other modalities, systematized delusions, depression, relative preservation of medial temporal lobe structures on structural neuroimaging, reduced occipital activity on functional neuroimaging, prominent slow wave activity on electroencephalogram, and low uptake myocardial scintigraphy. Management of DLB includes pharmacological and nonpharmacological interventions for its cognitive, neuropsychiatric, motor, and sleep disturbances.

Visual hallucinations in Lewy body disease relate to Lewy bodies in the temporal lobe.

Consensus opinion characterizes dementia with Lewy bodies (DLB) as a progressive dementing illness, with significant fluctuations in cognition, visual hallucinations and/or parkinsonism. When parkinsonism is an early dominant feature, consensus opinion recommends that dementia within the first year is necessary for a diagnosis of DLB. If dementia occurs later, a diagnosis of Parkinson's disease with dementia (PDD) is recommended. While many previous studies have correlated the neuropathology in DLB with dementia and parkinsonism, few have analysed the relationship between fluctuating cognition and/or well-formed visual hallucinations and the underlying neuropathology in DLB and PDD. The aim of the present study was to determine any relationship between these less-studied core clinical features of DLB, and the distribution and density of cortical Lewy bodies (LB). The brains of 63 cases with LB were obtained over 6 years following population-based studies of dementia and parkinsonian syndromes. Annual, internationally standardized, clinical assessment batteries were reviewed to determine the presence and onset of the core clinical features of DLB. The maximal density of LB, plaques and tangles in the amygdala, parahippocampal, anterior cingulate, superior frontal, inferior temporal, inferior parietal and visual cortices were determined. Current clinicopathological diagnostic criteria were used to classify cases into DLB (n = 29), PDD (n = 18) or parkinsonism without dementia (n = 16) groups. Predictive statistics were used to ascertain whether fluctuating cognition or visual hallucinations predicted the clinicopathological group. Analysis of variance and regressions were used to identify any significant relationship(s) between the presence and severity of neuropathological and clinical features. Cognitive fluctuations and/or visual hallucinations were not good predictors of DLB in pathologically proven patients, although the absence of these features early in the disease course was highly predictive of PDD. Cases with DLB had higher LB densities in the inferior temporal cortex than cases with PDD. There was no association across groups between any neuropathological variable and the presence or absence of fluctuating cognition. However, there was a striking association between the distribution of temporal lobe LB and well-formed visual hallucinations. Cases with well-formed visual hallucinations had high densities of LB in the amygdala and parahippocampus, with early hallucinations relating to higher densities in parahippocampal and inferior temporal cortices. These temporal regions have previously been associated with visual hallucinations in other disorders. Thus, our results suggest that the distribution of temporal lobe LB is more related to the presence and duration of visual hallucinations in cases with LB than to the presence, severity or duration of dementia.