Mild Dementia With Lewy Bodies Research Articles

Neuroanatomical substrates of depression in dementia with Lewy bodies and Alzheimer's disease.

Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) are often associated with depressive symptoms from the prodromal stage. The aim of the present study was to investigate the neuroanatomical correlates of depression in prodromal to mild DLB patients compared with AD patients. Eighty-three DLB patients, 37 AD patients, and 18 healthy volunteers were enrolled in this study. Depression was evaluated with the Mini International Neuropsychiatric Interview (MINI), French version 5.0.0. T1-weighted three-dimensional anatomical images were acquired for all participants. Regression and comparison analyses were conducted using a whole-brain voxel-based morphometry (VBM) approach on the grey matter volume (GMV). DLB patients presented a significantly higher mean MINI score than AD patients (p = 0.004), 30.1% of DLB patients had clinical depression, and 56.6% had a history of depression, while 0% of AD patients had clinical depression and 29.7% had a history of depression. VBM regression analyses revealed negative correlations between the MINI score and the GMV of right prefrontal regions in DLB patients (p < 0.001, uncorrected). Comparison analyses between DLB patients taking and those not taking an antidepressant mainly highlighted a decreased GMV in the bilateral middle/inferior temporal gyrus (p < 0.001, uncorrected) in treated DLB patients. In line with the literature, our behavioral analyses revealed higher depression scores in DLB patients than in AD patients. We also showed that depressive symptoms in DLB are associated with decreased GMV in right prefrontal regions. Treated DLB patients with long-standing depression would be more likely to experience GMV loss in the bilateral middle/inferior temporal cortex. These findings should be taken into account when managing DLB patients.

Who am I with my Lewy bodies? The insula as a core region of the self-concept networks.

Dementia with Lewy bodies (DLB) is characterized by insular atrophy, which occurs at the early stage of the disease. Damage to the insula has been associated with disorders reflecting impairments of the most fundamental components of the self, such as anosognosia, which is a frequently reported symptom in patients with Lewy bodies (LB). The purpose of this study was to investigate modifications of the self-concept (SC), another component of the self, and to identify neuroanatomical correlates, in prodromal to mild DLB. Twenty patients with prodromal to mild DLB were selected to participate in this exploratory study along with 20 healthy control subjects matched in terms of age, gender, and level of education. The Twenty Statements Test (TST) was used to assess the SC. Behavioral performances were compared between LB patients and control subjects. Three-dimensional magnetic resonance images (MRI) were acquired for all participants and correlational analyses were performed using voxel-based morphometry (VBM) in whole brain and using a mask for the insula. The behavioral results on the TST showed significantly impaired performances in LB patients in comparison with control subjects (p < .0001). Correlational analyses using VBM revealed positive correlations between the TST and grey matter volume within insular cortex, right supplementary motor area, bilateral inferior temporal gyri, right inferior frontal gyrus, and left lingual gyrus, using a threshold of p = .001 uncorrected, including total intracranial volume (TIV), age, and MMSE as nuisance covariates. Additionally, correlational analysis using a mask for the insula revealed positive correlation with grey matter volume within bilateral insular cortex, using a threshold of p = .005. The behavioral results confirm the existence of SC impairments in LB patients from the prodromal stage of the disease, compared to matched healthy controls. As we expected, VBM analyses revealed involvement of the insula, among that of other brain regions, already known to be involved in other self-components. While this study is exploratory, our findings provide important insights regarding the involvement of the insula within the self, confirming the insula as a core region of the self-networks, including for high-order self-representations such as the SC.

Neural basis of writing in prodromal to mild dementia with lewy bodies.

We have previously demonstrated difficulties in written production in dementia with Lewy bodies (DLB) patients. We now aim to determine the neural correlates of writing production in DLB, combining clinical data and structural MRI measures. Sixteen prodromal to mild DLB patients were selected to participate in the study. The GREMOTS test was used to assess writing production. Using three-dimensional T1 brain MRI images, correlations between the GREMOTS test and grey matter (GM) volume were performed using voxel-based morphometry (VBM; SPM12, XjView and Matlab R2021b softwares). VBM analysis (p<0.001, uncorrected) revealed a positive and significant correlation between both left anterior insula and left supramarginal gyrus GM volumes and DLB patients' ability to write logatoms using the phonological route. The handwriting deficit was negatively and significantly correlated to the supplementary motor area. The parkinsonism-like characteristics of agraphia were negatively and significantly correlated with both right anterior and right posterior cerebellum GM volumes. Our study also revealed a negative and significant correlation between grammatical spelling impairments and an area of the orbitofrontal gyrus, and a negative and significant correlation between supramarginal gyrus and general slowness in dictation tasks. Writing disorders in early DLB patients appears to be GM decreases in several brain regions, such as the left anterior insula, the left supramaginal gyrus, as well as two areas of the right cerebellum.

P185: Comparison of social function in mild cognitive impairment and mild dementia using the Japanese version of the Social Functioning in Dementia scale (SF-DEM-J)

Objective:The present study aimed to compare the social function between mild cognitive impairment (MCI), mild Alzheimer’s disease (AD) dementia, and mild dementia with Lewy bodies (DLB) using the Japanese version of Social Functioning in Dementia scale (SF-DEM-J).Methods:We interviewed 103 patients and family caregivers from June 2020 to March 2021: 54 patients with MCI, 34 with mild AD dementia, and 15 with mild DLB. We compared the caregiver-rated SF-DEM-J, Clinical Dementia Rating (CDR), MMSE, age, length of education, Geriatric Depression Scale (GDS), the University of California, Los Angeles Loneliness Scale (UCLA-LS), Neuropsychiatric Inventory (NPI), and informant version of the Apathy Evaluation Scale (AES) between MCI, mild AD dementia, and mild DLB groups using Kruskal-Wallis test with Dunn-Bonferroni correction for post-hoc analyses. We compared sex, living situation, and caregiver demographics between three groups using chi-square test. We performed correlation analysis between the score of each psychological test and the scores of SF-DEM-J within group using Spearman’s rank correlation coefficient.Results:For SF-DEM-J, the score of section 2 (communicating with others) was significantly worse in mild AD dementia than in mild DLB. The scores of section 1 (spending with others) and section 3 (sensitivity to others) and the total score did not significantly differ between three groups. The score of section 1 was significantly associated with MMSE in MCI, with anxiety and disinhibition of NPI, and AES in mild AD dementia, and with GDS in mild DLB. The score of section 2 was significantly associated with AES in MCI and mild AD dementia, with UCLA-LS in MCI, and with the length of education in mild DLB. The score of section 3 was significantly associated with agitation and irritability of NPI in MCI and mild AD dementia. The total score was associated with UCLA-LS and AES in MCI, and with AES in mild AD dementia.Conclusion:Factors affecting social functioning differed between MCI, mild AD dementia, and mild DLB. Apathy, agitation and irritability affected social functioning in MCI and mild AD dementia while depressive mood affected social functioning in mild DLB.

The ANeED Study: Ambroxol in New and Early Dementia with Lewy bodies

AbstractBackgroundNo disease modifying treatment is available for dementia with Lewy bodies (DLB). DLB patients have a rapid disease progression to the end stage of severe dementia, nursing home admission and death as compared to persons living with AD (1). Reported findings suggests reduced glucocerebrosidase (GCase) activity may be involved in pathomechanisms of synucleinopathies. Ambroxol is a well‐known drugs able to enhance GCase activity and thus increases synuclein clearance in CNS (2,3).MethodThe ANeED study is a national, multicentre, phase IIa RCT, placebo controlled clinical intervention trial including patients with prodromal and mild DLB with MMSE &gt;14 (NCT04588285). The drug intervention is 1260 mg/d and treatment duration is 18 month. We additionally stratify participants based on genotypes for APOE and the CSF biomarker amyloid‐beta. Allocation ratio 1:1 for ambroxol and placebo.ResultThe study started in May 2021. As of February 2023, six out of seven sites have started recruitment. Of 47 included patients 38 started treatment with compliance &gt;90%. Five patients completed the blind phase after 18 months and continue in the extended open label phase with ABX for 12 months. Adverse events reported are falls, nausea and sleep disturbances, but the relationship with ambroxol is uncertain. The goal for inclusions is 180 participants. Demographical and clinical data we present in table.ConclusionThe ANeED study continue to recruit patients as planned. We did not register any serious adverse events related to the study medication. The compliance is high and the tolerability and safety of study medication is good.

Mastermind of the Alzheimer’s blood‐based biomarkers: development of cutoffs and a visualization tool for use in clinical practice

AbstractBackgroundPhosphorylated (P‐)tau, amyloid‐beta (Abeta)1‐42/1‐40, glial fibrillary acidic protein (GFAP) and neurofilament light (NfL) are the current key Alzheimer’s disease (AD) blood‐based biomarkers. Interpreting results of the four biomarkers simultaneously in a clinical context is challenging. A decision algorithm could aid in the interpretation, tailored to clinically relevant questions: 1) identify positive amyloid status among preclinical and prodromal AD stages, 2) discriminate AD‐dementia from frontotemporal dementia (FTD), 3) discriminate AD‐dementia from dementia with Lewy bodies (DLB). We aimed to develop such an interpretation tool.MethodWe included 1199 participants from the Amsterdam Dementia Cohort (table 1) with subjective cognitive decline (SCD), mild cognitive impairment (MCI), AD‐dementia, FTD (mixed pathologies) or DLB. Plasma P‐tau181, Abeta1‐42/1‐40, GFAP and NfL were measured with Simoa. NfL levels were adjusted for age (method: https://doi.org/10.1002/acn3.51676). We used LASSO regression with bootstrap (1000 iterations) to identify which plasma markers robustly contribute to the prediction of the outcomes of our clinically relevant questions. When a marker was selected in &gt;95% of the iterations in at least one of the clinical scenarios, we qualified it as a contributing marker. Subsequently, we constructed UpSet plots applying Youden’s cutoffs as interpretation tool for the plasma results.ResultP‐tau181, GFAP and NfL were selected as contributing biomarkers. Abeta1‐42/1‐40 was not selected. The panel of P‐tau181, GFAP and NfL had an AUC = 83% (95%CI: 76‐90%) to identify amyloid positivity in SCD+MCI, AUC = 87% (95%CI: 79‐94%) to differentiate AD‐dementia from FTD, and AUC = 73% (95%CI: 62‐84%) to differentiate AD‐dementia from DLB. The UpSet plots show the simultaneous interpretation of P‐tau181, GFAP and NfL results for each clinically relevant question (figure 1): e.g., when all three biomarkers are abnormal in participants with SCD+MCI, there is 83% agreement with an abnormal PET or CSF amyloid status, and when all three plasma markers are normal, there is 88% agreement with a normal amyloid status.ConclusionThe combination of P‐tau181, GFAP and NfL in plasma could support decision making in different clinical contexts. UpSet plots enable easy interpretation of a combination of the markers, and could serve as a tool to support both detection and differential diagnosis of Alzheimer’s disease.

Neural Correlates of Photophobia in Prodromal and Mild Dementia with Lewy Bodies.

Photophobia is a sensory disturbance provoked by light. Little is known about the association between photophobia and dementia with Lewy bodies (DLB). In this study, we aimed to identify the frequency and the neural basis of photophobia in prodromal and mild DLB. One hundred thirteen DLB patients, 53 Alzheimer's disease (AD) patients, 20 AD and DLB patients, 31 patients with other neurocognitive diseases - including prodromal and mild demented patients -, and 31 healthy elderly controls were included in this case-control study. Photophobia was systematically looked for and compared between groups. Among a selection of 77 DLB patients, we used voxel-based morphometry (VBM) to compare those with and those without photophobia (gray matter volume; SPM12, XjView and Matlab R2021b software). The frequency of photophobia was higher in the DLB group (47.3%) than in the other groups (P=.002). The photophobia questionnaire score was higher in the DLB group than in the AD group (P=.001). Comparison between DLB patients with and those without photophobia showed decreased gray matter in the photophobia subgroup, in the right precentral cortex, in the eyelid motor region of Penfield's homunculus (P=.007, FWE corrected). Photophobia is a quite frequent symptom of prodromal and mild DLB. The neural basis of photophobia in DLB involves the right precentral cortex, which could have a role in the decrease of cerebral excitability, but also the motricity of the eyelids.

Memory Outcome in Prodromal and Mild Dementia with Lewy Bodies and Alzheimer's Disease: A Longitudinal Study.

Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) are likely to induce memory impairments from the prodromal stage but, to our knowledge, no longitudinal study of these patients' memory profile has been conducted to date. The aim of our study was to describe the characteristics and the evolution of the long-term memory profile of patients with prodromal and mild DLB and AD. We collected verbal (RL/RI-16) and visual (DMS48) memory scores from 91 DLB patients, 28 AD patients, 15 patients with both conditions (DLB/AD), and 18 healthy control subjects at their inclusion visit and at 12, 24, and 48 months. On the RL/RI-16, DLB patients performed better than AD patients in terms of total recall (p < 0.001), delayed total recall (p < 0.001), recognition (p = 0.031), and loss of information over time (p = 0.023). On the DMS48, differences between these two groups were not significant (p > 0.05). Longitudinally, the memory performance of DLB patients was stable over 48 months, unlike that of AD patients. Four indicators were relevant to distinguish between DLB and AD patients in terms of memory performance: DLB patients benefitted greatly from semantic cueing, their recognition and consolidation abilities were well-preserved, and both their verbal and visual memory performance remained remarkably stable over four years. However, no performance differences between DLB and AD patients were found regarding visual memory, either qualitatively (memory profile) or quantitatively (severity of impairment), indicating the lesser relevance of this test in distinguishing between these two diseases.

A simple method to evaluate the pentagon copy test of the Mini-Mental State Examination for the differentiation of dementia with Lewy bodies

There are many commonalities between the clinical symptoms of dementia with Lewy bodies (DLB) and those of Alzheimer’s disease (AD). The accurate differentiation of these two diseases is an important neuropsychological issue. The Mini-Mental State Examination (MMSE) is often used as a screening test for dementing disorders. We created evaluation items for the pentagon copy test of MMSE and developed a simple, highly accurate evaluation method for differentiating DLB in combination with conventional evaluation items such as the Qualitative Scoring MMSE Pentagon Test (QSPT). Subjects were divided into three groups: DLB (n = 119), AD (n = 50), and Normal (n = 26). The severities of DLB and AD ranged from mild cognitive impairment (MCI) to mild dementia. We compared the results of the pentagon copy test. We found that the rates of patients with abnormalities in “motor incoordination” and “gestalt destruction” were higher in the DLB group than the AD group. Furthermore, receiver operating characteristic curve analysis suggested the differentiation of DLB with high accuracy (sensitivity: 0.70, specificity: 0.78) using the criterion of patients meeting one of the following three characteristics: “the number of angles on QSPT: scores other than 4,” “major tremor (Parkinsonism-related tremor) is present,” and “gestalt destruction (distortion in overall coherence) is present.” This evaluation method may be clinically useful for evaluating MCI to mild DLB patients because the burden on patients is low.

Neural basis of impaired narrative discourse comprehension in prodromal and mild dementia with lewy bodies.

Narrative discourse (ND) comprehension is a complex task that implies not only linguistic abilities but also other cognitive abilities, including efficient executive functioning. An executive dysfunction has been described in dementia with Lewy bodies (DLB) from the early stage. Here, we question the link between executive dysfunction in DLB and narrative comprehension. The aim of our study was to evaluate ND comprehension and to investigate the neuroanatomical basis for its impairment in the early stage of DLB. DLB patients (N = 26) and controls (N = 19) underwent the ND comprehension test of the Montreal Protocol for Evaluation of Communication (MEC). An additional, qualitative analysis was conducted on their verbal productions. Cognitive tests assessing verbal episodic memory, executive functions, naming and oral syntactic comprehension were also performed. Brain gray matter correlates of the ND comprehension test were examined using voxel-based morphometry (VBM). An ND comprehension impairment was found for prodromal and mild DLB patients as compared to controls. These difficulties were correlated with the Frontal Assessment Battery (FAB) score. ND comprehension impairment in DLB was further characterized by a deficit in the organization and the logic of the discourse. Moreover, VBM analysis revealed a correlation between striatal gray matter volumes and DLB patients’ ability to extract and organize relevant information (p < 0.05, FDR correction, cluster level). The ND comprehension impairment in DLB patients could be related to their executive dysfunction through a deficit of information selection and organization that correlates with the volumetric reduction of striatal gray matter.

Tongue muscle mass is associated with total grey matter and hippocampal volumes in Dementia with Lewy Bodies

BackgroundAge-related neurodegeneration, sarcopenia, and ectopic fat accumulation are conditions with shared pathways that remain poorly understood. We have measured muscle volume and fat accumulation in masseter and tongue muscle, and aim to explore their association with the total grey matter volume using MRI in older adults recently diagnosed with Alzheimer's disease (AD) and Dementia with Lewy bodies (DLB). MethodsIn this cross-sectional study, people newly diagnosed with mild AD (n=33) and DLB (n=20) underwent structural head MRI. Muscle volume and intramuscular fat (iMAT) of the tongue and masseter were computed using Slice-O-Matic software for segmentation. Total grey volume and hippocampal volumetric segmentation were performed with the FreeSurfer image analysis suite version 6.0. Independent regression models were employed to analyse the associations. ResultsTongue iMAT was higher and total grey volume lower in DLB compared to AD. In the DLB group, tongue muscle was positively associated with total grey matter volume Est 0.92 (SE 0.24 p-value 0.002), left- Est 0.01 (SE 0.0028 p-value 0,002), and right- Est 0.0088 (SE 0.0027 p-value: 0.005) hippocampal volume. There were no statistically significant results for AD. ConclusionTongue muscle volume was positively associated with hippocampal and total grey volume in DLB. Longitudinal designs are required to explore the extent and significance of this association.

Who am I with my Lewy bodies? A self‐concept study

AbstractBackgroundNeurodegenerative diseases are marked by changes in personal identity, including the self‐concept (SC), which refers to a collection of knowledge about oneself, made up of personal semantic information. Modifications of the Self have been extensively investigated in Alzheimer's disease (AD), whereas it has never been studied in dementia with Lewy bodies (DLB). Yet, key regions for Self‐processing such as the medial prefrontal, the anterior cingulate and the insular cortices, are damaged early in the course of DLB. Thus, the purpose of this study was to investigate the SC integrity and to explore its neuroanatomical correlates in early DLB as compared to AD and normal ageing.MethodTwenty prodromal to mild DLB patients were compared to twenty‐one prodromal to mild AD patients, and to twenty‐one healthy control subjects, matched in terms of age and educational level. For all participants, SC was assessed using the Twenty Statements Test (TST) during which the subjects were asked to produce up to twenty affirmations answering the question: who am I? Behavioral performance was compared between the groups. 3D MRI images were acquired for DLB patients and correlational analyses were performed using voxel‐based morphometry (VBM).ResultBehavioral results obtained in the TST showed significantly decreased performances in both DLB and AD groups compared to healthy control subjects (p&lt;0.001). Moreover, DLB patients tended to produce less Self‐affirmations than AD patients. Additionally, correlational analyses between behavioral scores and neuroimaging data in the DLB group revealed positive correlations between the number of produced Self‐affirmations and grey matter volume in the medial and orbitofrontal prefrontal cortices and in the lateral temporal cortex, among other regions (central sulcus, hippocampus, cerebellum).ConclusionOur behavioral results confirmed that SC is affected from the early stage in both DLB and AD, and tends to be even more deteriorated in DLB. Interestingly, VBM analyses revealed that decreased performance in DLB patients was related to focal atrophy in regions such as medial prefrontal and lateral temporal cortices, which are central in the networks of Self‐processing and semantic memory, respectively.

Differentiating Mild Cognitive Impairment, Alzheimer's Disease, and Dementia With Lewy Bodies Using Cingulate Island Sign on Perfusion IMP-SPECT.

The cingulate island sign (CIS) on fludeoxyglucose (FDG)-positron emission tomography (PET) is a supporting biomarker of dementia with Lewy bodies (DLB). Its diagnostic accuracy has only been investigated in FDG-PET, however. The present prospective study compared the CIS on I-iodoamphetamine-single photon emission computed tomography (SPECT) among patients with mild cognitive impairment (MCI), AD, or DLB. Fifty-eight patients with MCI, 42 with probable AD, and 58 with probable DLB were enrolled. The “CIScore” used to evaluate the CIS was defined as the ratio of volume of interest (VOI)-1 (indicating posterior cingulate gyrus [PCG]) to VOI-2 (area of significantly reduced regional cerebral blood perfusion [rCBF] in DLB patients compared with in healthy controls). It was calculated using eZIS software. The CIScore for MCI, DLB, and AD was 0.22, 0.23, and 0.28, respectively. The CIScore in the AD group was significantly higher than that in the DLB or MCI groups (AD vs. DLB: p < 0.001, AD vs. MCI: p < 0.005). This suggests that the CIScore can discriminate DLB from AD, if the decrease in rCBF in the PCG is similar between them. We believe that it is difficult to identify MCI based on the CIScore, as the decrease in rCBF in the PCG is not severe. The diagnostic accuracy of the CIScore may be low as it often shows an increase in elderly DLB patients, in whom the pathologically common form is most prevalent (1). Further study should include assessment of multiple components such as symptom classification and age.

A Model to Assess the Outcomes Associated With Dementia With Lewy Bodies.

Research investigating outcomes associated with dementia with Lewy bodies (DLB) disease progression is scarce. Developing models of DLB disease progression will provide information on the burden of disease and facilitate the evaluation of treatments for DLB from a clinical and cost perspective. Longitudinal, cognitive evaluation data were utilized in order to identify distinct health states for DLB and to estimate transition probabilities across the DLB disease continuum. These probabilities were applied to a health state transition model to evaluate disease progression and associated outcomes for a closed cohort over a fixed time horizon. The effect of a reduction in the risk of disease progression on outcomes was assessed. Estimated transition probabilities indicate that a patient >60 years of age with mild DLB has a 54%, 30%, 4%, and 12% chance of remaining mild, progressing to severe DLB, being institutionalized, and dying after 1 year, respectively. Reducing the annual risk of transitioning from mild to severe DLB by 40% decreased time institutionalized and increased time to death. This study used real-world longitudinal data to create a clinically relevant DLB disease progression model. Reducing the rate of disease progression resulted in meaningful benefits with potentially significant public health implications.

Hippocampal Subfields and Decline in Activities of Daily Living in Alzheimer’s Disease and Dementia With Lewy Bodies

Background: Hippocampal atrophy is presented in Alzheimer's disease (AD) and dementia with Lewy bodies (DLB).Cognition, dual-tasks, muscular function, goal-related behaviors and neuropsychiatric symptoms are linked to hippocampal volumes and may lead to functional decline in activities of daily living. We examined the association between baseline hippocampal subfield volumes (HSv) in mild AD and DLB, and functional decline. Materials & methods:12HSv were computed from structural magnetic resonance images using Freesurfer 6.0 segmentation. Functional decline was assessed using the rapid disability rating scale score. Linear regressions were conducted. Results: In AD, HSv were smaller bilaterally. However, HSv were not associated with functional decline. Conclusion: Functional decline does not depend on HSv in mild AD and DLB.

Magnetic Resonance Imaging Texture of Medial Pulvinar in Dementia with Lewy Bodies

Introduction: Executive dysfunction is common in dementia with Lewy bodies (DLB). The pulvinar nucleus plays a role in executive control and synchronizes with cortical regions in the salience network that are vulnerable to Lewy pathology. Objective: We investigated the pulvinar subregions in patients with mild DLB and their associations with executive function. Methods: The sample consisted of 38 DLB patients and 38 age- and sex-matched normal controls. We evaluated cognitive function using the Consortium to Establish a Registry for Alzheimer’s Disease Assessment Packet. We obtained four pulvinar nuclei using preprocessed T1-weighted magnetic resonance images. We compared volumes and textures of the DLB patients and the normal controls for each nucleus. We used a linear regression to determine the association of textures and neuropsychological test scores. Results: The DLB patients showed comparable volumes to the normal controls in all pulvinar nuclei. However, the DLB patients showed different texture of the left medial pulvinar (PuM) from the normal controls. The entropy, contrast, and cluster shade were lower but autocorrelation of left PuM was higher in the DLB patients compared to the normal controls. These texture features of the left PuM were associated with the set-shifting performance measured by the Trail Making Test. Conclusions: In DLB, the left PuM may be altered from early stage, which may contribute to the development of executive dysfunction.

Cingulate island sign temporally changes in dementia with Lewy bodies

The cingulate island sign (CIS) that reflects sparing of the posterior cingulate cortex (PCC) relative to the precuneus plus cuneus on FDG-PET and brain perfusion SPECT, has been proposed as a feature of dementia with Lewy bodies (DLB). As the CIS is influenced by concomitant Alzheimer’s disease (AD)-type neurofibrillary tangle (NFT) pathology, we postulated that the CIS gradually disappears as DLB progresses. To determine temporal changes in the CIS, 24 patients with mild DLB and 7 with prodromal DLB underwent 123I-IMP–SPECT and MMSE twice at an interval of two years. The CIS was evaluated as a ratio that was derived by dividing IMP accumulation in the PCC with that in the precuneus plus cuneus. We found that the CIS changed over time and that the relationship between CIS ratios and MMSE scores was inverted U-shaped. Thus, the CIS was most obvious in the vicinity of an MMSE score of 22 and it gradually diminished as the MMSE score decreased. Moreover, a lower CIS ratio in mild DLB was associated with a worse prognosis for cognitive decline, presumably due to concomitant AD-type NFT pathology. Our findings would provide a foundation for the appropriate usage of CIS as a biomarker.

Comparing Cognitive Profiles of Licensed Drivers with Mild Alzheimer's Disease and Mild Dementia with Lewy Bodies.

Purpose. Alzheimer's disease (AD) and dementia with Lewy Bodies (DLB) constitute two of the most common forms of dementia in North America. Driving is a primary means of mobility among older adults and the risk of dementia increases with advanced age. The purpose of this paper is to describe the cognitive profile of licensed drivers with mild AD and mild DLB. Method. Licensed drivers with mild AD, mild DLB, and healthy controls completed neuropsychological tests measuring general cognition, attention, visuospatial/perception, language, and cognitive fluctuations. Results. The results showed differences between healthy controls and demented participants on almost all neuropsychological measures. Participants with early DLB were found to perform significantly worse on some measures of attention and visuospatial functioning in comparison with early AD. Discussion. Future research should examine the relationship between neuropsychological measures and driving outcomes among individuals with mild AD and mild DLB.

Driving Competence in Mild Dementia with Lewy Bodies: In Search of Cognitive Predictors Using Driving Simulation.

Driving is a multifactorial behaviour drawing on multiple cognitive, sensory, and physical systems. Dementia is a progressive and degenerative neurological condition that impacts the cognitive processes necessary for safe driving. While a number of studies have examined driving among individuals with Alzheimer's disease, less is known about the impact of Dementia with Lewy Bodies (DLB) on driving safety. The present study compared simulated driving performance of 15 older drivers with mild DLB with that of 21 neurologically healthy control drivers. DLB drivers showed poorer performance on all indicators of simulated driving including an increased number of collisions in the simulator and poorer composite indicators of overall driving performance. A measure of global cognitive function (i.e., the Mini Mental State Exam) was found to be related to the overall driving performance. In addition, measures of attention (i.e., Useful Field of View, UFOV) and space processing (Visual Object and Space Perception, VOSP, Test) correlated significantly with a rater's assessment of driving performance.

Comparing Hippocampal Atrophy in Alzheimer’s Dementia and Dementia with Lewy Bodies

Background/Aims: Dementia with Lewy bodies (DLB) and Alzheimer’s disease (AD) are the two most common neurodegenerative dementias. During the early stages, clinical distinction between them is often challenging. Our objective is to compare hippocampal atrophy patterns in mild AD and mild DLB. We hypothesized that DLB subjects have milder hippocampal atrophy relative to AD subjects. Methods: We analyzed the T1-weighted magnetic resonance imaging data from 113 subjects: 55 AD, 16 DLB and 42 cognitively normal elderly (normal controls, NC). Using the hippocampal radial distance technique and multiple linear regression, we analyzed the effect of clinical diagnosis on hippocampal radial distance, while adjusting for gender and age. Three-dimensional statistical maps were adjusted for multiple comparisons using permutation-based statistics with a threshold of p < 0.01. Results: Compared to NC, AD exhibited significantly greater atrophy in the cornu ammonis (CA)1, CA2–3 and subicular regions bilaterally while DLB showed left-predominant atrophy in the CA1 region and subiculum. Compared directly, AD and DLB did not reveal statistically significant differences. Conclusion: Hippocampal atrophy, while present in mildly impaired DLB subjects, is less severe than atrophy seen in mildly impaired AD subjects, when compared to NC. Both groups show predominant atrophy of the CA1 subfield and subiculum.