Differentiation Of Dementia With Lewy Bodies Research Articles

Utility of combining multiple parameters of 123I-IMP SPECT and voxel-based morphometry MRI using a multiparametric scoring system for differentiating dementia with Lewy bodies from Alzheimer's disease.

Brain magnetic resonance imaging voxel-based morphometry (VBM) and perfusion single-photon emission computed tomography (SPECT) are useful for differentiating dementia with Lewy bodies (DLB) from Alzheimer's disease (AD). To determine whether combining multiple parameters of VBM and SPECT using a multiparametric scoring system (MSS) improves diagnostic accuracy in differentiating DLB from AD. In total, 23 patients with DLB and 57 patients with AD underwent imaging using a voxel-based specific regional analysis system for AD (VSRAD), an easy Z-score imaging system, and a Z-Graph using three-dimensional stereotactic surface projection. The cutoff values were determined using the receiver operating characteristic curve to differentiate DLB from AD for all parameters. Patients were scored 1 (DLB) or 0 (AD) for each statistically significant parameter, according to a threshold. The total score was determined for each case to obtain a cutoff value for the MSS. The mean Z-scores in the medial temporal lobes using the VSRAD were significantly lower in patients with DLB than in those with AD. Each Z-score of the summed Z-scores in all four segmented regions of the occipital lobes using the Z-Graph was significantly higher in patients with DLB than in those with AD. Among the five parameters, the highest accuracy was 80% for the Z-score of the summed Z-scores in the left medial occipital lobe. For the MSS, a cutoff value of four improved the diagnostic accuracy to 82%. MSS was more accurate than any single parameter of VBM or SPECT in differentiating DLB from AD.

Diagnostic performance of the cingulate island sign ratio for differentiating dementia with Lewy bodies from Alzheimer's disease changes depending on the mini-mental state examination score

BackgroundThe cingulate island sign (CIS) ratio is a diagnostic adjunct for differentiating dementia with Lewy bodies (DLB) from Alzheimer's disease (AD). A recent study showed that the CIS ratio in DLB changed depending on the Mini-Mental State Examination (MMSE) score. We aimed to evaluate whether the diagnostic performance (sensitivity and specificity) of the CIS ratio for differentiating DLB from AD changes depending on the MMSE score. MethodsTwenty-two patients with DLB and 26 amyloid-positive patients with AD, who underwent 18F-FDG PET and completed an MMSE examination, were classified into three groups according to MMSE scores: Group A (MMSE >24), Group B (20 ≤ MMSE ≤24), and Group C (MMSE <20). In each group, we compared the CIS ratio between patients with DLB and AD and conducted receiver operating characteristic (ROC) curve analysis to calculate the sensitivity and specificity. ResultsWithin Group B, the CIS ratio in DLB was significantly higher than that in AD (p = 0.0005), but not within Groups A (p = 0.5117) and C (p = 0.8671). ROC curve analyses showed that the sensitivities and specificities of the CIS ratio for differentiating DLB from AD were 66.7% and 77.8% in Group A, 91.7% and 100.0% in Group B, and 75.0% and 66.7% in Group C, respectively. ConclusionsThe present study suggests that the diagnostic performance of the CIS ratio for differentiating DLB from AD changes depending on the MMSE score, with higher sensitivity and specificity at MMSE scores of 20–24.

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.

Generalized Rhythmic Delta Activity Frontally Predominant Differentiates Dementia with Lewy Bodies From Alzheimer's Disease and Parkinson's Disease Dementia: A Conventional Electroencephalography Visual Analysis.

Introduction. An easily accessible and inexpensive neurophysiological technique such as conventional electroencephalography may provide an accurate and generally applicable biomarker capable of differentiating dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) and Parkinson's disease-associated dementia (PDD). Method. We carried out a retrospective visual analysis of resting-state electroencephalography (EEG) recording of 22 patients with a clinical diagnosis of 19 probable and 3 possible DLB, 22 patients with probable AD and 21 with PDD, matched for age, duration, and severity of cognitive impairment. Results. By using the grand total EEG scoring method, the total score and generalized rhythmic delta activity frontally predominant (GRDAfp) alone or, even better, coupled with a slowing of frequency of background activity (FBA) and its reduced reactivity differentiated DLB from AD at an individual level with an high accuracy similar to that obtained with quantitative EEG (qEEG). GRDAfp alone could also differentiate DLB from PDD with a similar level of diagnostic accuracy. AD differed from PDD only for a slowing of FBA. The duration and severity of cognitive impairment did not differ between DLB patients with and without GRDAfp, indicating that this abnormal EEG pattern should not be regarded as a disease progression marker. Conclusions. The findings of this investigation revalorize the role of conventional EEG in the diagnostic workup of degenerative dementias suggesting the potential inclusion of GRDAfp alone or better coupled with the slowing of FBA and its reduced reactivity, in the list of supportive diagnostic biomarkers of DLB.

Usefulness of texture analysis in 123I-FP-CIT for the differentiation of AD and DLB subtypes.

I-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (123I-FP-CIT) is well known to be a useful tracer for differentiating dementia with Lewy bodies (DLB) and Alzheimer disease (AD). However, clinically, there are some cases in which these diseases cannot be differentiated by ordinary quantitative methods. Therefore, in this study, we established an index that reflects not only the total count but also the distribution and heterogeneity of tracer uptake. We investigated whether assessment of the heterogeneous depletion of 123I-FP-CIT is useful for the differentiation of various types of dementia, i.e., probable DLB, possible DLB, and AD, using texture analysis. A total of 122 patients with either probable DLB (n=35), possible DLB (n=23), AD (n=44), and normal controls (n=20) were analyzed. Summated single photon emission computed tomography (SPECT) images (7 to 10 slices) of the patients, including the bilateral striatum, were analyzed using the gray-level histogram method (GLHM) of texture analysis. Mean, variance, skewness, and kurtosis of GLHM were compared with the specific binding ratio by Livia Tossici-Bolt's method (SBR). The sensitivity and specificity for differentiating probable DLB from possible DLB, AD, and normal controls were 97.1% and 77.0%, respectively, for skewness, using a cut-off point of 6.8%, and 97.1% and 81.6%, respectively, for kurtosis, using a cut-off point of 53.4%. The sensitivity and specificity for differentiating probable and possible DLB from AD and normal controls was 65.5% and 98.4%, respectively, for skewness, using a cut-off point of 6.4%, and 79.3% and 93.8%, respectively, for kurtosis, using a cut-off point of 53.4%. In the assessment of the efficacy of 123I-FP-CIT to differentiate AD and DLB subtypes, mean, variance, skewness, and kurtosis by GLHM was as useful as the SBR method. Moreover, possible DLB and probable DLB could be differentiated by skewness and kurtosis. Our results demonstrate that texture analysis is more useful than conventional quantitative methods for obtaining valuable information of the brain. Textural features as such may have considerable potential as imaging biomarkers of DLB progression.

123I-MIBG scintigraphy utility and cut-off value in a clinically representative dementia cohort

ObjectiveTo determine the utility of 123I-metaiodobenzylguanidine cardiac scintigraphy (MIBG), and optimum heart: mediastinum ratio (HMR) for differentiating dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) in a clinically representative population, comparing findings with those of 123I-2β -carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (FP-CIT) SPECT. MethodsWe recruited subjects with probable DLB (n = 17) and probable AD (n = 16) from clinical services. Each participant underwent clinical examination, cardiac MIBG scintigraphy and FP-CIT SPECT. Diagnosis was made on the basis of clinical symptoms using validated criteria. Cardiac MIBG uptake was measured by the planar HMR, blind to clinical diagnosis, with values below a cut-off taken from a previous study (<2.2 at four hours) defining scans as abnormal. FP-CIT scans were blindly rated according to a visual rating scale. ResultsMIBG had a sensitivity, specificity and overall accuracy of 71%, 81% and 76% for distinguishing DLB from AD. FP-CIT demonstrated a sensitivity, specificity and accuracy of 82%, 88% and 85%. Using a lower HMR cut-off to distinguish between abnormal and normal MIBG scans improved the accuracy of MIBG, raising specificity (100%) and overall accuracy (85%) without compromising sensitivity (71%). Neither prescription of potentially interfering medications, nor a history of myocardial infarction (MI), had a significant effect on HMR. ConclusionWe found that MIBG did not demonstrate superior sensitivity and overall accuracy to FP-CIT. HMR cut-off influences biomarker utility, and clinical and Caucasian populations may require a lower cut-off than those reported elsewhere. Future MIBG studies should include clinically representative cohorts as neither medications nor previous MI appear to influence HMR.

Technical note: can resting state functional MRI assist in routine clinical diagnosis?

Despite some differences in clinical presentation, it is often difficult to differentiate between dementia with Lewy bodies (DLB), clinical Alzheimer’s dementia (AD) and Parkinson’s disease dementia. However, differentiation can be crucial, especially as patients with DLB characteristically have a hypersensitivity to most antiemetic and neuroleptic drugs as they affect the cholinergic and dopaminergic system, potentially leading to life-threatening catatonia, loss of cognitive function and muscle rigidity. The aim of this study is to evaluate if resting state (RS) functional MRI (fMRI) can be used in routine practice on a 1.5 T scanner to differentiate between AD and DLB on an individual basis. We age- and gender-matched a known DLB patient with an AD patient and a human control (HC). Individual independent component analysis was carried out. Region of interest seeds were chosen from the midcingulate and insula regions. Functional connectivity from insula to midcingulate and within the midcingulate network (part of the Salience network) was lower in DLB than AD or HC. RS-fMRI on a 1.5 T scanner, in a routine clinical setting, detected abnormal functional connectivity patterns and allowed differentiation of DLB and AD in a routine clinical setting. This is the first evaluation of RS-fMRI in a routine clinical setting. It shows that incorporating RS-fMRI into the clinical scanning protocol can assist in early diagnosis and likely assist in monitoring the natural history of the disease or disease modifying treatments.

Transcranial Sonography in Neurodegenerative Diseases with Cognitive Decline.

Transcranial sonography (TCS) of the brain parenchyma detects alterations in the substantia nigra (SN), raphe nuclei and basal ganglia; this technique has been established as a tool for the early diagnosis of Parkinson's disease and differential diagnosis from atypical parkinsonian syndromes. Here, we aimed to review the main applications of TCS in neurodegenerative diseases presenting with dementia syndrome, focusing on Alzheimer's disease (AD), dementia with Lewy bodies (DLB), frontotemporal lobar degeneration, idiopathic normal pressure hydrocephalus, and atypical and secondary parkinsonisms. The finding of bilaterally marked hyperechogenicity of the SN appears as a characteristic feature of DLB, while it is found only in a minority of AD patients. SN hyperechogenicity is also detected in most patients with corticobasal degeneration and in about one third of patients with progressive supranuclear palsy, in which is constantly associated with hyperechogenic alterations of the basal ganglia. In conclusion, TCS is a valid supportive tool in the diagnostic workup of patients with dementia due to different neurodegenerative conditions. A promising new application is the differentiation of DLB from AD even at the early stages of these diseases.

A new potential biomarker for dementia with Lewy bodies: Skin nerve α-synuclein deposits.

To investigate whether (1) phosphorylated α-synuclein (p-syn) deposits in skin nerves could be useful in differentiating dementia with Lewy bodies (DLB) from different forms of dementia and (2) small fiber neuropathy (SFN) is associated with DLB. We studied 18 well-characterized patients with DLB (11 with autonomic dysfunction), 23 patients with nonsynucleinopathy dementia (NSD; 13 with young-onset Alzheimer disease dementia, 6 frontotemporal dementia, and 4 vascular dementia), and 25 healthy controls. All participants underwent skin biopsies from proximal (i.e., cervical) and distal (i.e., thigh and distal leg) sites to study small nerve fibers and deposits of p-syn, considered the pathologic form of α-synuclein. No p-syn was detected in any skin sample in patients with NSD and controls but was found in all patients with DLB. SFN was found in patients with DLB and the autonomic denervation of skin was more severe in patients with autonomic dysfunctions. (1) In autonomic skin nerves, p-syn is a sensitive biomarker for DLB diagnosis, helping to differentiate DLB from other forms of dementia, although this needs to be confirmed in a larger, more representative sample; and (2) skin autonomic neuropathy is part of the DLB pathology and may contribute to autonomic symptoms. This study provides Class III evidence that p-syn in skin nerve fibers on skin biopsy accurately distinguishes DLB from other forms of dementia.

Biomarkers Differentiating Dementia withLewy Bodies from Other Dementias: AMeta-Analysis.

Several nuclear imaging and cerebrospinal fluid (CSF) biomarkers are under investigation, aimed at facilitating the differential diagnosis of dementias. To quantitatively synthesize data on test performance in differentiating dementia with Lewy bodies (DLB) from other dementias. We searched PubMed (January 2000- March 2015) for English-language publications that assessed a selected set of five imaging and three CSF biomarkers for this purpose. We meta-analyzed measures of agreement between biomarker results and clinical diagnosis. Forty-five publications were eligible. The majority of evidence was based on studies that enrolled representative disease populations. For differentiating between DLB and Alzheimer's disease (AD) or other dementias, metaiodobenzylguanidine scintigraphy and dopamine transporter (DAT) single photon emission computed tomography (SPECT) showed, respectively, excellent (summary kappa = 0.85; 95% confidence interval [95% CI], 0.74-0.96) and good (summary kappa = 0.71; 95% CI, 0.43-0.99) agreement. Metaiodobenzylguanidine scintigraphy appeared superior to fluorodeoxyglucose- positron emission tomography (summary kappa = 0.53; 95% CI, 0.36-0.69) and cerebral blood flow SPECT (summary kappa = 0.40; 95% CI, 0.33-0.47). For differentiating DLB from AD, CSF t-tau levels (summary kappa = 0.68; 95% CI, 0.55-0.82) performed comparably to metaiodobenzylguanidine scintigraphy and DAT SPECT. Sparse direct comparative evidence failed to corroborate these indirect comparisons. Metaiodobenzylguanidine scintigraphy and DAT SPECT are highly concordant with clinical diagnosis in differentiating DLB from other dementias. However, given the limitations in the study design, the applicability of these results to real-world differential diagnosis remains unclear. Prospective studies targeting patients with atypical presentations that adopt gold standard tests would reliably estimate the true test performance of these promising biomarkers.

Random forest to differentiate dementia with Lewy bodies from Alzheimer's disease

IntroductionThe aim of this study was to build a random forest classifier to improve the diagnostic accuracy in differentiating dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) and to quantify the relevance of multimodal diagnostic measures, with a focus on electroencephalography (EEG). MethodsA total of 66 DLB, 66 AD patients, and 66 controls were selected from the Amsterdam Dementia Cohort. Quantitative EEG (qEEG) measures were combined with clinical, neuropsychological, visual EEG, neuroimaging, and cerebrospinal fluid data. Variable importance scores were calculated per diagnostic variable. ResultsFor discrimination between DLB and AD, the diagnostic accuracy of the classifier was 87%. Beta power was identified as the single-most important discriminating variable. qEEG increased the accuracy of the other multimodal diagnostic data with almost 10%. DiscussionQuantitative EEG has a higher discriminating value than the combination of the other multimodal variables in the differentiation between DLB and AD.

Imaging and cerebrospinal fluid (CSF) biomarkers for differentiating dementia with Lewy bodies (DLB) from Alzheimer's disease (AD): A meta-analysis of test performance

Imaging and cerebrospinal fluid (CSF) biomarkers for differentiating dementia with Lewy bodies (DLB) from Alzheimer's disease (AD): A meta-analysis of test performance

Differentiation of frontotemporal dementia from dementia with Lewy bodies using FP-CIT SPECT

IntroductionThere is increasing evidence that imaging with [123I]FP-CIT SPECT is helpful in differentiating dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) but it is not known how well the...

CSF Tau, Aβ42, and MHPG Differentiate Dementia with Lewy Bodies from Alzheimer's Disease

Differentiating dementia with Lewy bodies (DLB) from Alzheimer's Disease (AD) can be difficult because of the substantial overlap in clinical features. Since deficits in serotonergic and dopaminergic pathways seem more pronounced in DLB patients, we investigated whether cerebrospinal fluid (CSF) analysis of neurotransmitter metabolites, in addition to brain-specific proteins, may improve the differentiation between DLB and AD. We retrospectively compared CSF concentrations of the neurotransmitter metabolites homovanillic acid (HVA), 5-hydroxyindolacetic acid (5-HIAA), and 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) and the brain-specific proteins total tau (t-tau), phosphorylated tau protein (p-tau), and amyloid-β42 (Aβ42) in 45 patients with AD (mean age 71.6 years; 34 (76%) men; 44 probable AD, 1 definite) and 23 patients with DLB (mean age 71.6 years; 18 (78%) men; 6 possible DLB, 16 probable, 1 definite). The concentrations of all neurotransmitter metabolites, as well as those for t-tau and p-tau protein, were significantly lower in DLB compared to AD, irrespective of the diagnostic certainty (i.e., possible or probable). The currently used combination of Aβ42, p-tau, and t-tau yielded a sensitivity of 92.9% and a specificity of 90%. The addition of MHPG resulted in an increased sensitivity of 97.6% and a specificity of 95% for the discrimination between DLB and AD. In conclusion, the combination of MHPG and the brain specific proteins t-tau, p-tau, and Aβ42 in CSF were associated with the clinical diagnosis of DLB and discriminated between AD and DLB with high diagnostic accuracy, suggesting this combination as a potential biomarker for DLB.

Differential levels of α-synuclein, β-amyloid42 and tau in CSF between patients with dementia with Lewy bodies and Alzheimer's disease

BackgroundThe clinical diagnosis of dementia with Lewy bodies (DLB) is made on the basis of consensus criteria; however, the sensitivity of the criteria is relatively low. There are no generally...

A comparison of 99mTc-exametazime and 123I-FP-CIT SPECT imaging in the differential diagnosis of Alzheimer's disease and dementia with Lewy bodies

The aim of this study is to investigate the diagnostic value of perfusion 99mTc-exametazime single photon emission computed tomography (SPECT) in the diagnosis of dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) in comparison with dopaminergic 123I-2beta-carbomethoxy-3beta-(4-iodophenyl)-n-(3-fluoropropyl) nortropane (FP-CIT) SPECT imaging. Subjects underwent 99mTc-exametazime scanning (39 controls, 36 AD, 30 DLB) and 123I-FP-CIT scanning (33 controls, 33 AD, 28 DLB). For each scan, five raters performed visual assessments blind to clinical diagnosis on selected transverse 99mTc-exametazime images in standard stereotactic space. Diagnostic accuracy of 99mTc-exametazime was compared to 123I-FP-CIT results for the clinically relevant subgroups AD and DLB using receiver operating characteristic (ROC) curve analysis. Inter-rater agreement for categorizing uptake was "moderate" (mean kappa = 0.53) for 99mTc-exametazime and "excellent" (mean kappa = 0.88) for 123I-FP-CIT. For AD and DLB, consensus rating matched clinical diagnosis in 56% of cases using 99mTc-exametazime and 84% using 123I-FP-CIT. In distinguishing AD from DLB, ROC analysis revealed superior diagnostic accuracy with 123I-FP-CIT (ROC curve area 0.83, sensitivity 78.6%, specificity 87.9%) compared to occipital 99mTc-exametazime (ROC curve area 0.64, sensitivity 64.3%, specificity 63.6%) p = 0.03. Diagnostic accuracy was superior with 123I-FP-CIT compared to 99mTc-exametazime in the differentiation of DLB from AD.

Value of Combining Activated Brain FDG-PET and Cardiac MIBG for the Differential Diagnosis of Dementia

Dementia with Lewy bodies (DLB) is the second most common cause of dementia. The diagnosis of DLB is particularly important because these patients show good response to cholinesterase inhibitors. Clinical and neuroimaging criteria for DLB have not been acceptable for predictive accuracy. We report a case of progressive dementia in which the differentiation of DLB and Alzheimer disease (AD) on the basis of clinical criteria alone was not possible. The patient was admitted to the hospital because he became worse after he had started treatment for severe AD. Both MRI and brain magnetic resonance spectroscopy were normal. The patient underwent myocardial scintigraphy with I-123 MIBG showing marked reduction in cardiac MIBG accumulation. The heart to mediastinum ratio of MIBG uptake was impaired in both early and delayed images. FDG-PET scan before and after activation with a visual attention task showed occipital cortex hypometabolism as compared with AD and a normal control. This case illustrates the value of combining activated brain FDG PET and cardiac MIBG. The association of these 2 techniques could be used as a potential diagnostic tool in a patient with dementia misdiagnosed as AD.

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.

The Mini-Mental State exam may help in the differentiation of dementia with Lewy bodies and Alzheimer's disease.

Since patients with dementia with Lewy bodies (DLB) tend to have greater impairment of attention and construction and better memory ability on neuropsychological tests than patients with Alzheimer's disease (AD), we determined if the items that measure attention, memory, and construction in the Mini-Mental State Examination (MMSE) help to distinguish DLB from AD early in the course of the dementia. We retrospectively studied the first available MMSE exam for each of our patients with DLB or AD and compared their MMSE subscores for attention, memory, and construction. A university dementia brain bank in central Illinois, USA. All patients with neuropathologically-proven DLB or AD with MMSE scores > or =13. We identified 17 DLB and 27 AD patients for whom we had MMSE exams. The attention and construction subtest scores of the DLB group were worse (p=0.0071 and p=0.0038, respectively) than those of the AD group. The memory subscores of the DLB group were better, although the difference did not reach statistical significance (p=0.22). When a mathematical equation was used to combine the three subscores with equal weighting (Attention-5/3Memory+5.Construction), the scores of the DLB group were worse (p=0.00007). Using this equation, a score less than 5 points was associated with DLB with a sensitivity of 0.82 (95% Confidence Interval (CI)=0.57-0.96) and a specificity of 0.81 (95% CI=0.62-0.94). Our findings support the work of others regarding the relative neuropsychological impairments of DLB and AD and indicate that the MMSE may be helpful in the differentiation of DLB and AD.

Medial temporal lobe atrophy on MRI in dementia with Lewy bodies.

To investigate whether medial temporal lobe atrophy (MTA) on MRI is less frequent in dementia with Lewy bodies (DLB) compared with AD and vascular dementia (VaD), and to determine the diagnostic utility of MTA in the differential diagnosis of dementia. Coronal T1-weighted 1.0-T MR images were acquired in patients with DLB (consensus criteria; n = 26; mean age, 75.9 years), AD (National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association; n = 28; mean age, 77.4 years), VaD (National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences; n = 24; mean age, 76.9 years), and normal control subjects (n = 26; mean age, 76.2 years). Cognitive function was assessed using the Cambridge Cognitive Examination (CAMCOG), and MTA was rated visually using a standardized scale. MTA was more frequent and severe in all dementia groups compared with control subjects (AD, 100%; VaD, 88%; DLB, 62%; control subjects, 4%; p < 0.001). Comparing dementia groups, MTA scores were significantly lower in DLB than AD (p = 0.002), with a trend toward less atrophy in DLB compared with VaD (p = 0.07). The absence of MTA had a specificity of 100% and 88% for separating DLB from AD and VaD respectively, and a sensitivity of 38%. In patients with DLB, MTA increased with age (r = 0.58, p = 0.002), and in all dementia patients MTA correlated with memory impairment (combined memory score, r = -0.34, p = 0.003) but not total CAMCOG score or other subscales. Patients with DLB have significantly greater MTA than control subjects but significantly less than those with AD. The authors confirmed that the presence of MTA is useful in detecting AD but less useful in differentiating between dementias. However, in the differentiation of DLB from AD and VaD, the absence of MTA is highly suggestive of a diagnosis of DLB.