A prospective study of delusional misidentification syndromes in Parkinson's disease with dementia

Delusional misidentification syndromes (DMS) are a group of neuropsychiatric disorders due to disturbances in familiarity. DMS in organic diseases have been related to deficits in executive, memory, and visuospatial function. DMS are frequently reported in dementia with Lewy bodies (DLB). The presence of DMS in Parkinson's disease with dementia (PDD), which shares similar clinical and neuropsychological features with DLB, has not been studied. We describe the frequency and clinical features of DMS in a cohort of PDD patients, and we compare the neuropsychological profile between PDD patients with and without DMS. Prospective study of 30 PDD patients recruited from an outpatient setting, who received a structured behavioral interview assessing DMS and hallucinations, and a neuropsychological battery assessing executive function, memory, language, and visuospatial abilities. DMS were found in 16.7% of PDD patients. All DMS subjects also exhibited hallucinations that were significantly more severe than in PDD without DMS. DMS were responsive to neuroleptic drugs. PDD subjects with DMS presented a different neuropsychological profile than PDD subjects without DMS, with more severe memory and language deficits, but similar levels of executive and visuospatial impairment. DMS is a neuropsychiatric feature associated with PDD. Greater impairment in language and memory in PDD with DMS suggests a prominent role of the temporal cortex in the genesis of DMS in PDD. © 2007 Movement Disorder Society     

Pareidolias and cognition in isolated REM sleep behavior disorder

BackgroundThough visual illusions and hallucinations are common in dementia with Lewy bodies (DLB) and Parkinson's disease (PD), they are not typically observed clinically in prodromal stages, including isolated REM sleep behavior disorder (iRBD). False-noise errors on the pareidolia test (seeing faces when none are present) may be an effective measure of susceptibility to future hallucinations in iRBD.MethodsOne hundred patients with iRBD underwent the 20-image pareidolia test. Clinical markers were assessed and a neuropsychological battery was administered. An exploratory analysis on the impact of pareidolic errors on phenoconversion was also performed.ResultsIn our cohort, 17 patients (17%) made false-noise pareidolic errors. These patients had significantly lower total Montreal Cognitive Assesment (MoCA) scores (26.7 ± 2.3 vs. 24.4 ± 2.6, B = −1.88, 95% CI: [-3.17, −0.59]), with lower subcomponent MoCA scores on memory and visuospatial-executive sections. Pareidolic errors were also associated with lower visuospatial, attention/executive, and memory scores on the neuropsychological tests. Furthermore, after 1.6 years follow-up, 3/16 (19%) patients making pareidolic errors had phenoconverted at time of publication compared to 6/71 (8%) patients who did not make errors.ConclusionPareidolic errors in patients with iRBD are associated with poorer overall cognition and may indicate higher risk of DLB.     

Neuropsychological comparison of Alzheimer's disease and dementia with lewy bodies

BACKGROUND/AIMS: The present study examined the patterns of memory and cognitive performance associated with Alzheimer's disease (AD) and dementia with Lewy bodies (DLB). METHODS: A battery of standardized neuropsychological tests was administered to individuals with these disorders as well as to a group of cognitively intact controls. The battery included measures of memory (learning, recall and recognition), language, visuospatial ability, psychomotor speed, executive functioning and mood. All subjects (n = 115) were evaluated at a memory disorder clinic and were diagnosed based on published criteria. RESULTS: The controls outperformed both dementia groups on all cognitive measures. With respect to memory, the DLB group scored significantly higher than the AD group on measures of word list free recall and recognition (p < or = 0.001). In other cognitive domains, the AD group performed significantly better than the DLB group on constructional praxis, sustained attention, phonemic fluency, spatial judgment, psychomotor speed and working memory (all p < or = 0.01). CONCLUSION: These findings support the usefulness of memory and other cognitive test score patterns as in distinguishing AD from DLB, particularly in mild to moderately demented populations that may not present with hallmark symptomology.     

Longitudinal change in neuropsychological performance using latent growth models: a study of mild cognitive impairment

The goal of the current study was to examine cognitive change in both healthy controls (n?=?229) and individuals with mild cognitive impairment (MCI) (n?=?397) from the Alzheimer’s Disease Neuroimaging Initiative (ADNI). We applied latent growth modeling to examine baseline and longitudinal change over 36 months in five cognitive factors derived from the ADNI neuropsychological test battery (memory, executive function/processing speed, language, attention and visuospatial). At baseline, MCI patients demonstrated lower performance on all of the five cognitive factors when compared to controls. Both controls and MCI patients declined on memory over 36 months; however, the MCI patients declined at a significantly faster rate than controls. The MCI patients also declined over 36 months on the remaining four cognitive factors. In contrast, the controls did not exhibit significant change over 36 months on the non-memory cognitive factors. Within the MCI group, executive function declined faster than memory, while the other factor scores changed slower than memory over time. These findings suggest different patterns of cognitive change in healthy older adults and MCI patients. The findings also suggest that, when compared with memory, executive function declines faster than other cognitive factors in patients with MCI. Thus, decline in non-memory domains may be an important feature for distinguishing healthy older adults and persons with MCI.     

Early differentiation of dementia with Lewy bodies and Alzheimer’s disease: Heart rate variability at mild cognitive impairment stage

Objective

Our study aimed to investigate whether heart rate variability (HRV) could be a useful diagnostic screening tool at MCI (mild cognitive impairment) stage of Dementia with Lewy bodies (DLB) from Alzheimer’s disease (AD).

Repetition priming in mild cognitive impairment and mild dementia: Impact of educational attainment

Objective: To examine the role of education on repetition priming performances in healthy aging, mild cognitive impairment (MCI), and mild dementia.

Method: A total of 72 participants (healthy = 27, with MCI = 28, with mild dementia = 17) took part in the present study. Priming was assessed using the Word Stem Completion Test, and delayed and recognition memory was assessed using the Rey Auditory Verbal Learning Test. A multinomial regression analysis was used to examine whether years of education moderated priming and declarative memory performances in predicting group membership.

Results: Priming performances discriminated between individuals with MCI and mild dementia but not between MCI and healthy. Additionally, this effect was most salient in individuals with low levels of education. Education did not moderate explicit memory performances in predicting group membership.

Conclusion: Little is known about the impact of education on priming in verbal memory. Our findings indicate that formal years of education impact priming performances in MCI and individuals with mild dementia, which may have implications for designing interventions targeting “intact” cognitive abilities in these groups.     

Neuropsychiatric symptoms in mild dementia with lewy bodies and Alzheimer's disease

Background/Aims: To compare neuropsychiatric symptoms in patients with Alzheimer's disease (AD) and dementia with Lewy bodies(DLB). Methods: Neuropsychiatric symptoms and caregiver distress were assessed using the Neuropsychiatric Inventory (NPI) in mild DLB (n = 57) and AD (n = 126), and compared across the two groups using non-parametric tests. Results: The DLB patients had a higher NPI totalscore (median 24 vs. 11.5, p < 0.005), more numerous symptoms (median 5 vs. 4, p = 0.001) and more clinically significant symptoms (3 vs. 1, p = 0.001). They also had higher item hallucinations (6 vs. 2, p < 0.005) and apathy (7 vs. 5, p = 0.002) subscores. Caregivers scored higher on the NPI total caregiver distress scale (12.5 vs. 6, p = 0.003). Conclusions: In mild dementia, DLB patients have more neuropsychiatric symptoms and more associated caregiver distress compared with AD.     

Persistent cognitive deficits after whiplash injury: a comparative study with mild traumatic brain injury patients and healthy volunteers

In this study, we evaluated persistent cognitive deficits in whiplash injury (WI) patients and compared these to cognitive functioning in mild traumatic brain injury (MTBI) patients and healthy controls (HC). Sixty-one patients suffering from a WI were compared with 57 patients suffering from a MTBI and with 30 HC. They were examined with an extensive neuropsychological test battery assessing attention, memory, and visuospatial and executive functions. In both patient groups, participants showed persistent cognitive symptoms (more than 6 months post-injury). The two patient groups did not differ significantly with regard to measurements of attention, memory, and visuospatial and executive functions. The WI group, as compared to the HC group, was found to be significantly more deficient in speed of performance during sustained and divided attention, focused attention, alternating attention, the storage of new auditory-verbal unrelated information into memory, the long-term delayed recall of stored auditory-verbal related information from memory, abstract reasoning and accuracy of performance during planning and problem solving. No differences could be found between both groups concerning speed of information processing, visuospatial abilities and verbal fluency.     

Domain specific cognitive impairment in Parkinson’s patients with mild cognitive impairment

Mild cognitive impairment (MCI) affects nearly 20–50% patients with Parkinson’s disease (PD). It may be the prodromal stage of dementia and impacts quality of life of the patient and caregiver. Characterizing PD cognition at the stage of MCI may help in understanding of cognitive pathophysiology. This study assessed and compared cognition in patients with PD and mild cognitive impairment (PD-MCI, n = 32, age = 61.09 ± 5.97 years), PD patients with normal cognition (PD-NC, n = 32, age = 58.81 ± 6.15 years) and healthy controls (HC, n = 38, age = 57.39 ± 7.14 years). Montreal Cognitive Assessment Test (MoCA) was used for categorization of subjects. Cognitive assessment of five domains: executive function, attention, visuospatial function, memory and language (using two tests in each domain) were performed. The effect of PD clinical scores on cognition and cognitive domain specificity in diagnosing PD-MCI were assessed by correlation and receiver operating curve (ROC) analyses, respectively. All the analyses followed removal of potential confounds (age, education and clinical scores). Attention, memory, executive and visuospatial functions were impaired in PD-MCI on comparison with HC and PD-NC groups. Performance in digit span forward and trail making tests for attention and memory (immediate recall) were comparable in both the PD groups. Both the PD groups revealed impairment in attention, memory and language with respect to HC, suggesting the fronto-striatal and posterior cortical syndrome in PD. Highly significant Visual-N-back correlation with UPDRS-III may implicate the shared motor-visuospatial neural pathways. Visual-N-back/PGI delayed recall domains are promising in characterizing PD-MCI stage.     

Neural correlates of photophobia in prodromal and mild dementia with Lewy bodies

Background and objectives

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.

Methods

One hundred and 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).

Results

The frequency of photophobia was higher in the DLB group (47.3%) than in the other groups (p = 0.002). The photophobia questionnaire score was higher in the DLB group than in the AD group (p = 0.001). 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 = 0.007, family-wise error [FWE] corrected).

Conclusions

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.     

Neuropsychological prediction of conversion to Alzheimer disease in patients with mild cognitive impairment

CONTEXT: The likelihood of conversion to Alzheimer disease (AD) in mild cognitive impairment (MCI) and the "optimal" early markers of conversion need to be established. OBJECTIVES: To evaluate conversion rates to AD in subtypes of MCI and to identify neuropsychological measures most predictive of the time to conversion. DESIGN: Patients were followed up semiannually and controls annually. Subtypes of MCI were determined by using demographically adjusted regression norms on neuropsychological tests. Survival analysis was used to identify the most predictive neuropsychological measures. SETTING: Memory disorders clinic. PARTICIPANTS: One hundred forty-eight patients reporting memory problems and 63 group-matched controls. MAIN OUTCOME MEASURE: A consensus diagnosis of probable AD. RESULTS: At baseline, 108 patients met criteria for amnestic MCI: 87 had memory plus other cognitive domain deficits and 21 had pure memory deficits. The mean duration of follow-up for the 148 patients was 46.6 +/- 24.6 months. In 3 years, 32 (50.0%) of 64 amnestic-"plus" and 2 (10.0%) of 20 "pure" amnestic patients converted to AD (P = .001). In 148 patients, of 5 a priori predictors, the percent savings from immediate to delayed recall on the Selective Reminding Test and the Wechsler Adult Intelligence Scale-Revised Digit Symbol Test were the strongest predictors of time to conversion. From the entire neuropsychological test battery, a stepwise selection procedure retained 2 measures in the final model: total immediate recall on the Selective Reminding Test (odds ratio per 1-point decrease, 1.10; 95% confidence interval, 1.05-1.14; P < .0001) and Digit Symbol Test coding (odds ratio, 1.06; 95% confidence interval, 1.01-1.11; P = .01). The combined predictive accuracy of these 2 measures for conversion by 3 years was 86%. CONCLUSIONS: Mild cognitively impaired patients with memory plus other cognitive domain deficits, rather than those with pure amnestic MCI, constituted the high-risk group. Deficits in verbal memory and psychomotor speed/executive function abilities strongly predicted conversion to AD.     

Visual evoked potential abnormalities in dementia with Lewy bodies

ObjectivesVisuo-perceptual deficits and visual hallucinations (VHs) are common disturbances in patients with dementia with Lewy bodies (DLB) and those with Parkinson’s disease (PD). In particular, delays in visual evoked potential (VEP), reversed by l-dopa administration, have previously been observed in PD patients. Impairment in metabolic functions of dopaminergic amacrine cells within the inner plexiform layer of the retina has been largely documented and has been posited as the underlying cause of visual and retinal alterations in PD. The aims of the present study were to investigate the presence of VEP abnormalities in DLB patients, as compared to a PD control group, and to assess the presence of significant correlations between neurophysiological measures and clinical symptoms (i.e., presence of visuospatial deficits and/or visual hallucinations).MethodsFifteen DLB patients and fifteen matched PD patients underwent pattern reversal before and after l-dopa administration, and a short neuropsychological assessment.ResultsIn DLB patients, we observed delay of the P100 latency to foveal stimuli in both eyes compared to normative values. Compared to PD, DLB patients showed higher values of the P100 latency for foveal stimulation from the right eye prior to l-dopa administration (p = 0.018). No correlations between VEP alterations, visuo-spatial deficit and visual hallucinations were found.DiscussionOur findings demonstrated a longer P100 delay in DLB than in PD patients, especially along the right visual pathway. In contrast to previous studies, which focused on a dopaminergic pre-geniculate impairment of visual pathways, our evidence suggests that other mechanisms, possibly relying on thalamic involvement, which is known to be dysfunctional in DLB, can interfere with VEP abnormalities.     

Systematic review and meta-analysis show that dementia with Lewy bodies is a visual-perceptual and attentional-executive dementia

To resolve differences in the literature, we have systematically reviewed 21 controlled comparisons of the cognitive performance of patients with dementia with Lewy bodies (DLB) These were identified by end May 2002 by Medline and PsycInfo searches, checking reference lists and contacting authors. Nine had comparisons between DLB patients (total n = 180) and age-matched controls (n = 172). Sixteen had comparisons between DLB (n = 312) and Alzheimer's disease (AD, n = 380). Three compared DLB (n = 48) with Parkinson's disease (PD, n = 65). Two raters independently scored the methodological quality. This was variable with a lack of high-quality studies (median rating 3 on a 0-7 scale, Kw = 0.41). There was a significant heterogeneity in results with marked discrepancies between studies. In a meta-analysis, DLB patients were more cognitively impaired than were AD or PD patients (95% CI of inverse variance weighted average of effect size relative to controls DLB 2.0-2.2; AD 1.4-1.6; PD 0.7-1.0). To permit an analysis of impairments in specific cognitive areas, the cognitive abilities underpinning the wide variety of tasks used were classified by a group of experienced neuropsychologists. Reducing overlapping task classifications using factor analysis showed large effect sizes relative to controls, AD and PD on two factors (combined variance 30%): attentional/executive impairment (effect sizes 1.1-2.9) and visual-perceptual impairment (0.7-3.6). There were small differences on two other factors (combined variance 39%): general verbal/non-verbal impairment (-0.12 to -0.5) and relative verbal memory impairment (-0.33 to 0.21). The cognitive performance is also more variable in DLB than in controls or in AD, but not PD (ratio of DLB to comparator standard deviations estimated from linear regression: DLB/controls 2.5-3.6; DLB/AD 2.1-2.6; DLB/PD 0.8-1.0). The greater variability of patients with DLB is seen only on tasks needing timed or motor responses, visual learning, executive or attentional abilities, or with visual content. Further stratification indicated that recent consensus diagnostic criteria, clinical diagnoses, and milder dementia were all associated with a more distinctive cognitive profile. The uniquely profound visual-perceptual and attentional-executive impairments that characterize DLB are consistent with the most frequent locations of Lewy bodies in frontal, cingulate, and inferior temporal cortex and may be related to the characteristic visual hallucinations and clinical fluctuations of this disease. These findings need to be confirmed in prospective, longitudinal, clinicopathological studies.     

肌萎缩侧索硬化患者轻度认知功能损害

目的 探讨肌萎缩侧索硬化(ALS)患者认知功能状态、ALS轻度认知功能损害(ALS-MCI)的受累领域和各种亚型及其可能的危险因素.方法 收集ALS患者29例,健康对照者58名,选用改良Norris量表评价ALS患者的延髓功能及肢体功能.根据美国精神病学会精神障碍诊断和统计手册(DSM-Ⅳ-R)痴呆的诊断标准,将ALS患者分为痴呆和非痴呆;对于非痴呆的ALS患者,通过常用的认知功能(包括精神状态、记忆力、执行功能、注意力、视空间功能)量表、汉密尔顿焦虑量表(HAMA)、汉密尔顿抑郁量表(HAMD)进行评分,按照Petersen等修订的MCI诊断标准,将其分为认知功能正常(ALS-CogNL)组和ALS-MCI组,分析ALS-MCI受累的领域及其亚型;比较2组在年龄、起病年龄、病程、起病部位、延髓性麻痹症状、肢体运动功能损害等方面的差异,分析ALS患者出现MCI的相关危险因素.结果 29例ALS患者中,认知功能正常14例(48.3%),MCI有15例(51.7%),未发现痴呆患者.15例ALS-MCI患者中,执行功能损害12例,注意力损害9例,记忆力损害8例,未发现视空间功能损害;其中遗忘型(ALS-aMCI)1例,非记忆单一领域损害型(ALS-sdMCI)6例,多领域受损型(ALS-mdMCI)8例.ALS-MCI组与ALS-CogNL组的教育年限[(8.7±2.8)年与(11.3 ±3.0)年]、Norris量表延髓功能评分[(28.4±7.7)分与(34.0±3.4)分]差异有统计学意义(t=-2.435、-2.576,均P＜0.05),性别、年龄、起病年龄、病程、起病部位、HAMA及HAMD评分、Norris量表肢体功能评分差异无统计学意义.结论 ALS患者常出现MCI,其中以执行功能损害最常见,记忆力、注意力亦有损害,未发现视空间功能损害,ALS-mdMCI是最常见的亚型.文化程度低、严重延髓性麻痹症状是ALS患者出现认知功能损害的危险因素.

Abstract：

Objective To explore the cognitive status of amyotrophic lateral sclerosis (ALS) patients, and to explore the involved cognitive domains, subtypes and risk factors of mild cognitive impairment in ALS ( ALS-MCI).Methods Twenty-nine cases of ALS and 58 healthy volunteers were included.The severity of the bulbar and spinal functions of the patients was evaluated by the Improved Norris Scale.According to the Diagnostic and Statistical Manual of Mental Disorders 4th Edition-Revised( DSM-Ⅳ-R) criteria of dementia, ALS cases were classified as demented and non-demented.For non-demented ALS cases, the common cognitive batteries evaluating mental state, verbal memory, executive, attentional and visuospatial abilities were performed.Hamilton Anxiety Scale ( HAMA) and Hamilton Depression Scale (HAMD) were evaluated too.They were further classified into ALS-cognitively normal (ALS-CogNL) and ALS-MCI groups according to Petersen criteria of MCI.Risk factors possibly correlated with ALS-MCI were analyzed by comparing the differences in age, age of onset, duration of the disease, sites of onset, symptoms of bulbar and limb function between ALS-CogNL and ALS-MCI groups.Results Among 29 ALS cases, 14 (48.3% ) cases with cognitively normal( ALS-CogNL), 15 cases (51.7% ) with ALS-MCI,and none with dementia were identified.Among 15 ALS-MCI cases, 12 cases with executive dysfunction, 8 cases with memory deficits,9 cases with attention impairment and none with visuospatial impairment were found.ALSMCI cases could be further classified into three subtypes; 1 case with amnestic MCI (aMCI) ,6 cases with single domain non-memory MCI ( sdMCI), and 8 cases with multiple domains slightly impaired MCI (mdMCI).Between ALS-MCI and ALS-CogNL groups, there were significant differences (t = -2.435,- 2.576, both P ＜ 0.05) in education ((8.7 ± 2.8) years vs (11.3 ± 3.0) years) and Improved Norrisscale (bulbar score: (28.4 ± 7.7) scores vs ( 34.0 ± 3.4) scores) , however, no significant differences in sex, age, age of onset, duration,site of onset,HAMA or HAMD scores,and Improved Norris scale( spinal score) were found.Conclusions Cognitive deficits commonly exist in ALS patients.For the involved domains, executive dysfunction is the most common, deficits of attention and memory are also common, and deficit in visuospatial function is not found.The most common subtype of ALS-MCI is mdMCI.Severe bulbar symptoms and lower education may be the risk factors of ALS-MCI.     

Visual recognition memory differentiates dementia with Lewy bodies and Parkinson's disease dementia

Objective

To compare cognitive impairments in dementia with Lewy bodies (DLB) and Parkinson''s disease dementia (PDD), to discriminate between the two entities.

Methods

10 DLB and 12 PDD consecutive patients performed a neuropsychological battery designed to assess several cognitive domains: verbal and visual memory (Delayed Matching to Sample (DMS)‐48), language, gnosia, praxia and executive functions.

Results

DLB patients had poorer performances in orientation (p<0.05), Trail Making Test A (p<0.05) and reading of names of colours in the Stroop Test (p<0.05). Their scores were also lower in the visual object recognition memory test (DMS‐48), in both immediate (p<0.05) and delayed recognition (p<0.05). No differences were observed in the other tests.

Conclusion

Despite global similarities in cognitive performances between DLB and PDD patients, we observed important differences: in particular, DMS‐48, a test of visual object recognition memory and visual storage capacity, was poorer in DLB patients.Parkinson''s disease dementia (PDD) and dementia with Lewy bodies (DLB) share some common clinical features, such as extrapyramidal symptoms and neuropsychological impairment.^1,2,3 In practice, consensus guidelines recommend an arbitrary distinction between the two disorders based on a temporal sequence of 1 year between the presentation of extrapyramidal motor symptoms and the manifestation of dementia: PDD is diagnosed if dementia occurs belatedly in the context of well established Parkinson''s disease; DLB is diagnosed when motor and cognitive signs appear during the first year of evolution.⁴ A key question is whether this is a meaningful distinction between the two different clinical entities.Subtle clinical distinction in terms of cognitive pattern could prove useful for clinicians.In this study, we compared cognitive performances in a group of patients with a clinical diagnosis of “probable” DLB with those of PDD patients. As the clinical symptoms overlap, our aim was to determine possible differences in the cognitive abilities between DLB and PDD.     

Heterogeneity in executive impairment in patients with very mild Alzheimer's disease

BACKGROUND/AIMS: The presence of executive impairment in mild Alzheimer's disease (AD) has primarily been demonstrated by means of group comparison. Whether executive dysfunction is a common feature of mild AD or only present in a subgroup of patients remains unclear. The aim of this study was to describe the frequency of impairment on a set of internationally well-known executive tests in patients with very mild AD. METHODS: Thirty-six patients with very mild AD (MMSE scores above 23) and 32 healthy control subjects were administered a battery of 7 executive tests: Trail Making part B, Stroop Interference Test, modified Wisconsin Card Sorting Test (WCST), category- and letter-based verbal fluency, a design fluency task and the Similarities subtest from WAIS. Impairment was defined as a score of 2 SD or more below control means. RESULTS: Executive impairment on at least 1 measure was seen in 76% of the patients, and 50% were impaired on 2 or more tests. Trail Making B and Stroop Interference Test were impaired in more than 40%, whereas only few patients were impaired on Similarities, WCST and design fluency. A wide variation of executive test profiles was seen among the patients. CONCLUSION: Executive impairments are common in early AD and not just a feature characteristic of a subgroup of patients. Complex attentional skills are more frequently affected than other executive functions. There is, however, considerable heterogeneity among AD patients in the pattern of executive dysfunction.     

Utility of the Bender Gestalt Test for differentiation of dementia with Lewy bodies from Alzheimer's disease in patients showing mild to moderate dementia

AIMS: We examined the utility of the Bender Gestalt Test (BGT) for the differentiation of dementia with Lewy bodies (DLB) from Alzheimer's disease (AD), comparing BGT scores between DLB and AD patients showing mild to moderate dementia. METHODS: Eighteen DLB patients, 36 AD patients controlled by age, years of education, Clinical Dementia Rating and Mini Mental State Examination scores, and 21 nondemented elderly participants controlled by age and years of education were subjected to the BGT. Their BGT performances were scored according to the Pascal-Suttell method. RESULTS: The DLB group showed significantly higher (that is worse) BGT scores than the other groups. When a cutoff point of 98 was used to differentiate DLB from AD, the patients exceeding 98 were 94% in the DLB group, 17% in the AD group and 0% in the control group. The sensitivity and specificity of this cutoff point were 0.94 and 0.89, respectively. CONCLUSION: The BGT is a useful neuropsychological test to differentiate DLB from AD.     

Cortical thinning associated with mild cognitive impairment in Parkinson's disease

The aim of this study was to investigate patterns of cortical atrophy associated with mild cognitive impairment in a large sample of nondemented Parkinson's disease (PD) patients, and its relation with specific neuropsychological deficits. Magnetic resonance imaging (MRI) and neuropsychological assessment were performed in a sample of 90 nondemented PD patients and 32 healthy controls. All underwent a neuropsychological battery including tests that assess different cognitive domains: attention and working memory, executive functions, memory, language, and visuoperceptual‐visuospatial functions. Patients were classified according to their cognitive status as PD patients without mild cognitive impairment (MCI; n = 43) and PD patients with MCI (n = 47). Freesurfer software was used to obtain maps of cortical thickness for group comparisons and correlation with neuropsychological performance. Patients with MCI showed regional cortical thinning in parietotemporal regions, increased global atrophy (global cortical thinning, total gray matter volume reduction, and ventricular enlargement), as well as significant cognitive impairment in memory, executive, and visuospatial and visuoperceptual domains. Correlation analyses showed that all neuropsychological tests were associated with cortical thinning in parietotemporal regions and to a lesser extent in frontal regions. These results provide neuroanatomic support to the concept of MCI classified according to Movement Disorders Society criteria. The posterior pattern of atrophy in temporoparietal regions could be a structural neuroimaging marker of cognitive impairment in nondemented PD patients. All of the neuropsychological tests reflected regional brain atrophy, but no specific patterns were seen corresponding to impairment in distinct cognitive domains. © 2014 International Parkinson and Movement Disorder Society     

Natural history of mild cognitive impairment in older persons

BACKGROUND: Cognitive abilities of older persons range from normal, to mild cognitive impairment, to dementia. Few large longitudinal studies have compared the natural history of mild cognitive impairment with similar persons without cognitive impairment. METHODS: Participants were older Catholic clergy without dementia, 211 with mild cognitive impairment and 587 without cognitive impairment, who underwent annual clinical evaluation for AD and an assessment of different cognitive abilities. Cognitive performance tests were summarized to yield a composite measure of global cognitive function and separate summary measures of episodic memory, semantic memory, working memory, perceptual speed, and visuospatial ability. The authors compared the risk of death, risk of incident AD, and rates of change in global cognition and different cognitive domains among persons with mild cognitive impairment to those without cognitive impairment. All models controlled for age, sex, and education. RESULTS: On average, persons with mild cognitive impairment had significantly lower scores at baseline in all cognitive domains. Over an average of 4.5 years of follow-up, 30% of persons with mild cognitive impairment died, a rate 1.7 times higher than those without cognitive impairment (95% CI, 1.2 to 2.5). In addition, 64 (34%) persons with mild cognitive impairment developed AD, a rate 3.1 times higher than those without cognitive impairment (95% CI, 2.1 to 4.5). Finally, persons with mild cognitive impairment declined significantly faster on measures of episodic memory, semantic memory, and perceptual speed, but not on measures of working memory or visuospatial ability, as compared with persons without cognitive impairment. CONCLUSIONS: Mild cognitive impairment is associated with an increased risk of death and incident AD, and a greater rate of decline in selected cognitive abilities.