Altered circadian cortisol secretion in Alzheimer's disease: clinical and neuroradiological aspects

We determined circadian salivary cortisol levels in 18 outpatients affected by probable Alzheimer's disease (AD) and looked for a possible correlation with both cognitive impairment and brain CT scan findings. The diagnosis of probable AD was made according to the NINCDS-ADRDA criteria. The severity of cognitive impairment was quantified using the Mini Mental State Examination (MMSE) and the Global Deterioration Scale (GDS). Cortisol levels were measured on saliva samples collected at 08:00 AM and 08:00 PM. For each sample, a duplicate cortisol measurement was performed on 50 microl of saliva by means of a modified commercial radioimmunoassay kit. At the same time, 11 of the 18 AD patients enrolled also underwent a brain CT scan to estimate cerebral atrophy by using linear indexes. The mean value of cortisol levels was significantly higher in AD patients than in controls at both the morning and the evening measurements, and the circadian fluctuation of cortisol was less marked in AD patients than in controls, although this difference did not reach statistical significance. Morning cortisol levels were significantly correlated to both the MMSE and the GDS scores. A significant correlation was also found between morning cortisol levels and all the cerebral atrophy indexes. By contrast, no correlation was observed between evening cortisol levels or cortisol circadian fluctuations and either cognitive impairment or cerebral atrophy. In conclusion, despite the potential biases deriving from the small sample and the limitations of the CT scan study, our results suggest that, in AD patients, hypercortisolemia is correlated with severity of the disease.     

Hippocampal atrophy correlates with the severity of cognitive decline

BACKGROUND: The aim of this study is to compare the results of magnetic resonance (MR) imaging, particularly the decline in hippocampal volume, of patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) with healthy age-matched controls, to examine the reliability of hippocampal volumetry in the early diagnosis of AD and the correlation of the severity of hippocampal atrophy with the severity of cognitive decline. METHODS: Twenty-six AD, 22 MCI and 15 normal cognitive status (NCS) patients were scanned with a 3 Tesla MR scanner. Hippocampus volumes were detected manually by Osiris 4.18. RESULTS: Multivariate regression analysis, which was performed to adjust the covariate effects of education, age, gender, hypertension and diabetes mellitus, showed that hippocampal atrophy was correlated with AD and MCI for right hippocampus; AD, MCI and age for left hippocampus independent of other parameters. A second regression analysis revealed that MMSE was correlated with hippocampal volume. CONCLUSIONS: Hippocampal volumetry can be used in early diagnosis of cognitive impairment, as well as grading cognitive decline.     

Plasma cortisol levels, brain volumes and cognition in healthy elderly men

PURPOSE: In ageing animals, exposure to chronic high levels of glucocorticoids is associated with cognitive impairment and hippocampal atrophy. However, there are few studies examining relationships among glucocorticoids, brain volumes and cognitive function in healthy older humans. This study examined the hypotheses that higher plasma cortisol levels and altered sensitivity to glucocorticoids are associated with worse cognition and more brain atrophy in elderly men. MATERIALS AND METHODS: Ninety-seven healthy men aged 65-70 had plasma cortisol measured at 09:00, 14:30 h, and post-dexamethasone (0.25mg, 09:00 h), and had dermal sensitivity to glucocorticoids measured. They also underwent cognitive testing, with scores adjusted for estimated prior mental ability, and had MRI measurements of intracranial area (a validated estimate of intracranial capacity), and hippocampus, temporal lobe and frontal lobe volumes. RESULTS: Plasma cortisol levels at 09:00 h were significantly and negatively correlated with a summary General Cognitive Factor accounting for 51% of the variance of cognitive function (rho=-0.22, p=0.035), and specific cognitive tests: delayed paragraph recall (rho=-0.28, p=0.036) and processing speed (rho=-0.23, p=0.026). Regional brain volumes adjusted for intracranial area generally did not correlate with cortisol levels. Tissue glucocorticoid sensitivity did not correlate with any measure of cognition or brain volume. CONCLUSIONS: In healthy older men, higher plasma cortisol levels are associated with worse ageing-related overall cognitive change but not ageing-related brain atrophy.     

阿尔茨海默病患者外周血IL-6、IL-8、TNF-α水平与认知功能的相关性

目的 探讨阿尔茨海默病(AD)患者外周血白细胞介素-6(IL-6)、IL-8及肿瘤坏死因子α(TNF-α)水平与认知功能的相关性.方法 选择2015年1月~2016年1月在济宁医学院附属医院兖州院区治疗的AD患者90例作为研究组,并选择同期在我院体检的90名健康人作为对照组,采用酶联免疫吸附法(ELISA)检测两组研究对象的外周血IL-6、IL-8及TNF-α水平,并采用简易精神状态量表(MMSE)和临床痴呆评定量表(CDR)对其认知功能和日常行为能力进行评估.比较各组间炎性因子水平的差异,分析炎性因子表达水平与认知功能的相关性.结果 研究组AD患者外周血的IL-6、IL-8及TNF-α水平均明显高于对照组[(128.64±10.28)pg/ml比(103.59±8.72)pg/ml,(134.32±9.67)pg/ml比(101.45±7.32)pg/ml,(221.39±23.54)pg/ml比(109.68±18.76)pg/ml],差异均有统计学意义(P<0.05).受教育年限为AD患者认知功能的保护因素,IL-6、IL-8及TNF-α水平为危险因素(P<0.05).整体人群中IL-6、TNF-α水平与MMSE得分呈负相关(r=-0.314,-0.079;P<0.05),IL-8与MMSE无相关性.结论 外周血IL-6及TNF-α水平与轻度AD患者的认知功能相关.     

Hippocampal atrophy correlates with severe cognitive impairment in elderly patients with suspected normal pressure hydrocephalus.

Measurements of hippocampal formation atrophy using MRI have been useful in distinguishing demented patients with a diagnosis of probable Alzheimer's disease from cognitively normal controls. To determine whether there is a similar relationship between hippocampal size and dementia in elderly patients suspected of normal pressure hydrocephalus (NPH), the authors obtained mini-mental status examination (MMSE) scores and MRI measurements of hippocampal size and CSF volume on 16 elderly patients whose severe ventriculomegaly and unexplained gait impairment made NPH a probable diagnosis. Hippocampal size correlated strongly with MMSE score (r = 0.75, p < 0.001); no significant MMSE correlation was found for ventricular CSF volume or extra-ventricular/ventricular CSF ratio. It was concluded that hippocampal atrophy is associated with severe cognitive dysfunction in many elderly patients with a diagnosis of NPH. As a hypothesis for further investigation, the detection of such atrophy may help identify cases where the presence of a pathology of Alzheimer's disease complicates the diagnosis of NPH.     

Amyloid-β peptides in plasma and cognitive decline after 1 year follow-up in Alzheimer's disease patients

Plasma levels of amyloid-β (Aβ) peptides are potential biomarkers of early cognitive impairment and of Alzheimer's disease (AD) risk. However, the association of Aβ peptides with the rate of cognitive decline in AD patients is still unclear. In the present study we demonstrate that Aβ???? plasma levels show a significant correlation with the rate of cognitive decline and are significantly increased in AD patients with fast cognitive decline (decrease of Mini-Mental Status Examination (MMSE) score ≥ 5/year; n = 12) compared to AD patients with slow cognitive decline (decrease of MMSE score ≤ 4/year; n = 28), independent of baseline MMSE scores, age and cholinesterase inhibitor intake, but dependent on history of myocardial infarction and history of stroke in a multivariate analysis. These results suggest that Aβ???? plasma levels are associated with the rate of cognitive decline in AD patients and may be influenced by atherosclerotic vasculopathies such as stroke and myocardial infarction.     

Stem cell factor plasma levels are decreased in Alzheimer's disease patients with fast cognitive decline after one-year follow-up period: the Pythia-study

Alzheimer's disease (AD) is the most common cause of cognitive decline in the elderly and is characterized by massive neuronal loss in the brain. Stem cell factor (SCF) is a hematopoietic growth factor that promotes neuroprotective effects and supports neurogenesis in the brain. Decreased SCF plasma levels have been described in AD patients. Whether SCF plasma levels are also associated with the rate of cognitive decline in AD patients has not been reported so far. In the present study, we demonstrate that SCF plasma levels are significantly decreased in AD patients with fast cognitive decline (decrease of Mini-Mental State Examination [MMSE] score > 4 after one year; n = 12) compared to AD patients with slow cognitive decline (decrease of MMSE score ≤ 4 after one year; n = 28) (fast versus slow cognitive decline: mean ± SD: 1051.1 ± 178.7 versus 1237.9 ± 274.2 pg/ml; p = 0.037). Moreover, SCF plasma levels correlated with the rate of cognitive decline after one year follow-up period (r = 0.315; p = 0.048). In a multiple linear regression analysis, independent predictors of the rate of cognitive decline in our study cohort were age, MMSE scores at baseline, SCF plasma levels, as well as brain-derived neurotrophic factor and activated glycoprotein (GP) IIb/IIIa. These results suggest that lower SCF plasma levels are associated with a higher rate of cognitive decline in AD patients. Thus, treatment strategies increasing SCF plasma levels could be useful for delaying the progression of AD. Further prospective studies are needed to elucidate the value of plasma SCF in a multimarker approach determining AD prognosis.     

血清S100B蛋白抗脑抗体海马体积变化与阿尔茨海默病患者认知功能变化的关系

目的探讨血清S100B蛋白、抗脑抗体(ABAb)、海马体积大小变化与阿尔茨海默病(AD)患者认知功能变化的关系。方法选取濮阳市油田总医院确诊的88例阿尔茨海默病患者(AD组),选取正常体检者90例为对照组,检测并对比2组血清S100B蛋白、ABAb、海马体积,采用线性相关、多元线性回归分析各项研究指标与简易精神状态量表(MMSE)的相关性。结果AD组血清S100B蛋白、ABAb测定值均高于对照组(P<0.05);AD组海马体积、MMSE评分均低于对照组(P<0.05);AD组血清S100B蛋白、ABAb测定值与MMSE评分呈负相关性(P<0.05);AD组海马体积与MMSE评分呈正相关性(P<0.05);多元线性回归模型显示,血清S100B蛋白、ABAb增高与AD患者MMSE评分呈负相关(P<0.05),海马体积、受教育年限与MMSE评分呈正相关(P<0.05)。结论AD患者的血清S100B蛋白、ABAb增高,海马体积较健康人群降低,且与患者认知功能受损程度有关。     

Corpus callosum atrophy,white matter lesions,and frontal executive dysfunction in normal aging and Alzheimer's disease. A community-based study: the Tajiri Project

BACKGROUND AND OBJECTIVES: Cerebral MRIs of normal aging and Alzheimer's disease (AD) frequently reveal corpus callosum (CC) atrophy, white matter hyperintensity (WMH), and hippocampal atrophy. However, their relationship or the relationship between these findings and cognitive function has not been fully studied. We investigated the relationship between CC atrophy, WMH, and hippocampal atrophy, together with frontal executive dysfunction in both normal aging and AD. METHOD: We examined 170 randomly selected residents from a designated community: 99 Clinical Dementia Rating (CDR) 0 (healthy, control group, HC) participants, 54 CDR 0.5 (very mild AD) patients, and 17 CDR 1 & 2 (probable AD) patients. By means of MRI, WMH and CC atrophy were visually rated. Four portions of the CC and the hippocampal width were measured. A Mini-Mental State Examination and Cognitive Abilities Screening Instrument (CASI) were performed to assess global function. For the frontal function, the CASI subitems of attention and word fluency, letter-based fluency, the Digit Symbol test of the WAIS-R, and Trail Making Tests were performed. RESULTS: Those patients with CDR 1 & 2 had both hippocampal and CC atrophy, whereas the CDR 0.5 patients had only hippocampal atrophy. Frontal executive dysfunction was associated with CC atrophy in both the HC and AD groups. Significant Spearman correlations were noted between CC atrophy and WMH in both groups. The combined effect of CC atrophy and WMH was noted only in the verbal fluency test in the HC group. CONCLUSION: In both groups, CC atrophy was associated with frontal executive dysfunction. The combined effect of CC atrophy and WMH in normal aging was probably due to subclinical ischemic conditions.     

Amygdala atrophy is prominent in early Alzheimer's disease and relates to symptom severity

Despite numerous studies on the role of medial temporal lobe structures in Alzheimer's disease (AD), the magnitude and clinical significance of amygdala atrophy have been relatively sparsely investigated. In this study, we used magnetic resonance imaging (MRI) to compare the level of amygdala atrophy to that of the hippocampus in very mild and mild AD subjects in two large samples (Sample 1 n=90; Sample 2 n=174). Using a series of linear regression analyses, we investigated whether amygdala atrophy is related to global cognitive functioning (Clinical Dementia Rating Sum of Boxes: CDR-SB; Mini Mental State Examination: MMSE) and neuropsychiatric status. Results indicated that amygdala atrophy was comparable to hippocampal atrophy in both samples. MMSE and CDR-SB were strongly related to amygdala atrophy, with amygdala atrophy predicting MMSE scores as well as hippocampal atrophy, but predicting CDR-SB scores less robustly. Amygdala atrophy was related to aberrant motor behavior, with potential relationships to anxiety and irritability. These results suggest that the magnitude of amygdala atrophy is comparable to that of the hippocampus in the earliest clinical stages of AD, and is related to global illness severity. There also appear to be specific relationships between the level of amygdala atrophy and neuropsychiatric symptoms that deserve further investigation.     

Nutritional biomarkers in Alzheimer's disease: the association between carotenoids, n-3 fatty acids, and dementia severity

Carotenoids are fat-soluble antioxidants that may protect polyunsaturated fatty acids, such as n-3 fatty acids from oxidation, and are potentially important for Alzheimer's disease (AD) prevention and treatment. Fasting plasma carotenoids were measured in 36 AD subjects and 10 control subjects by HPLC. Correlations between plasma carotenoid levels, red blood cell (RBC) n-3 fatty acids, and dementia severity were examined in AD patients.Moderately severe AD patients (MMSE=16-19) had much lower plasma levels of two major carotenoids: lutein and beta-carotene, compared to mild AD patients (MMSE=24-27) or controls. Among AD patients, variables (lutein, beta-carotene, RBC docosahexaenoic acid (DHA) and LDL-cholesterol) were significantly correlated with MMSE. A lower MMSE score was associated with lower lutein, beta-carotene and RBC DHA levels, and a higher LDL-cholesterol level. These variables explained the majority of variation in dementia severity (55% of variance in MMSE). Lutein, beta-carotene and beta-cryptoxanthin were positively correlated with RBC DHA in AD patients. The association between higher carotenoids levels and DHA and higher MMSE scores, supports a protective role of both types of nutrients in AD. These findings suggest targeting multiple specific nutrients, lutein, beta-carotene, and DHA in strategies to slow the rate of cognitive decline.     

阿尔茨海默病患者血浆脂联素与Aβ水平的变化

目的 探讨AD患者血浆脂联素、Aβ水平的变化及其与MMSE评分的关系。方法 对20例AD患者(AD组)、20例正常认知老年组的血浆脂联素、Aβ40和Aβ42水平进行检测,比较2组血浆脂联素和Aβ水平的差异,并分析血浆脂联素、Aβ与MMSE评分的关系。结果 AD组MMSE评分、血浆脂联素(APN)、Aβ42和Aβ42/Aβ40均低于对照组(P<0.05)。Aβ40水平与Aβ42水平呈显著正相关、与Aβ42/Aβ40呈显著负相关(P<0.01),Aβ42水平与APN水平呈显著正相关(P<0.05),MMSE评分与Aβ42、APN、Aβ42/Aβ40呈显著正相关(P<0.01)。结论 AD组血浆APN、Aβ42水平和Aβ42/Aβ40明显降低,其改变与认知功能评分存在一定的正相关性。     

阿尔茨海默病与轻度认知障碍患者血浆sCD40及sCD40L浓度研究

目的 探索阿尔茨海默病(Alzheimer’s disease,AD)及遗忘型轻度认知障碍(amenstic mild cognitive impairment,a MCI)患者血浆可溶性CD40(soluble CD40,s CD40)和可溶性CD40配体(soluble CD40 ligand,s CD40L)浓度变化特点及其临床意义。方法 采用酶联免疫吸附法检测20例AD患者、35例a MCI患者和32名正常对照者血浆s CD40和s CD40L浓度水平,简易精神状态检查表(mini-mental state examination,MMSE)评估患者认知功能。结果 AD组、a MCI组和对照组血浆s CD40浓度中位数(上下四分位数)分别为[123.3(97.4,149.5)pg/m L]、[102.9(63.6,124.0)pg/m L]和[70.66(51.0,90.8)pg/m L],3组间s CD40浓度差异均有统计学意义(P0.05)。AD组、a MCI组和对照组血浆s CD40L浓度中位数(上下四分位数)分别为[537.0(316.0,1134.0)pg/m L]、[316.0(190.0,546.0)pg/m L]和[167.0(107.5,478.0)pg/m L],3组间s CD40L浓度差异均有统计学意义(P0.05)。a MCI组血浆s CD40L浓度与MMSE得分呈负相关(r=-0.74,P0.01)。结论 s CD40和s CD40L浓度水平在AD和a MCI患者血浆中异常增高,因此s CD40和s CD40L可作为AD的早期检测指标,并提示CD40-CD40L信号可能参与AD的发生发展。     

Baylor profound mental status examination: a brief staging measure for profoundly demented Alzheimer disease patients

There is no brief patient-derived rating scale for staging and following profoundly demented Alzheimer disease (AD) patients. We developed the Baylor Profound Mental Status Examination (BPMSE) modeled after the Mini-Mental State Examination (MMSE) to meet this need. The BPMSE consists of 25 cognitive questions that assess orientation, language, attention, and motor functioning; 10 examiner ratings of presence or absence of problem behaviors; and 2 qualitative observations of language and social interaction. Two hundred eight probable or possible AD patients (MMSE scores of 20 or less) received the BPMSE. Some were also rated on the clinical dementia rating (CDR) and Lawton activities of daily living (ADL). A ceiling effect occurred at MMSE scores above 11. BPMSE cognitive scores and MMSE scores correlated significantly (r = 0.76, p < 0.0001). Subareas of the BPMSE also intercorrelated significantly. The BPMSE correlated with both CDR and ADL scores (p < 0.001). Internal consistency, interrater reliability, and test-retest stability were excellent. There was no floor effect, and BPMSE scores continued to decline after the MMSE reached 0. The BPMSE is a quick and easy staging tool with excellent validity and test-retest stability that measures cognitive function successfully in patients with MMSE scores below 12. The scale is sensitive to longitudinal change and continues to assess decline when performance has reached the lowest levels on conventional measures.     

Automated 3D mapping of hippocampal atrophy and its clinical correlates in 400 subjects with Alzheimer's disease,mild cognitive impairment,and elderly controls

We used a new method we developed for automated hippocampal segmentation, called the auto context model, to analyze brain MRI scans of 400 subjects from the Alzheimer's disease neuroimaging initiative. After training the classifier on 21 hand‐labeled expert segmentations, we created binary maps of the hippocampus for three age‐ and sex‐matched groups: 100 subjects with Alzheimer's disease (AD), 200 with mild cognitive impairment (MCI) and 100 elderly controls (mean age: 75.84; SD: 6.64). Hippocampal traces were converted to parametric surface meshes and a radial atrophy mapping technique was used to compute average surface models and local statistics of atrophy. Surface‐based statistical maps visualized links between regional atrophy and diagnosis (MCI versus controls: P = 0.008; MCI versus AD: P = 0.001), mini‐mental state exam (MMSE) scores, and global and sum‐of‐boxes clinical dementia rating scores (CDR; all P < 0.0001, corrected). Right but not left hippocampal atrophy was associated with geriatric depression scores (P = 0.004, corrected); hippocampal atrophy was not associated with subsequent decline in MMSE and CDR scores, educational level, ApoE genotype, systolic or diastolic blood pressure measures, or homocysteine. We gradually reduced sample sizes and used false discovery rate curves to examine the method's power to detect associations with diagnosis and cognition in smaller samples. Forty subjects were sufficient to discriminate AD from normal and correlate atrophy with CDR scores; 104, 200, and 304 subjects, respectively, were required to correlate MMSE with atrophy, to distinguish MCI from normal, and MCI from AD. Hum Brain Mapp 2009. © 2009 Wiley‐Liss, Inc.     

Plasma cortisol levels in elderly female subjects with Alzheimer's disease: a cross-sectional and longitudinal study

We investigated the plasma cortisol levels at a fasting state in elderly female Alzheimer's disease (AD), vascular dementia (VD), and non-demented subjects (n=66, 28 and 21, respectively). Twenty-eight AD subjects were followed for 40 months. The plasma cortisol levels in AD and VD subjects were significantly higher than those of non-demented subjects at baseline. In AD subjects in relatively early stages of the disease [Mini-Mental State Examination (MMSE)], at baseline, high plasma cortisol led to rapid declines in MMSE scores over a 40-month period.     

The frontal assessment battery does not differentiate frontotemporal dementia from Alzheimer's disease

BACKGROUND: An early differentiation of Alzheimer's disease (AD) from frontotemporal dementia (FTD) is important, since these conditions are essentially different regarding prognosis and therapeutical approach. Until now, no single test is available which allows a reliable differentiation. The Frontal Assessment Battery (FAB) has been found to have good reliability in identifying an executive deficit in frontal syndromes and in extrapyramidal disorders. The ability of the FAB to distinguish AD from FTD in mildly demented patients is less clearly assessed. METHODS: We compared FAB scores in a consecutive series of 33 FTD (frontal variant) and 85 AD patients. RESULTS: FAB global scores in the two groups were very similar, also when considering only mildly demented subgroups [Mini Mental State Examination (MMSE) score > or = 20; 20 FTD and 38 AD patients]. Considering FAB subscores, only the 'go-no go' subtest showed a significant difference, reflecting a poorer inhibitory motor control in AD patients. FAB scores in the two groups of patients correlated with global cognitive decline (MMSE), and with executive and visuospatial test scores, showing good concurrent validity. CONCLUSION: The FAB does not differentiate patients with AD from those with FTD, like all other executive tests. However, it may be useful in the examination of executive function in AD, FTD and several other pathological conditions.     

Hippocampal atrophy and ventricular enlargement in normal aging, mild cognitive impairment (MCI), and Alzheimer Disease

Alzheimer disease (AD) is the most common type of dementia worldwide. Hippocampal atrophy and ventricular enlargement have been associated with AD but also with normal aging. We analyzed 1.5-T brain magnetic resonance imaging data from 46 cognitively normal elderly individuals (NC), 33 mild cognitive impairment and 43 AD patients. Hippocampal and ventricular analyses were conducted with 2 novel semiautomated segmentation approaches followed by the radial distance mapping technique. Multiple linear regression was used to assess the effects of age and diagnosis on hippocampal and ventricular volumes and radial distance. In addition, 3-dimensional map correction for multiple comparisons was made with permutation testing. As expected, most significant hippocampal atrophy and ventricular enlargement were seen in the AD versus NC comparison. Mild cognitive impairment patients showed intermediate levels of hippocampal atrophy and ventricular enlargement. Significant effects of age on hippocampal volume and radial distance were seen in the pooled sample and in the NC and AD groups considered separately. Age-associated differences were detected in all hippocampal subfields and in the frontal and body/occipital horn portions of the lateral ventricles. Aging affects both the hippocampus and lateral ventricles independent of AD pathology, and should be included as covariate in all structural, hippocampal, and ventricular analyses when possible.     

Cholinergic-serotonergic imbalance contributes to cognitive and behavioral symptoms in Alzheimer's disease

Neuropsychiatric symptoms seen in Alzheimer's disease (AD) are not simply a consequence of neurodegeneration, but probably result from differential neurotransmitter alterations, which some patients are more at risk of than others. Therefore, the hypothesis of this study is that an imbalance between the cholinergic and serotonergic systems is related to cognitive symptoms and psychological syndromes of dementia (BPSD) in patients with AD. Cholinergic and serotonergic functions were assessed in post-mortem frontal and temporal cortex from 22 AD patients who had been prospectively assessed with the Mini-Mental State examination (MMSE) for cognitive impairment and with the Present Behavioral Examination (PBE) for BPSD including aggressive behavior, overactivity, depression and psychosis. Not only cholinergic deficits, but also the cholinacetyltransferase/serotonin ratio significantly correlated with final MMSE score both in frontal and temporal cortex. In addition, decreases in cholinergic function correlated with the aggressive behavior factor, supporting a dual role for the cholinergic system in cognitive and non-cognitive disturbances associated to AD. The serotonergic system showed a significant correlation with overactivity and psychosis. The ratio of serotonin to acetylcholinesterase levels was also correlated with the psychotic factor at least in women. It is concluded that an imbalance between cholinergic-serotonergic systems may be responsible for the cognitive impairment associated to AD. Moreover, the major findings of this study are the relationships between neurochemical markers of both cholinergic and serotonergic systems and non-cognitive behavioral disturbances in patients with dementia.     

Cognitive and functional neuroimaging correlate for anosognosia in mild cognitive impairment and Alzheimer's disease

OBJECTIVES: To investigate the correlation between anosognosia and behavioural symptoms, performance on executive tests, and frontal cortex regional cerebral blood flow (rCBF) in patients with 'amnestic mild cognitive impairment' (MCI) and mild Alzheimer's disease (AD). METHODS: From a prospective Memory Clinic cohort including consecutively referred patients, age 60 years or above, and with MMSE score 20 or above, 36 patients with AD and 30 with MCI were included in this study. Anosognosia was assessed using a categorical scale and discrepancy scores between patients' and relatives' reports on a 20-item Memory Questionnaire (MQ). Behavioural symptoms were assessed with Frontal Behavioural Inventory (FBI). Executive functions were examined with a range of neuropsychological tests. Tc99m-HMPAO SPECT was obtained in an unselected sample of 55 of the 66 patients, and rCBF was analysed in six cortical frontal regions. RESULTS: Insight was equally impaired in the two patient groups. A significant correlation was found between impaired awareness and dementia severity (MMSE). Discrepancy-scores on the MQ were significantly correlated to scores on FBI and to rCBF in the right inferior frontal gyrus, but not to executive tests. The groups classified by the categorical ratings 'full', 'shallow' and 'no' awareness were not characterized by differences in behavioural symptoms, executive performance or frontal rCBF. CONCLUSIONS: Impaired awareness is associated with behavioural symptoms and may reflect functional impairment in the right inferior frontal cortex.