Absent gender differences of hippocampal atrophy in amnestic type mild cognitive impairment.

Hippocampus displayed progressively gender-associated damage in Alzheimer's disease. However, gender effects have been largely neglected in studies of amnestic type mild cognitive impairment (aMCI) patients who were believed to represent an early stage of this disease. The goal of this study was to use in vivo neuroimaging techniques to determine whether there were any evidences of gender differences in hippocampal atrophy in aMCI. A region of interest-based magnetic resonance imaging approach was used to compare hippocampal volume between aMCI patients (22 male, 17 female) and normal aging controls (12 male, 11 female). Independent of group, male hippocampal volumes were larger than female volumes and right hippocampal volumes were typically smaller than left volumes. Hippocampal volumes were significantly reduced in the clinical group but no gender differences were noted in terms of degree of atrophy present. However, female patients showed more impaired cognitive function than male patients despite this apparent equivalence in atrophy. The absence of a gender difference suggested that early neuropathological progression might be independent of gender. However, the data also suggested female aMCI patients had an increased vulnerability to cognitive impairment earlier in the illness course.

Abnormal Functional Connectivity of Hippocampus During Episodic Memory Retrieval Processing Network in Amnestic Mild Cognitive Impairment.

BACKGROUND: Functional connectivity magnetic resonance imaging technique has revealed the importance of distributed network structures in higher cognitive processes in the human brain. The hippocampus has a key role in a distributed network supporting memory encoding and retrieval. Hippocampal dysfunction is a recurrent finding in memory disorders of aging such as amnestic mild cognitive impairment (aMCI) in which learning- and memory-related cognitive abilities are the predominant impairment. The functional connectivity method provides a novel approach in our attempts to better understand the changes occurring in this structure in aMCI patients. METHODS: Functional connectivity analysis was used to examine episodic memory retrieval networks in vivo in twenty 28 aMCI patients and 23 well-matched control subjects, specifically between the hippocampal structures and other brain regions. RESULTS: Compared with control subjects, aMCI patients showed significantly lower hippocampus functional connectivity in a network involving prefrontal lobe, temporal lobe, parietal lobe, and cerebellum, and higher functional connectivity to more diffuse areas of the brain than normal aging control subjects. In addition, those regions associated with increased functional connectivity with the hippocampus demonstrated a significantly negative correlation to episodic memory performance. CONCLUSIONS: aMCI patients displayed altered patterns of functional connectivity during memory retrieval. The degree of this disturbance appears to be related to level of impairment of processes involved in memory function. Because aMCI is a putative prodromal syndrome to Alzheimer's disease (AD), these early changes in functional connectivity involving the hippocampus may yield important new data to predict whether a patient will eventually develop AD.

Blood pressure lowering in patients without prior cerebrovascular disease for prevention of cognitive impairment and dementia

Background: This is an update of a previous review (McGuinness 2006). Hypertension and cognitive impairment are prevalent in older people. Hypertension is a direct risk factor for vascular dementia (VaD) and recent studies have suggested hypertension impacts upon prevalence of Alzheimer's disease (AD). Therefore does treatment of hypertension prevent cognitive decline?
Objectives: To assess the effects of blood pressure lowering treatments for the prevention of dementia and cognitive decline in patients with hypertension but no history of cerebrovascular disease.
Search strategy: The Specialized Register of the Cochrane Dementia and Cognitive Improvement Group, The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS as well as many trials databases and grey literature sources were searched on 13 February 2008 using the terms: hypertens$ OR anti-hypertens$. Selection criteria: Randomized, double-blind, placebo controlled trials in which pharmacological or non-pharmacological interventions to lower blood pressure were given for at least six months.
Data collection and analysis: Two independent reviewers assessed trial quality and extracted data. The following outcomes were assessed: incidence of dementia, cognitive change from baseline, blood pressure level, incidence and severity of side effects and quality of life.
Main results: Four trials including 15,936 hypertensive subjects were identified. Average age was 75.4 years. Mean blood pressure at entry across the studies was 171/86 mmHg. The combined result of the four trials reporting incidence of dementia indicated no significant difference between treatment and placebo (236/7767 versus 259/7660, Odds Ratio (OR) = 0.89, 95% CI 0.74, 1.07) and there was considerable heterogeneity between the trials. The combined results from the three trials reporting change in Mini Mental State Examination (MMSE) did not indicate a benefit from treatment (Weighted Mean Difference (WMD) = 0.42, 95%CI 0.30, 0.53). Both systolic and diastolic blood pressure levels were reduced significantly in the three trials assessing this outcome (WMD = -10.22, 95% CI -10.78, -9.66 for systolic blood pressure, WMD = -4.28, 95% CI -4.58, -3.98 for diastolic blood pressure). Three trials reported adverse effects requiring discontinuation of treatment and the combined results indicated no significant difference (OR = 1.01, 95% CI 0.92, 1.11). When analysed separately, however, more patients on placebo in Syst Eur 1997 were likely to discontinue treatment due to side effects; the converse was true in SHEP 1991. Quality of life data could not be analysed in the four studies. Analysis of the included studies in this review was problematic as many of the control subjects received antihypertensive treatment because their blood pressures exceeded pre-set values. In most cases the study became a comparison between the study drug against a usual antihypertensive regimen.
Authors' conclusions: There is no convincing evidence fromthe trials identified that blood pressure lowering in late-life prevents the development of dementia or cognitive impairment in hypertensive patients with no apparent prior cerebrovascular disease. There were significant problems identified with analysing the data, however, due to the number of patients lost to follow-up and the number of placebo patients who received active treatment. This introduced bias. More robust results may be obtained by conducting a meta-analysis using individual patient data.

DemTect:a new, sensitive cognitive screening test to support the diagnosis of mild cognitive impairment and early dementia

To design a new, highly sensitive psychometric screening to identify patients with mild cognitive impairment (MCI) and patients with dementia in the early stages of the disease.

Encouraging lifestyle behaviour change in mild cognitive impairment patients:development of appropriate educational material

Objectives: A healthy lifestyle may help maintain cognitive function and reduce the risk of developing dementia. This study employed a focus group approach in order to gain insight into opinions of mild cognitive impairment (MCI) patients, caregivers (CG) and health professionals (HP) regarding lifestyle and its relationship with cognition. The qualitative data were used to design, develop and pilot test educational material (EM) to help encourage lifestyle behaviour change. Method: Data gathering phase: structured interviews were conducted with HP (n = 10), and focus groups with MCI patients (n = 24) and CG (n = 12). EM was developed and pilot tested with a new group of MCI patients (n = 21) and CG (n = 6). Results: HP alluded to the lack of clinical trial evidence for a lifestyle and MCI risk link. Although they felt that lifestyle modifications should be recommended to MCI patients, they appeared hesitant in communicating this information and discussions were often patient-driven. MCI patients lacked awareness of the lifestyle cognition link. Participants preferred EM to be concise, eye-catching and in written format, with personal delivery of information favoured. Most pilot testers approved of the EM but were heterogeneous in terms of lifestyle, willingness to change and support needed to change. Conclusion: MCI patients need to be made more aware of the importance of lifestyle for cognition. EM such as those developed here, which are specifically tailored for this population would be valuable for HP who, currently, appear reticent in initiating lifestyle-related discussions. Following further evaluation, the EM could be used in health promotion activities targeting MCI patients.