遗忘型轻度认知障碍内隐记忆启动效应的研究

目的探讨遗忘型轻度认知障碍患者(aMCI)内隐记忆概念性启动和知觉性启动损害的特征。方法采用分类产生和图片辨别对35例aMCI患者和35名正常老年人的内隐记忆(概念性启动和知觉性启动)进行测试,同时进行外显记忆(即刻回忆、延时回忆、延时再认)和其他神经心理学背景测试,并进行组间比较和分析。结果与正常老年组相比,aMCI患者组即刻回忆、延时回忆、延时再认、概念性启动成绩均差于正常对照组(P0.01)。两组在知觉性启动成绩差异无统计学意义(P0.05)。患者组概念性启动成绩与词汇流畅性成绩呈正相关(r=0.74,P0.01)。结论aMCI患者外显记忆及内隐记忆的概念性启动存在损害,且其概念性启动损害可能与其额叶功能减退存在一定的相关性。     

Prospective memory on a novel clinical task in older adults with mild cognitive impairment and subjective cognitive decline

Despite the relevance of prospective memory to everyday functioning and the ability to live independently, prospective memory tasks are rarely incorporated into clinical evaluations of older adults. We investigated the validity and clinical utility of a recently developed measure, the Royal Prince Alfred Prospective Memory Test (RPA-ProMem), in a demographically diverse, non-demented, community-dwelling sample of 257 older adults (mean age = 80.78?years, 67.7% female) with amnestic mild cognitive impairment (aMCI, n = 18), nonamestic mild cognitive impairment (naMCI, n = 38), subjective cognitive decline (SCD, n = 83) despite intact performance on traditional episodic memory tests, and healthy controls (HC, n = 118). Those with aMCI and naMCI performed significantly worse than controls on the RPA-ProMem and its subtasks (time-based, event-based, short-term, long-term). Also, those with SCD scored significantly lower than controls on long-term, more naturalistic subtasks. Additional results supported the validity and inter-rater reliability of the RPA-ProMem and demonstrated a relation between test scores and informant reports of real-world functioning. The RPA-ProMem may help detect subtle cognitive changes manifested by individuals in the earliest stages of dementia, which may be difficult to capture with traditional episodic memory tests. Also, assessment of prospective memory can help guide the development of cognitive interventions for older adults at risk for dementia.     

Progression to dementia in a population with amnestic mild cognitive impairment: clinical variables associated with conversion

The aim of this study was to investigate clinical predictors of, and rates of conversion to, dementia syndrome in a case series of patients with amnestic mild cognitive impairment (aMCI). Two hundred and eight aMCI subjects were followed over a six-year period. A lower Mini Mental State Examination score was a significant predictor of dementia, and mild cognitive impairment patients with behavioral and psychiatric symptoms showed a faster conversion rate.     

Visual and visuospatial short-term memory in mild cognitive impairment and Alzheimer disease: role of attention

It has been proposed that visual recognition memory and certain attentional mechanisms are impaired early in Alzheimer disease (AD). Little is known about visuospatial recognition memory in AD. The crucial role of the hippocampus on spatial memory and its damage in AD suggest that visuospatial recognition memory may also be impaired early. The aim of the present study was to evaluate which modality, i.e. visual or visuospatial, is more implicated in the early memory impairment in AD. First, to determine onset of memory impairment, we compared the performances of patients with AD to those with amnestic mild cognitive impairment (MCI). Second, to determine the relative contribution of attentional impairment on the performance of MCI and AD patients, we tested the influence of a distractor in the interval between the memory image and recognition tests. Results showed that visuospatial short-term deficits appear earlier than visual short-term ones. In addition to mnemonic deficits, results showed attentional deficiency in both MCI and AD patients. Deficits of performances in visual modality seemed of attentional origin whereas those of visuospatial modality seemed of memory origin. The combination of attentional and mnemonic evaluation is likely to be a promising approach to finding predictive markers that distinguish MCI patients that convert to AD.     

Prospective memory in idiopathic REM sleep behavior disorder with or without mild cognitive impairment: A preliminary study

Objective: The ability to execute delayed intentions, known as prospective memory (PM), is crucial to everyday living. PM failures are reported in mild cognitive impairment (MCI) and Parkinson’s disease, however, no study to date has investigated PM functioning in individuals at high risk of developing these conditions, precisely those diagnosed with idiopathic REM sleep behavior disorder (iRBD). We aimed to assess PM in iRBD according to patients’ cognitive status and to determine the underlying nature of their difficulties. Method: Fifty-eight participants, including 20 healthy controls (HC) and 38 polysomnographic-confirmed iRBD patients with (iRBD-MCI = 13) or without (iRBD-nMCI = 25) MCI participated in this study. Following a neuropsychological assessment, PM was evaluated using a self-administered questionnaire (PRMQ), a simple clinical measure (envelope test), and a laboratory cue salience task. Results: No significant group differences were noted on the PRMQ and envelope test. On the PM laboratory task, non-parametric analyses revealed better detection accuracy in HC than both iRBD groups for all high and low salient cues. While iRBD-nMCI and iRBD-MCI patients performed similarly on the high salient condition, the latter showed significant difficulty in detecting low salient cues. Multiple regression analyses revealed executive dysfunction as the best predictor to significantly account for differences in the low salient condition in iRBD. Conclusion: PM difficulties in iRBD are most important in patients with MCI (vs without MCI) and may be attributed to a gradual alteration in executive mechanisms. PM impairment could act as a promising indicator of early cognitive dysfunction in iRBD.     

Impaired digit span can predict further cognitive decline in older people with subjective memory complaint: a preliminary result

Subjective memory complaint (SMC) is common among elderly people, and is thought to be part of mild cognitive impairment (MCI). We evaluated whether impaired digit span (IDS) in older people with SMC can predict wider impairment in future neuropsychological tests that correspond to MCI. After a mean of 6.6 years from the initial assessment, we reevaluated 16 subjects with SMC and normal digit span (NDS) scores (mean age 57.6 ± 8.1 years) and 28 subjects with SMC and IDS scores (mean age 59.7 ± 9.9 years). The IDS group showed wider cognitive decline in tests of short-term verbal memory and category verbal fluency compared to the NDS group. IDS scores indicate an earlier step for conversion of SMC to MCI.     

Pattern of cognitive impairment in older veterans with posttraumatic stress disorder evaluated at a memory disorders clinic

Background: We determined the pattern of clinically significant cognitive impairment (CI) among older veterans with posttraumatic stress disorder (PTSD) evaluated in a memory disorders clinic. Methods: Data were collected from 19 ethnically diverse veterans. Cognitive functioning in six domains (verbal learning, memory, attention, language, executive functioning, and information processing speed) was assessed. Results: The majority of veterans (57%) demonstrated CI on a measure of single trial list learning, 44% exhibited CI on short delay memory for lists, and 31% exhibited CI in long delay memory for lists. CI on measures of memory for stories (14%) and executive functioning (6%) were less common, and none of the participants demonstrated CI on measures of attention, language, or information processing speed. Conclusions: CI on measures of single trial list learning and memory for lists are common in older patients with PTSD evaluated in a memory disorders clinic and are likely to contribute to functional deficits. Copyright © 2011 John Wiley & Sons, Ltd.     

Memory complaint in attenders at a self-referral memory clinic: The role of cognitive factors,affective symptoms and personality

Memory complaint has been shown to be poorly correlated with objective memory performance in non-demented elderly people. A previous study indicated the possible importance of depression and personality in the presentation of memory complaint in people with mild memory impairment. The present study overcomes some previous methodological limitations and describes memory complaint, cognitive, affective and personality variables in subjects with mild cognitive impairment self-referring to a memory clinic, with non-presenting age- and sex-matched community controls. Self-referrers had a higher original IQ, but no evidence of greater decline in memory despite having more memory complaint. Personality factors were demonstrated to be important alongside affective symptoms in the presentation of memory complaint in these subjects.     

Randomized double-blind placebo-controlled donepezil augmentation in antidepressant-treated elderly patients with depression and cognitive impairment: a pilot study

OBJECTIVE: To assess combined antidepressant and cognitive enhancer treatment in elderly patients presenting with depression plus cognitive impairment. METHODS: Twenty-three elderly (>50 years old) depressed, cognitively impaired (DEP-CI) patients participated in a pilot study. We evaluated whether, after 8 weeks of open antidepressant treatment, donepezil HCl (Aricept) would afford added cognitive benefit compared to placebo in a randomized 12-week trial. A subsample continued in an 8-month extension phase of open treatment with donepezil. Neuropsychological testing (NPT) was performed and antidepressant response monitored at baseline and the 8, 20, and 52-week time points. RESULTS: At 8-weeks, the antidepressant response rate was 61% (14/23). Improvement in SRT immediate recall (SRT-IR; e.g. episodic verbal memory) was observed in responders compared to non-responders. During the 12-week, placebo-controlled, donepezil add-on trial, patients on donepezil showed further improvement in SRT-IR versus patients on placebo. In the open extension phase, patients who continued open donepezil treatment (n = 6) maintained improvement in memory and tended to show an advantage over patients who never received donepezil and were evaluated at the 52-week time point (n = 6). There were no observed significant donepezil effects on non-memory cognitive domains. CONCLUSION: These preliminary findings suggest that addition of a cholinesterase inhibitor (AChEI) following antidepressant medication treatment in elderly Dep-CI patients may improve cognition, and support the need for a confirmatory, larger randomized placebo-controlled trial.     

Effects of movement music therapy with a percussion instrument on physical and frontal lobe function in older adults with mild cognitive impairment: a randomized controlled trial

ABSTRACT

Objectives: We tested the hypothesis that performing a rhythmic physical task accompanied by a cognitive task, such as multitask movement music therapy (MMT) involving repetitive rhythmic movement with a musical instrument (the Naruko clapper), may improve pre-frontal cortex (PFC) function and cognitive performance.

Method: Forty-five older adult participants with MCI (74.62 ± 5.05 years) participated in this randomized, controlled, single-blind intervention trial. 35 were assigned to the MMT group and 10 to the control STT group. Before and after the 12-week exercise program, we administered six physical function tests, the Frontal Assessment Battery (FAB), and measured relative oxyhemoglobin concentrations using 45-multichannel functional near-infrared spectroscopy as a reflection of hemodynamic responses in the PFC.

Results: We observed significant improvements in FAB scores only in the MMT group. Cerebral blood flow (CBF) in the PFC during the exercise was significantly increased in the MMT group compared with the STT group. The CBF increase was significantly correlated among various channels in the MMT group.

Conclusions: The MMT program appeared to stimulate the PFC and improve cognitive performance in our older adult participants with MCI, suggesting that the repetitive, rhythmic movements of MMT can activate the prefrontal area in older adults.

Trial registration: Clinical Trial Registry Numbers: R000026130, UMIN000022671 (2016/06/08) [(University Hospital Medical Information Network (UMIN) Center] retrospectively registered.     

Randomized,double-blind,placebo-controlled international clinical trial of the Ampakine CX516 in elderly participants with mild cognitive impairment: a progress report

This progress report briefly describes the rationale and study design for the first cross-national clinical study of a positive AMPA-type glutamate receptor modulator in subjects with mild cognitive impairment (MCI). The study medication for the double-blind, placebo-controlled trial, the AMPAKINE CX516, represents a novel pharmacological approach to the treatment of memory disorders. Previous preclinical and pilot clinical studies have shown that CX516 has the ability to enhance memory and cognition. Design of the trial, including outcome measures and inclusion criteria, was aided by an international panel of experts in the newly emerging field of MCI.     

Effects of repetitive transcranial magnetic stimulation on improvement of cognition in elderly patients with cognitive impairment: a systematic review and meta‐analysis

Objective

This systematic review and meta‐analysis aimed to examine the effects of repetitive transcranial magnetic stimulation (rTMS) on cognitive function in older patients with cognitive impairment.

Methods

A literature search was performed for articles published in English using the 10 databases (MEDLINE, EMBASE, PsycINFO, INSPEC, the Cumulative Index to Nursing and Allied Health Literature Plus, AMED, Biological Sciences, ClinicalTrials.gov , the Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews) from their inception to May 2016. The primary outcome was cognitive function as measured by the Mini‐Mental State Examination or the Alzheimer's Disease Assessment Scale‐cognitive subscale.

Results

Seven RCTs were included in the meta‐analysis, with a sample of 107 active and 87 sham rTMS. Active rTMS was found to be more effective in improving cognition (Hedges' g = 0.48; 95% confidence interval 0.12 to 0.84).

Conclusions

High‐frequency rTMS showed a benefit on cognition amongst older patients with mild to moderate Alzheimer's disease. rTMS was shown to have great potential as a safe and well‐tolerated alternative intervention for cognition. Copyright © 2017 John Wiley & Sons, Ltd.     

Rey verbal learning test is a useful tool for differential diagnosis in the preclinical phase of Alzheimer's disease: comparison with mild cognitive impairment and normal aging

OBJECTIVE: To confirm that performance in verbal learning and memory test (Rey's Auditory Verbal Learning Test-RAVLT) is a helpful early neuropsychological marker of dementia of Alzheimer's type (DAT). METHODS: RAVLT was administered as part of a more extensive neuropsychological battery at baseline evaluation in 116 unselected patients referred by subjective memory complaints (SMC). Patients were followed longitudinally for 2 years (average interval of 27.7+/-4 months). Seventy patients were included in the study: 27 developed probable DAT; 17 were diagnosed as cognitively normal persons and 26 were diagnosed with Mild Cognitive Impairment (MCI). Remaining patients abandoned or they did not meet the criteria for DAT, MCI or control. Performance on RAVLT at the baseline evaluation was compared between groups. RESULTS: Patients diagnosed two years later with probable DAT showed lower results, more frequently performed a score of zero at the delayed recall test (Trial 6) and had a percentage of forgetting (difference between Trials 5 and 6) higher than 75%. Score at delayed recall test and percentage of forgetting correlated with functional scales such as MMSE, Geriatric Depression Screening, Informant Questionnaire and Blessed's Dementia Rating. CONCLUSIONS: RAVLT could help to identify those patients with SMC who would progress to DAT over a few years, and also to differentiate between the preclinical phase of Alzheimer's disease, mild cognitive impairment and normal aging. A score of zero at the delayed recall test or a percentage of forgetting > or =75% in patients with SMC is suggestive of probable DAT in the future.