Neurodegenerative dementia and parkinsonism

Computer-based cognitive interventions for mild cognitive impairment and dementia in older adults: protocol for a systematic review of published studies and meta-analysis

BACKGROUND

A growing number of older adults experience mild cognitive impairment (MCI) and dementia. Recent technological advances allow for traditional cognitive interventions to be administered via computers and other devices. The aim of the proposed systematic review and meta-analyses is to determine the efficacy of computerised cognitive interventions for MCI and dementia in older adults.

METHODS

We will systematically search electronic databases and reference lists to identify randomised controlled trials. We will include studies that examine the use of computer-based cognitive interventions for adults aged over 60 with MCI or dementia. Primarily outcomes are global and domain-specific cognitive function. Secondary outcomes are attitudes (usability, understandability, acceptability of the intervention), mood and quality of life. Risk of bias will be assessed. Finally, the summary effect sizes will be reported.

DISCUSSION

This systematic review will summarise existing high-quality primary studies on computerised-cognitive interventions for MCI and dementia. Results from this review will provide the basis for future research in developing computer-based interventions for this population.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016050236.

Quantitative detection of amyloid-β peptides by mass spectrometry: state of the art and clinical applications

Alzheimer’s disease (AD) is the most common form of dementia in humans, and a major public health concern with 35 million of patients worldwide. Cerebrospinal fluid (CSF) biomarkers being early diagnostic indicators of AD, it is essential to use the most efficient analytical methods to detect and quantify them accurately. These biomarkers, and more specifically amyloid-β (Aβ) peptides, are measured in routine clinical practice using immunoassays. However, there are several limits to this immunodetection in terms of specificity and multiplexing of the multiple isoforms of the Aβ peptides. To overcome these issues, the quantification of these analytes by mass spectrometry (MS) represents an interesting alternative, and several assays have been described over the past years. This article reviews the different Aβ peptides quantitative MS-based approaches published so far, compares their pre-analytical phase, and the different quantitative strategies implemented that might be suitable for clinical applications.

Targets for AD treatment: conflicting messages from γ-secretase inhibitors

Current evidence suggests that Alzheimer's disease (AD) is a multi-factorial disease that starts with accumulation of multiple proteins. We have previously proposed that inhibition of γ-secretase may impair membrane recycling causing neurodegeneration starting at synapses (Sambamurti K., Suram A., Venugopal C., Prakasam A., Zhou Y., Lahiri D. K. and Greig N. H. A partial failure of membrane protein turnover may cause Alzheimer's disease: a new hypothesis. Curr. Alzheimer Res., 3, 2006, 81). We also proposed familal AD mutations increase Aβ42 by inhibiting γ-secretase. Herein, we discuss the failure of Eli Lilly's γ-secretase inhibitor, semagacestat, in clinical trials in the light of our hypothesis, which extends the problem beyond toxicity of Aβ aggregates. We elaborate that γ-secretase inhibitors lead to accumulation of amyloid precursor protein C-terminal fragments that can later be processed by γ-secretase to yields bursts of Aβ to facilitate aggregation. Although we do not exclude a role for toxic Aβ aggregates, inhibition of γ-secretase can affect numerous substrates other than amyloid precursor protein to affect multiple pathways and the combined accumulation of multiple peptides in the membrane may impair its function and turnover. Taken together, protein processing and turnover pathways play an important role in maintaining cellular homeostasis and unless we clearly see consistent disease-related increase in their levels or activity, we need to focus on preserving their function rather than inhibiting them for treatment of AD and similar diseases.

An approach to the patient with cognitive impairment: delirium and dementia

Patients with cognitive impairment can be divided into 2 broad groups: those with chronic cognitive decline (most likely diagnosable with a dementia) and those with acute cognitive changes (most likely experiencing a delirium). However, diagnosis in clinical practice is far more complicated than it is in textbooks. Perhaps the greatest hurdle in evaluating the cognitively impaired patient is the clarification of a cohesive history. Unfortunately, the cognitively impaired patient is most often unable to provide such a history, and in the absence of a reliable family member, friend, or caregiver to fill in the gaps, diagnostic clarity can be difficult to achieve. This article outlines the broad diagnostic spectra of delirium and dementia, reviews current understanding of their pathogenesis, and discusses useful diagnostic and therapeutic techniques.