Dementia prevention — a call for contextualized evidence

Dual-target inhibitors based on acetylcholinesterase: Novel agents for Alzheimer's disease

Alzheimer's disease (AD) is the most common form of dementia among the elderly, accounting for 60 %-70 % of cases. At present, the pathogenesis of this condition remains unclear, but the hydrolysis of acetylcholine (ACh) is thought to play a role. Acetylcholinesterase (AChE) can break down ACh transmission from the presynaptic membrane and stop neurotransmitters' excitatory effect on the postsynaptic membrane, which plays a key role in nerve conduction. Acetylcholinesterase inhibitors (AChEIs) can delay the hydrolysis of acetylcholine (ACh), which represents a key strategy for treating AD. Due to its complex etiology, AD has proven challenging to treat. Various inhibitors and antagonists targeting key enzymes and proteins implicated in the disease's pathogenesis have been explored as potential therapeutic agents. These include Glycogen Synthase Kinase 3β (GSK-3β) inhibitors, β-site APP Cleaving Enzyme (BACE-1) inhibitors, Monoamine Oxidase (MAO) inhibitors, Phosphodiesterase inhibitors (PDEs), N-methyl--aspartic Acid (NMDA) antagonists, Histamine 3 receptor antagonists (H3R), Serotonin receptor subtype 4 (5-HT4R) antagonists, Sigma1 receptor antagonists (S1R) and soluble Epoxide Hydrolase (sEH) inhibitors. The drug development strategy of multi-target-directed ligands (MTDLs) offers unique advantages in the treatment of complex diseases. On the one hand, it can synergistically enhance the therapeutic efficacy of single-target drugs. On the other hand, it can also reduce the side effects. In this review, we discuss the design strategy of dual inhibitors based on acetylcholinesterase and the structure-activity relationship of these drugs.

Cognitive Benefits of Hearing Aids in Elderly Indian Population: A Longitudinal Study

Age-related hearing loss is common among older individuals and is linked to cognitive impairment and a decrease in overall quality of life. Although hearing aids enhance auditory capabilities, their influence on cognitive performance in the Indian context has not been thoroughly investigated. This study investigates the cognitive benefits of hearing aids in elderly Indian patients with age-related hearing loss. A prospective cohort study was conducted at a tertiary care centre between January 2021 and December 2022. The study included 200 elderly patients who were fitted with behind-the-ear (BTE) or receiver-in-canal (RIC) hearing aids. The assessment of cognitive function was conducted using two standardised tests: the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). The assessment of quality of life was conducted using the WHOQOL-OLD questionnaire, while hearing acuity was examined by pure-tone audiometry and speech perception tests. Data were collected at baseline, 6 months, and 18 months. Multiple linear regression analysis identified predictors of cognitive outcomes. There were significant enhancements in MMSE, MoCA, HHIE, and WHOQOL-OLD scores across the 18-month duration (p < 0.001). The pure-tone audiometry thresholds and speech perception scores demonstrated significant improvement (p < 0.001). Regression analysis indicated that baseline cognitive function, hearing ability, and quality of life were significant predictors of cognitive outcomes at 18 months. No severe cognitive impairment or other confounding severe medical conditions were reported. This study revealed that the use of hearing aids has a substantial positive impact on cognitive function, quality of life, and hearing ability in the older Indian population suffering from age-related hearing loss. Timely intervention and the availability of hearing aids are essential for improving cognitive health and overall well-being in this demographic. Future study should look into the consequences and influence of various hearing aid models.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-024-04939-7.

MIND food and speed of processing training in older adults with low education, the MINDSpeed Alzheimer's disease prevention pilot trial

BACKGROUND

Multiple national organizations and leaders have called for increased attention to dementia prevention in those most vulnerable, for example persons with limited formal education. Prevention recommendations have included calls for multicomponent interventions that have the potential to improve both underlying neurobiological health and the ability to function despite neurobiological pathology, or what has been termed cognitive reserve.

OBJECTIVES

Test feasibility, treatment modifier, mechanism, and cognitive function effects of a multicomponent intervention consisting of foods high in polyphenols (i.e., MIND foods) to target neurobiological health, and speed of processing training to enhance cognitive reserve. We refer to this multicomponent intervention as MINDSpeed.

DESIGN

MINDSpeed is being evaluated in a 2 × 2 randomized factorial design with 180 participants residing independently in a large Midwestern city. Qualifying participants are 60 years of age or older with no evidence of dementia, and who have completed 12 years or less of education. All participants receive a study-issued iPad to access the custom study application that enables participants, depending on randomization, to select either control or MIND food, and to play online cognitive games, either speed of processing or control games.

METHODS

All participants complete informed consent and baseline assessment, including urine and blood samples. Additionally, up to 90 participants will complete neuroimaging. Assessments are repeated immediately following 12 weeks of active intervention, and at 24 weeks post-randomization. The primary outcome is an executive cognitive composite score. Secondary outcomes include oxidative stress, pro-inflammatory cytokines, and neuroimaging-captured structural and functional metrics of the hippocampus and cortical brain regions.

SUMMARY

MINDSpeed is the first study to evaluate the multicomponent intervention of high polyphenol intake and speed of processing training. It is also one of the first dementia prevention trials to target older adults with low education. The results of the study will guide future dementia prevention efforts and trials in high risk populations.

Dementia: Dementia prevention - a call for contextualized evidence

This corrects the article DOI: 10.1038/nrneurol.2017.136.