A growing interest in cognitive effects associated with speech and hearing processes is spreading throughout the scientific community essentially guided by evidence that central and peripheral hearing loss is associated with cognitive decline. For the present research, 125 participants older than 65 years of age (105 with hearing impairment and 20 with normal hearing) were enrolled, divided into 6 groups according to their degree of hearing loss and assessed to determine the effects of the treatment applied. Patients in our research program routinely undergo an extensive audiological and cognitive evaluation protocol providing results from the Digit Span test, Stroop color-word test, Montreal Cognitive Assessment and Geriatric Depression Scale, before and after rehabilitation. Data analysis was performed for a cross-sectional and longitudinal study of the outcomes for the different treatment groups. Each group demonstrated improvement after auditory rehabilitation or training on short- and long-term memory tasks, level of depression and cognitive status scores. Auditory rehabilitation by cochlear implants or hearing aids is effective also among older adults (median age of 74 years) with different degrees of hearing loss, and enables positive improvements in terms of social isolation, depression and cognitive performance.

In this study we assessed whether widely accepted risk factors for atherosclerotic vascular diseases such as lipoprotein(a) [Lp(a)], a cholesterol-rich lipoprotein under strict genetical control, and other lipid parameters change with age. The variations of blood levels and the pathophysiological role of Lp(a) in old people, and particularly in the oldest old, are unknown. Accordingly, we measured Lp(a) levels as well as total, LDL, and HDL cholesterol (CT), and triglycerides (TG) in sera from 75 healthy centenarians, 114 randomly selected subjects under 65 years, 73 randomly selected elderly people, and 30 healthy selected elderly people. The results showed that Lp(a) serum levels did not vary by age group, including centenarians. Remarkably, one-quarter of the centenarians had high Lp(a) serum levels even though they never suffered from atherosclerosis-related diseases. At variance with young and aged people, centenarians with high Lp(a) serum levels also had high plasma concentrations of the proinflammatory cytokine IL-6, suggesting that genetic control of the Lp(a) serum level may attenuate with age and that environmental factors such as chronic subclinical inflammatory processes may play a role. We also showed that most centenarians are paradoxically characterized by low HDL-CT and relatively high TG levels, which together are considered to be strong risk factors for coronary heart disease. On the whole, these data support the hypothesis that a continuous and complex reshaping of lipid metabolism occurs in physiological aging, likely contributing to successful aging.

Sensorineural systems play a crucial role in the diagnosis, treatment and management of several neurological disorders. The function of the eye and ear represents a unique window for testing various conditions in cognitive decline or dementia. Touch and smell have also been found to be strongly involved in neurodegenerative conditions, and their decline has been significantly associated with the progression of the disease; hence, the idea that restoring sensory function in cognitively impaired adults might enable a significant improvement in their cognitive status, reducing the worldwide incidence and prevalence of dementia. Not all sensorineural ‘windows' can benefit equally from the same procedures; however, hearing and vision can certainly gain the most from dependable therapeutic and other diagnostic options. The ear, including the vestibular system, deserves an honored place among the sensory organs in this context due mainly to the sophisticated electrical devices available that have amply demonstrated their effectiveness in treating hearing loss. Restoring an individual's hearing can reduce the cognitive ‘load', i.e. the neural activity needed to understand/recognize the spoken word - an activity that becomes more demanding if the brain is obliged to recruit different neural populations to achieve the same performance, as happens in older adults with sensory impairments. The sensory interfaces may also facilitate the early diagnosis of conditions characterized by a lengthy preclinical phase, as well as enabling noninvasive, follow-up procedures to assess the outcome of rehabilitation measures and distinguish physiological brain aging from neurodegenerative disorders. The present study is a brief literature review on the issues and prospects relating to the unique relationship between hearing and cognitive decline, with a general introduction to the main topics before focusing on rehabilitation training with hearing aids and cochlear implants to combat cognitive decline.

BackgroundAlzheimer's Disease (AD) is the most common neurodegenerative disease and the leading cause of dementia among senile subjects. It has been proposed that AD can be caused by defects in mitochondrial oxidative phosphorylation. Given the fundamental contribution of the mitochondrial genome (mtDNA) for the respiratory chain, there have been a number of studies investigating the association between mtDNA inherited variants and multifactorial diseases, however no general consensus has been reached yet on the correlation between mtDNA haplogroups and AD.Methodology/Principal FindingsWe applied for the first time a high resolution analysis (sequencing of displacement loop and restriction analysis of specific markers in the coding region of mtDNA) to investigate the possible association between mtDNA-inherited sequence variation and AD in 936 AD patients and 776 cognitively assessed normal controls from central and northern Italy. Among over 40 mtDNA sub-haplogroups analysed, we found that sub-haplogroup H5 is a risk factor for AD (OR = 1.85, 95% CI:1.04–3.23) in particular for females (OR = 2.19, 95% CI:1.06–4.51) and independently from the APOE genotype. Multivariate logistic regression revealed an interaction between H5 and age. When the whole sample is considered, the H5a subgroup of molecules, harboring the 4336 transition in the tRNAGln gene, already associated to AD in early studies, was about threefold more represented in AD patients than in controls (2.0% vs 0.8%; p = 0.031), and it might account for the increased frequency of H5 in AD patients (4.2% vs 2.3%). The complete re-sequencing of the 56 mtDNAs belonging to H5 revealed that AD patients showed a trend towards a higher number (p = 0.052) of sporadic mutations in tRNA and rRNA genes when compared with controls.ConclusionsOur results indicate that high resolution analysis of inherited mtDNA sequence variation can help in identifying both ancient polymorphisms defining sub-haplogroups and the accumulation of sporadic mutations associated with complex traits such as AD.

This paper addresses a tenet of the literature on APOE, i.e., the relationship between the effects of the ε4, one of the established genetic risk factor for Alzheimer's disease (AD), and its expression levels as determined by APOE promoter polymorphisms. Five polymorphisms (-491 rs449647, -427 rs769446, -219 rs405509, and ε rs429358-rs7412) were studied in 1308 AD patients and 1082 control individuals from the Central-Northern Italy. Major findings of the present study are the following: 1) the variants -219T and ε4 increase the risk for late onset AD (LOAD) when they are both present in cis on the same chromosome (in phase); 2) the correlation between the haplotype (-219T/ε4) and AD risk persists when the data are stratified by age; 3) this haplotype likely anticipates the age of onset of the disease. These data, while confirming the association between -219T and AD, highlight the importance of the phase of the alleles for the observed effects on AD risk, suggesting that this information has to be taken into account when assessing the AD genetic risk. Moreover, the data help to clarify the apparent discrepancy that emerges from the genetic analysis where an SNP characterizing the haplotype responsible for an increased risk for LOAD is coherently associated with a reduced expression of ApoE levels. Our data are compatible with the hypothesis of a complex role of ApoE in the AD pathogenesis, with positive and negative effects occurring concomitantly according to its expression levels and its protein-protein interactions largely unclarified.