Auditory confrontation naming in Alzheimer's disease

Investigating sentence processing and working memory in patients with mild Alzheimer and elderly people

INTRODUCTION

Linguistic disorders are one of the common problems in Alzheimer's disease, which in recent years has been considered as one of the key parameters in the diagnosis of Alzheimer (AD). Given that changes in sentence processing and working memory and the relationship between these two activities may be a diagnostic parameter in the early and preclinical stages of AD, the present study examines the comprehension and production of sentences and working memory in AD patients and healthy aged people.

METHODS

Twenty-five people with mild Alzheimer's and 25 healthy elderly people participated in the study. In this study, we used the digit span to evaluate working memory. Syntactic priming and sentence completion tasks in canonical and non-canonical conditions were used for evaluating sentence production. We administered sentence picture matching and cross-modal naming tasks to assess sentence comprehension.

RESULTS

The results of the present study revealed that healthy elderly people and patients with mild Alzheimer's disease have a significant difference in comprehension of relative clause sentences (P <0.05). There was no significant difference between the two groups in comprehension of simple active, simple active with noun phrase and passive sentences (P> 0.05). They had a significant difference in auditory and visual reaction time (P <0.05). Also there was a significant difference between the two groups in syntactic priming and sentence completion tasks. However, in non-canonical condition of sentence completion, the difference between the two groups was not significant (P> 0.05).

CONCLUSION

The results of the present study showed that the mean scores related to comprehension, production and working memory in people with mild Alzheimer's were lower than healthy aged people, which indicate sentence processing problems at this level of the disease. People with Alzheimer have difficulty comprehending and producing complex syntactic structures and have poorer performance in tasks that required more memory demands. It seems that the processing problems of these people are due to both working memory and language problems, which are not separate from each other and both are involved in.

Expanded Exploration of the Auditory Naming Test in Patients with Dementia

BACKGROUND

Auditory naming tests are superior to visual confrontation naming tests in revealing word-finding difficulties in many neuropathological conditions.

OBJECTIVE

To delineate characteristics of auditory naming most likely to reveal anomia in patients with dementia, and possibly improve diagnostic utility, we evaluated a large sample of patients referred with memory impairment complaints.

METHODS

Patients with dementia (N = 733) or other cognitive impairments and normal individuals (N = 69) were evaluated for frequency of impairment on variables of the Auditory Naming Test (ANT) of Hamberger & Seidel versus the Boston Naming Test (BNT).

RESULTS

Naming impairment occurred more frequently using the ANT total score (φ= 0.41) or ANT tip-of-the tongue score (TOT; φ= 0.19) but not ANT mean response time compared to the BNT in patients with dementia (p < 0.001). Significantly more patients were impaired on ANT variables than on the BNT in Alzheimer's disease (AD), vascular dementia (VaD), mixed AD/VaD, and multiple domain mild cognitive impairment (mMCI) but not in other dementias or amnestic MCI (aMCI). This differential performance of patients on auditory versus visual naming tasks was most pronounced in older, well-educated, male patients with the least cognitive impairment. Impaired verbal comprehension was not contributory. Inclusion of an ANT index score increased sensitivity in the dementia sample (92%). Poor specificity (41%) may be secondary to the inherent limitation of using the BNT as a control variable.

CONCLUSION

The ANT index score adds diagnostic utility to the assessment of naming difficulties in patients with suspected dementia.

Auditory Agnosia for Environmental Sounds in Alzheimer's Disease: Not Hearing and Not Listening?

Auditory agnosia for environmental sounds (AES) is an example of central auditory dysfunction. It is presumed to be independent of language deficits and in presence of normal hearing. We undertook a detailed neuropsychological assessment including environmental sound naming and recognition in 34 clinically mild Alzheimer's disease (AD) patients and 29 age-matched healthy control subjects. In patients with AD, audiometry was performed to assess the impact on test performance, and in normal controls the Hearing Handicap Inventory for the Elderly - Screening Version to exclude more than mild hearing loss. We adapted a validated environmental sound battery and found near perfect scores in controls. We found that environmental sound agnosia is common in mild AD. We found a statistically significant difference in mean pure tone audiometry in the best ear between patients with and those patients without naming deficits of 11.3 dB (p = 0.010) and of 14.7 dB (p = 0.000) between those with and without recognition deficits. Statistical significance remained after correcting for age, aphasia, Mini-Mental State Examination score, and working memory. Slight and moderate peripheral hearing loss increases the odds ratio of recognition deficits by 13.75 (confidence interval 2.3-81.5) compared to normal hearing patients. We did not find evidence for different forms of AES. This work suggests that an interaction between peripheral hearing loss and AD pathology produces problems with environmental sound recognition. It confirms that the relationship between hearing and dementia is complex but also suggests that interventions to prevent and treat hearing loss could have an effect on AD in its clinical expression.

Analysis of naming processing stages in patients with mild Alzheimer

In the evaluation of the nature of naming disorders, there is a rapid increase of anomia with the progression of Alzheimer's disease (AD), which is associated with whole brain atrophy. Although numerous studies have investigated this naming disorder, there is limited information on naming procedures in these patients. Reaction time (RT) is highly sensitive to dementia and provides an accurate measurement. The present study investigated the RT of each underlying level of naming in patients with mild AD and identified the nature of anomia in these patients. The study consisted of 24 healthy elderly and 22 mild AD patients who participated in experiments that were designed for evaluating each level of Levelt's model. Responses were divided into three groups of correct, false, and no-response and their RTs were calculated. The statistical analyses showed significant differences between healthy elderly and patients with mild AD in terms of access to the concept and the phonological form of the words. Moreover, significant differences in the type of responses were observed between correct and false responses of both groups. There was a significant difference between the no-response cases except in the case of lemma access for singular and plural names in other tasks. The results suggest that patients with mild AD have problems at the conceptual stage and access to the phonological form of a word.

Hearing and dementia

Hearing deficits associated with cognitive impairment have attracted much recent interest, motivated by emerging evidence that impaired hearing is a risk factor for cognitive decline. However, dementia and hearing impairment present immense challenges in their own right, and their intersection in the auditory brain remains poorly understood and difficult to assess. Here, we outline a clinically oriented, symptom-based approach to the assessment of hearing in dementias, informed by recent progress in the clinical auditory neuroscience of these diseases. We consider the significance and interpretation of hearing loss and symptoms that point to a disorder of auditory cognition in patients with dementia. We identify key auditory characteristics of some important dementias and conclude with a bedside approach to assessing and managing auditory dysfunction in dementia.

Impact of auditory-visual bimodality on lexical retrieval in Alzheimer's disease patients

The aim of this study was to generalize the positive impact of auditory-visual bimodality on lexical retrieval in Alzheimer's disease (AD) patients. In practice, the naming skills of healthy elderly persons improve when additional sensory signals are included. The hypothesis of this study was that the same influence would be observable in AD patients. Sixty elderly patients separated into three groups (healthy subjects, stage 1 AD patients, and stage 2 AD patients) were tested with a battery of naming tasks comprising three different modalities: a visual modality, an auditory modality, and a visual and auditory modality (bimodality). Our results reveal the positive influence of bimodality on the accuracy with which bimodal items are named (when compared with unimodal items) and their latency (when compared with unimodal auditory items). These results suggest that multisensory enrichment can improve lexical retrieval in AD patients.

Hearing and music in dementia

Music is a complex acoustic signal that relies on a number of different brain and cognitive processes to create the sensation of hearing. Changes in hearing function are generally not a major focus of concern for persons with a majority of neurodegenerative diseases associated with dementia, such as Alzheimer disease (AD). However, changes in the processing of sounds may be an early, and possibly preclinical, feature of AD and other neurodegenerative diseases. The aim of this chapter is to review the current state of knowledge concerning hearing and music perception in persons who have a dementia as a result of a neurodegenerative disease. The review focuses on both peripheral and central auditory processing in common neurodegenerative diseases, with a particular focus on the processing of music and other non-verbal sounds. The chapter also reviews music interventions used for persons with neurodegenerative diseases.