Impairments of auditory scene analysis in posterior cortical atrophy.

Chris J D Hardy,Keir X X Yong,Johanna C Goll,Sebastian J Crutch,Jason D Warren

doi:10.1093/brain/awaa221

Chris J D Hardy, Keir X X Yong + Show 3 more

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https://doi.org/10.1093/brain/awaa221

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Journal: Brain	Publication Date: Sep 1, 2020
Citations: 21	License type: CC BY 4.0

Affiliation: National Hospital for Neurology and Neurosurgery

Abstract

Although posterior cortical atrophy is often regarded as the canonical ‘visual dementia’, auditory symptoms may also be salient in this disorder. Patients often report particular difficulty hearing in busy environments; however, the core cognitive process—parsing of the auditory environment (‘auditory scene analysis’)—has been poorly characterized. In this cross-sectional study, we used customized perceptual tasks to assess two generic cognitive operations underpinning auditory scene analysis—sound source segregation and sound event grouping—in a cohort of 21 patients with posterior cortical atrophy, referenced to 15 healthy age-matched individuals and 21 patients with typical Alzheimer’s disease. After adjusting for peripheral hearing function and performance on control tasks assessing perceptual and executive response demands, patients with posterior cortical atrophy performed significantly worse on both auditory scene analysis tasks relative to healthy controls and patients with typical Alzheimer’s disease (all P < 0.05). Our findings provide further evidence of central auditory dysfunction in posterior cortical atrophy, with implications for our pathophysiological understanding of Alzheimer syndromes as well as clinical diagnosis and management.

Highlights

Posterior cortical atrophy (PCA) is conventionally defined as a syndrome characterized by progressive impairment of higher visual function, in particular visuoperceptual and visuospatial skills, often designated the ‘visual variant’ of Alzheimer’s disease (Benson et al, 1988; Crutch et al, 2017)
Results for group comparisons of demographic and clinical characteristics and experimental test performance are summarized in Table 1 and additional data are presented in Supplementary Tables 2 and 3; individual participant performance plots on the auditory scene analysis (ASA) tests are shown for each participant group in Fig. 1C and D
We have presented evidence that patients with PCA perform worse on tasks of ASA-segregation and ASA-grouping than healthy older individuals or patients with typical amnestic Alzheimer’s disease

Summary

Introduction

Posterior cortical atrophy (PCA) is conventionally defined as a syndrome characterized by progressive impairment of higher visual function, in particular visuoperceptual and visuospatial skills, often designated the ‘visual variant’ of Alzheimer’s disease (Benson et al, 1988; Crutch et al, 2017). Patients with PCA have particular difficulty interpreting and navigating ‘busy’, dynamic visual environments requiring parsing of multiple objects distributed in space (Shakespeare et al, 2013; Yong et al, 2018) Posterior cortical functions such as calculation, spelling and praxis are affected in PCA (Benson et al, 1988; Crutch et al, 2017), along with other cognitive domains including language (Crutch et al, 2013), episodic memory (Ahmed et al, 2018), working memory (Trotta et al, 2019), executive functioning (Putcha et al, 2018), and visuo-vestibular integration (Crutch et al, 2018).

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