Ageing-related changes in the cortical processing of otolith information in humans

作者：zu Eulenburg Peter; Ruehl Ria Maxine; Runge Pia; Dieterich Marianne

来源：European Journal of Neuroscience, 2017, 46(12): 2817-2825.

DOI：10.1111/ejn.13755

<jats:title>Abstract</jats:title><jats:p>Acoustic short tone bursts (<jats:styled-content style="fixed-case">STB</jats:styled-content>) trigger ocular and cervical vestibular‐evoked myogenic potentials (<jats:styled-content style="fixed-case">oVEMP</jats:styled-content>s/<jats:styled-content style="fixed-case">cVEMP</jats:styled-content>s) by activating irregular otolith afferents. Simultaneously, <jats:styled-content style="fixed-case">STB</jats:styled-content>s introduce an artificial net acceleration signal of otolith origin into the vestibular network. <jats:styled-content style="fixed-case">VEMP</jats:styled-content> parameters as diagnostic otolith processing markers have been shown to decline after the age of thirty. To delineate the differential effects of healthy ageing on the cortical vestibular subnetwork processing otolith information, we measured <jats:styled-content style="fixed-case">cVEMP</jats:styled-content>s and the differential effects of unilateral <jats:styled-content style="fixed-case">STB</jats:styled-content> in three age groups (20–40, 40–60 and 60+; <jats:italic>n</jats:italic> = 42) using functional neuroimaging. <jats:styled-content style="fixed-case">STB</jats:styled-content> evoked responses in the main vestibular hubs in the parieto‐opercular cortex. Whereas <jats:styled-content style="fixed-case">cVEMP</jats:styled-content> amplitudes declined linearly with age, analysis of the <jats:styled-content style="fixed-case">BOLD</jats:styled-content> response size depicted a u‐shaped curve. Vestibular perception of the otolith stimulus on the other hand remained unchanged with age. Therefore, we propose that the comparably larger <jats:styled-content style="fixed-case">BOLD</jats:styled-content> responses past the age of sixty could reflect a mechanism of central sensitisation for otolith perception to counterbalance the concurrent peripheral vestibular and somatosensory function decline.</jats:p>

• 出版日期2017-12