Silent neurovestibular frailty: a conceptual model integrating vestibular dysfunction, dual-task mobility and cognitive load as candidate contributors to falls, delirium and functional decline in older adults.

Falls, delirium and functional decline are commonly treated as distinct geriatric outcomes despite sharing vulnerabilities in sensory integration, gait regulation, attention and physiological reserve. We propose silent neurovestibular frailty as a conceptual model describing a latent ageing phenotype in which vestibular dysfunction, dual-task gait deterioration and sensitivity to cognitive load interact before overt disability becomes apparent. This construct is presented as a hypothesis-generating framework rather than a validated diagnostic entity, intended to integrate currently separate lines of evidence into a testable model. Vestibular impairment in later life is associated with balance deficits, mobility limitation and reduced functional reserve, whilst dual-task gait assessment may reveal cognitive-motor interference that remains undetected during routine walking evaluation, although dual-task cost may reflect impairment, strategic task prioritisation, or both. Delirium introduces additional clinical urgency because acute cognitive deterioration frequently develops in older adults with sensory impairment, immobility, multimorbidity, medication exposure and diminished adaptive reserve. We argue that vestibular function, dual-task mobility and cognition deserve coordinated assessment as a candidate translational risk triad for older adults vulnerable to falls, hospital-acquired delirium and accelerated functional decline, whilst recognising that prospective evidence validating this integrated phenotype is currently lacking. The model extends rather than replaces multifactorial fall prevention and provides an empirical agenda for operationalisation, validation and intervention testing across community, perioperative, inpatient and rehabilitation settings.