For years, those of us who are neurologists have recognized the multiple sensory deficit syndrome as a major cause of impaired ambulation and falls. Many older patients have impairments of sensory function (such as vision, hearing, vestibular function, and proprioception) that individually are not severe enough to produce disability but collectively have an additive or synergistic effect that does result in disability.
Geriatricians have now begun to take a broader look at a related concept, global sensory impairment (GSI), and its impact on overall health. Correia and colleagues assessed the 5 classical primary sensations (vision, hearing, touch, taste, and smell) in community-dwelling U.S. adults aged 57 to 85 (Correia 2016). They found that two-thirds of subjects had two or more sensory deficits, 27% had just one, and 6% had none. Seventy-four percent had impairment in taste, 70% in touch, 22% in smell, 20% in corrected vision, and 18% in corrected hearing. Older adults, men, African Americans, and Hispanics had greater multisensory impairment.
Many of the same authors then evaluated global sensory impairment (GSI, an integrated measure of sensory dysfunction) as a predictor of physical function, cognition, overall health, and mortality (Pinto 2017). A national probability sample of 3,005 home-dwelling older U.S. adults was assessed at baseline (200506) and 5-year follow-up (201011) for gait speed, activity, disability, cognition, overall health, and 5-year mortality. A GSI score was calculated based upon assessment of those 5 classical sensory modalities (see the Pinto article for details of the score methodology). At baseline, older adults with worse GSI were slower on the Timed Up and Go test and had more activity of daily living deficits. Five years later, they were still slower, had more disabilities, were less active, had worse cognitive function, were more likely to have poorer overall health and lose weight, and have died.
The authors note that GSI predicts many of the components of physical frailty included in three of the major, standard models (e.g., slow gait, weight loss, low activity). Weve done numerous columns on the health consequences of frailty (see the list below).
The authors also note that inclusion of additional clinical measures of sensory function (e.g., near and distance vision, audiometry) may well add to the usefulness of the GSI score. It is likely that the burden of sensory impairments was underestimated, and they felt that better precision in the measures would probably make the results more robust.
There are obvious potential clinical implications of these findings. First, the GSI score might serve as a biomarker for patients who are vulnerable to health deterioration. But, perhaps more importantly, they point out the need for future studies to determine whether interventions that improve sensory function (eg. eye glasses, hearing aids) can mitigate against that overall deterioration. However, we also need to keep in mind that sometimes there are unintended consequences. For example, several of our prior columns have noted paradoxical increases in falls after certain types of vision correction.
Some of our prior columns on preoperative assessment and frailty:
Some of our previous columns on falls after correction of vision:
June 2010 Seeing Clearly a Common Sense Intervention
June 2014 New Glasses and Fall Risk
August 2014 Cataract Surgery and Falls
Some of our prior columns related to falls:
Correia C, Lopez KJ, Wroblewski KE et al. Global sensory impairment in older adults in the United States. J Am Geriatr Soc 2016; 64: 306-313
Pinto JM, Wroblewski KE, Huisingh-Scheetz M, et al. Global Sensory Impairment Predicts Morbidity and Mortality in Older U.S. Adults. J Am Geriatr Soc 2017; 65: 2587-2595