Rethinking dementia through the lens of sensory changes

Memory problems have long been considered the primary hallmark of dementia, but a team of researchers is now challenging this view. They argue that changes in sensory perception – from vision to balance – may be equally important indicators that many healthcare providers are currently missing.

According to experts, current approaches to the care and support of people with dementia need an overhaul, relying too heavily on the assessment of memory functions, when the condition also impairs taste, touch, balance, hearing, or vision.

Professor Andrea Tales, Professor of Dementia Research at Swansea University, Dr. Emma Richards of Public Health Wales (formally Swansea University) and Professor Jan Kremláček, head of Medical Biophysics LFHK at Charles University, who are all experts in dementia research say substantial evidence now supports the existence of sensory and perceptual changes for some people living with dementia.

The experts lay out the body of evidence supporting this shift in understanding in A New Approach to Dementia.

Importantly, this book is co-produced by people living with dementia and sensory/perceptual challenges, facilitated by Aimee Day and Paula Brown. This group of co-researchers has navigated their own sensory and memory challenges to provide the context of human experience to the academic research. 

The lesser-known characteristics of dementia for some individuals include abnormalities such as altered visual and hearing perception, changes in hearing ability and sound processing, especially in noisy environments, diminished sense of smell and taste, and tactile sensitivity issues. These changes in sensory and perceptual processing may accompany the more commonly recognized memory problems associated with conditions like Alzheimer's disease.

Dr. Emma Richards, who works with individuals living with dementia, notes: "Many patients report experiencing these sensory changes years before receiving a diagnosis, but these symptoms may be overlooked during standard cognitive assessments.

"Understanding and addressing these issues, and providing support earlier could be transformative, enabling health care providers to offer the vital emotional and social support patients need at a potentially confusing and distressing time. In addition to this, understanding changes in a person's senses can help support a clinician in determining a dementia diagnosis."

This emerging understanding has significant implications for clinical practice and caregiving. The authors suggest that incorporating comprehensive sensory and perceptual testing into standard diagnostic, care, support and management protocols could enable a better understanding of the experience of the person living with dementia and their signs and symptoms, lead to a more targeted or personalised approaches, help maintain independence, and thus improve the quality of life for people living with dementia.

"Broadening the diagnostic approach beyond memory testing raised the potential to identify dementia at preclinical stages when therapies and life modifications may be most effective," says Professor Jan Kremláček, who specializes in neurophysiological assessment.

Sensory and perceptual changes can be hugely detrimental to everyday functioning and quality of life. Individuals living with dementia may experience increased difficulty navigating familiar environments, challenges with reading and interpreting visual information, communication difficulties due to auditory processing issues, and heightened anxiety in complex sensory environments.

Healthcare providers are being encouraged to listen more carefully when patients report subtle changes in how they perceive and interact with their environment, as disruption in sensory function and perception may be manifestations of dementia.

This includes developing standardized protocols for assessing sensory and perceptual function, training healthcare providers to recognize non-memory symptoms, designing environments and interventions that accommodate sensory changes, and including sensory assessments in routine cognitive screening.

"This isn't about replacing memory assessment, but rather expanding our toolkit to improve our capture of the full, more holistic, spectrum of dementia-related changes," explains Professor Tales.