Understanding Sensory Systems and Dementia

Posted by Elaine C. Pereira on August 12, 2019
Our guest blogger, Elaine C. Pereira, MA OTR/L CDP CDC is an author, speaker, and certified dementia practitioner and caregiver. Contact her at elainep@iwillneverforgetbook.com.

Alzheimer’s Disease causes a cornucopia of issues across all neurological spheres. No system is spared from AD’s steady assault on the brain, including sensory awareness. 

Symptoms of dementia can include personality changes, confusion, impaired judgment, irrational thinking and more. Alzheimer’s also impacts language skills, compromising the ability to process directions, engage in meaningful reciprocal conversation, and identify and correct errors.  

Alzheimer’s neurological wrath is pervasive. Although a magician’s sleight of hand and misdirection dazzles captivated audiences, sensory misinformation can be very disturbing to someone with Alzheimer’s.

“The mind can play tricks on you.”

Shadows. Silhouettes cast on the ground by the sun are benign indications of daytime. Those same moving dark forms we know as shadows, however, may be perceived as threatening to someone with Alzheimer’s who see the images as confusing or disturbing.

Mirror Reflections. A dementia patient's reaction to seeing their face reflected back in a mirror may run the gamut from indifferent disregard (not processing the image as their own) to confusion and other stress responses. The face in the mirror might also be perceived as that of another person (especially from the past), or a close friend or relative (possibly already deceased).

Consider removing or covering mirrors if your loved one is disturbed by their own reflection.

Visual Hallucinations. “Seeing” things that aren't there but are very real to the individual with a neurological disorder such as Parkinson’s and Alzheimer’s. Like all sensory disturbances, hallucinations can be threatening but also oddly comforting. It’s not uncommon for someone to identify a visual hallucination as the image of someone they knew or know – deceased parent, friend, spouse – and feel calmed or comforted. Theoretically, as they drift back in time, images from their past may appear real.

In the early stages of Parkinson’s Disease, the person can usually distinguish a visual hallucination from a genuine image. Not so with Alzheimer’s; psychotic breaks create a false and flawed “reality.”

As language continues to erode, a person with AD cannot process and describe what they see or how they feel. However, body language and non-verbal behaviors can provide more clues.

Auditory Hallucinations. “Hearing” what isn’t there. With advancing age comes common loss of hearing acuity along with noise distortion and difficulty localizing the direction of sound. Hearing aids can improve volume and clarity, but less so distortion and orientation. Again, in part due to deteriorating language, detailing what one “hears” – a voice, a sound, familiar or disconcerting – eludes someone with dementia. 

Touch perception. Massages, shoulder rubs, hugs, etc., are typically well received by individuals with neurological issues. Our skin is our largest organ and sensory vehicle. Touching someone or being touched in a positive manner instantly launches a flood of wonderful endorphins or “internal morphine,” the analgesic-causing peptides in our brains. 

Conversely, light touch might be disconcerting. Neurological synapses, once brisk, precise and accurate, steadily deteriorate with AD, becoming unreliable.

Smell and Taste. As taste declines with age, older adults often supplement food with unhealthy seasonings such as salt and sugar. Sweetness lingers longer and people with dementia frequently gravitate to sugary foods. 

Olfaction, commonly known as the sense of smell, is underrated and often taken for granted. But it serves as the silent back-up to the sense of taste. The flavor of the food we savor is dependent on smelling it before and as we eat it.

The mind can indeed play tricks; mean ones at that!  

Be observant to changes in behavior in your aging loved ones (twitching, grimacing, agitation, fumbling, moaning, avoidance) that might indicate any uncomfortable situation. Be cognizant to how fragile and fluid their reality is.