Dementia Aware  

Dementia and the senses

What you need to know about dementia’s effect on the five senses

As we age, many different changes occur in the body, including changes in the sensory organs that enable us to see, to hear, to touch, to smell and to taste.

With some modifications to the environment and dietary adjustments, most people can adapt.

However, for people with dementia, these sensory changes are confusing, stressful, and can put the person’s safety at great risk.  

Vision changes

  • Pupils size becomes smaller and slower to constrict which creates problems with glare. Reflection of light on anything shiny is too stimulating and a falls risk (Meisami, Brown and Emerle, 2003)
  • Slowness of pupils to dilate in the dark creates difficulty in seeing where one is going
  • Visual acuity is less sharp in dim lights, sees shadows, shapes
  • In dementia, the field of vision can narrow to 12 inches around, almost like wearing binoculars. This means the person has a very limited line of sight. If they cannot see it, it does not exist
  • When brain processes information that is too stimulating, it reacts by shutting down information from one eye leaving the person with dementia to see with one eye (monocular vision). This loss of depth perception and contrast sensitivity results in the person with dementia doing strange things e.g. exaggerated stepping, picking at air (Snow, 2016)
  • Colour agnosia reduces ability to differentiate between colours of similar dark or light tones therefore hard to identify objects that are set against a background consisting of similar colours
  • Most people with dementia find vision changes the most difficult to deal with because the brain does not understand and process the picture/image it is receiving


  • Wear glasses
  • Clear demarcation between floors, walls, toilet and wall/floor
  • Remove throw rugs, clutter to create clear pathways
  • Low glare light/automatic lights indoors and outdoors
  • Avoid busy patterns, checkerboard or zigzag designs
  • Appropriate footwear, use mobility aide

Hearing changes

  • Auditory canal narrows, cerumen glands atrophy causing thicker, dryer ear wax that is more difficult to remove and increases hearing impairment
  • Everyday sounds can become too loud, too stimulating, creating distortion in what the person with dementia hears/understands
  • Problems with hearing and ear pain will have an impact on person’s ability to concentrate on eating. An interesting study found a correlation between development of ear wax and reduced ability to chew among people who did not have their back teeth (Frasman, 2005)
  • Many people with dementia have difficulty chewing and this may increase susceptibility to impacted earwax, pain and hearing loss
  • Difficulty hearing/understanding creates feelings of isolation and frustration


  • Clean ears daily, assist with hearing aids
  • Regular visits to doctor and dentist
  • Reduce noise in person’s environment
  • Avoid crowded, busy, noisy areas as too stimulating for person to process
  • Face person when talking, speak slowly and clearly, write down message, show item

Touch changes

  • Tactile sensitivity decreases because of skin changes and loss of large numbers of nerve endings particularly in fingertips, palms of hands and lower extremities (Meisami, 1995)
  • Skin becomes thinner and more susceptible to open areas increasing risk of infection
  • Inability to distinguish between hot and cold
  • Decreased nerve endings reduce pain sensitivity, feelings of soreness and discomfort. e.g. pressure ulcer
  • For some people, any touch to the skin is painful e.g. in the shower, water feels like needles


  • Inspect skin and nails, especially toes, look for sores, areas of redness, bluish hues, areas of extreme cold/warm
  • Identify hot and cold faucets, reduce temperature in hot water tank
  • Wear footwear indoors/outdoors, wear mittens in cold weather
  • Ensure sharp corners are padded e.g. table

Sense of smell

  • Studies have shown that an impaired sense of smell is one of the earliest symptoms of Alzheimer’s and Parkinson’s disease
  • Of all the senses, age takes the greatest toll on smell perception
  • Changes in smell are attributed to loss of cells in the olfactory bulbs of the brain and a decrease in sensory cells in the nasal lining
  • Unable to detect smoke, leaking gas, spoiled food


  • Install smoke detectors and gas detector
  • Write expiry dates on food, check fridge contents weekly

Sense of taste

Taste, along with smell and nerve stimulation determine flavour of foods and helps distinguish between safe and harmful foods.

  • With age, there is atrophy of the taste buds and decrease in saliva production
  • As taste buds diminish and insulin in the brain drops, many people with dementia experience changes in appetite and can overuse salt, spices, sugar
  • Studies have shown when dementia attacks part of the brain responsible for self-restraint in diet, unhealthy cravings increase (Sauer, 2014)
  • Unable to identify food by taste, including mouldy food, sour milk
  • May eat toothpaste, mouthwash, household cleaners mistaking them for food


  • Remove medications, toiletries, cleaning items
  • Limit access to salt, sugar, junk food
  • Wear properly fitting dentures, perform good oral care
  • Remove any small objects that resemble candies/food
  • Use saliva substitutes, encourage fluids
  • See dietician for meal suggestions

The sixth sense

People with dementia, even if unable to communicate, still have an awareness of the world around them, and they can sense when someone is being unkind or disrespectful.

"They may forget what you said, they may forget what you did, but they will never forget how you made them feel." (Maya Angelou). 

Is it really dementia?

What you need to know about conditions mistaken for dementia

You misplace items, you forget to take your medications, you feel tired and weak, you cannot remember what you did five days ago.

You are scared and anxious, but will not see your physician because you are worried he/she will say you have dementia.

But is it really dementia? Or could it be something else?

It is estimated that approximately 15-20 per cent of people diagnosed with an irreversible dementia, actually have dementia symptoms caused by an underlying medical condition e.g. normal pressure hydrocephalus (NPH)* (see rare and unusual dementias).

Once the condition is treated, cognitive function usually improves, and often, completely resolves (Senties and Estanol, 2006).

It is very important that anyone experiencing memory loss and confusion see a physician for a thorough physical and cognitive assessment, blood tests, and CT Scan/MRI of head, as there are many different conditions that present with symptoms that masquerade as dementia.


  • Depression: acute depression can cause a syndrome of cognitive impairment called pseudo dementia. Depression can make the brain less efficient, cause cognitive clouding and confusion and difficulty with decision making. There is also evidence that important memory structures in the brain can shrink during episodes of depression; however, once the depression resolves, these structures recover and the dementia like symptoms resolve (Wint, 2017).
  • Chronic subdural hematoma (bleeding in the brain): is a common and treatable cause of dementia. Symptoms include headache, gait and balance problems, confusion, and seizures.
  • Sleep apnea: results in decreased flow of oxygenated blood to the brain causing dementia like symptoms
  • Brain tumour: the early symptoms of a slow growing tumour, often resemble dementia, especially in the older person. The tumour can press on areas of the brain that control mobility, memory, mood, etc.
  • Post Concussion Syndrome: see Dementia and Concussion


Reactions to a specific drug, a combination of several different drugs, or combining prescriptions medications, herbal supplements and/or over the counter medications can cause confusion and poor functioning especially in the older person.

As we age, the body metabolizes and eliminates medications less efficiently, drugs can build up in the body, and the side effects often look like dementia.

There are also specific medications that can cause dementia-like symptoms:

  • Opioids: painkillers e.g. morphine
  • Benzodiazepines: anti-anxiety drugs e.g. ativan
  • Steroids: iatrogenic glucocorticosteroid dementia syndrome is often unrecognized but occurs in about one in 250 people treated with steroids and is most common in the elderly (Varney, 1984). Clinically, there is impairment of memory, concentration and attention. Cushingoid features (puffy face, weight gain) may also be present
  • Cocaine/heroin: if taken in high doses or over a long period of time, may cause dementi-like symptoms especially in the older person. Medically supervised withdrawal from the drug(s) usually reverses the symptoms
  • Any medications that cause dry mouth, constipation or sedation (anticholinergic side effects)


  • Lyme disease: is a bacterial infection transmitted through bites of infected ticks. Initially a person will present with flu-like symptoms, however, if left untreated, the infection can present in a multitude of symptoms including arthritis. Overall, 10-15 per cent of individuals develop neurological problems such as inattention and cognitive impairment. Subjective memory loss has been suggested, but clear dementia syndrome is very rare (Finkel, 1992)
  • Cerebral toxocariasis: is transmitted from roundworm in dogs to humans. As the infection progresses, the larvae migrate to the central nervous system, especially the brain. Clinically, the person presents with cognitive impairment and other dementia like symptoms. Treatment with antihelmintic agents (antiparasitic drugs) reverses the symptoms
  • Syphilis: see Rare and Unusual Dementias

Toxic exposure

  • Chronic lead poisoning: presents with gastrointestinal and neurological symptoms e.g. depression, confusion, cognitive impairment. Treatment with chelating agents reduces body stores of lead and symptoms eventually resolve (Chisholm, 1990)
  • Chronic mercury or arsenic poisoning: symptoms include neuropathy and confusion. Treatment for both is chelation therapy

Metabolic Disorders

Diseases of the liver, pancreas or kidneys can lead to dementia by disrupting the electrolyte and chemical balance in the body e.g.  sodium and calcium, glucose e.g. renal encephalopathy, hepatic encephalopathy.


People who do not have enough oxygen in their blood, may develop dementia symptoms. Blood brings oxygen to the brain cells, and all cells need oxygen to live.

Common causes of hypoxia:

  • Chronic Obstructive Disease (COPD) e.g. emphysema
  • Heart disease e.g. congestive heart failure (CHF)

Nutritional Deficiencies

  • Chronic anemia: a low red cell count decreases oxygen delivery to all cells in the body. In the brain, this can reduce memory and thinking abilities and may contribute to damage to neurons (Yaffe, 2013).
  • Vitamin B12 deficiency (pernicious anemia) can result in neuropathy (tingly prickly sensation in hands and feet), memory problems, confusion, irritability, depression and/or paranoia. Symptoms resolve with treatment
  • Thiamine deficiency (Vit B1): see Five Common Dementias
  • Niacin Deficiency (Vit B3): symptoms related to skin, digestive system and nervous system e.g. memory loss, disorientation

Endocrine Disorders

  • Hyperparathyroidism: recurrent kidney stones, peptic ulcers, depression and cognitive impairment. Treatment can be medical or surgical (Geffken, 1998)
  • Hypocalcaemia secondary to Hypoparathyroidism: can cause confusion, dementia, psychosis. Treatment is replacement of vitamin D or calcitriol with oral calcium (Gupta, Fiertag, et al., 2012)
  • Hypothyroidism: memory impairment ranges from mild cognitive impairment to severe dementia. Treatment with thyroid replacement medication may reverse cognitive impairment

Young onset dementia

What you need to know about younger people with dementia (YOD)

Young onset dementia, also known as early onset dementia, describes any neurocognitive disorder (dementia) diagnosed in someone under 65.

Due to the population increase from the Baby Boomer generation, young people developing young onset dementia is becoming more common, with approximately one person in every 1,000 below 65 developing young onset dementia (Draper and Withall, 2016).

In 2016, approximately 200,000 people were diagnosed with young onset dementia in the United States, 42,325 in the United Kingdom, 25,938 in Australia, and 16,000 in Canada (Alzheimer Society, 2016).

While each person’s experience with dementia is different and although the symptoms of dementia are similar regardless of age, younger people with dementia have many different needs and challenges compared to the older person with dementia.

The most common types of young onset dementia include:

  • Familial Alzheimer’s disease (30 per cent)
  • Vascular dementia (18 per cent)
  • Frontotemporal dementia (12 per cent)
  • Alcohol related dementia (10 per cent)
  • Lewy Body dementia (10 per cent)
  • Rare and unusual dementia (20 per cent)
         • Down’s syndrome dementia
         • Creutzfeldt Jakob disease(CJD)
         • HIV-neurosyphilis
         • Corticobasal degeneration

Young onset dementia can be difficult to recognize and can mimic other illnesses — depression, anxiety, stress related illnesses, peri-menopause.

It is extremely important that any person suspected of having early onset dementia has a full assessment: cognitive and neurological assessment, blood work, and CT scan of head.

Some of the early signs are:

  • Memory loss
  • Easily stressed, frustrated or angered
  • Behaviour and/or personality change “does not seem like him/herself”
  • Changes in walking, balance, coordination
  • Subtle changes in communication — forgetting words, mixes up words

For the young person, the diagnosis of dementia is much harder to accept as it is completely unexpected; it is a life-changing moment for everyone in the family unit.

The person is usually in the prime of life, employed, supporting and caring for a family, socially outgoing, physically active and healthy, he/she may also be caring for older parents.

Now, the person, the entire family must adapt to a different way of life, to the changing circumstances, and to the changing roles and responsibilities.


The emotional impact upon hearing the diagnosis will be different for each person, and can range from disbelief, denial, frustration, anger, sadness, and depression. All these emotions are perfectly normal and to be expected.

Consider going to family counselling, the opportunity to share feelings and fears will help everyone as they try to understand the diagnosis, If the dementia is genetic, then counselling/testing may be necessary.

You may want to share the diagnosis with friends; it is your decision, but is a good idea for you to have a support network of people you trust who can help support you and your family.


It important to remember you can still do the things you enjoy and live a full life.

Yes, it will be different, you will likely have to make some changes; however, living well means adapting to changes as they occur. Continue to meet with friends, go out for dinner, hockey games, etc.

Unfortunately, many community programs for dementia support the older/retired person and may not be a good fit, so contact the Alzheimer Society of B.C. or Interior Health for information about resources and supports.

Financial and Legal Planning

The sooner you make decisions about your health care, your finances and your estate, the more in control you will feel and the better prepared you are for the future and ensuring your family are taken care of.

You should have:

  • Will
  • Filed income tax
  • Enduring Power of Attorney (financial/legal affairs) *
  • Representation Agreement (personal care/health care decisions) *
  • Advance Directive which is a written summary of your wishes and instructions for future health care*
  • If you are the ‘Breadwinner’ talk to a Financial Advisor/ Bank re: assets, mortgage, debts
  • For advice re: disability, financial aid, contact Interior Health for Social Worker support

​*For further information on Power of Attorney, Representation Agreements and Advance Care Planning see www.nidus.ca.


You may be able to continue working, however, if your job requires driving, operating machinery, or may affect safety, then your employer must be notified.

Depending on the work you do, some adjustments to work environment and/or work schedule may be necessary. Working will provide income, socialization, a sense of purpose/satisfaction, and a temporary distraction.

Daily Life

  • Follow a healthy diet, exercise, cognitive stimulation exercises
  • Continue to participate in sporting, social activities
  • Focus on your strengths, remain active and involved in family life and community activities
  • Initially, you may continue driving, however, over time, you may find it becomes more difficult and not safe. Talk with your doctor and family. If you wish to continue driving, you will be required to take a road safety test
  • If mobility or balance is worsening, consider using adaptive aids — shower stool, grab bars and request a home safety assessment from Interior Health Community Care
  • To help stay organized and remember appointments, keep a journal or diary, write important events on large calendar on wall or refrigerator, look at assistive technology options e.g. talking clock, medication reminders
  • Write letters, make videotape, compile a memory book for family and friends


www.uwaterloo.ca/ ..../young-onset-dementia-us-us-guide
First Link Dementia Helpline, 1-800-936-6033


Rare, unusual dementias

What you need to know about other types of dementia

Dementia is a common and growing problem worldwide.

While 95 per cent of cases are attributable to Alzheimer’s disease, vascular dementia, Lewy body dementia etc., little is known about the remaining five per cent of dementia cases.

These types of dementia are extensive, and are known as rare and unusual dementias.

In 2002, a European Union project on rarer forms of dementia estimated a prevalence of five cases per 10,000 people in the community (Alzheimer’s Europe 2002-2003).

Rare and unusual dementias are classified into 4 groups:

  • Degenerative Causes: Familial Alzheimer’s disease, progressive supranuclear palsy
  • Vascular Causes: CADASIL, normal pressure hydrocephalus
  • Infectious Causes: neurosyphilis, HIV and AIDS dementia complex
  • Human Prion Disease: fatal familial insomnia, Creutzfeldt-Jakob disease

Degenerative Causes of Dementia
Progressive Supranuclear Palsy:

  • Also called Steele-Richardson-Olszewsky syndrome
  • Occurs around age 60 years
  • Characterised by tauopathy (abnormal levels of tau protein) with nigral (eye movement, motor skills) and corticobasal (movement) degeneration which involves the cerebral cortex (outer layer of neural tissue of the cerebrum), plays a key role in memory, awareness, thought, language, attention and perception
  • Classic symptoms: supranuclear gaze palsy (inability to look in a direction based on area of brain affected), backwards arching and rigidity of neck with gait problems and imbalance (tend to fall backwards)
  • Cognitive symptoms: reduced verbal fluency, inattention and executive dysfunction (planning, abstract thinking, behavioural control)
  • Disease progression is slow with initial retention of insight

Vascular Causes of Dementia
Normal Pressure Hydrocephalus:

  • Pathophysiology is unclear, but there is a possible cerebrovascular role
  • Easily mistaken for Alzheimer’s disease or Parkinson’s disease
  • A build up of CSF (cerebrospinal fluid) in the brain ventricles (hollow fluid filled chambers) caused by an obstruction or absorption is impeded
  • Can be secondary to other conditions e.g. brain hemorrhage, meningitis
  • Alzheimer like symptoms occur because the enlarged brain ventricles press on and damage nearby brain structures that affect memory, walking and bladder control
  • Signs and symptoms known as the classic triad: “wet, wacky, wobbly”
    • urinary urgency, frequency and incontinence
    • cognitive impairment, confusion, prominent memory loss, slowness of thought
    • gait disturbance (like walking on a boat), weakness, short, shuffling, wide steps
  • Diagnosis: CT Scan/MRI of head, presence of the classic triad, thorough case history
  • Treatment: CSF drained by lumbar puncture and/or drain CSF from brain by a shunt
  • Prognosis: if effective, gait will improve almost immediately, and the milder the dementia, the more likely it will improve. However, for those with moderate to advanced dementia, there is unlikely to be a significant improvement

Infectious Causes of Dementia

Syphilis is a sexually transmitted disease caused by a bacterial infection. It is treated with Penicillin. Syphilis has been increasing since the advent of the HIV epidemic. Since 1996, rates of syphilis have increased significantly amongst homosexual men and men/women 55 years and older.


  • Neurosyphilis develops in 25-40 per cent of untreated people (Mehrabian, et al., 2009)
  • Usually presents more than 10-25 years after initial infection
  • It is a slow, progressive destructive infection of the brain and spinal cord
  • Changes in personality, cognition, mood, severe executive dysfunction, can present as a frontal lobe type dementia
  • Psychiatric symptoms include mania, grandiose delusions, paranoia
  • Neurological signs include ataxia (poor coordination), disturbed speech, abnormal pupils, nerve pain, pain in extremities, seizures, paralysis
  • Diagnosis: blood tests – rapid plasma regain (RPR)
  • Treatment: IV Penicillin
  • Prognosis: symptoms may be ‘potentially reversed’ if person responds to treatment

Human Prion Disease

A prion is an infectious particle. When it enters the body, the prion begins folding into an abnormal almost 3D shape and triggers the existing normal forms of protein to change into the prion shape.

In the brain, the prion protein affects the grey matter with subsequent nerve loss, gliosis (scarring) and characteristic spongiform change (small round empty spaces).

There are four types of human prion disease that cause dementia:

Sporadic Creutzfeldt-Jakob disease:

  • Most common form (85 per cent)
  • Occurs after age 50 years
  • Early signs: headaches, weight gain, fatigue and depression
  • Then rapidly progressing global dementia, myoclonus, ataxia, progressive pyramidal, extrapyramidal and cerebellar dysfunctions with gait, vision (leading to blindness) and speech problems
  • Diagnosis: EEG (electroencephalograph) CSF analysis, MRI, tonsil biopsy is negative
  • Medications may be given to reduce the severity of movement disorders and for comfort measures
  • Prognosis: rapidly progressing disease where the person can neither move nor speak (akinetic mutism), death follows in six months to one year

Iatrogenic Creutzfeldt-Jakob disease:

  • Caused by inadvertent transmission of CJD between humans mostly via medical procedures e.g. corneal graft, prion infected surgical instruments
  • Symptoms, investigations, treatment as per sporadic CJD, progresses very rapidly

Variant Creutzfeldt-Jakob disease:

  • Also known as mad cow disease
  • Caused by transmission of prion protein variants via food originating from cattle e.g. beef
  • Psychiatric symptoms: depression, personality changes, irritability, aggression, fleeting delusionNeurological deficits: chorea, ataxia, myoclonus, dysaesthesias and dementia
  • Diagnostic tests: MRI, tonsil biopsy for prion protein is positive
  • Life expectancy usually 12–14 months

Familial Creutzfeldt-Jakob disease:

  • Also called human spongiform encephalopathy
  • Accounts for 10-15 per cent of all CJD cases
  • Age at onset can be as early as age 20, but more common ages 40-50 years
  • Symptoms and treatment as per sporadic CJD
  • As this if familial, genetic testing may identify carriers and early/late onset varieties of this disease, therefore genetic counselling is essential.

More Dementia Aware articles

About the Author

Tracey Maxfield, RN, BSN, GNC(c), DDS, is a dementia educator, consultant and advocate with over 35 years experience working with dementia populations in the U.K. and Canada.

She has worked in a variety of heath-care settings: acute care, palliative care, community care, residential care, physicians offices and community health centres..

Maxfield is a Central Okanagan Purple Angel Dementia Ambassador.

She can be reached at [email protected].

The views expressed are strictly those of the author and not necessarily those of Castanet. Castanet does not warrant the contents.

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