Diagnosis and screening

Overview

Alzheimer's disease and other dementias are progressive, degenerative diseases. Individuals or their family members may consult a family physician when they begin to notice symptoms such as loss of memory, judgment and reasoning, difficulty with day-to-day tasks and changes in communication abilities, mood and behaviour.

Cognitive impairment and dementia are present in about 20 per cent of the elderly population and are consistently rated among the top three concerns of older adults.¹ Early detection of dementia provides an opportunity for the individual to adjust to the diagnosis and to participate actively in planning for the future.

The importance of early diagnosis

Symptoms of irreversible dementia can be similar to those of other conditions such as depression, thyroid or heart disease, infections, drug interactions or alcohol abuse.

Finding out the cause of the symptoms can help people understand the source of the symptoms, get the proper care, treatment and support and plan for the future.

Download our PDF brochure: The importance of early diagnosis (print-friendly version).

How to communicate a diagnosis of dementia

Communicating the diagnosis (PDF)

A diagnosis of Alzheimer’s disease or other dementia may take a long time. People experience different symptoms. One person may have memory problems, another may have language difficulties, or changes in personality or behaviour. Also, some people may not be aware or may not let others know that they are having difficulties.

It takes time to conduct a thorough assessment to determine if a person’s symptoms are caused by Alzheimer’s disease or other dementias.

Global Deterioration Scale

Some healthcare providers use the Global Deterioration Scale, also called the Reisberg Scale, to measure the progression of Alzheimer's disease. This scale divides Alzheimer's disease into seven stages of ability.

Stage 1: No cognitive decline

Experiences no problems in daily living.

Stage 2: Very mild cognitive decline

Forgets names and locations of objects.
May have trouble finding words.

Stage 3: Mild cognitive decline

Has difficulty travelling to new locations.
Has difficulty handling problems at work.

Stage 4: Moderate cognitive decline

Has difficulty with complex tasks (finances, shopping, planning dinner for guests).

Stage 5: Moderately severe cognitive decline

Needs help to choose clothing.
Needs prompting to bathe.

Stage 6: Severe cognitive decline

Loss of awareness of recent events and experiences.
Requires assistance bathing; may have a fear of bathing.
Has decreased ability to use the toilet or is incontinent.

Stage 7: Very severe cognitive decline

Vocabulary becomes limited, eventually declining to single words.
Loses ability to walk and sit.
Requires help with eating.

Reisberg, B., Ferris, S. H., de Leon, M. J., and Crook, T. (1982). Modified from Global Deterioration Scale. American Journal of Psychiatry, 139:1136–1139.

Screening resources

Instruments to detect cognitive impairment in older adults
The Assessment and Treatment of Delirium 2014 guideline update from the Canadian Coalition for Seniors' Mental Health
Burns A, Bagshaw P, A new dementia currency in primary care. NHS England, March 2016.
Cognitive screening of older patients. By Frank Molnar and Chris Frank. Source: Canadian Family Physician.
Screening tools for virtual assessment of cognition. By Chris Frank, Philip St John and Frank Molnar. Source: Canadian Family Physician.
Canadian Indigenous Cognitive Assessment. Distributed by the Indigenous Cognition and Aging Awareness Research Exchange.

Watch the video I’m a doctor - is there a good way to check out a memory complaint? A five-step brain health check for doctors.

The material was created by TCD, through the NEIL Programme at the Institute of Neuroscience with support from GENIO.
© 2014 The Provost, Fellows, Foundations Scholars, and the Other Members of Board, of the College of the Holy and Undivided Trinity Of Queen Elizabeth, near Dublin. Permission to use this material was granted by TCD which reserves all rights in the material.

Cognitive screening tests

Instrument	Reference	Time (min)	Cut-off score/Total score
Mini-mental state examination	Folstein et al., 1975	7-10	≤23-26/30
Hopkins verbal learning test – total recall	Frank and Byrne, 2000	5	≤14-18/36
Memory impairment screen	Buschke et al., 1999	4	≤4/8
Clock drawing test	Royall et al., 1992	1-3	Scoring methods varied
Cambridge cognitive examination	Lolk et al., 2000	20	≤80/107
Modified mini-mental state examination	McDowell et al., 1997	10-15	≤77-86/100
Community screening interview for dementia	Hall et al., 1993	30	Formula used
Montreal cognitive assessment	Nasreddine et al., 2005	10	≤25/30
Behavioural neurology assessment Long form	Darvesh et al., 2005	40-50	≤182/250
Behavioural neurology assessment Short form	Darvesh et al., 2005	20-30	≤82/114

Cognitive loss and hearing loss

Did you know…

There is a clinically significant association between hearing loss and cognitive decline. Individuals with hearing loss demonstrate an accelerated rate of cognitive decline and an increased risk for cognitive impairment³.
The potential mechanisms behind this relationship between hearing loss and cognitive loss, in particular the increased risk for incident dementia⁴, remain to be determined. Possible rationales for this association may include increased social isolation, changes to the brain, and/or a common process that is influencing both hearing and cognitive functioning in older individuals.

Below you will find some issues that may be common in your practice, some implications for assessment, and some suggestions for solutions you can implement to ensure that you are providing your patients with the best care possible.

Issue	Implications for Cognitive Assessments and Treatment
As individuals age, they may experience changes in their auditory processing and/or cognitive abilities.	These changes may lead older individuals to require additional time to process and understand the sounds they hear³. Ensure ample time for your assessments in order to maximize your patient’s ability to understand your questions, instructions, and/or important information you are sharing with them. Encourage patients to ask for repetitions. If possible, involve a family member. Provide patients with written instructions (e.g., take your Metoprolol with food or just after eating) that they can refer to at home.
People with hearing loss may be hesitant to seek help.	The average time between an individual noticing a hearing loss and seeking help is 10 years⁴. Do not assume that, simply because your patient does not own hearing aid(s), they do not have trouble hearing you. There are a few simple questions you can ask to screen for hearing loss, e.g., “Do you find that you have to ask people to speak up?”; “Do you have to increase the volume on the radio or television in order to understand what is being said?”; “During conversations, does it sound like other people are mumbling?”; “Is it difficult for you to follow conversations when in a noisy restaurant?” Consider investing in a personal amplification system, such as a “Pocketalker” to use during your appointments. If you have a question about your patient’s hearing, refer them to an Audiologist. Throughout Canada, there are various options for funding both hearing tests and hearing devices such as hearing aids. Talk to an Audiologist to find out more.
Cognitive testing (e.g. the MMSE, the MoCA) often relies heavily on an individual’s ability to hear and respond to questions and instructions given⁵.	Not taking hearing loss into account may result in an inaccurate assessment of cognitive ability. Patients may not hear test questions and/or may not understand test instructions. This may result in an artificially low score on the cognitive test, which could in turn lead to over-estimation of the individual’s level of cognitive impairment. Test patients in a quiet room, and ensure that the volume of your voice is appropriate. Consider using a personal amplification device. Refer your patient to an ENT if they complain of ear pain or a plugged/fullness sensation; they may have cerumen (ear wax) build-up. Removal of cerumen can improve performance on measures of both hearing and cognition^6,7.
Behavioural symptoms (e.g. repetition, agitation) that are commonly attributed to the individual’s cognitive loss, may be related to and/or exacerbated by hearing loss.	When individuals with cognitive loss present to a clinic, many of their symptoms overlap with behaviours related to hearing loss. For example, decreased speech understanding, increased requests for repetition, short-term memory problems, and difficulty following conversations may all be related to either hearing and/or cognitive loss. Physicians may not automatically consider hearing loss as a factor in these symptoms. At later stages of cognitive loss, behavioural symptoms such as agitation, wandering, and hallucinations may be related to disruptions in auditory processing. Ensure that clients who own hearing aids are wearing them, that the wax guard in the aids is clear, and that the batteries are working.

5th Canadian Consensus Conference on Diagnosis and Treatment of Dementia

The 5th CCCDTD convened in October 2019 in Quebec City to address topics chosen by the steering committee to reflect advances in the dementia field and build on previous guidelines.

Topics include:

the National Institute on Aging research framework for Alzheimer's disease diagnosis;
updating diagnostic criteria for vascular cognitive impairment, and its management;
dementia case finding and detection;
neuroimaging and fluid biomarkers in diagnosis;
use of non-cognitive markers for better dementia detection;
risk reduction/prevention;
psychosocial and non-pharmacological interventions; and
deprescription of medications.

Read the recommendations of the 5th CCCDTD.

Alzheimer Society brochures for further reading

Some of the following brochures are written for clinicians and others are intended for individuals and their families, or both.

Clinicians:

Individuals and family members:

References

Feldman H, et al., Diagnosis and treatment of dementia. Canadian Medical Association Journal, 178 (March 2008), 825- 36.
"Assessing patients complaining of memory impairment",Geriatrics & Aging (April 08, volume 11, number 3), Dr. M. Masellis and Dr. S. E. Black.
Gurgel RK et al. “Relationship of hearing loss and dementia: A prospective, population-based study”, Otology & Neurotology, 2014.
Lin FR et al. “Hearing loss and incident dementia”, Archives of Neurology, 2011, 68(2), 214-220.
Schneider BA et al. “Effects of senescent changes in audition and cognition on spoken language comprehension”, The Aging Auditory System, Springer Handbook of Auditory Research, 2010, Vol. 34, 167-210. Schneider BA et al. “Effects of senescent changes in audition and cognition on spoken language comprehension”, 2010, Vol. 34, 167-210.
Davis A et al. “Acceptability, benefit and costs of early screening for hearing disability: A study of potential screening tests and models”, Health Technology Assessment Journal, 2007, 11(42):1-294.
Pichora-Fuller MK et al. “Helping older people with cognitive decline communicate: Hearing aids as part of a broader rehabilitation approach”, Seminars in Hearing, 2013, 34(04): 308-330.
Lewis‐Cullinan C, Janken JK, “Effect of cerumen removal on the hearing ability of geriatric patients”, Journal of advanced nursing, 1990, 15 (5), 594-600.
Moore A et al. “Cerumen, hearing, and cognition in the elderly”, Journal of the American Medical Directors Association, 2002, 3 (3), 136-139.

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