Diagnosis and screening

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Tools for healthcare professionals to support dementia screening, assessment, and early diagnosis.

At the doctor's office, with a patient and a family member.

Overview

Alzheimer's disease and other dementia 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.

Early diagnosis

Early diagnosis is important. 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 an early diagnosis (print-friendly version).

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

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 cognition6,7.
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.

4th Canadian Consensus Conference on Diagnosis and Treatment of Dementia

The 4th CCCDTD convened in May 2012 in Montreal with the primary aim of updating the previous diagnostic approach to Alzheimer’s disease, taking into account the revised diagnostic criteria proposed by the International Working Group (IWG) and the recommendations made by the National Institute on Aging—Alzheimer Association workgroups.

Read the recommendations of CCCDTD4.

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

  1. Feldman H, et al., Diagnosis and treatment of dementia. Canadian Medical Association Journal, 178 (March 2008), 825- 36.
  2. "Assessing patients complaining of memory impairment",Geriatrics & Aging (April 08, volume 11, number 3), Dr. M. Masellis and Dr. S. E. Black.
  3. Gurgel RK et al. “Relationship of hearing loss and dementia: A prospective, population-based study”, Otology & Neurotology, 2014.
  4. Lin FR et al. “Hearing loss and incident dementia”, Archives of Neurology, 2011, 68(2), 214-220.
  5. 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.
  6. 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.
  7. 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.
  8. 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.
  9. Moore A et al. “Cerumen, hearing, and cognition in the elderly”, Journal of the American Medical Directors Association, 2002, 3 (3), 136-139.

More useful links and resources

Joining up: Why people with hearing loss or deafness would benefit from an integrated response to long-term conditions, a report from Action on Hearing Loss and the Deafness Cognition and Language (DCAL) Research Centre, 2013.

The importance of considering hearing needs in individuals with cognitive impairment, ASC CDRAKE webinar, presented by Kate Dupuis, Clinical Neuropsychologist, and Debbie Ostroff, Registered Audiologist (May 14, 2014). You can also read the transcript.

Exploring the connections between hearing loss and cognitive health, a brainXchange webinar presented by Dr. Kate Dupuis, hosted by brainXchange in partnership with the Alzheimer Society of Canada and the Canadian Consortium on Neurodegeneration in Aging (CCNA).