Dementia

last authored: Jan 2009, David LaPierre
last reviewed:

 

Introduction

Dementia is a decline in cognition and function. It is a devestating disease with a high burden of symptoms. It is greatly underrepresented in the patient population receiving formal palliative care supports. It might be called brain failure. Memory is one aspect of the brain, but everything that has to do with the brain can fail.

 

A diagnosis can be helpful for both patient and family, explaining changing behaviours. It is helpful with ensuring safety (driving, stoves, wandering, meds) and ensuring future care.

Lastly, medications can help slow or even reverse progression for some causes.

 

Dementia is characterized by the gradual and continuous development of multiple cognitive deficits. These symptoms need to be significant enough to affect social or occupational functioning.

 

Diagnosis of dementia requires:

Memory impairment: impaired ability to code new information or recall previously learned information

 

Deficits in another cognitive demain:

  • apraxia: impaired ability to carry out motor activities, despite intact motor function
  • aphasia: language
  • visuospatial function (agnosia)
  • executive function: sequencing, organizing, abstracting, and planning (SOAP)

Functional impairment

Acquired and progressive

No other diagnosis.

 

Dementia is common and prevalence increases with age - 10% of people over 65 and 25% of people over 85 have dementia.

 

 

 

The Case of Mr Thomas

Mr Thomas is a 67 year-old man who is admitted to hospital after falling and fracturing his hip. During his post-operative recovery, his clinical clerk notices Mr Thomas is having some difficulty remembering answers her questions and wonders why.

question: what could be causing Mr. Thomas' memory impairments?

question: how should she go about investigating a possible diagnosis of dementia?

 

return to top

 

 

 

Types of Dementia

Over 50% of cases of dementia are caused by Alzheimer's Disease, and vascular causes account for 15%. The remaining are caused by a number of various diagnoses.

  • Alzheimer's
    disease
  • vascular
    dementia
  • Lewy-body
    dementia
  • frontotemporal lobar
    degeneration
  • mixed
    dementia
  • basilar
    dementia
  • Pick's
    disease

Alzheimer's Disease

Alzhemier Disease (AD) is the most common dementia in the elderly.

  • usually first begins with impairment of higher intellectual functions, such as mood and behaviour
  • progressive disorientation, memory loss, and aphasia usually follow
  • within 5-10 years patients are profoundly disabled, mute, and immobile
  • affects memory (amygdala and hippocampal formation
  • language - reading, writing, speaking, but not repetition
  • visuospatial function -
  • executive function - judgment

 

Vascular Dementia

 

Inschemic damage in most cases - mini-strokes

Step-wise loss can happen, but less common than small vessel disease with slow declines.

Variable progression, with fluctuation.

patchy, with issues with attention and cueing. Language and visuospatial.

cueing

Bradyphrenia.

hallucinations, delusions

peculiar gait

incontinence

history of vascular risk factors

focal neurological signs and symptoms

Lewy-Body Dementia

Lewy-body dementia, or Parkinson's disease dementia, is dementia with unique qualities. These include:

  • parkinsonism
  • fluctuations of symptoms and consciousness
  • falls
  • hallucinations
  • neuroleptic sensitivity, leading to marked rigidity (avoid antipsychotics)
  • postural hypotension
  • REM sleep disturbance

 

Frontotemporal Lobar Degeneration

A dementia with prominent change in personality and/or language functions

 

frontotemporal dementia - disorder of social conduct

primary progressive aphasia - language disturbance

semantic dementia - loss of memory for meaning of words

Mixed Dementia

 

Common, notably AD plus vascular dementia.

 

Basilar Dementia

Pick's Disease

return to top

 

 

 

Pathophysiology

Memory is not all that is affected; language expression and comprehension, visuospatial skills, decreased attention and concentration, apraxia, apathy, hallucinations, and delusions are all possible.

 

Executive functions affected by dementia include sequencing, organizing, abstracting, and planning (SOAP).

 

Dementia is increased in prevalence in people with Down Syndrome and head trauma. Dementia can be cortical or subcortical.

 

Alzheimer's disease is characterized by a loss of cholinergic neurons from the basal forebrain. This can be evidenced by substantial loss of acetylcholine transferase and acetylcholine esterase, mainly in the temporal cortex. Amyloid plaques and neurofibrillary tangles form. From 90-95% of cases of AD are sporadic, with involvement of ApoE4 (Ch 19). Mutations have been identified in amyloid precursor protein (Ch 21), presenilin 1 (Ch 14), and presenilin 2 (Ch 1).

 

Lewy Body Dementia

Lewy Body dementia is also characterized by a loss of cholinerigic neurons. Intracytoplasmic inclusion bodies can be seen in these neurons (Lewy Bodies), and alpha-synuclein involved somehow.

 

Frontotemporal Lobar Degeneration

Frontotemporal lobar degeneration has a number of causes and cellular processes that occur. These include apoptosis, necrosis, genetic, neurotoxicity (free radicals, excitotoxicity), and idiopathic.

return to top

 

 

Signs and Symptoms

Dementia is a heterogenous disease.

Behaviours vary with stages of dementia, but are often most problematic at later stages. These can be viewed as physical vs verbal, aggressive vs non-aggressive.

 

  • history
  • physical exam
  • cognitive testing
  • staging of AD

History

Dementia requires changing interactions; collateral history becomes indespensible. Family needs to be involved in decisions regarding tests, drugs, or surgeries.

Identifying Information:

  • age
  • here with:
  • lives with:
  • supports:

Caregiver history

  • onset of cognitive difficulties (usually gradual)
  • memory impairment (events, appointments, names)
  • repetitive questions, head-turning sign (always looking to collateral for input)
  • language: word-finding difficulties
  • personality change: irritability, apathy, depression, aggression, disinhibition (social skills are usually preserved early)

 

 

IADLs

As for other aspects, get collateral and details. Ask if they ever performed these tasks (ie men who don't cook, women who don't deal with finances), and ask if someone helps now, when did it start, and why?

 

Finances: money management (cheques, bank, ATM) missed bills, or overpayment; help required; appropriate payment at store or restaurant

Cooking: changes in cooking, baking; forgetfulness; cooking for crowds

Shopping: Planning for groceries, redundant groceries, prompting required, independent shopping

Medications: Missed medications; dossette (who fills it?) call pharmacy

Driving: Would you let your daughter drive with him? accidents; tailgating, driving too slowly; trouble with turns, merging; getting lost

Telephone: Still make calls; call the wrong person; remember numbers; pass on messages

Household chores

Other: TV remote, hobbies

 

ADLs

Repetitive dressing

Bathing: prompting, help

Toileting

Eating

 

 

Other symptoms

  • hallucinations
  • gait impairment
  • urinary incontinence

 

Past medical history

  • hypertension
  • ischemic heart disease
  • malignancy (brain metastases)
  • stroke
  • vascular risk factors
  • EtOH
  • Parkinson's Disease, multiple sclerosis

 

 

 

Some collateral sources are hesitant to 'tattle' on the patient, and it can be helpful to speak with them alone. A question to hone in on their opinion is "would you let your children drive with 'John'?

 

 

do mental status exam

 

The most important aspect of these tests is to get patients talking about things that will help you determine diagnosis.

 

It is important to recognize typical Alzheimer disease and thereby atypical presentations.

Physical Exam

Assess general health and appearance. A full physical exam, especially neurological and cardiovascular, are warranted.

Findings in Alzheimer's disease include:

  • clothing (watch dress, undress)
  • hygiene
  • paratonia
  • gait disturbance

Atypical findings

  • EPS: Parkinson's, Lewy Body dementia
  • neurological findings: normal with AD; localizing signs suggestive of vascular dementia, stroke, or malignancy
  • orthostatic hypotension

Cognitive Testing

 

test

pros

cons

mini-mental status exam

common, easy, many cognitive domains

affected +/- by education, doesn't test executive functions

MOCA (Montreal Cognitive Assessment)

more difficult, tests executive functions

 

clock (10 past 11)

frontal lobe functions (planning)

many disputed ways of scoring

Frontal Assessment Battery (12/18 cutoff)

frontal lobe functions

 

verbal fluency (F words in one minute; four-legged animals)

 

frontal lobe functions

 

brief cognitive rating scale (BCRS)

11 axes for cognitive domains, seven stages

 
     

BCRS

CURE

Current events: news, TV shows (plot, characters, etc) evening meal, children's spouses and grandchildren

US president/ prome minister

relatives: children and spouse

everything: knows name only

 

 

 

 

Stages of Dementia

Each stage tends to last two years, but there is significant variability.

 

The brief cognitive rating scale (BCRS) has five axes and is rated against seven stages.

Stage

Signs and Symptoms

1

normal

2

 

3

questionable; isolated memory ir memory plus other deficits

4

mild

5

moderate

6

severe

7

very severe

8

 

BCRS Axis 2 pnemonic: CURE

4: Current events, television shows, evening meal, recent events

5: US president, prime minister

6: Relatives

7: Everything

 

BCRS Axis 5 pnemonic: IRAN

mild: IADLs

moderate: Repetitive dressing

severe: ADLs

very severe: Non-ambulatory,non-verbal

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The Functional Assessment Staging (FAST) is related to Axis 5 of the BCRS.

1. No difficulties

2. Forgets location of objects; subjective work difficulties

3. Decreased job functioning

4. Decreased ability to perform complex tasks

5. Assistance in choosing proper clothing

6. Difficulty with cloting, bathing, toileting, incontinence

7. Difficulty speaking, ambulating, sitting, smiling, holding head up

 

return to top

 

 

Investigations

  • lab investigations
  • diagnostic imaging

Lab Investigations

Blood tests that should be done to rule out other causes include:

  • CBC
  • electrolytes
  • TSH
  • BUN, creatinine
  • liver function tests
  • glucose
  • B12, folate
  • calcium, albumin

Diagnostic Imaging

While many physicians will order head imaging on everyone as a course of cognitive workup, particular indications for CT include:

  • age below 60
  • rapid onset or change
  • early gait abnormality
  • early incontinence
  • focual neurological findings
  • hx malignancy
  • head injury
  • anticoagulant use
  • new onset of severe headache/seizure

return to top

 

 

 

Differential Diagnosis

Dementia, which is progressive and usually irreversible, should be distinguished from:

You should also rule out

Other causes of cognitive decline can also include:

return to top

 

 

Management

 

Supports

Caregivers should be involved to assist with adherence to medications, appointments, and tests.

Educate about disease stage and prognosis.

Provide awareness of delirium and the need for medical attention if it occurs

Support Groups (ie Alzheimer's Society)

home safety (stoves, food, medication, wandering, knives, water temperature)

future care

adult protection, if necessary

 

Legal Issues

During early days, ensure:

Driving is not absolutely contraindicated with a diagnosis of dementia. Frequent re-assessment is required. A helpful question can be to ask a member of their family "would you feel comfortable letting your child drive with 'John'?"

 

 

 

Education

 

Provide orientation cues, ie clock, calendar

 

 

 

Medications

Cholinesterase inhibitors (ie donepezil, rivastigmine, galantamine) is useful for mild to moderate AD and Lewy Body dementia, particularly during early stages. They are not cures, though can slow progression of cognitive decline and decrease caregiver burden and apathy. Commonest side effects are GI (nausea), cardiac (bradycardia), respiratory (exacerbating CPOD, asthma), nightmares, irritability.

 

 

Mematine (NMDA) receptor agonist blocks excitatory glutamate. Used in late moderate to severe dementia. Renally dosed.

 

Low dose neuroleptics (ie haloperidol, risperidone) or antidepressants can also be used as appropriate. AVOID NEUROLEPTICS for Lewy Body dementia due to increased sensitivity.

Trazodone can be used for insomnia, agitation, aggression, anxiety

Benzodiazepines should be avoided, as the cause cognitive impairment, falls, fractures, and dependence

 

Foll

ow-up for adverse effects and efficacy

 

NSAIDs, estrogen?

 

 

Other Conditions

Treat medical problems and prevent others.

It can be challenging to decide on investigating and treating conditions and diseases, such as pneumonia, dissecting aneurysm, dialysis, or anemia, weight loss.

Some symptoms can be difficult to identify in advanced dementia.

 

Addressing Challenging Behaviours

Define behaviour and whether it is stage-congruent. Apathy and irritability are common in the early stages, while aggressive behaviour and delusions and hallucinations are more common later.

Consider atypical disease presentation.

Non-pharmacological approaches include: being calm, reducing distractions, ensuring glasses and hearing aids, structured routine, simplification, redirect instead of argue, and help them function to their maximum capacity.

ggressive behaviour

Consider delirium, polypharmacy, urinary retention, constipation, overwhelming environment, stimuli, or tasks.

 

Bathing: consider decreasing frequency, and get patient to help.

Eating: Abdominal pain, constipation? Give one food at a time. food in cups (ie soup, milkshake). Accept decreased oral intake as disease progresses.

Incontinence: UTI, constipation, caffeine

Toilet regularly; watch for pacing. Put a sign on the door as a cue for toilet location.

Dressing: reduce options, and simplify

Sleep: consider causes of insomnia

Wandering/pacing: drug effect? looking for bathroom? over or under stimulation, enough regular exercise

yelling

 

 

return to top

 

 

 

Consequences and Course

Alzheimer's disease is progressive and incurable. The average duration of illness, from onset of symptoms to death, is 8-10 years.

However, up to 10% of cases of dementia, mostly those with vascular causes, are potentially curable.

 

Dementia is the greatest risk of developing post-operative delirium, requiring care when choosing elective surgery.

return to top

 

 

The Case of...

 

 

return to top

 

 

Additional Resources

Hogan DB et al. 2008. Diagnosis and treatment of dementia: Approach to management of mild to moderate dementia. CMAJ. 179:787-93.

 

return to top

 

 

Topic Development

created:

authors:

editors:

reviewers:

 

return to top