dementia Flashcards
definition
- Chronically impaired cognition that affects multiple cognitive domains: memory, attention, language, non-cognitive symptoms: agitation, aggression, apathy
- No impairment of consciousness
- Acquired and progressive
epidemiology
↑s w/ age >80y - 20%
Differentiating dementia from delirium and depression as causes of cognitive impairment
Differentiating dementia from delirium and depression as causes of cognitive impairment
Dementia
Delirium
Depression
Conscious state
Alert
Impaired
Alert
Onset
Insidious/gradual
Abrupt
Variable
Course tempo
Gradually progressive
Fluctuant – may be circadian disruption
Fluctuant
Orientation
Initially preserved
Early prominent disorientation
Variable
Hallucinations
Late feature
Prominent
Rare (auditory typically)
Behaviour
Depends on cause
Restless
Withdrawn
classification of dementia
young-onset dementia – formerly known as “pre-senile dementia”, refers to patients who develop dementia before the age of 65 years
late-onset dementia – previously known as “senile dementia”, refers to patients who develop dementia after the age of 65 years
non modifiable risk factors
- age – advancing age is the most important risk factor in developing dementia
- learning disabilities – in people with Down’s syndrome, dementia develops 30–40 years earlier than in a normal person
- gender – rate of dementia is higher in women than in men (specially for Alzheimers disease)
- genetic factors
modifiable risk factors
- alcohol consumption
- smoking – particulary for Alzheimers
- obesity
- hypertension
- hypercholesterolaemia
- head injury
- education and mental stimulation
aetiology of dementia
The most common causes of dementia are age-related neurodegenerative processes.
Dementia is becoming an increasing problem as the population ages
- Infection
- Viral: HIV
- syphilis
- Vascular
- Chronic subdural haematoma
- Inflammation
- SLE
- Sarcoid
- Neoplasia: meningioma
- Nutritional
- Thiamine deficiency (EtOH)
- B12 and folate deficiency
- Pellagra (B3 / niacin deficiency)
- Hypothyroid
- Hydrocephalus (normal pressure)
Whipple disease
what assessment tools can be used to assess dementia?
assessment tools include the
- Abbreviated mental test score (AMTS),
- 6-Item cognitive impairment test (6CIT),
- General practitioner assessment of cognition (GPCOG) and the
- mini-mental state examination (MMSE) is widely used.
- A MMSE score of 24 or less out of 30 suggests dementia
what qs would you ask in a dementia hx
he history should be gathered from a person who has known the patient for a period of six months at least and if possible directly from the patient and includes:
- age
- medical and psychiatric history of the family e.g. - dementia or other mental health problems (1)
- origin and progression of condition
- associations:
- myoclonus
- seizures
- depression, anxiety
- past and present medical and psychiatric history - e.g. diabetes, hypertension, cerebrovascular accident
exposure to toxins:
- alcohol
- lead
- drugs e.g. barbiturates
how would you examine a pt with dementia?
Examination of the demented patient should:
🍭 exclude dysphasia as a cause for apparent dementia
🍭 find information about the patient’s social functioning which would not be normal in dementia
🍭 physical examination – to recognize physical disorders which may be responsible for cognitive impairment
- cardiovascular system – for evidence of CVA
- neurological examination – to detect focal deficits, gait abnormalities, speech abnormalities
- endocrine system – signs of hypothyroidism
🍭 mental state examination – to identify other psychiatric disorders (e.g. – depression) or non-cognitive symptoms that may be associated with dementia (e.g. – delusions, hallucinations) (1)
🍭 cognitive examination – to estimate the extent of how different cognitive domains are affected and should include examination of attention and concentration, orientation, short and long-term memory, praxis, language and executive function. Standardised screening tests used for this purpose include (2)
- 30-item Mini Mental State Examination (MMSE) – commonly used
- 6-item Cognitive Impairment Test (6-CIT)
- the General Practitioner Assessment of Cognition (GPCOG)
- 7-Minute Screen
- the clock drawing test – to assess praxis and executive function (1)
🍭 investigations
- FBC
- urea and electrolytes
- blood sugar
- thyroid and liver function test
- B12 and folate levels
- lipid profile (3)
screening ix in dementia
Perform a midstream urine test if delirium is a possibility.
🍬 Blood tests:
- FBC, ESR, CRP - anaemia, vasculitis
- T4 and TSH - hypothyroidism
- biochemical screen - hypercalcium or hypocalcaemia
- urea and creatinine - renal failure, dialysis dementia
- glucose
- B12 and folate - vitamin deficiency dementia
- clotting and albumin - liver function
🍬 Other possible blood tests (though not routinely requested in primary care) include:
- syphilis serology
- HIV - if in young person
- caeruloplasmin - Wilson’s disease
🍬 Conduct investigations such as chest X-ray or (ECG) as determined by clinical presentation.
🍬 Other possible specialist investigations include:
- Genetic testing – can be offered to patients or to their unaffected relatives if a genetic cause is suspected
mx of dementia
A valid consent should be obtained from the patient before starting management. If the patient lacks the capacity to make any decisions on their own, the provisions of the Mental Capacity Act 2005 should be followed
It is sometimes desirable to admit the patient for observation and investigation with blood tests, CSF analysis and brain imaging. The tests can be performed as an outpatient but several visits should be arranged to permit repeated assessment.
Also patients should be offered written information and advice about
- signs and symptoms of dementia
- course and prognosis of the disease
- treatments
- local care and support services
- support groups
- sources of financial and legal advice and advocacy
- medico-legal issues, including driving
- local information sources, including libraries and voluntary organizations
Interventions in dementia can be aimed at
- cognitive symptoms
- noncognitive symptoms and challenging behavior
- reduction of comorbid emotional disorders
alzheimer’s
Epidemiology
- Slightly more common in females.
- The most common cause of dementia in the UK, accounts for about half of all dementia diagnoses.
Pathophysiology
- REMEMBER THESE TWO: Amyloid plaques + Neurofibrillary tangles.
- Amyloid plaques: clumps of beta amyloid and degenerating bits of neurons and other cells which lurk in between nerve cells.
- Neurofibrillary tangles: bundles of twisty filaments within neurons, mostly made from tau protein.
- The accumulation of these leads reduction in transmission of information, and eventually to death of brain cells, with abnormal depositions remaining post-mortem.
Symptoms
- Usually begin after the age of 60 (though there are “early-onset” cases, most of which involve genetics).
- Can affect all areas of the brain: many functions and abilities can be impacted upon and eventually lost.
- Most common presenting symptom is memory loss, with evidence of varying changes in planning, reasoning, speech and orientation.
General progression
- Alzheimer’s dementia tends to progress steadily over time.
vascular dementia
Epidemiology
- More common in males, generally thought to be due to their increased risk of vascular disease.
- Second most common type of dementia. Increased prevalence in those who have had a stroke (9x higher than the general population).
Pathophysiology
- There are several subtypes of vascular dementia, the most common of which are multiple (commonly small) cerebrovascular infarcts, small vessel disease and a single cerebrovascular accident.
- The most commonly affected areas of the brain are the white matter of both cerebral hemispheres, grey nuclei, thalamus and the striatum.
- Hypertension is a major risk factor for diffuse vascular dementia. Other general “vascular” risk factors increase the chances of developing vascular dementia and can increase cognitive decline – smoking, diabetes mellitus, hyperlipidaemia, obesity, hypercholesterolaemia etc.
Symptoms
- Single infarct vascular disease: classically cognitive impairment (acutely or subacutely) following the event.
- Functional deficits are often seen before memory impairment.
- Mood disturbances and mood disorders are common in vascular dementia
- Psychosis, delusions, hallucinations and paranoia can often be seen, especially in later stages.
- Patients should be screened for depression and for signs of psychomotor retardation (often a more common feature than positive signs of depression).
- Emotional lability can be prominent.
General progression
- ‘Stepwise’ – often shows a period of stability at one level of functioning, before an acute decline progression, followed by another period of stability. There is little way to predict how quickly (or when) these declines will occur.
Lewy-Body dementia
Epidemiology
- Appears to affect slightly more men than women. Mostly affects those over the age of 50.
Pathophysiology
- Spherical “Lewy Body” proteins are deposited in the brain (alpha-synuclein for those who love the science words). These Lewy Bodies are also present in Parkinsons – the difference being that in Parkinsons they are mainly deposited in the substantia nigra, whereas they are more widespread in Lewy-Body dementia.
Symptoms
- Often involves visual hallucination and Parkinson-like symptoms.
- If physical symptoms precede cognitive decline by more than a year, the diagnosis is often Parkinsons, with superimposed cognitive decline.
- Fluctuation in cognitive ability is common.
- At presentation, problems multitasking and performing complex cognitive actions are more likely to be issues than memory.
- Sleep disorders are a common manifestation.
General progression
- Fairly rapidly progressive, with death most commonly in the first 7 years post-diagnosis.
