Dementia

Question 1

Aetiology:

1. Reversible conditions
2. Mild cognitive impairment
3. Degnerative
4. Vascular
5. Psychiatric
6. Neurological
7. Neoplastic
8. Endocrinological/Metabolic/Nutritional
9. Trauma
10. Infectious
11. Inflammatory
12. Medication
13. Toxic

Answer 1

1. 10-20% potentially reversible conditions.
2. newly acquired cognitive decline beyond that expected for age and educational background but not causing significant functional impairment. can be amnestic/non-amnestic. 10-15% progress Alzheimer’s a year.
3. Alzheimer’s(most common at 60%), Lewy body, Parkinson’s, Huntington’s
4. 5-20% cases
5. delirium, depression, amnestic syndromes
6. Normal pressure hydrocephalus
7. Metastatic lesions, brain and meningeal tumours
8. Cushing’s, thyroid, parathyroid, porphyria, Wilson’s disease, hypopituitarism, vit B12/folate deficiency
9. Controversial evidence but retrospective data show that risk f for dementia/Alzheimer’s
10. Lyme disease, neurosyphilis, TB meningitis, CJD
11. Demyelinating disease, Sjorgen’s, Lupus erythematosus
12. Antihistamines, anticholinergics
13. Alcohol, arsenic, lead, mercury, CO, Cyanide

Question 2

Red flags:

Answer 2

1. Delirium
2. Depression
3. Head injury(controversial evidence)

Question 3

History:

1. Onset
2. FHx, drug and alcohol, risk f for stroke
3. Parkinson’s

Answer 3

1. a) Insidious(months to years), progressive course –> degenerative
   b) Abrupt change/stepwise decline after clinical event ie CVA –> vascular
   c) Acute(days to weeks)/subacute(weeks to months) –> infectious/metabolic/neoplastic/medication/CJD/hydrocephalus
2. 80% prevalence of dementia after 10y

Question 4

Cognitive exam:

1. Indications
2. Exams
3. Functional assessment questionnaire

Answer 4

1. > 80y; moving to new situations; >65y in hospital; undergoing surgery; old person with history of delirium, depression, diabetes, Parkinson’s, recently unexplained functional losses
2. Folstein MMSE(<24), MoCA, ADAS-Cog, MDRS
3. Can diff btw MCI and dementia.

Question 5

Physical examination:

1. Cranial nerves
2. Motor examination
3. Co-ordination and gait
4. Sensory examination
5. Reflexes
6. Hearing
7. CV exam

Answer 5

1. Visual field defects –> Vascular dementia.
   Lateral gaze palsy, nystagmus, ataxia –> alcohol-related dementia
2. Hemiparesis –> vascular dementia. Extrapyramidal signs ie resting tremor –> Alzheimer’s and normal ageing
3. Transient gait abn –> vascular.
   gait abn, impaired vibration/position sense, spasticity, paraesthesias –> vit B12 def.
   Pronounced gait disturbance –> NPH
4. Peripheral neuropathy –> underlying nutritional def/metabolic/toxic
5. Usually normal in Alz, primitve reflexes may be present.
   Generalised myoclonus and motor disorder –> CJD.
   Asymmetric deep tendon reflexes, unilat extensor plantar resp –> vascular
6. Hearing loss from central auditory dysfunction
7. Abn findings –> vascular

Question 6

Features of cortical vs subcortical dementia:

1. Language
2. Speech
3. Praxis
4. Agnosia
5. Calculation
6. Motor sys
7. Extra movements

Answer 6

1. aphasia early vs normal
2. Normal until late vs dysarthria
3. Apraxia vs normal
4. Present vs absent
5. Early impairment vs normal until late
6. usually normal posture/tone vs stooped/extended posture, increased tone.
7. None(possibly myoclonus in Alz) vs tremor, chorea, tics

Question 7

Delirium vs Dementia:

1. Onset
2. Duration
3. Course
4. Consciousness
5. Context
6. Perceptual disturbance
7. Sleep-wake cycle
8. Orientation
9. Speech

Answer 7

1. Acute vs Gradual
2. Hours-weeks vs Months-Years
3. Fluctuating vs Progressive Deterioration
4. Altered vs Normal (Lewy body dementia and multiple infarcts may feature transient episodes of impaired consciousness)
5. New illness/medication vs Health unchanged
6. Common vs late stages
7. Disrupted vs Normal
8. Usually impaired for time & unfamiliar people/places vs late stages
9. Inchoerent, rapid/slow vs Word finding difficulties

Question 8

Env Risk f:

1. Alz
2. Vascular
3. Both

Answer 8

1. Head injury, low education attainment, vascular
2. Past stroke, AF
3. Smoking, hypert., hypercholesterolaemia, diabetes, obesity, prev MI

Question 9

Px with cognitive impairment:

Answer 9

1. Is it objective?(standard test)
2. Onset?
   - acute/fluctuating → rule out delirium
3. Mood Sx → rule out depression and reassess cognition after tx.
4. Functional impairment
   - if none → mild cognitive impairment
5. Progressive over at least 6/12
   - if no → stable cognitive impairment

Question 10

DDx of cognitive impairment:

Answer 10

1. Dementia
2. Delirium
3. Mood disorders
   - Depression=pseudodementia, risk f for dementia
   - may trial tx then reassess cognition
4. Mild cognitive impairment
5. Stable cognitive impairment
   - stroke, traumatic/hypoxic brain injury, viral encephalitis
6. Psychotic illness
7. Intellectual disability
8. Dissociative disorders
9. Factitious disorder and malingering
10. Amnesic syndrome
11. Subjective cognitive impairment(increased risk MCI and dementia)

Question 11

Genes implicated in early onset AD:

*ApoE gene associated with late onset AD

Answer 11

1. APP -Chr 21
2. Presenilin-1 -Chr 14
3. Presenilin-2 -Chr 1

Question 12

Management:

1. Cognitive fn.
2. BPSD

Answer 12

1. -structured group stimulation programmes.
   - Ch-esterase inhibitors: donepezil, rivastigmine, galantamine.
   - rivastigmiine best evidence in Lewy body dementia
   - Medication ineffective in frontotemporal dementia.
   - Memantine(NMDA-R antagonist) in moderate-severe Alz. when intolerant to Ch-esterase inhibitors.
2. -Assess for pain and depression.
   - Massage, aromatherapy, animal-assisted therapy.
   - Trazodone for disturbed behaviour. Avoid benzodiazepines.
   - Antipsychotics if needed. In Lewy Body Dementia, antipsychotics can precipitate irreversible parkinsonism, impaired consciousness, severe autonomic symptoms and 2-3x increase in mortality. Benzodiazepine and Cholinesterase inhibitors safer here.
   - avoid anti-Ch for depression.
   - 50% pts w Lewy body dementia have adverse reaction to antipsychotics(irreversible parkinsonism, impaired consciousness, severe autonomic Sx, increased mortality). Benzodiazepines/Ch-esterase inhibitors more suitable.

Question 13

TYPES OF DEMENTIA:

1. Alzheimer’s(62%)
2. Vascular/multi-infarct(17%)
3. Mixed(10%)
4. Lewy body dementia(4%)
5. Parkinson’s disease with dementia(2%)
6. Frontotemporal dementia(Pick’s disease)(2%)

Answer 13

1. • Gradual onset with progressive cognitive decline
     - Early memory loss
2. • Focal neurological signs and symptoms
     - Evidence of cerebrovascular disease
     - Stepwise/uneven deterioration
     - Fluctuating course(nocturnal confusion)
     - patchy cognitive deficits
     - abnormal gait
3. Features of both Alzehimer’s and vascular dementias
4. • Day-to-day(shorter) fluctuations in cognitive performance
     - recurrent visual hallucinations
     - Parkinsonisian motor signs(rigidiy, bradykinesia, tremor)
     - Recurrent falls and syncope
     - Transient disturbances of consciousness
     - Extreme sensitivity to antipsychotics
5. Dx of Parkinson’s disease prior to cognitive symptoms. Dementia features similar to Lewy body dementia
6. • Early decline in social & personal conduct
     - early emotional blunting
     - attenuated speech otuput, echolalia, perseveration, mutism
     - primary progressive aphasia
     - early loss of insight
     - relative sparing of other cognitive functions

Question 14

CORTICAL VS SUBCORTICAL DEMENTIA:

1. Language
2. Speech
3. Praxis
4. Agnosia
5. Calculation
6. Motor system
7. Extra movement

Cortical: Alzheimer’s, frontotemporal dementias
Subcortical: Parkinson’s, Lewy body dementia, Huntington’s, progressive supranuclear palsy, Wilson’s disease, NPH, MS, HIV-related dementia
Mixed: vascular dementia, infection-induced dementias(CJD, neurosyphilis, chronic meningitis)

Answer 14

1. Early aphasia vs Normal
2. Normal until late vs Dysarthric
3. Apraxia vs Normal
4. Present vs usually absent
5. Early impairment vs normal until late
6. Usually normal posture/tone vs stooped/extended posture, increased tone
7. None vs tremor, chorea, tics