Dementia

Question 1

dementia

Answer 1

global deterioration of intellectual function in the face of unimpaired consciousness
impaired cognition - memory, abstract thinking, judgement, processing/organizing daily lives

Question 2

assessment

Answer 2

general medical and neurological history, neurobehavioural and psychiatric history, toxic/drug history, family history
assess mental state → level of consciousness, orientation, memory, attention + concentration, knowledge, language
MMSE/MOCA - quantification measures decline over time

Question 3

pathology

Answer 3

deficits depend on the initial affected area of brain and the rate of progression

Question 4

progression of deterioration of intellectual function

Answer 4

acute = weeks - encephalitis
subacute = months - CJD
chronic = years - Alzheimer’s disease

Question 5

frontal lobe

Answer 5

motor speech area - speech apraxia

pre-motor cortex - behavioural changes

also: Pick’s, Huntington’s

Question 6

parietal lobe

Answer 6

visuo-spatial orientation
constructional apraxia (inability to draw/copy)
disturbances in cognitive function

Question 7

dysfunction in frontal lobe

Answer 7

lead to abnormal reflexes → primitive

Question 8

primitive reflexes

Answer 8

present as babies but fade → return in dementia

1. pout reflex - lips pout when tapped
2. glabellar reflex - cannot inhibit blinking response to stimulation
3. grasp reflex - stroking palm induces grasp
4. palmo mental reflex - scratching hand causes contraction of chin muscles

Question 9

causes

Answer 9

1. degenerative
2. cerebrovascular
3. structural
4. infection
5. toxic/metabolic
6. immune/cancer
7. depression

Question 10

degenerative cause

Answer 10

most common cause (80-85%)
dysfunction + degeneration of neurons and brain cells
age progression
vulnerable regions: parietal, temporal - hippocampus (memory + cognition)
specific targets: Huntington’s = basal ganglia; Parkinson’s = substantia nigra

protein misfolding + abnormal deposition

Question 11

cerebrovascular cause

Answer 11

2nd most common cause
inflammation of blood vessels - CNS vasculitis

Question 12

laboratory investigations

Answer 12

clinical history/exam
blood tests/screens for treatable causes, infections
neuroimaging

Question 13

Alzheimer’s disease

Answer 13

irreversible, progressive - destroys memory + thinking
risk increases with age
disrupts neuron communication, metabolism, + repair

most common cause of dementia

Question 14

Alzheimer’s clinical features

Answer 14

memory impairment
hallucinations
paranoia
cognitive impairment, personality changes, disorientation

motor and gait disturbances
falls
seizures
autonomic dysfunction

Question 15

etiology of Alzheimer’s

Answer 15

familial forms
sporadic (unknown cause) - majority of cases
early onset - 40-50 (usually genetic = APP, presenilin 1 and 2 mutations)

late onset - mostly sporadic; apolipoprotein E4, SORL1, CLU, CR1

Question 16

amyloid precursor protein

Answer 16

membrane protein important for neuronal growth and repair

secreatases cut it into fragments → B-amyloid is sticky fragment - cling together = plaques

Question 17

neuropathology of Alzheimer’s

Answer 17

cortical atrophy
synaptic + neuronal loss

neurofibrillary tangles - twisted fibres
B-amyloid plaques - deposition in hippocampus and amygdala
tau proteins

Question 18

neurotransmitter abnormalities in Alzheimer’s

Answer 18

decreased acetylcholine in cortex and hippocampus

neurons in the basal forebrain synthesize Ach - project forward into cortex → neurons die = deficiency in Ach

Question 19

Alzheimer’s treatment

Answer 19

cholinesterase inhibitors - more Ach
NMDA receptor blockers - glutamate

less effective over time as cells die = no targets

Question 20

imaging

Answer 20

CT + MRI - show atrophy in hippocampus
PET scan - visualize amyloid in brain

Question 21

Lewy Body dementia

Answer 21

fluctuating cognition
recurrent visual hallucinations
Parkinsonism

lewy bodies contain alpha-synuclein protein

loss of pigmented dopamine neurons in substantia nigra

Question 22

Frontotemporal dementia (Pick’s)

Answer 22

bias to females
younger age
frontal and temporal lobe atrophy
Tau pathology
familial forms - gene on chromosome 17

Question 23

vascular dementia

Answer 23

10-15%
accumulation of strokes causes progressive loss of function
risk factors: hypertension, diabetes, high cholesterol