Dementia and delirium

Question 1

Alzheimer’s
- risk factors

Answer 1

RFs:
- Family history
- Genetics - APOE4, presenilin-1 (PS1), amyloid-precursor protein (App)
- Cardiovascular - HTN, DM, IHD, high cholesterol, obesity
- Down syndrome
- TBI

Question 2

Normal pressure hydrocephalus
a) Pathophysiology
b) Gait
c) Investigation results
d) Treatment

Answer 2

a) - Unknown pathogenesis ?CSF flow disturbance
- Enlargement of ventricles causes distortion of the corticospinal motor fibres in the corona radiata, causing gait disturbance and urinary incontinence
- Ventriculomegaly also compresses the limbic areas of the brain causing cognitive dysfunction

b) Gait apraxia:
- Stuck to the floor with difficulty initiating movement and turning
- Slow and shuffling (like PD), but also broad based and wobbly (unlike PD)
- Normal arm swing (unlike PD)
- Different to cerebellar ataxic gait (which is more all over the place, more swaying and uncoordinated)

c) - LP - normal CSF opening pressure
- CT/MRI brain - ventriculomegaly without significant cortical atrophy, periventricular hyperintensities, wide Sylvian fissures, narrowed subarachnoid space

d) - Initial - therapeutic LP. Neuropsychological test and timed walking test should be performed before and after
- Definitive - VP or VA shunt

Question 3

DLB
a) vs PD dementia
b) 3 core features, + supporting features
c) Management

Answer 3

a) - DLB - cognitive impairment that precedes movement disorder, or presents within 1 year of movement disorder
- PDD - cognitive impairment that begins at least 1 year after movement disorder (usually many years after)

b) Core fx:
- Fluctuating course
- Visual hallucinations
- Parkinsonism

Supporting fx:
- Autonomic disturbance - postural instability, falls, syncope
- REM sleep disorder

c) - Dopaminergic agents worsen hallucinations but help Parkinsonism
- Rivastigmine for hallucinations
- Donepezil, memantine for dementia
- Clonazepam for REM sleep disorder
- Antidepressants
- Supportive - physio, OT, dietitian, psychologist, etc.

Question 4

Round silver staining inclusions, containing hyperphosphorylated Tau protein

Answer 4

Pick bodies - in FTD

Question 5

Neurofibrillary tangles and senile plaques
- Which dementia has both?
- Which dementia has one but not the other

Answer 5

AD has both
LBD has senile plaques but no NFTs
CTE has NFTs but no senile plaques

Question 6

Vascular dementia
a) common gait disturbance (how is this different to Parkinsonian gait?)

Answer 6

Marche à petits pas
- Small shuffling steps
- Different to PD gait as patients are upright (stooped in PD) and have normal arm swing (reduced in PD)

Question 7

Eosinophilic inclusions

Answer 7

Lewy bodies

Question 8

Cortical vs subcortical dementias
a) Examples of each
b) Which dementia has overlap (cortico-subcortical)
c) Differentiating features

Answer 8

a) Cortical: AD, FTD
Subcortical: VD, HD, PDD, PSP, MS, NPH, HIV, Wilson’s

b) Overlap: DLB (but PDD is subcortical only)

c) Cortical vs. subcortical
- Language: aphasia vs dysarthria/low output
- Agnosia more common in cortical
- Slow processing more common in subcortical
- Memory: more affected in cortical
- Visuospatial: more affected in cortical
- Attention/alertness/conscious levels: more affected in subcortical
- Movement disorder more common in subcortical
- Focal neurology more common in subcortical
- Depression/apathy more common in subcortical

Question 9

FTD
a) Gene implicated in FTD-ALS overlap
b) Gene implicated in FTD-Parkinsonism overlap
c) Variants

Answer 9

a) C9orf72

b) MAPT

c) bvFTD:
- Loss of inhibition, apathy, rituals

Semantic FTD:
- Loss of vocabulary and the meaning of words/ understanding of common objects

PNFA:
- Slow or delayed speech, grammatical errors, difficulty in understanding

Question 10

Neuroimaging.
a) Patterns of atrophy in different dementias

Answer 10

a) - Alzheimer’s - medial temporal lobes
- FTD - frontal lobes
- DLB - generalised atrophy