Differential diagnosis of dementia Flashcards
What is Charles Bonnet Syndrome (CBS)?
Complex visual hallucinations in indivduals w/ acquired visual loss with insight and without cognitive impairment (10-60%)
[high incidence of non reporting + diagnosis of exclusion]
Common characteristics of CBS?
- Simple geometric shapes
- Complex shapes with reconisable forms (faces, objects)
- Tessellopsia (regular, overlapping patterns)
- Prosometamorphopsia (facial distorsion)
- Dendropsia (branching forms)
- Hyperchromatopsia (all objects appear coloured)
- Polyopia (multiple forms of one image)
- Micropsia (objects appear smaller than normal)
- Macropsia
General features of the nature of dementia presentation
- no implied aetiology
- insidious onset, progressive decline
- clear consciousness
- deficits in behaviour, attention, memory, language, visuospatial dys
- reversible/irreversible; indolent/rapid progress; multiple def/isolated def
1st and 2nd most common dementia forms?
- AD
- DLB (and PDD)
[there is also vasc. dement and FTD)
How to definitively diagnose dementia?
Brain tissue required (biopsy)
Features that should be preserved w/ ageing?
- Temporal Orientation
- Immediate Attention
- Vocabulary
- Visuospatial skills
- Judgement & Insight
Features that suffer mild decrements w/ ageing
- Sustained Attention
- Visual > Verbal recall
- Naming
- Response speed
- Flexibility
What is Mild Cognitive Impairement (MCI)?
Cognitive impairment that is insufficient to reach criterion of “dementia”
Amnestic/non-amnestic
10-15% annually convert to dementia
NB: rule out psyc/drug/other
Features of Depressive Pseudodementia (DPD)?
- apathy
- social withdrawal
- mutism
- incontinence
- lack of “sadness”
[depression is misdiagnosed as dementia in 8-15% of mentally declining pts]
NB: depression is present in 20-30% of demented pts
Clues of DPD?
- FHx
- subacute onset
- agitation/pacing
- precipitants
- poor memory
- poor effort
- spared language + praxis
- normal EEG/imaging
What is Balint’s syndrome
[focal lesion]
Unable to perceive visual field as a whole:
- occulomotor apraxia
- optic ataxia
- visual stimultagnosia
What is Gerstmann’s syndrome?
[focal lesion]
- dysgraphia/agraphia
- acalculia
- finger agnosia
- unable to distinguish R/L side of body
Types of anatomical classification of dementia pathology?
- subcortical
- cortical
Describe subcortical features of dementia?
- slow, inefficient
- apathy, mood, personality
- motor signs
[e.g. PDD, huntingtons, PSP, MS, Wilson’s, HIV)
Describe cortical features of dementia?
- language
- praxis (visuospatial)
- disinhibition
- (memory)
[e.g. AD, FTD, DLC, CJD]
