Degenerative Diseases of the CNS Flashcards
What are the common features of neurodegenerative diseases?
- Aetiology largely unknown
- > rarely mendelian genetic cases: often younger onset
- Usually late onset
- Gradual progression
- Neuronal loss (specific neuropathology)
- Structural imaging often normal (atrophy)
What is the definition of Dementia?
Progressive impairment of multiple domains of cognitive function in alert patient, leading to loss of acquired skills and interference in occupational and social role
What are the main aetiologies of Young onset vs. Late onset Dementia?
- often mixed pathology*
- Young onset (<65 yrs)
- > Alzheimer’s (most common)
- > Vascular
- > Frontotemporal (MND/ALS)
- > Other: toxic, genetic (ie. Huntington’s), infection (HIV, CJD), inflammatory (MS)
- Late onset (>65yrs)
- > Alzheimer’s (most common)
- > Vascular
- > Lewy Body
- > Others
What are the treatable causes of Dementia?
- Vit B12 deficiency
- Thyroid disease (endocrine)
- Infective: HIV, Syphilis
What is the differential diagnosis of Dementia?
- use a brain CT scan to exclude these pathologies!*
- Hydrocephalus
- Tumour
- Depression: “pseudodementia”
How do you make the diagnosis of Dementia?
- History (independent witness)
- Examination:
- > cognitive function:
- various domains: memory, attention, visuospatial, behaviour, emotion, executive function, apraxias, agnosias
- screening tests (MMSE, MoCA)
- neurophysiological assessment
- > neurological
- > vascular
- Investigations:
- > routine: bloods, CT (first-line), MRI
- > others: CSF, EEG, functional imaging, genetics
Which additional clinical features would raise suspicion of Huntington’s Dementia?
- Abnormal movements
Which additional clinical features would raise suspicion of Lewy Body Dementia?
- Parkinsonism
Which additional clinical features would raise suspicion of CJD Dementia?
- Rapid progression
- Myoclonus
Which additional clinical features would raise suspicion of Vascular Dementia?
- Stepwise progression
What is the most common neurodegenerative disease?
Alzheimer’s disease
Temporo-parietal Dementia
Which features are pathognomonic for Alzheimer’s disease?
- Beta-amyloid plaques
- Neurofibrillary tangles
What are the clinical features of Alzheimer’s?
- Temporo-parietal Dementia
- Early change in memory disturbance
- Language and Visuospatial problems
- Personality preserved until later (frontal lobe)
Which feature is pathognomonic for Frontotemporal Dementia?
Tau protein
What are the clinical features of Frontotemporal Dementia?
- Early change in personality + behaviour -> often changes in eating habits
- Early change in dysphasia (Broca’s)
- Memory/visuospatial relatively preserved
