Degenerative Diseases of the CNS Flashcards
What are some common features of neurodegenerative diseases?
- Aetiology largely unknown
- Mendelian genetic cases are rare, often younger onset
- Usually late onset
- Gradual progression
- Neuronal loss (specific neuropathology)
- Structural imaging often normal
What is dementia?
a syndrome consisting of progressive impairment of multiple domains of cognitive function in alert patient leading to loss of acquired skills and interference in occupational and social role
Describe the epidemiology of dementia?
- Incidence 200/100,000
- Prevalence 1500/100000
- Very costly, about £35 billion per year (NH, social and unpaid work)
- Projected to increase to £94 billion by 2040
How does the incidence of dementia change with age?
Increases with age
What are some causes of dementia?
- Late onset (over 65 years old)
- Alzheimer’s (55%)
- Vascular (20%)
- Lewy body (20%)
- Other (5%)
- Young onset (younger than 65 years old)
- Alzheimer’s (33%)
- Vascular (15%)
- Frontotemporal (15%)
- Other (30%)
When is dementia onset considered to be young and late onset?
Young onset <65 years old
Late onset > 65 years old
What are the most common causes of late onset dementia?
- Alzheimer’s (55%)
- Vascular (20%)
- Lewy body (20%)
- Other (5%)
What are the most common causes of young onset dementia?
- Alzheimer’s (33%)
- Vascular (15%)
- Frontotemporal (15%)
- Other (30%)
What are some treatable causes of dementia?
- Vitamin B12 deficiency
- Endocrine
- Thyroid disease
- Infective
- HIV, syphilis
What are some other diseases that dementia mimics?
- Hydrocephalus
- Tumour
- Depression (psudodementia)
What parts of the history are important for diagnosing dementia?
- Type of deficit, progression, risk factors, family history
What parts of the examination are important for diagnosing dementia?
- Cognitive function, neurological, vascular
What investigations are important for diagnosing dementia?
- Routine
- Bloods, CT/MRI
- Others
- CSF, EEG, functional imaging, genetics
Why is imaging used to diagnose dementia?
Imaging is done to rule out other things that can cause cognitive deficit such as tumour, other investigations are rarely done
What different parts of cognition can be examined?
- Memory, attention, language, visuospatial, behaviour, emotion, executive function, apraxias (difficulty with the motor planning to perform tasks when asked) agnosias (inability to process sensory information)
What is apraxias?
Difficulty with the motor planning to perform tasks when asked
What is agnosias?
Inability to process sensory information
What are different ways of examining cognitive function?
- Screening tests
- Mini-mental (MMSE), Montreal (MOCA)
- Neuropsychological assessment
Which of MOCA and MMSE is better?
MOCA due to testing more domains