Degenerative Diseases of the CNS Flashcards
Name two of the main diseases of the CNS
Dementia and parkinsonism
Define dementia
It is a syndrome consisting on:
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 impact of dementia
- Areas of cognition deteriote, it is not just a memory deficit
- There is history of loss of cognitive function – not due to ability but they can’t process the action
- Can’t maintain same social relationships due to impaired cognitive function
Name the causes of dementia with a late onset (65yrs)
- Alzheimer’s
- Vascular*
- Lewy body**
- Other
- Repetitive little strokes, might not even be aware
- *Form of parkinsons – abnormal aggregates of protein that develop inside nerve cells
Name the causes of dementia with an early onset (<65yrs)
• Alzheimer’s • Vascular • Frontaltemporal • Other o Toxic (alcohol) o Genetic (Huntington’s) o Infection (HIV, CJD) o Inflammatory (MS)
What are three treatable causes of dementia?
- Vit deficiency - B12
- Endocrine - thyroid disease
- Infective - HIV, syphilis
What are three conditions which mimic dementia?
- Hydrocephalus
- Tumour
- Depression: ‘pseudodementia’
To diagnose dementia, what do you need to find out in the history?
From an independent witness:
• Types of deficit – areas where theyre struggling; memory, getting lost, wandering, failing with finances, change in behaviour (drive, motivation) etc
• Progression
Family history
To diagnose dementia, what do you need to find out in the examination?
Cognitive function neurological, vascular
To diagnose dementia, what do you need to find out in the lab results in dementia?
- Routine – bloods (not B12 deficient, hypothyroid, screen for HIV), CT/MRI
- Others (for under 65yrs) – CSF, EEG, functional imaging, genetics (biopsy)
What is involved in examination of cognitive function in dementia?
- Various domains
- Screening tests
- Neuropsychological assessment
What do you look for in the various domains involved in examination of cognitive function in dementia?
- Memory, attention, language, visuospatial,
- Behaviour, emotion, executive function
- Apraxia (can’t do a motor take as you can’t plan it), agnosias (inability to put sensory meaning to something)
Name two screening test for cognitive function of dementia
Mini-mental (MMSE) and Montreal (MOCA)
Name three clues to diagnosis of dementia
- Type of cognitive deficit
- Speed of progression
- Other neurological signs
What are two different types of speed progression in dementia
- Rapid progression (CJD*)
- Stepwise progression (vascular)
*Creutzfeldt-jakob disease (CJD) is a fatal form of dementia caused by a protein found in the brain called prion
What is alzheimer’s disease?
Commonest neurodegenerative condition (mean age onset 70yr) which causes temporo-parietal dementia
What are the features of dementia caused by alzheimer’s disease (temporo-parietal dementia)?
Temporo-parietal dementia:
• Early memory disturbance
• Language and visuospatial problems
• Personality preserved until later (as it doesn’t affect frontal lobe)
• “Does he/she have the same personality, just more forgetful?”
What are the features of frontotemporal dementia?
- Early change in personality / behaviour
- Often change in eating habits (frontal and temporal lobes drive appetite)
- Early dysphasia
- Memory / visuospatial relatively preserved
What is speed of progression in vascular dementia?
Stepwise decline (i.e. worsen with each stroke)
What is the non-pharmacological symptomatic treatment of dementia?
- Information & support, dementia services
- OT
- Social work / support / respite / placement
What is the pharmacological symptomatic treatment of dementia?
- Insomnia
- Behaviour (care with antipsychotics)
- Depression
What is the specific treatment of Alzheimer’s (+/- Lewy body dementia)?
• Cholinesterase inhibitors (cholinergic deficit) – prevents break down of ACh in the brain so more is available for communication between brain cells
o Donepezil, rivastigmine, galanamine
• NMDA antagonist (memantine)
Is there a specific treatment for frontotemporal dementia?
No
What are the treatment measures for vascular dementia?
No good evidence for decrease in vascular risk factors
What is parkinsonism and its features?
A clinical syndrome with >= 2 of: • Bradykinesia (slowness of movement) • Rigidity (stiffness) • Tremor (shakiness) • Postural instability (unsteadiness / falls)
What is the pathology in basal ganglia causing parkinsons?
Loss of nerves in the substantia nigra which leads to a reduction in dopamine in the brain. Dopamine plays a role in regulating movement in the body, so a reduction causes the signs that you see in Parkinson’s.
What are the causes of parkinson’s?
• Idiopathic Parkinson’s Disease dementia with Lewy bodies
• Drug induced (i.e. dopamine antagonists)
• Vascular parkinsonism (lower-half)
• Parkinson’s plus syndrome
o Multiple system atrophy – postural hypotension, impotence, incontinence
o Progressive supranuclear palsy / corticobasal degeneration
How do you get a definitive diagnosis of parkinsons?
Post mortem
What are the clinical features of parkinson’s?
- Bradykinesia + >= tremor, rigidity, postural instability
- No other cause / atypical features
- Slowly progressive (> 5-10yrs)
What investigation in used for parkinsons?
Functional Imaging: Dopamine Transporter SPECT (Not diagnostic)
What is the early treatment of PD?
- Levadopa is a precursor of dopamine, give with carbidopa or benserazide to block the enzymes
- CMOT inactivates levodopa, so can use COMT inhibitor (i.e. entacapone)
- These drugs are purely symptomatic, no prevention of progression of disease
What are drug induced later complications that occur in PD?
- Motor fluctuations – levodopa wears off
- Dyskinesias – involuntary movements (levodopa)
- Psychiatric – hallucinations, impulse control
What are non-drug induced later complications that occur in PD?
- Depression
- Dementia
- Autonomic: BP, bladder, bowel
- Speech, swallow
- Balance
What is the later treatment of PD?
• Prolong levodopa half life: o MAO-B inhibitors o COMT inhibitor o Slow release levodopa • Add oral dopamine agonist • Continuous infusion (apomorphine, duodena)
Function neurosurgery (deep brain stimulation)
Allied health professional +/- care package
