Degenerative Diseases of the CNS Flashcards
what are common features of neurodegenerative diseases?
aetiology largely unknown
(mendelian genetic cases rare, often younger onset)
usually late onset
gradual progression
neuronal loss (specific neuropathology)
structural imaging often normal (atrophy)
what is 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 causes of dementia in late onset (65+)?
Alzheimer’s (55%)
Vascular (20%)
Lewy body (20%)
Others (5%)
what are causes of dementia in early onset (<65)?
Alzheimer’s (33%)
Vascular (15%)
Frontotemporal (15%)
Other (33%)
what are the “other” causes of dementia?
Toxic (alcohol)
Genetic (Huntington’s)
Infection (HIV, CJD)
Inflammatory (MS)
what are treatable causes of dementia?
Vitamin deficiency - B12
Endocrine - thyroid disease
Infective - HIV, syphilis
(however left too long, it becomes untreatable)
what are mimics of dementia?
Hydrocephalus
Tumour
Depression: “pseudodementia”
what is the diagnostic history and examination of dementia?
History (independent witness) - type of deficit, progression, risk factors, FH
Examination:
cognitive function, neurological, vascular
what are the investigations for dementia?
routine - bloods, CT / MRI
others - CSF, EEG, functional imaging, genetics (biopsy)
how do you examine cognitive function?
Various domains:
Memory, attention, language, visuospatial,
Behaviour, emotion, executive function
Apraxias, agnosias
how can the type of cognitive function help diagnose the cause?
rapid progression (CJD) stepwise progression (vascular) abnormal movements (Huntington’s) parkinsonism (Lewy body) myoclonus (CJD)
what is Alzheimer’s disease?
Commonest neurodegenerative condition mean age onset 70 yr Temporo-parietal dementia Early memory disturbance Language and visuospatial problems Personality preserved until later
describe Frontotemporal dementia
Early change in personality / behaviour
Often change in eating habits
Early dysphasia
Memory / visuospatial relatively preserved
what is the non pharmacological symptomatic treatment of dementia?
Information & support, dementia services
Occupational therapy
Social work / support / respite / placement
Voluntary organisations
what is the pharmacological symptomatic treatment of dementia?
Insomnia
Behaviour (care with antipsychotics)
Depression
what is the treatment for Alzheimer’s (+/- Lewy body dementia)?
Cholinesterase inhibitors (cholinergic deficit) Small symptomatic improvement in cognition (wash-out) No delay in institutionalisation NMDA antagonist (memantine)
what is the no good evidence treatment for Vascular dementia?
↓ vascular risk factors
what is Parkinsonism?
A clinical syndrome with 2 of: Bradykinesia (slowness of movement) Rigidity (stiffness) Tremor (shakiness) Postural instability (unsteadiness / falls)
Pathology in basal ganglia
predominantly dopamine loss
what are the causes of Parkinsonism?
Idiopathic Parkinson’s disease (Dementia with Lewy bodies) Drug-induced (e.g. dopamine antagonists) Vascular parkinsonism (lower-half) Parkinson’s plus syndromes (Multiple system atrophy)
what are the symptoms of Parkinsonism?
Bradykinesia + ≥1 tremor, rigidity, postural instability Slowly progressive (> 5-10 yrs) Supported by asymmetric rest tremor, good response to dopamine replacement treatment
what are the investigations for Parkinsonism?
Dopamine transporter SPECT
Less dye will bind to transporters as there are less neurones/transporters
what is the early medical treatment of PD?
Dopamine agonists
COMT inhibitor
MAO-B inhibitor
what causes PD?
associated with loss of dopaminergic neurons
what are drug-induced later complications of PD?
Motor fluctuations - levodopa wears off
Dyskinesias - involuntary movements (levodopa)
Psychiatric - hallucinations, impulse control
what are non-drug induced later complications of PD?
Depression (20%) Dementia (~50% after 10 yrs) Autonomic: BP, bladder, bowel Speech, swallow Balance
what is the late treatment of PD?
Prolong levodopa half life: MAO-B inhibitors COMT inhibitor slow release levodopa Add oral dopamine agonist Continuous infusion (apomorphine, Duodopa)
Functional neurosurgery (deep brain stimulation)
