Degenerative Diseases of the CNS Flashcards
What are the common features of neurodegenerative diseases?
Aetiology is largely unknown, usually later onset, gradual progression, neuronal loss and structural imagining is often normal
What is dementia?
Progressive impairment of multiple domains of cognitive function in alert patient
Leads to loss of acquired skills and interference of occupational and social role
What is the incidence and prevalence of dementia?
Incidence is 200 pre 100000
Prevalence is 1500 pre 100000
Why is dementia important?
High incidence and prevalence
Devastating impact on patient and family
Is expensive for the NHS - esp. care homes
What are the causes of later onset dementia?
Alzheimer’s, vascular, Lewy body and others
Often mixed pathology
What are the causes of young onset dementia?
Alzheimer’s, vascular, frontotemporal and other - alcohol, Huntington’s, HIV, CJD and MS
What are treatable causes of dementia?
Vitamin B12 deficiency
Thyroid disease
HIV and syphilis
What are mimics of dementia?
Hydrocephalus, tumour and depression - pseudodementia
How is dementia diagnosed?
History - type of deficit, progression, risk factors, FH
Exam - cognitive function, neurological and vascular
Investigations - Bloods, CT/MRI, CSF, EEG, functional imaging and genetics
How is cognitive function examined?
Screening testes - Mini-mental MMSE and Montreal MOCA
Neuropsychological assessment
Examine memory, attention, language, visuospatial, behaviour, emotion…
What are some clues to diagnosis of dementia?
Type of cognitive deficit, speed of progression - rapid (CJD) and stepwise (vascular)
Other neurological signs - abnormal movements (Huntington’s), parkinsonism (Lewy body) and myoclonus (CJD)
Describe Alzheimer’s disease
Commonest neuro-divergent condition - mean onset is 70 years old
Tempero-parietal dementia - early memory disturbance, language + visuospatial problems and personality is persevered until later
What is the pathology of Alzheimer’s disease?
B amyloid plaques and neurofibrillary tangles
What are the risks of Alzheimer’s disease?
Genetic - APOE, APP, PSEN1+2
Environmental
Increase risk - smoking, obesity, diabetes and hypertension
Decrease risk - cognitive reserve, exercise and diet
Describe frontotemporal dementia
Tau pathology
Early change in personality/ behaviour
Early dysphasia and often change in eating habits
Memory and visuospatial is relatively persevered
Describe dementia with Lewy bodies
Early visuospatial and executive dysfunction
Prominent fluctuation
Parkinsonism and visual hallucinations common
Describe vascular dementia
Mixed picture (parts of brain affected)
Stepwise decline
What is non pharmacological treatment of dementia?
Occupational therapy, social work, support, and voluntary organisations
What symptoms can be treated in dementia?
Insomnia, behaviour (care with antipsychotics) and depression
What is specific treatment for Alzheimer’s disease (also Lewy body)?
Cholinesterase inhibitors - donepezil, rivastigmine, galantamine. Small symptomatic improvement of cognition
NDMA antagonist - memantine
What is the frontotemporal specific treatment?
None
What is the specific treatment for vascular dementia?
No robust evidence for decreased vascular risk factors
Describe parkinsonism
Clinical syndrome with more than 2 of - bradykinesia, rigidity, tremor, and postural instability
Describe the pathology of parkinsonism
Predominantly dopamine loss
Lewy bodies
