Revision 2 Flashcards
what area is affected early in alzheimers
nucleus basalis of meynert (group of CHOLINERGIC neurones)
what is the treatments for alzheimers
acetylcholinesterase inhibitors- donzepezil, galantamine, rivastigime (monotherapies) for milf to mod
memantine (NMDA receptor antagonist) for severe/ AChEi CI
what mutation= 100% penetrance of huntingtons
40 or more CAG repeats
what types of inheritance does huntingtons have
genetic anticipation
autosomal dominant
what are parkinson plus syndromes
diseases that cause parkinsonism + other symptoms:
- multi system atrophy
- dementia with lewey bodies
- progressive supranuclear palsy
- corticobasal degeneration
what is multi system atrophy
group of disorders that progressively affect the central and autonomic nervous by system damaged oligodentrocytes (myelination) by accumulation of alpha synuclein
two types- MSA-P: characterised by parkinsons motor symptoms, deteriorates faster. MSA-C: cerebellar, lack of coordination and balance, intention tremor, slurred speech and difficulty swallowing (dysphasia)
both types characterised by autonomic symptoms- orthostatic hypotension, constipation, increased sweating, sleep apnoea, sexual dysfunction
what protein is found in dementia with lewey bodies
alpha synuclein
what are the symptoms of DLB
cognitive impairments, visual hallucinations, inability to focus, inflexible thinking and paranoia. DLB patients initially have these cognitive symptoms but also develop motor symptoms similar to PD such as bradykinesia, tremor, rigidity, and shuffling walk. Similar to PD, DLB patients also have REM sleep behavior disorder in which they act out their dreams.
what is progressive supranuclear palsy
chronic neurodegenerative syndrome which affects cognition, eye movements and posture
what are the symptoms of progressive supranuclear palsy
supranuclear (primarily vertical) gaze palsy
extrapyramidal - akinesia
cognitive dysfunction
postural instability
vague fatigue, HAs, arthralgia, dizziness, depression, modd changes, progressive dementia
what is a supranuclear palsy
the inability to look in a particular direction as a result of cerebral impairment:
- frontal lobe (frontal eye field)-> pontine horizontal gaze centre (PPRF) -> abducens nucleus-> lateral rectus
- occipital cortex-> oculomotor nucleus -> CN3 and medial longitudinal fasciulus -> pontine horizontal gaze centre
loss of voluntary movements of eye
as brainstem intact, all reflex conjugate eye movements normal
how do you distinguish a vertical gaze palsy from a cranial nerve palsy
both eyes affected
pupils unequal but fixed
no diplopia
reflexes intact
what is corticobasal degeneration
where multiple areas of the brain atrophy
begins around 60
start unilateral then go to other side
- poor coordination, rigidity, impaired balance, dysphagia
-personality changes, inappropriate behaviours, compulsive behaviours
what causes most postural tremors
essential- autosomal dominant inheritance, gets better when you drink alcohol
what is a treatment for an essential tremor
propanolol
what does an intention tremor suggest
cerebellar diseases
how does huntingtons usually present
strange movements and behavioural changes
what is sydenham chorea
form of chorea that is more common in females adolescents and linked to rheumatic fever (group A beta haemolytic strep infection)
what does myoclonus look like
brief electric shock like movements
e.g. 20 y/o guy gets milk but drops it= juveline myoclonic epilepsy
why is alzheimers linked to downs syndrome
alzheimers cause by beta amyloid precursor protein (insoluble, forms plaques which disrupt neuronal signalling) and the gene that codes for this is on chromosome 21 (trisomy 21= more production of amyloid= build up of plaques)
loss of dopaminergic neurones in the substantia nigra =?
parkinsons disease
what does the globus paladus alway inhibit
the thalamus - main job of direct pathway is to reduce this inhibition
what is the tremor like in parkinsons
resting
4-6 Hz
pill rolling
starts on one side then becomes bilateral
sudden onset bilateral parkisons with resting tremor= ?
drug induces parkinsonism