Parkinson's disease Flashcards
List the differences between psychiatric and neurodegenerative disorders?
ND- loss of neurones, disrupted motor functions, some behaviour changes maybe
PS- no loss of neurones, some structural changes, changes in behaviour
List 3 upper motor neurone disorders
MS, stroke, amyotrophic lateral sclerosis
List 3 lower motor neurone disorders
MG, poliomyelitis, peripheral neuropathy
List 4 involuntary movement disorders
Parkinson’s
Huntington’s
Dystonia
Tremor
List one cerebellar disorder
Tremor-loss of balance/co ordination
Which part of the brain allows us to perform normal motor functions?
Basal ganglia
Movement programming
Decide when, where to act, put in action learned motor plans.
Describe the process of movement programming
Stimuli to move, assemble motor plans, select motor plans from memory stores, assemble appropriate sequence, execute motor plan, initiate, run sequence, terminate
Define Parkinson’s disease
Neurodegenerative disease of extrapyramidal system where pigmented presynaptic nerve terminals die in substantia niagra pars compacta (SNPC)
- loss of striatal dopamine
- inability to perform normal motor function
Little change in post synaptic dopamine receptors
What are the signs and symptoms of Parkinson’s?
Shuffling gait Mask like face Akinesia Rigiidty Tremor Postural abnormalities Bradykinesia
What are the later stages of Parkinson’s?
dementia, endocrine dysfunction due to a decrease in hypothalamic amines, dementia
Which pathways are associated with Schizophrenia
Mesolimbic
Mesocortical
Which pathways are associated with prolactin release?
Tubuleroinfundibular pathway
Which pathway is associated with Parkinson’s
Nigrostriatal
Which neurotransmitter changes are associated with Parkinsons’s
- Loss of striatal dopamine (60-70% of symptoms)
- Loss of dopamine in mesolimbic areas
- Decrease in hypothalamic amines
- Cortical NA and Ach decrease- dementia and cognitive defects
- Neuropeptides in striatum decrease (CCK-8, substance P, enkephalins)
What are the causes of sporadic Parkinson’s disease?
Unknown
Oxidative stress
Mitochondrial/proteasome dysfunction
What are the causes of familial Parkinson’s disease?
PARK 1 mutation- codes alpha synuclein- in Lewy bodies
PARK2 mutation- codes Parkin- part of ubiquitin proteasome
LRRK2 gene mutation (leucine rich repeat kinase 2 gene)
What are the other causes of Parkinson’s?
Drug induced neurodegeneraton MTTP
Drug induced symptoms- dopamine antagonists eg anti psychotics in schizophrenia Phenothazine
Viral encephalitis
What is the main drug treatment for Parkinson’s
L DOPA + CARBIDOPA
Dopamine precursor and DOPA Decarboxylase inhibitor
LDOPA crosses BBB, converted to dopamine in brain
What are the side effects of L DOPA
Choreic movement
Nausea, anorexia
Psychotic effects
Stops working after 10-15 years
What is the second option?
Dopamine agonists eg Bromocriptine, Ropinirole
acts on D2 receptors- which are inhibitory and in basal ganglia
What is the third option?
Monoamine oxidase inhibitors eg Selegiline
given with L DOPA
COMT inhibitors- Entacapone
only use with L DOPA
Which drugs can be used to increase dopamine release
Amantidine
Which drugs can be used to control tremor?
Muscarinic receptor antagonists
Outline the main drugs used to treat Parkinson’s
SALAD
Selegiline Amantidine L DOPA and Carbidopa Anti cholinergic drugs Dopamine agonists
Describe Tourette’s disorder
tic disorder
affects 1/1000 people
Transient, long term- odd movements, inappropriate behaviour
Altered basal ganglia function- uncontrolled motor movements
Which drugs can be used if Tourettes is causing harm?
Dopamine receptor antagonists
Outline Huntington’s disease
Autosomal dominant, affects 0.01% of pop
Symptoms: dyskinesia, lower motor impairment, depression, dementia, psych component
due to loss of GABA (inhibitory) not dopamine
Increased BG activity- choreic movements, opposite symptoms to Parkinson’s
Cause: Mutant Huntington’s gene- 36 repeats of CAG coding for glutamine
Huntington protein assoc with neuronal cytoskeleton and vesicles
Upregulate BDNF transcription
BDNF loss- apoptosis of GABA neurones
Treat: decrease dopamine function Tetrabenazine
