Parkinson's Flashcards
degenrative parkinsons
Parkinsons is a slowly progressing neurologic movement disorder that eventually leads to disability.
degenerative form is most common although there is also a secondary form with a known cause
when do parkinsonian symptoms generally manifest
in fifties but can be as early as thirties
risk factors
genetics, atherosclerosis, excess accumulation of oxygen free radicals, viral infections, head trauma, chronic antipsychotic medication use, some environmental exposures. gender (Affects men more often than women)
etiology
combo of genes and environment (usually called complex trait when its like this?)
genes involved: alpha-synuclein, UCH-L1, and a gene that codes the protein parkin.
It may be an outcome of severe carbon monoxide poisoning or a postencephalitic syndrome. Oxidative stress to Lewy bodies may cause the neurodegeneration but it may also be due to protein aggregation or a combination of the two.
Apoptosis and mitochondrial disorder may lead to degeneration as well.
what is a lewy body
Lewy bodies are abnormal aggregates of protein that develop inside nerve cells in Parkinson’s disease (PD), Lewy body dementia, and some other disorders.))
patho
- dec dopamine d/t destr of substantia nigra in basal ganglia. fibres from here project to CORPUS STRIATUM. The transmission of NTM here will lead to complex body movement. This loss of dopamine leads to difficulty with voluntary movement as there are too many excitatory NTM and not enough inhibitory. Which leads to impairment of EXTRAPYRIMIDAL TRACTS that control complex body movement.
- Depeletion of dopamine leads to degeneration of the dopaminergic nigrostriatal pathway.
dopamine function
Dopamine is a chemical that relays messages between the substantia nigra and other parts of the brain to control movements of the human body. Dopamine helps humans to have smooth, coordinated muscle movements.
diagnosis of parkinsons
pt hx and
- presence of 2 or more of 4 cardinal signs
1. tremor
2. muscle rigidity
3. bradykinesia
4. postural changes
labs and imaging arent helpful
often need family for hx as they help w pinpointing the symptoms and onset
also use neurologic exam
when do symptoms appear in parkinsons
late. it has gradual onset. ((Clinical symptoms do not appear until 60% of the pigmented neurons are lost and the striatal dopamine level is decreased by 80%. ))
mnfts of parkinsons
which is preset in 75% of all pts at dx
which is one of most common features
tremor (unilateral. present in 75% of pts at Dx)
rigidity
bradykinesia. one of most common
postural instability
how do you characterize rigidity?
where does it occur
Resistance to passive limb movement characterizes muscle rigidity, this may cause the limb to move in jerky movements called cogwheeling. Stiffness is common in the arms, legs, face, and posture
bradykinesia
causes difficutly to
Bradykinesia is one of the most common features and may cause patients to take longer to complete most activities and struggle to initiate movement.
how does postural instability mnft
The patient often develops postural and gait problems. Due to a loss of postural reflexes the patient stands with the head bent forward and walks with a propulsive gait. The patient may walk faster. They are at a risk of falls due to difficulty in pivoting that cause a lack of balance. There are also autonomic symptoms and psychiatric changes
tx of parkinsons. which drugs are used
levodopa, anticholinergic drugs, amantadine, dopamine agonists and MAO inhibitors
mao inhibitors
Monoamine oxidase (MAO) inhibitors inhibit dopamine breakdown and are thought to slow the progression of the disease. (MAO is an enzyme that breaks down dopamine)
