Motor System and Disorders Flashcards
Give two differentials for Parkinson’s.
Benign essential tremor
MSA
What is the difference between chorea and athetoid movements?
Chorea - irregular, jerky movements of low amplitude
Athetoid movement - slow continuous stream of writhing movements.
Give two conditions that can arise due to loss of the indirect pathway.
Huntingdon’s chorea
Hemiballismus
Common cause of hemiballismus.
Posterior cerebral artery thrombosis
Name 3 enzymes which degrade dopamine.
What is the ultimate breakdown product
Aldehyde dehydrogenase
COMT
MAO
Homovallinic acid
What converts L-dopa to dopamine in peripheral tissues?
What percentage enters the CNS?
DOPA decarboxylase
1%
Why should L-DOPA not be taken post meals?
Absorbed by active transport in competition with amino acids.
Name two L-dopa and peripheral L-dopa decarboxylase inhibitor medications.
Give 3 advantages of giving dopa like this.
Co-careldopa
Co-benedopa
Reduced dose needed
Reduced side effects
Increased L-dopa reaching the brain
Give some side effects of L-dopa.
Long term motor complication of L-dopa usage?
Nausea/anorexia
Hypotension
Psychosis
Tachycardia
Can lose the affect of the drug and enter an “off state” (freezing, dyskinesia, dystonia)
Why is multi-vitamin usage an issue when taking L-dopa?
HIgh dose MOA(b)I?
B6 (pyridoxine) increases peripheral breakdown of L-Dopa
Hypertensive crisis
Why are ergot derived dopamine receptor antagonists no longer used (Bromocryptine, cabergoline)?
Retroperitoneal and cardiac fibrosis
Name 4 dopamine receptor antagonists.
Which one of these is not first line and has uses when dysphagia and severe motor fluctuations are seen?
Give two disadvantages to their use
Ropinirole
Pramipexole
Rotigotine
Apomorphine
Apomorphine
Impulse control disorders (pathological gambling, punding, hypersexuality, compulsive shopping, describe to increase dosage)
Expensive
Give some features of dopamine dysregualtion syndrome.
Punding Hypersexuality Compulsive shopping Desire to increase dosage Pathological gambling
Give some side effects of dopamine receptor agonists.
Sedation Hallucinations Confusion Nausea Hypotension
Name two MOABI.
Selegiline
Rasagaline
What does COMT breakdown L-dopa to?
Name two COMTi.
Side effect of the one that crosses BBB.
3-O-Methyldopa
Competes with L-dopa for active transport into the CNS
Entacapone
Tolcapone
Liver toxicity
Why are anticholinergics used to in PD
Name 3 used.
What symptoms do they have no effect on? What symptom do they work on?
ACh may have antagonist effects on dopamine.
Trihexyphenidydyl
Orphenadrine
Procyclidine
Bradykinseas and rigidity
Tremors
Draw back of amantadine use?
Poorly effective (little effect on the tremor_
In which cases may surgery for PD be considered.
Dopamine resposive but large side effects to L-dopa with NO psychiatric illness
Give some treatments for myasthenia gravis.
ACEi Plasmapheresis IVIG Azathioprine Corticosteroids
Out of the pyridostigmine and neostigmine which one is more useful in ITU and why?
What is the drawback of this though?
IV therefore quicker action.
Significant antimuscarinic side-effect/
Describe the bimodal age of onset of MG.,
Affect young woman in their 20-30
But old men in their 60-70s
MG surgical Tx?
Thymus removal
What is tensilon test?
Give edrophonium - worsening signs and symptoms (cholinergic crisis)
Improve - positive test result - positive sign - myasthenic crisis
