RT Book, Section
A1 Tinklepaugh, Mark S.
A2 Atchabahian, Arthur
A2 Gupta, Ruchir
SR Print(0)
ID 57260694
T1 Chapter 29. Parkinson Disease
T2 The Anesthesia Guide
YR 2013
FD 2013
PB The McGraw-Hill Companies
PP New York, NY
SN 978-0-07-176049-2
LK accessanesthesiology.mhmedical.com/content.aspx?aid=57260694
RD 2024/04/18
AB Common  neurodegenerative  disease  of  the  CNS  characterized  by  loss  of  dopaminergic  input  in  the  basal  gangliaCause:Generally  considered  idiopathic  with  some  evidence  of  genetic  and  environmental  componentsDecreased  incidence  with  exposure  to  cigarette  smoking  and  increased  with  exposure  to  pesticidesPrevalence  and  incidence:Affects  1  million  people  in  the  United  States  with  approximately  50,000  new  cases  reported  annuallyAverage  age  of  onset  is  60Main  signs:Resting  tremorRigidityBradykinesiaFestinating  gaitPostural  instabilityOther  signs:Autonomic  dysfunction  (orthostatic  hypotension,  GERD,  sialorrhea,  cramps)Pharyngolaryngeal  involvement  with  aspiration  (most  common  cause  of  death)Respiratory  involvement  (chest  rigidity,  mixed  obstructive–restrictive  syndrome,  decreased  response  to  hypoxemia)DementiaDepressionOculogyric  crisesTreatment:Goal  of  treatment:  decrease  cholinergic  activity  through  anticholinergics  or  dopamine  agonistsLevodopa:Levodopa  absorbed  in  proximal  small  bowelConverted  to  dopamine  by  dopa  decarboxylaseFive  to  10%  levodopa  crosses  blood–brain  barrier;  remainder  converted  to  dopamine  peripherallySide  effects  are  N/V,  vasoconstriction,  hypovolemia,  hypotension,  decreased  myocardial  NE  storesLevodopa  supplementation  leads  to  decreased  endogenous  production  of  dopaminePeripheral  decarboxylase  inhibitor  (carbidopa)  in  combination  with  levodopa  (Sinemet®)  decreases  peripheral  levodopa  metabolism  which  decreases  dopamine  side  effectsEntacapone,  a  COMT  inhibitor,  used  alone  (Comtan®)  or  in  combination  with  carbidopa  and  levodopa  (Stalevo®)  to  decrease  peripheral  metabolism  of  levodopaAmantadine  (Symadine®)  releases  Dopa  in  the  striatumDopamine  agonists:Bind  to  postsynaptic  receptors  in  the  brainPreferred  in  younger  patients  since  they  delay  motor  complicationsSide  effects  include  somnolence,  insomnia,  nausea,  hallucinations,  and  cardiac  valvular  fibrosis  with  pergolide  (Permax®)  and  cabergoline  (Dostinex®,  Cabaser®)Other  dopamine  agonists  include  bromocriptine  (Parlodel®),  pramipexole  (Mirapex®),  and  ropinirole  (Requip®)Apomorphine  (Apokyn®),  another  agonist,  is  the  only  injectable  medication  (SQ  only,  not  IV)MAO-B  inhibitors:Increase  peripheral  bioavailability  of  levodopa.  Selegiline  (Eldepryl®,  Emsam®,  Zelapar®)  and  rasagiline  (Azilect®)  commonly  usedDeep  brain  stimulation  (DBS):Used  when  drug  therapy  inadequatePacemaker  implanted  in  brain  to  stimulate  the  subthalamic  nucleus  in  the  basal  ganglia  (see  chapter  102,  Awake  craniotomy)