Parkinson's Disease

• dysfunction of the extrapyramidal motor system,
• progressive degenerative changes in basal ganglia (small nuclei in the brain involved in regulating motor movements)
• The age of onset is generally 60+,
• many causal factors suggested - mainly a decrease in a regulatory neurotransmitter (brain signalling molecule) called Dopamine
  

Symptoms:

• motor deficits
• weakness
• fatigue
• bradykinesia (slow movements)
• stereotypic movements
• Main four (T.R.A.P):
  • Tremor (when resting, but sometimes kinetic, ie. when moving)
  • Rigidity ("cogwheeling" when moving limb)
  • Akinesia (lack of mov't)
  • Postural Instability

Treatment:

• L-Dopa: precursor to dopamine; it can cross the blood-brain barrier and the body converts it to dopamine for its action to take effect. Oral dopamine cannot cross the blood-brain barrier. It is administered orally.
• L-Dopa given with Carbidopa, which prevents the peripheral breakdown of L-Dopa (by enzyme L-AAD, L-amino acid decarboxylase) and allows time to for L-Dopa to cross the Blood Brain Barrier to have its effects .