This is a disease brought into the public’s eye by such people as the actor Michael J. Fox and Former President George H.W. Bush. This condition is a degenerative condition of the central nervous system. The symptoms of Parkinson’s disease come about through the death of the cells that generate dopamine. Dopamine acts as a neurotransmitter, which is a chemical released by nerve cells that send signals to other nerve cells. In the early phases of the disease the most observable symptoms are movement related and can include; rigidity, shaking, a slowness of movement, and difficulty with walking. Later on in the illness one can develop problems with thinking and behavior. It can also result in a dementia.
Treatments are effective at managing the motor symptoms. The main medications act as dopamine agonist (an agonist is a chemical that binds to a receptor activating the receptor to produce a response). As far as the FAA is concerned about this condition, it does require a special issuance. Only the more “milder” of cases can gain certification. In calendar year 2013 there were only 10 first-class, 8 second-class and 25 third-class airmen flying with Parkinson’s disease. I trust you can tell from my explanation that an airman with this condition could have problems flying.
The only medication currently acceptable is one of the original medications used to treat this condition -> Sinemet (a combination of carbidopa and levodopa.) Levodopa is a metabolic precursor of dopamine that as I mentioned above is what is depleted in Parkinson’s and Carbidopa that can inhibit the breakdown of levodopa and thus increasing the availability of the drug. The FAA has also approved airmen who have had a deep brain stimulator. This device is inserted into the area of the brain involved in Parkinson’s. The fact that the FAA only accepts one medication is also restrictive as many patients develop a tolerance to the drug and it becomes non-functional.