Parkinson’s disease is a disorder that affects small regions in the brain that control movement, posture and balance. It is a complex disease that has many different symptoms, so that not everyone with the condition suffers from the same problems.
Parkinson’s disease is named after the British doctor who wrote the first book about the disease, in 1817, that made it an easily recognized entity. Parkinson called it, “The Shaking palsy,” or “paralysis agitans.” In his day, the term “agitans” referred to tremors. “Palsy” meant weakness and “paralysis” meant paralyzed, so the condition was considered a disorder of weakness and tremors, which is not completely true, as we shall see. Parkinson was famous in his day because of his political activities as an advocate for the poor, his scientific publications on geology and his invention of the truss, in the days before surgery for hernias was available.
It took 100 years before the major brain changes were first noted in the brains of people with Parkinson’s disease, and another 50 years after that before most experts agreed that these changes were, in fact, the disease process itself. In the early 1960’s the understanding of the importance of the brain chemical, dopamine (di-ortho-phenyl-alanine), came about, followed shortly thereafter by the first substantive treatment for Parkinson’s disease, L-Dopa. The treatment for Parkinson’s Disease was very poor before this. Parkinson himself recommended that a vertical incision be made in the back of the neck and that cork should be inserted to keep the wound from healing. He thought that the pus that developed in the infection represented the diseased fluids that were causing the disease so that drawing off this material would improve the patient. As you probably would guess, this never became too popular. L-Dopa wasn’t very popular at first either, even though it had a much better scientific rationale, because it caused so much nausea and vomiting. Carbodopa was developed soon thereafter, to prevent the vomiting, leading to the combined medication, carbidopa/levodopa, marketed as Sinemet (sine=without, emesis=vomiting). This drug remains the single best drug we have for treating the symptoms of Parkinson’s disease.
PD is common. It affects about 500,000- one million Americans, or about 1% of people over the age of 60. After Alzheimer’s disease, it is the second most common progressive, neurological disorder in the US. In the state of Rhode Island alone, with a population of only one million people, there are an estimated 1-2,000 people with PD. Although there is a large amount of research on PD, we still don’t know what causes it. And we even have some trouble diagnosing it at times.
The more that Parkinson’s Disease is studied, the more intricate we find the condition to be. Although most people think of it as a disorder of movement, posture and balance, it may also affect behavior. Only over the past 15 years or so have doctors started to investigate this important area. Treatments of PD have focused until recently only the movements, but we now see the disorder in a more realistic, holistic way. Quality of life has become a more central focus as we deal with a disease we cannot yet cure.
When we talk about treating Parkinson’s Disease we currently only mean treating the symptoms. The actual disease is an attack on the nerve cells in the brain, and, to a lesser extent, outside the brain. Our current medications have been shown to improve symptoms, meaning that by helping to restore a more normal chemical balance in the brain, we improve the tremor, stiffness, slowness, mobility, etc, but we haven’t really altered the process that is causing the damage. It is very similar to treating a cold. We take medications that make the sore throat feel less painful, the cough less severe and the aching much less, but we haven’t done anything to stop the virus that is causing the problem. Our body fights it off over the next few days, while we take medications to make us more comfortable. Unfortunately, of course, in PD, the illness doesn’t get better.
There are many who believe that once you start medications for Parkinson’s Disease that they stop working in five years. This is actually written in many places, and I’ve met doctors who told me they were taught this in medical school. This is UNTRUE. The medications for Parkinson’s Disease may not keep up with the progression of the disease. They may start to cause side effects. But they always continue to provide benefit. Sometimes, it is true, when the disease has become extremely severe, which is quite rare, the medications stop helping. How this happens will be explained in another chapter.