What is Parkinson’s disease?
Nearly everyone at one time or another has heard of Parkinson’s disease. A vast majority of people have little to no understanding as to what it really is and what it entails, although a large majority know someone or know of someone who has been afflicted with it. The extent of public knowledge is typically displayed in a couple of blanket statements. The first is almost always “Isn’t that what Michael J. Fox has?” and the second is usually “Doesn’t it make you shake and move funny?” Well, both are true, the second only to a certain degree because a majority of the time the involuntary movements or dyskinesias are a result of the medications not the disease itself. It clearly represents a lack of public education in regards to neurological disorders such as Parkinson’s.
Unfortunately Parkinson’s is becoming more known. I say unfortunately because it is becoming far more common and affecting a much broader age group in a much wider demographic area. It is becoming more common than some types of cancer. Parkinson’s is no longer known only for its tremor, stooped posture and shuffling gate, it is comprised of an entire range of symptoms, many of which would not previously be associated with the disease.
Estimations as to the number of people afflicted with Parkinson’s vary widely. It is suspected that somewhere between 500,000 and 1.5 million people in the United States currently have Parkinson’s and anywhere from 7 to 10 million worldwide are afflicted. It is also estimated that approximately 60,000 new cases are diagnosed annually in the United States. This estimated number has been used since around 2005, so the actual incidence is probably much higher. Another important factor that only receives partial consideration is the fact that a large number of cases are misdiagnosed. Many people are diagnosed with Parkinson’s that actually suffer from another type of illness. The clinical manifestations are present so it becomes a case of idiopathic Parkinson’s. Sadly, once this diagnosis is given the patient is immediately put on a maintenance program and any further attempts at finding the cause of the condition are almost immediately ceased. The clinical diagnosis of secondary Parkinsonism is most often determined shortly before or after death. Neurologists often claim that the rate of misdiagnosis represents only about 6 percent of patients, though many scientists will put the rate closer to 50-60 percent which is something to note (We'll address this later). The actual numbers are truly unknown because Parkinson’s is not considered a reportable illness and there is currently no requirement to document the actual number of cases diagnosed.
A mandate to report neurological diseases and their incidence in a national database failed twice in the U.S. Congress even though the cost was estimated at $20 million over 5 years which is a paltry sum compared to other expenditures on far less important items and initiatives. If you are a member of Congress that buried these bills, shame on you for deterring research and preventing science from determining the cause of this disease and finding a cure.
I’m not going to cover the history of Parkinson’s other than a few brief notes, as it is not relevant to this writing. There were a few notations in early times in Egypt, India and some biblical contexts of illnesses that resembled Parkinson’s. Any other mention was apparently absent until the 17th and 18th century. In the early 1800’s Dr. James Parkinson described cases of paralysis agitans or “Shaking Palsy” in 6 patients. During the next 150 years the essential clinical features, brain interactions and basic biochemical foundations were laid. Most of the pertinent biochemical studies including etiology have occurred primarily in the last 45 years. A majority of the clinical trials and efforts to find the root cause or find a cure have ended in failure and several relevant theories have essentially been abandoned. Parkinson’s wears many different faces and every case is different in some way making it difficult to understand.
Parkinson’s is a progressive disorder that affects the nervous system, both autonomic and sympathetic. It is most often referred to as a “Neurological Disorder”. I personally make a slight distinction to the wording because even though symptomatically Parkinson’s is in fact a neurological disorder, the root cause of the disease may ultimately lie in other organ dysfunction or through other metabolic pathways that directly affect brain chemistry. The primary biological feature is the death of dopamine-producing cells in the brain. There are a large number of enzymatic and metabolic functions related to this. In addition, there are other associated symptoms that vary amongst Parkinson’s patients that are certainly relative to the particular etiology of the disease. The same clinical features are not universally seen in all presentations of the disease.
Parkinson’s typically affects people later in life, mostly in their 50’s and 60’s but cases of people being diagnosed in their 30’s and 40’s are becoming frighteningly more common. This is known as Young Onset Parkinson’s Disease. The symptoms of Parkinson’s often go unnoticed or overlooked for many years and can present themselves in many different fashions. Tremor is most often cited as the predominant feature of Parkinson’s’ but this idea is slowly being re-evaluated. About 30 percent of Parkinson’s patients never develop tremor throughout the course of the disease.
Subtle signs of the disease are a feeling of weakness in a limb, lack of dexterity or coordination, clumsiness, imbalance, muscle cramps or small handwriting (microphagia). In addition there has been suggestion that loss of taste or smell, clinical depression, difficulty concentrating or memory loss may be early indications. None of the latter has been clinically or pathologically proven to date.
When symptoms become obvious they can present quite rapidly, even within a matter of weeks or days with no other indications. It most typically affects one side of the body first, which is actually a clinical distinction between Idiopathic Parkinson’s and Parkinsonism. Research as to whether it affects the dominant side of the body first appears to be almost completely absent. The onset of the disease can present in many different ways. Parkinson's can start with a limp, a tremor when resting, slow or uncoordinated movements in any part of the body, painful cramping, involuntary movements, imbalance, stumbling or ataxia are also common. Symptoms can also go unnoticed for years.
Even though there is a fairly well established set of criteria that define the symptoms of Parkinson’s it appears that nothing is off the table when the initial symptoms present themselves. In fact, the initial symptoms can be so broadly based and have so many different causes, it often takes years to diagnose the disease. It is only after a seemingly endless series of tests to eliminate other potential ailments or disorders that a clinical diagnosis can be given. The diagnosis is given by committee which means that all other possibilities have been eliminated. This is not entirely true when it comes to Parkinson’s. What actually happens is that after a battery of standard tests have been completed and no other cause of the ailment has been conclusive, a neurologist will typically prescribe a trial dose of Levodopa.
If the symptoms are alleviated this is considered conclusive evidence of the disease to a degree and is often the final stage of diagnosis leaving many possibilities unchecked. If the response to Levodopa is poor then considerations are made for Parkinson’s plus syndromes or Paraneoplastic causes (cancer) which is not often pursued. These have similar symptoms at onset but respond poorly to Levodopa and can often be clinically diagnosed later in the disease through MRI and PET, DAT scans or other methods as they progress. Parkinson’s plus syndromes often have several definitive clinical features that can be identified on these tests. In addition, the life expectancy for these syndromes is very short. Neither of these is the case with Parkinson’s. There is no definitive test and overall life expectancy does not change significantly in true variations of Parkinson’s. Unfortunately as previously stated, once a diagnosis is made, further investigations into the cause of the ailment are ceased. This in and of itself can be a death sentence for a Parkinson’s patient because there are a host other illnesses that can cause similar symptoms such as AIDS, encephalitis, meningitis, stroke, Diffuse Lewy Body Disease, MSA, PSP, Tertiary Syphilis, Advanced Lyme Disease, certain types of cancer, medications, carbon monoxide poisoning, mercury and chemical poisoning, narcotics and other yet unknown causes just to name a few. All of these possible causes should certainly be eliminated but it is actually infrequent that all of these tests are completed or clinically eliminated. Those that are diagnosed in a shorter period of time via Levodopa trial may in fact be at higher risk of dying from another disease than those with a lengthy diagnosis period. This is certainly due to the fact that they would undergo fewer tests leading up to the clinical diagnosis. All possible avenues should be exhausted even with a positive levodopa response.
A majority of doctors are not familiar with the signs and symptoms of Parkinson’s disease. They are trained to complete standard testing and make adequate referrals which they do strictly in accordance with current medical standards. Most frequently Parkinson’s patients are referred to an orthopedist when initial examination does not reveal a definitive cause of the complaint. The orthopedist will then perform some very basic neurological tests, X-Rays, and MRI’s. A competent orthopedist will immediately refer the patient to a competent neurologist for further examination. Neurosurgeons are another avenue of referral and will examine the patient more closely, take detailed imaging and refer patients for other neurological testing such as evoked potentials (SSEP), VNG, EMG and CSF testing to eliminate other causes. These are the same tests that will be called for by a neurologist to eliminate other diseases such as Multiple Sclerosis. Neurologists use two different scales to assess symptoms. One is the Hoehn and Yahr scale, the other is the Unified Parkinson’s Disease Rating Scale (UPDRS). Both scales could use amending or updating but they are clinically effective to a degree.
General clinical symptoms are as follows:
-Change in facial expression (staring, lack of blinking)
-Failure to swing one arm when walking
-Flexion (stooped) posture
-“Frozen” painful shoulder
-Limping or dragging of one leg
-Numbness, tingling, aching or discomfort in the neck or limbs
-Softness or quietness of the voice
-Sensation of internal trembling
-Tremor while at rest
-Decreased facial expressions
-Difficulty initiating and controlling movement
-Loss or weakness of movement (paralysis)
-Stiffness of the trunk, arms or legs
As you can see, there are definite correlations between the two but Idiopathic Parkinson’s certainly carries a wider range of symptoms. It would be prudent for scientists to look at each symptom individually and determine the individual causes of each symptom. This would lead to more effective treatments based on the different etiologies of the disease. The range of symptoms in Parkinson’s is relatively broad considering that only a portion of them are required for clinical diagnosis.
Perhaps understanding that Parkinson’s disease is not just one particular incantation of illness but rather that it is a culmination of many different things will lead to more specific definitions of individually treatable illnesses and lift the umbrella from the symptoms that we now know as Parkinson’s disease. The reality may in fact be that there is no ‘One pill fits all’ treatment in this disorder. Abandoning that approach could potentially lead to more rapid treatment and potential cures in this complex disease.
I will cover the many aspects of Parkinson’s disease and the scientific research already conducted in relation to this disease in the following pages. It is surprising how much we already know of this disease and how little we have actually accomplished. With the number of people that have been afflicted with this disease, it would be thought that we should have progressed much further than we have. In fact, aside from surgical treatments such as DBS, we have done little to progress in the methods of treatment as the most effective drug for Parkinson’s was developed more than 40 years ago. Research has literally been all over the board with few clinically effective results. The only known and proven effective treatment has been discovered by scientists in Russia but this discovery was more than 5 years ago and will take years before it eventually comes to market. This is largely due to financial and political reasons combined. It does not cure Parkinson’s but it does alleviate all of the symptoms with minimal side effects yet lacks the proper backing to enter clinical trial.