Of all the health threats facing elderly Americans, few are more ominous and threatening than Parkinson’s disease. With an alarmingly high mortality rate and symptoms strong enough to cripple a patient’s central nervous system, Parkinson’s has received intense focus from both medical researchers and media outlets over the last several decades. Unfortunately, these efforts have only had limited success in treating and preventing Parkinson’s, as the disease still takes a heavy toll on those unlucky enough to get it. Linda Ronstadt, a recording artist with over 100 million in album sales to her credit, announced in August 2013 that Parkinson’s had completely robbed her of her signing voice.
The Importance of Dopamine
Though you may have never heard of it, rest assured that dopamine is an essential ingredient for a healthy brain, and by extension a healthy body. Dopamine is classified as a neurotransmitter, meaning that it is a chemical tasked with carrying messages between nerve cells. The brain uses dopamine to control the body’s motor skills; without it, the body would be completely unable to perform specific motions with its muscles, bones and various tissues.
The effects of Parkinson’s can be directly traced to lack of dopamine output within the brain. In order to function properly, the brain relies on a collection of cells known as the “substantia nigra” to routinely produce dopamine. When these cells begin to wither and die, the brain’s production of dopamine steadily declines, allowing for the development of Parkinson’s disease. To date, medical researchers have yet to determine why the substantia nigra unexpectedly disintegrates.
The Five Stages of Parkinson’s
The prognosis for Parkinson’s patients is tragically grim. According to a 2012 study from Washington University in St. Louis, some 140,000 Medicare beneficiaries were diagnosed with Parkinson’s in 2002. A mere six years later, a stunning 64 percent of these patients had died. When compared with other diseases afflicting Medicare recipients, Parkinson’s claimed roughly as many lives as Alzheimer’s and was far deadlier than colorectal cancer or chronic obstructive pulmonary disease (COPD). Overall, Parkinson’s patients live an average of roughly 9 years before succumbing to the disease.
Despite its often-fatal effects on the body, the initial signs of Parkinson’s are often so minor that the disease remains undiagnosed for years. Ronstadt herself was only diagnosed with Parkinson’s in January 2013, even though she had experienced Parkinson’s-related symptoms for eight years prior to the diagnosis. Compounding this problem is that doctors have no blood or laboratory tests that can accurately identify Parkinson’s disease.
As subtle as they are, the first symptoms of Parkinson’s can be spotted with a keen eye. In total, the effects of Parkinson’s can be divided into five distinct stages, the details of which are described in the following section:
During the first stage of Parkinson’s disease, the patient and his or her loved ones might observe slight changes in posture and balance. The patient’s facial muscles can also be adversely affected, causing the face to appear blank and emotionless. Perhaps the most noticeable sign that something is amiss are tremors, which are defined simply as involuntary muscle movements in one or more parts of the body. In Parkinson’s patients, tremors frequently afflict the arms, legs and hands.
By the time Parkinson’s develops into its second stage, its symptoms have usually become bilateral in nature, meaning that they impact both sides of the body. With the spread of symptoms to previously unaffected areas, the patient’s coordination, balance and ability to walk all decline noticeably. This not only puts the patient at risk of suffering falls, but also makes performing once easy tasks much more difficult.
Stage 3 Parkinson’s patients often see their ability to walk or even stand become greatly diminished, to the point that both become exceedingly challenging. Physical movements in general require much effort from the patient, a development which greatly interferes with the performance of routine household actions. Doctors often refer to this stage of the disease as moderate Parkinson’s. Despite the obvious deterioration in the patient’s physical abilities, people with stage 3 Parkinson’s are usually able to live without assistance.
Stage 4 Parkinson’s disease is also known as advanced Parkinson’s disease, a fitting title considered the severity of the patient’s symptoms. By this point, many patients’ motor skills and coordination have deteriorated to the point where they can no longer care for themselves.
Bradykinesia, a condition in which the body’s movements become alarmingly slow, is a common feature of stage 4 Parkinson’s. Patients with bradykinesia experience a massive erosion of their motor skills, making it all but impossible for them to do things like button a shirt or use a fork. Another telltale sign of a worsening case of Parkinson’s is rigidity, which causes the body’s muscles to become stiff, painful and weak.
Predictably, the final stage of Parkinson’s is the most severe form of the disease. The patient is rendered completely dependent on the aid of caregivers, and may require assistance with performing every single physical action. Stage 5 Parkinson’s can prevent a patient from walking or even standing, and may also cripple the body’s cognitive functions and memory, leading to the onset of dementia.
Fighting Parkinson’s Symptoms
Like other incurable diseases, modern medicine can only seek to alleviate the symptoms of Parkinson’s. Some of these medications can be quite effective at reigning in Parkinson’s, albeit on a temporary basis. One such drug is levodopa, which is usually taken in conjunction with another medication called carbidopa. Upon entering the brain, levodopa is converted into sorely-needed dopamine. Carbidopa functions as a sort of protective escort, preventing the levodopa morphing into dopamine before reaching the brain. These two medications are not without side effects; patients have been known to experience nausea, fainting and involuntary movements called dyskinesia.
Though it may initially prove beneficial to the patient, the levodopa/carbidopa combination can only stave off Parkinson’s for so long. When these medications are no longer effective, the patient may be prescribed drugs known as dopamine agonists, which behave similarly to dopamine once inside the body. While lacking the effectiveness of the levodopa/carbidopa combination, dopamine agonists tend to have a longer shelf life than first-line Parkinson’s drugs. Unfortunately, they also carry with then a good deal of baggage. In addition to side effects caused by levodopa, dopamine agonists can also lead to hallucinations, swelling, fatigue and even compulsive behavior.
Some patients improve after being administered MAO-B inhibitors. This type of medication works in tandem with levodopa, shielding the latter drug from attacks by the body’s enzymes. MAO-B inhibitors can be prescribed in the initial stages of Parkinson’s, allowing the patient’s health to hold up longer without the use of levodopa. Conversely, they can also be employed in the latter stages of Parkinson’s, as a way to prolong the effects of levodopa and carbidopa. Undesirable side effects are not especially common with MAO-B inhibitors; when side effects do occur, they can appear in the form of nausea and headaches.
Aside from the medications outlined in the preceding paragraphs, other medications for Parkinson’s include anticholinergics and COMT inhibitors.
Some patients with Parkinson’s undergo a procedure known as a deep brain stimulation. Given that the disease has usually advanced into its latter stages by this point, the goal of this surgery is to treat Parkinson’s symptoms that cannot be contained by oral medications. During this procedure, electrodes are inserted into the patient’s globus pallidus, a section of the brain that helps to control the body’s voluntary movements. Immediately after being installed in the brain, the electrodes are subsequently activated, allowing them to transmit electrical pulses to certain areas in the brain.
At first glance, it might seem odd that electrical pulses could have any impact on Parkinson’s symptoms. After all, isn’t Parkinson’s caused by a shortage of dopamine within the brain? Well, that’s certainly true, but what must be mentioned is that this lack of dopamine negatively impacts on the brain’s nerve cells, causing them to emit impulses in an irregular and erratic pattern. In turn, these impulses cause the patient to develop tremors.
Though the electrodes can effectively neutralize these troublesome impulses, a deep brain simulation procedure is not without risk. A small number of patients have experienced complications such as paralysis, altered thinking patterns, noticeable shifts in personality, diminished memory and infection. The odds of encountering such side effects are fairly small, however, as only 2 to 3 percent of patients who undergo this surgery report such problems.
With its severe impact on the body and lack of a cure, a diagnosis of Parkinson’s is deservedly met with grave concern by the patient and his or her loved ones. While there is still no way to vanquish Parkinson’s, proper medical attention can serve to lessen Parkinson’s symptoms and prolong a patient’s life.