This guide will help you understand:
- how Parkinson’s Disease develops
- how Parkinson’s Disease affects the body
- rehabilitation for Parkinson’s Disease consists of
- research related to Parkinson’s Disease
Anatomy
What is Parkinson’s Disease?
Parkinson’s Disease—also known as Parkinson’s or PD—is a progressive neurodegenerative disorder that affects the nervous system. This condition develops when nerve cells (neurons) in a structure called the substantia nigra become impaired or die. The substantia nigra belongs to a group of midbrain structures called the basal ganglia. Under healthy states, nerve cells in this region produce a neurotransmitter (chemical messenger) called dopamine. This neurotransmitter helps regulate mood, memory, motivation, and coordination.
When substantia nigra nerve cells become impaired or begin to die, they gradually stop producing dopamine, which leads to physical symptoms such as uncontrollable shaking, balance and coordination issues, and stiffness. Mental and behavioral changes, memory problems, sleep disturbances, fatigue, and depression may also develop. Symptoms typically begin to appear gradually and slowly worsen over time. The reason why nerve cells stop producing is unknown, but certain risk factors a system in the midbrain (substanstia nigra) which produces the chemical called dopamine, stops producing this chemical. It is still unknown why the cells stop producing dopamine. The chemical dopamine is required in the body for many things including coordination, mood, memory and motivation. It is interesting to note that usually by the time someone is diagnosed with Parkinson’s disease, around half of the dopamine-producing cells have already died.
History of Parkinson’s Disease
James Parkinson, a British apothecary, was credited with providing the first publication about this disease in 1817. He reported a summary of six cases of what he called ‘shaking palsy’ or ‘paralysis agitans’. All six patients presented with similar symptoms such as tremors, stooped posturing, abnormal gait, paralysis, and diminished muscle strength.
Additional researchers, including Jean-Martin Charcot, continued to study the disease, which led to the expansion of the early description. Charcot’s contribution also distinguished Parkinson’s disease from multiple sclerosis. By the end of the 20th century, a great advancement in the discovery of a genetic component that occurs in some people with the disease was made.
In particular, the early onset of Parkinson’s is often inherited, and certain forms of this disease are linked to specific gene mutations. For one Italian family—in which five generations were studied—it was discovered that over 60 family members were diagnosed with Parkinson’s disease. To better understand the factors that lead to Parkinson’s, an abundance of research is ongoing throughout the 21st century.
Signs and Symptoms
The type and severity of symptoms a person with Parkinson’s may display differs for each individual. In most cases, symptoms that occur early on are subtle and progress gradually. For some individuals, mild tremors may develop or they may struggle to get out of a chair. Others may notice that their handwriting has changed or experience a frail voice when they are speaking.
Family members and friends may also be the first ones to notice small changes in an individual who has early Parkinson’s disease. For instance, they may observe blank, emotionless facial expressions from their loved one, or that the person is struggling to move there is no single symptom that determines that one has PD. Nor is there one single test that is used to delineate that you have the disease. Each individual who is diagnosed with Parkinson’s disease may exhibit distinct signs and symptoms. A series of tests usually need to be performed to confirm suspected cases of Parkinson’s. However, the most common signs and symptoms are:
- muscle tremors in the hands, arms, head, jaw, or legs
- postural instability and impaired balance (difficulty remaining upright, especially when standing still or getting up from a chair)
- difficulty walking, taking small rapid steps (festinating gait)
- with walking, often taking shuffling (festinating) steps,
- slowness of movements and speed (bradykinesia)
- delayed ability to perform desired movements (akinesia)
- twisting or repetitive movements due to involuntary muscle contractions (dystonia)
- tense, stiff muscles that limit movement (rigidity)
- stooped posture or postural instability (body is often bent forward)
- increased postural sway (bodily motion when standing still)
- sleep disturbances and sudden movements during sleep
- loss of automatic movements such as blinking or swinging arms when walking
- decline in automatic facial expressions (facial masking)
- problems projecting one’s voice (only able to speak softly)
- handwriting changes (may become too difficult to coordinate) and/or can become very small (micrographia)
- psychotic episodes (seeing, hearing, smelling items that are not real)
- loss of motivation
- frequent dizziness
- fatigue
- drooling
- loss of smell
- constipation
- depression
Risk Factors
There are several factors that appear to play a role in the development of PD: There are several factors that appear to play a role in the development of PD:
- Age: The biggest risk factor for developing Parkinson’s disease is advancing age. Most commonly people are diagnosed with PD around the age of 60 or older. However, the risk of getting Parkinson’s disease increases with age and is considerably higher by the time an individual reaches the age of 85. Although it is uncommon for people to be diagnosed with this disease before the age of 60, it does occur. This type of case is referred to as ‘young-onset Parkinson’s disease’.
- Sex/Gender: Research has consistently demonstrated that men are more frequently diagnosed with Parkinson’s disease than women.
- Heredity: Having one or two close relatives with Parkinson’s disease increases the chances of developing this condition. However, this risk remains low unless many members of the same family have Parkinson’s.
About 10-25% of people diagnosed with this disease have a genetic link, while the majority of people with Parkinson’s disease did not inherit the condition.
In addition, there are some genetic variations (mutations) that can increase the chance of developing Parkinson’s, but people who have these mutations do not always develop this disease. Ongoing research is focusing on genetics as a causative factor for the disease. . - Environmental Factors: Some environmental factors such as pollution, circulating viruses, heavy metals, pesticides, herbicides, illicit drugs, and exposure to additional toxins may play a role in the onset of Parkinson’s disease.
- Head trauma: There is some evidence that suggests a history of traumatic brain injury (TBI) or repeated head trauma (e.g., boxers) may increase the risk of developing Parkinson’s disease. A serious brain injury can lead to the accumulation of a harmful protein called alpha-synuclein that causes nerve cell deterioration and death. Elevated levels of alpha-synuclein in nerve cells and cerebrospinal fluid (CSF) are associated with the onset of Parkinson’s for some individuals.
- Ethnicity: Research regarding the ethnicity-related risk of acquiring Parkinson’s is ongoing, but most studies show that White populations generally have the highest prevalence of Parkinson’s disease. However, individuals of Hispanic or Black ethnicity who are diagnosed with this condition often have a higher risk of experiencing severe cognitive impairment
Diagnosis
How do healthcare providers diagnose Parkinson’s Disease?