What Is Parkinson’s Disease?
What Causes Parkinson’s Disease?
Parkinson’s disease, also known as Parkinson disease, PD, paralysis agitans, and shaking palsy is a gradually progressive, degenerative neurologic disorder which typically impairs the patient’s motor skills, speech, writing, as well as some other functions. Sufferers often have a fixed, inexpressive face, tremor at rest, slowing of voluntary movements (bradykinesia), an unusual posture, and muscle weakness. In extreme cases there is a loss of physical movement (akinesia).
Parkinson’s disease is both chronic and progressive. Chronic means long-term, while progressive means it gradually gets worse.
Parkinsonism is a neurological syndrome characterized by tremor, rigidity, postural instability, and hypokinesia (decreased bodily movement). A syndrome is the association of several clinically recognizable features, signs, symptoms, phenomena or characteristics that often occur together. Parkinson’s disease is the most common cause of Parkinsonism. Put simply – Parkinsonism includes the signs and symptoms that resemble Parkinson’s disease.
While about 5% of individuals with Parkinson’s disease are under the age of 40 years, the majority are over 50. When signs and symptoms develop in an individual aged between 21 and 40 years, it is known as Young-onset Parkinson’s disease. Approximately 1 in every 20 patients diagnosed with PD is under 40 years of age. When signs and symptoms appear in people under 18 years of age, it is known as Juvenile Parkinson’s disease. It affects both sexes; males slightly more than females.
According to the National Institutes of Health (NIH), USA, approximately 500,000 Americans are affected by Parkinson’s disease; about 50,000 new diagnoses are made each year. The National Health Service (NHS), UK, estimates that about 120,000 people in the United Kingdom are affected.
As a significant number of elderly patient with early Parkinson’s disease symptoms assume that their symptoms may form part of normal aging and do not seek medical help, obtaining accurate statistics is probably impossible. There are also a several different conditions which sometimes have comparable signs and symptoms to PD.
PD is named after James Parkinson (1755-1824), an English apothecary surgeon, paleontologist, geologist and political activist. In his most famous work An Essay on the Shaking Palsy (1817), he was the first person to describe paralysis agitans, which eventually was named after him.
Parkinson’s disease belongs to a group of conditions called movement disorders. Movement disorders describe a variety of abnormal body movements that have a neurological basis, and include such conditions as cerebral palsy, ataxia, and Tourette syndrome. Parkinson’s disease results from decreased stimulation of the motor cortex by the basal ganglia, typically caused by insufficient formation and action of dopamine.
There is no current cure for Parkinson’s disease (April, 2010). Treatment focuses on alleviating symptoms. Sometimes treatment may include surgery.
According to Medilexicon’s medical dictionary:
- A neurologic syndrome usually resulting from deficiency of the neurotransmitter dopamine as the consequence of degenerative, vascular, or inflammatory changes in the basal ganglia; characterized by rhythmic muscular tremors, rigidity of movement, festination, droopy posture, and masklike facies.
- A syndrome similar to parkinsonism. Some features seen with Parkinson’s disease that occur with other disorders (progressive supranuclear palsy) or as a side effect of certain medications (antipsychotic drugs).
What Are The Signs and Symptoms of Parkinson’s Disease?
A symptom is something the patient feels and describes, while a sign is something other people, such as the physician notice. For example, drowsiness may be a symptom while dilated pupils may be a sign.
Parkinson’s disease causes problems with movement, cognitive problems, neurobehavioral problems, as well as sensory and sleep difficulties. The signs and symptoms usually begin gradually, slowly and often randomly (in no set order).
Each sufferer will be affected differently, with a unique set of symptoms. Patients also tend to respond differently to treatment. Symptom severity also varies enormously. Some patients may experience tremor (shaking) as their primary symptom, while others may not have tremors, but have balance problems. While the disease may develop slowly for some individuals, for others it progresses rapidly.
The four main signs and symptoms include slow physical movements (bradykinesia), shaking (tremor), muscle stiffness (rigidity) and postural instability (impaired balance and coordination). They are called the primary motor symptoms:
Primary motor symptoms:
- Bradykinesia (slowness of movement, slowed motion) – initiating movement, such as beginning to get up from a chair can become more difficult. The patient typically takes longer to carry out tasks. There is also a lack of coordination. The difficulty is not only with the execution of movement, but also with its planning and initiation. Bradykinesia is often tolerated by elderly patients, who think they are entering normal milestones of aging – such patients may eventually be diagnosed with PD later on, when other signs and symptoms develop.
- Resting tremor (shaking) – the characteristic shaking frequently starts in one hand, such as a back-and-forth rubbing of the thumb or forefinger (pill-rolling). Tremor may start in a foot or one side of the body, and less commonly in the jaw or face. Tremor is usually more likely to occur when that part of the body is resting – stress and/or anxiety may make the tremor more noticeable. However, substantial tremor is not always present in many patients. Other conditions may include tremor as one of their symptoms, such as multiple sclerosis, encephalitis (inflammation of the brain), or alcoholism. The presence of tremor does not necessarily mean the individual has Parkinson’s disease. According to the Parkinson’s Disease Foundation, USA, approximately 70% of people with Parkinson’s experience a slight tremor in the early stages.
- Rigidity (muscle stiffness) – the muscles feel stiff. Doing some everyday tasks may be troublesome, such as getting out of a chair, rolling over in bed, using body language appropriately, or making fine finger movements. Most commonly, stiffness occurs in the limbs and neck. It can be so severe that the range of movements is severely undermined. Sometimes there is pain.
- Posture and balance – there may be instability when standing, or impaired balance and coordination. These symptoms, combined with bradykinesia significantly increase the risk of falling.
Secondary motor symptoms:
- A tendency to stoop, to lean forward
- Handwriting may be very small and cramped (micrographia)
- Impaired fine motor dexterity (fine finger movements)
- Impaired motor coordination
- Involuntary movements and prolonged muscle contractions (dystonia)
- Loss of facial expression – some individuals may appear uninterested (not animated) when speaking, while others stare fixedly with unblinking eyes.
- Sexual dysfunction
- Speech problems – the sufferer may have a softer voice, utterances may come out more rapidly or slowly, or in a monotone. There may be repeated words or slurring.
- Swallowing difficulties (dysphagia)
- The arms may not swing when walking
Other signs and symptoms may include:
- Dementia – this may develop in the later stages of the disease. The patient may have memory and mental clarity problems. A person with Parkinson’s is six times more likely to develop dementia, compared to other people.
- Sleep problems – which may be worsened by medications for Parkinson’s disease. However, sleep problems are a core feature of the disease. The patient may be excessively sleepy during the day; there may be disturbances in REM (rapid eye movement) sleep, as well as insomnia.
- Dysphagia (difficulty swallowing)
- Fatigue, tiredness, loss of energy
- Paresthesia – a sensation of tingling, pricking, or numbness of a person’s skin (pins and needles)
- Reduced sensation of pain
- Reduced sense of smell
- Urinary incontinence (bladder weakness)
- Urinary retention (difficulty getting rid of urine)