Symptoms and Diagnosis
Parkinson's disease does not affect everyone the same way. Symptoms of the disorder and the rate of progression differ among individuals. Sometimes people dismiss early symptoms of Parkinson's as the effects of normal aging. There are no medical tests to definitively detect the disease, so it can be difficult to diagnose accurately.
Early symptoms of Parkinson's disease are subtle and occur gradually. For example, affected people may feel mild tremors or have difficulty getting out of a chair. They may notice that they speak too softly or that their handwriting is slow and looks cramped or small. This very early period may last a long time before the more classic and obvious symptoms appear.
Friends or family members may be the first to notice changes in someone with early Parkinson's. They may see that the person's face lacks expression and animation, a condition known as "masked face," or that the person does not move an arm or leg normally. They also may notice that the person seems stiff, unsteady, or unusually slow.
As the Disease Progresses
As the disease progresses, symptoms may begin to interfere with daily activities. The shaking or tremor may make it difficult to hold utensils steady or read a newspaper. Tremor is usually the symptom that causes people to seek medical help.
People with Parkinson's often develop a so-called parkinsonian gait that includes a tendency to lean forward, small quick steps as if hurrying forward (called festination), and reduced swinging of the arms. They also may have trouble initiating or continuing movement, which is known as freezing.
Symptoms often begin on one side of the body or even in one limb on one side of the body. As the disease progresses, it eventually affects both sides. However, the symptoms may still be more severe on one side than on the other.
Four Primary Symptoms
The four primary symptoms of Parkinson's are tremor, rigidity, slowness of movement (bradykinesia), and impaired balance (postural instability).
- Tremor often begins in a hand, although sometimes a foot or the jaw is affected first. It is most obvious when the hand is at rest or when a person is under stress. It usually disappears during sleep or improves with a deliberate movement.
- Rigidity, or a resistance to movement, affects most people with Parkinson's. It becomes obvious when another person tries to move the individual's arm, such as during a neurological examination. The arm will move only in ratchet-like or short, jerky movements known as "cogwheel" rigidity.
- Bradykinesia, or the slowing down and loss of spontaneous and automatic movement, is particularly frustrating because it may make simple tasks somewhat difficult. Activities once performed quickly and easily, such as washing or dressing, may take several hours.
- Postural instability, or impaired balance, causes people with Parkinson's to fall easily. They also may develop a stooped posture with a bowed head and droopy shoulders.
A number of other symptoms may accompany Parkinson's disease. Some are minor; others are not. Many can be treated with medication or physical therapy. No one can predict which symptoms will affect an individual person, and the intensity of the symptoms varies from person to person. Many people note that prior to experiencing motor problems of stiffness and tremor, they had sleep problems, constipation, decreased ability to smell, and restless legs.
Other symptoms include
- emotional changes
- cognitive problems (problems with thinking and/or remembering)
- difficulty swallowing and chewing
- speech changes
- urinary problems
- skin problems, sleep problems
- orthostatic hypotension (a sudden drop in blood pressure when standing up from a sitting or lying down position)
- muscle cramps and dystonia (twisting and repetitive movements)
- fatigue and loss of energy
- sexual dysfunction.
Diseases and Conditions That Resemble Parkinson's
A number of disorders can cause symptoms similar to those of Parkinson's disease. People with Parkinson's-like symptoms that result from other causes are sometimes said to have parkinsonism. While these disorders initially may be misdiagnosed as Parkinson's, certain medical tests, as well as response to drug treatment, may help to distinguish them from Parkinson's. These disorders include multiple system atrophy, dementia with Lewy bodies, progressive supranuclear palsy, and corticobasal degeneration.
Diagnosis Can Be Difficult
There are currently no blood, or laboratory tests to diagnose sporadic Parkinson's disease. Diagnosis is based on a person's medical history and a neurological examination, but the disease can be difficult to diagnose accurately. Early signs and symptoms of Parkinson's may sometimes be dismissed as the effects of normal aging. A doctor may need to observe the person for some time until it is clear that the symptoms are consistently present. Improvement after initiating medication is another important hallmark of Parkinson's disease.
Doctors may sometimes request brain scans or laboratory tests to rule out other diseases. However, computed tomography (CT) and magnetic resonance imaging (MRI) brain scans of people with Parkinson's usually appear normal. Recently, the FDA (Food and Drug Administration) has approved an imaging technique called DaTscan, which detects signals related to dopamine function and may help to increase accuracy of the diagnosis of Parkinson’s disease. Since many other diseases have similar features but require different treatments, it is very important to make an exact diagnosis as soon as possible to ensure proper treatment.