As many as one million Americans live with Parkinson’s disease, a chronic movement disorder that develops in middle to late age, typically around 60, though younger people can also develop Parkinson’s; early-onset Parkinson’s affects individuals between 21 and 50. This neurological disease prevents the production of neurotransmitters that help regulate muscle movement in the body. Early symptoms of Parkinson’s disease are mild and may go unnoticed. However, they eventually worsen as the disease progresses.
Categories of Symptoms
Medical professionals divide Parkinson’s symptoms into three categories: primary motor symptoms, secondary motor symptoms, and non-motor symptoms.
- Primary motor symptoms affect primary motor movements. The brain sends messages to the spinal cord to cause contraction and movement of specific muscles.
- Secondary motor symptoms are those that result from the primary motor symptoms.
- Non-motor symptoms are those connected to cognition, memory, sleep, and natural bodily functions.
A person does not have to present all the symptoms to receive a Parkinson’s diagnosis.
Early Symptoms
Parkinson’s disease symptoms are often vague and non-specific in the early stages and may consist of all three types. Early on, the symptoms may come and go. Many people describe feeling increasingly exhausted for long periods. Others say they feel slower, both mentally and physically. Feelings of depression are not unusual. Physically active individuals sometimes discover issues during a normal workout. A runner may feel their leg does not move in coordination with the rest of their body, for example. Another person experiencing early symptoms of Parkinson’s may start to shuffle when they walk or develop a lack of movement in their face. Another early sign is a mild tremor in the hands or feet and a change in the size of a person’s handwriting. Sometimes, these early symptoms are more apparent to outside observers than the affected individual.
Primary Motor Symptoms
Physicians evaluate five primary motor symptoms associated with movement when diagnosing Parkinson’s. These symptoms vary in their intensity and how quickly they progress. Medical professionals look for tremors, rigidity, bradykinesia or slow movement, postural instability or balance problems, and gait issues during an evaluation. Some people may experience one or two of these symptoms, while others experience them all. In most cases, a neurologist or movement disorder specialist determines a Parkinson’s diagnosis.
Tremor
Although most people associate tremors with Parkinson’s disease, not everyone experiences them. Tremors are one of the five primary motor symptoms. Some people with Parkinson’s experience a resting tremor that starts in a hand, foot, or leg on one side of the body. It then spreads to both sides as the disease progresses. A resting tremor may also occur in the jaw, chin, mouth, or tongue. Some people diagnosed with Parkinson’s report feeling an inner tremor as well, which is not visible to anyone else.
Rigidity
Individuals move in unique ways. Some of these specific movements change with the onset of Parkinson’s disease. A person who normally swings their arms when they walk may stop doing so, and this could be a symptom of the disease. Rigidity is a tightness or stiffness of the limbs or torso. Instead of contracting and relaxing normally, the muscles remain tense, preventing the arms from moving freely. In the early stages of Parkinson’s, doctors sometimes misdiagnose rigidity as arthritis or an orthopedic injury.
Bradykinesia
Bradykinesia describes a slowness of movement and is another of the primary motor symptoms of the disease. This symptom causes the brain to become very slow in transmitting instructions to the body. Bradykinesia also results in a gradual reduction in spontaneous movement. The eyes may blink at a slower rate, the face may take on a mask-like appearance, and the individual may have trouble with simple tasks, such as buttoning a shirt. Some people experience a condition called freezing of gait. They feel that they are stuck to the floor and cannot move forward. This causes problems with balance and walking.
Secondary Motor Symptoms
Secondary motor symptoms of Parkinson’s include speech difficulties, stooped posture, and restless, fidgety movements called akathisia, which may also be a side effect of the medications used to treat the disease. Physicians will also evaluate reported symptoms such as unwanted accelerations in movement or speech. Many people begin to experience difficulty with precise hand movements, such as working a computer mouse or sewing. Micrographia is a change in a person’s handwriting resulting from bradykinesia; the individual’s handwriting becomes much smaller and the words crowd together. This may emerge as an early symptom, but is not present in every person with Parkinson’s.
Dysphagia
In recent years, researchers have dispelled an earlier belief that swallowing problems, a secondary motor symptom, occur only in the later stages of Parkinson’s disease. Some people experience disordered swallowing or dysphagia early on, and it may be one of the first symptoms of the disease. Most individuals with dysphagia report difficulty swallowing solid foods. A person may feel their food is getting stuck in the throat or chest. Others say food and liquids go down the wrong way, which causes aspiration. Dysphagia can make it harder to take medications and may become severe enough to cause malnutrition.
Dystonia
Some people with Parkinson’s disease experience a movement disorder called dystonia, a secondary motor symptom. This condition causes involuntary, repetitive muscle movements that twist the body into specific postures and prevent a person from moving the way they want to. It can be, but isn’t always, painful. Dystonia may affect the eyes, neck, torso, and limbs. However, dystonia can also be a symptom of brain lesions, medication side effects, and genetic disorders.
Non-Motor Symptoms
Non-motor symptoms of Parkinson’s incorporate reactions to both the disease itself and the medications used to treat it. They include sleep problems, depression, anxiety, and cognitive changes. Medications may cause vivid dreams, which could contribute to an inability to sleep through the night. Those in more advanced stages may have problems thinking and finding the right words during a conversation. Both depression and anxiety are common symptoms but usually improve with treatment and medications. People with Parkinson’s also have an increased risk of melanoma. Additional non-motor symptoms doctors evaluate include:
- Excessive sweating, especially in the upper body.
- Constipation
- Frequent urination and urinary urgency
- Eye and vision problems due to diminished eye movement and slowed blinking
- Personality changes, such as impulse control disorders
- Lightheadedness, blackouts, and fainting
- Weight loss
Diminished Sense of Smell
Most people with Parkinson’s experience a reduced sense of smell, which is a secondary symptom of the disease. Doctors say this symptom has to do with changes to the olfactory bulb in the brain, the primary relay station for smell signals. This condition, hyposmia, usually occurs before more noticeable symptoms appear. Most individuals do not realize they are experiencing a diminished sense of smell and it goes unnoticed, but researchers now know it is a prevalent symptom, occurring in more than 90 percent of people in the early stages of Parkinson’s.
Sialorrhea
Excessive saliva and drooling is another symptom of Parkinson’s. Some physicians see this as a motor symptom, but others say it is more likely a result of swallowing issues, such as dysphagia, or other automatic actions of the body. Individuals with Parkinson’s have a reduction in these automatic actions. They produce a normal amount of saliva, but they have difficulty swallowing and so the drool pools in their mouth. The more severe the drooling is, the more difficult it is to swallow.
Hypophonia
A majority of those with Parkinson’s experience voice problems because the disease causes alterations to the muscle tone that affect the muscles required for speech. One of the most common of these speech issues is hypophonia or soft speech. Some people also develop a reduced distinction between questions and answers. They may speak in a monotone voice and have difficulty hearing their own level of loudness. As the disease progresses, listeners often find it difficult to understand the affected individual.
Hypomimia
Facial masking, or hypomimia, results in the immobilization of the facial muscles, leading to a blank expression. Because the face exhibits emotional cues, listeners try to connect what a person is saying with the expression on his or her face. A person with Parkinson’s may be talking about an emotional topic, but their face will not reflect their emotion. Current research is focusing on occupational therapy and ways to help Parkinson’s patients with hypomimia express themselves more effectively so that others understand them.
Hyperhidrosis and Anhidrosis
Although it may not seem serious, hyperhidrosis — excessive sweating — is another symptom of Parkinson’s disease. Individuals tend to experience hyperhidrosis primarily on the bottoms of their feet, their palms, or the upper parts of the body. Some report severe night sweats that interrupt their sleep. Both Parkinson’s itself and medications can cause this issue; in the case of the latter, doctors may be able to alleviate the symptom by adjusting the dosage. Anhidrosis or hypohidrosis is the opposite issue, causing a lack of sweating. This symptom is usually due to medications but may also be caused by the disease itself.