Parkinson’s disease causes a wide variety of symptoms. These range from movement problems — such as poor balance, stiff muscles, shaking and slowed movement — to changes in mood and energy, pain and problems with thinking. Not all symptoms of Parkinson’s disease are present at the time of diagnosis, and the progression varies between people. The natural course of Parkinson’s disease symptoms is to worsen over time.
Earliest Signs and Symptoms
Several years before the movement problems of Parkinson’s disease occur, a person who will develop the disease may have certain symptoms. This reflects early changes already happening in the person’s nervous system. One example is the condition known as REM sleep behavior disorder, in which a person acts out vivid or scary dreams. Others include a decreased sense of smell, constipation and depression. Excessive daytime sleepiness, fatigue and pain have also been associated with later development of Parkinson’s disease. However, many of these symptoms are common among older people in general, and not everyone who experiences them will go on to develop Parkinson’s disease.
Movement Signs and Symptoms
One of the major symptoms of Parkinson’s disease is slowed movement, or bradykinesia. This causes soft speech, fewer spontaneous movements and decreased facial expression. It also results in a slow, shuffling walk and interferes with everyday activities. Rigidity, or muscle stiffness, may cause pain, as muscles of the neck, trunk and limbs don’t relax normally when they’re not being used. It also makes a person swing their arms less when they walk. Tremor, or shaking, can affect the hand, foot or face and occurs when the involved area is at rest. People with Parkinson’s disease may also have problems with balance, known as postural instability, that make them fall backward easily. Other symptoms include “freezing,” or stopping just as one is about to take a step forward, and dystonia, an involuntary, sometimes painful contraction of muscles. Symptoms like tremor, slowed movement and rigidity tend to be worse on one side of the body.
Late Movement Signs and Symptoms
Parkinson’s disease results from a loss of brain cells that make the vital chemical messenger dopamine. It is treated with medication that either replaces dopamine or helps the brain use it more effectively. But over time the disease progresses so that people don’t respond as well to medication. They start to experience motor fluctuations — changes in movement symptoms that happen when the medication is not working as well. The movement symptoms return, either gradually or suddenly (known as “off-time”). Periods when they are better controlled are called “on-time.” As the disease progresses, these “on-time” periods get shorter. Another late movement symptom is dyskinesia (abnormal involuntary movements). These may be in the form of jerking, twisting or writhing movements or of dystonia.
Non-Movement Signs and Symptoms
The non-movement signs and symptoms of Parkinson’s disease can occur at any stage of the disease and significantly impact quality of life. According to the February 2013 American Family Physician, 60 percent of people with Parkinson’s disease develop dementia — a severe disorder of memory, personality and thinking — within 12 years of diagnosis. Many others have milder problems with thinking. Sleep problems include difficulty falling or staying asleep, restless legs syndrome (an uncomfortable need to move one’s legs that is worse at night) and sleep apnea (periods in which one stops breathing at night). During the day, “sleep attacks” and fatigue are common. Other symptoms can include hallucinations (seeing things that aren’t there), depression and anxiety. Pain is common, as are urinary and sexual problems, constipation, low blood pressure upon standing, swallowing problems and drooling.