The symptoms of Parkinson’s disease result from the degeneration of nerve cells in the mid-brain, and the corresponding loss of the neurotransmitting chemical dopamine produced by those cells. Parkinson’s disease causes both non-motor and motor symptoms.
Many people are familiar with the motor symptoms, and Parkinson’s disease is considered a “movement disorder.” Non-motor symptoms of PD are often present 5-15 years before onset of any motor symptoms.
Main Non-Motor Symptoms
1. Hyposmia: Loss or impairment of the sense of smell. About 90% of people with diagnosed PD show a decrease in their sense of smell. This may be one of the earliest signs of PD. You can be part of research related to this pre-clinical symptom through the PARS study.
2. Problems in Sleep Behavior: Sleep Problems. A sleeping companion may notice changed sleep behavior first; the intensity may escalate.
3. Depression: Very commom symptom in PD patients, researchers note that depression may be considered a symptom of PD (and not a reaction to the diagnosis) when regarding the neurological changes in the PD brain. Dopamine fibers, found in the orbitofrontal cortex of the brain, become damaged and the patient is no longer able to process feelings of joy nor forsee future feelings of joy and reward.
4. Constipation: Caused by damage to the autonomic nervous system which regulates the involuntary muscle movement of the intestinal tract. This damage causes slowed digestion and movement through the intestional tract. You may be considered constipated if you have experienced two or more of the following: straining during a bowel movement more than 25% of the time, hard stools more that 25% of the time, incomplete evacuation more than 25% of the time, two or fewer bowel movements in one week’s time.
Main Motor Symptoms
1. Bradykinesia: Slowness in executing movements. This slowness may show itself in decreased arm swing when walking, micrographia (small handwriting), hypophonia (weakened voice), masked face, and slow gait.
2. Resting Tremor: Shaking in an arm or leg when the limb at rest. This tremor generally becomes less noticeable or disappears when the person moves the arm or leg.
3. Rigidity: Causes stiffness and inflexibility of the limbs, neck and trunk. Muscles normally stretch when they move, and then relax when they are at rest. With rigidity, there can be a tightness of the neck, shoulder and leg which can reduce the range of motion.
4. Postural Instability: A tendency to be unstable when standing upright. With a loss of some of the reflexes needed for maintaining an upright posture, a person may easily topple backwards, especially when rising from a chair, standing or turning.