Parkinson’s disease (PD) is most known for the primary motor symptoms: tremor, slowed movement (bradykinesia), rigidity, and balancing issues (postural instability). PD can also cause non-motor symptoms, those that are unrelated to movement. PD affects the nervous system, and the damage to the neurons (nerve cells) affects multiple areas and processes of the body. The major non-motor symptoms of PD include fatigue, constipation, sleep problems, pain, speech difficulties, orthostatic hypotension (a drop in blood pressure that occurs upon standing), mood changes, cognitive changes, psychotic symptoms, and the loss of the sense of smell. In addition to these, PD can cause several other non-motor symptoms, such as sexual dysfunction, weight loss or weight gain, vision or dental problems, skin problems, or impulsive behaviors.1,2
Sexual dysfunction in Parkinson’s disease
People with PD may experience sexual dysfunction, including decreased sex drive, inability to orgasm, erectile dysfunction in men, decreased lubrication in women, or pain with intercourse in women. Some studies have found that sexual dysfunction may occur in 60-80% of men and women with PD. Older patients with PD have more sexual dysfunction than younger patients, and sexual dysfunction is also greater in healthy older adults. In addition to age, conditions such as diabetes, hypertension, and depression can factor into sexual dysfunction.3,4
Weight changes in Parkinson’s disease
PD may cause a person to gain weight or to lose weight. Changes to weight (in either direction) can have negative effects on a person’s overall health. Weight loss can lead to losing muscle mass and strength and may increase the risk of infection or osteoporosis. Weight gain can lead to being overweight, increasing the risk of heart disease and high blood pressure, as well as putting extra stress on joints.1
Weight loss may be influenced by depression or the loss of the sense of smell and taste changes that some people with PD experience. Some medications for PD can cause nausea, which may make patients eat less. Motor symptoms of PD can also make it challenging to bring food to the mouth or to swallow.1
Weight gain can be a side effect of treatment for PD. Some medications for PD have been associated with compulsive behaviors, including binge eating. Medications for psychiatric symptoms of PD can also contribute to weight gain. Deep brain stimulation, a surgical treatment that involves implanting and stimulating electrodes in the brain, can also cause weight gain as a side effect.1
There are several strategies that can help people with PD to manage their weight, including eating a balanced diet with a variety of foods and getting regular exercise. A doctor or registered dietitian can provide specific strategies aimed at either gaining or losing weight.1
Vision problems in Parkinson’s disease
PD may cause changes to a person’s vision, such as:
- Blurry vision
- Double vision
- Dry eyes
- Trouble opening the eyes voluntarily (called apraxia)
- Spasms of the eyelid (blepharospasm)
- Excessive blinking
- Difficulty reading, due to the freezing of movement of the eyes
- Decreased sensitivity to color and brightness
- Difficulty judging distances
- Visual hallucinations1
In addition, there are many vision problems that are associated with aging, including glaucoma, cataracts, and macular degeneration, which can impact a person’s ability to see.1
Dental problems in Parkinson’s disease
Dental hygiene is often compromised in a person with PD due to their motor symptoms, which can lead to an increased risk of cavities and gum disease. In addition, the motor symptoms of PD may make periodic dental examinations challenging. People with PD may find it easier to use an electric toothbrush, using their stronger hand. Dentists may also recommend topical stannous fluoride gel treatments, which can protect tooth enamel from cavities. Visits to the dentist can be coordinated after a dosage of PD medication has taken effect.1
Skin problems in Parkinson’s disease
Many people with PD experience skin problems, including dry skin, oily skin, redness, dandruff, excessive sweating, or too little perspiration. There are several topical treatments and lifestyle approaches that can help with these skin conditions.1
In addition, people with PD are at a higher risk of developing skin cancer. One type of skin cancer, melanoma, is more likely to spread from the skin to other organs in the body, and research studies have suggested that the risk of developing malignant melanoma is 2-7 times higher in people with PD compared to the general population. Early diagnosis and treatment is critical in melanoma, and people with PD should visit a dermatologist for regular screening.1
Impulsive behaviors in Parkinson’s disease
The medications used to treat PD may cause impulsive behaviors as a side effect. Impulsive behaviors usually are in contrast to how a person would have acted before PD and may include excessive shopping, unusual or increased sexual behavior, gambling, abuse of medications, or binge eating. This side effect tends to occur in people whose PD is more advanced and who are taking high doses of medications for their PD; however, it can occur at any stage of the disease. Impulsive behaviors often begin when a new medication is added to a treatment regimen or when the dosage of a medication is increased. Any side effect, including impulsive behaviors, should be brought to the attention of a healthcare professional.1