The Non-Motor Features of Parkinson's Disease
by Alison P. Monette, RN, Erica L. Liszak, RN and Michael Rezak, MD, PhD
Movement Disorders Center, Neuroseiences Institute, Central DuPage Hospital, Winfield, IL
Parkinson's disease (PD) is commonly thought of as a movement disorder that can result in variable degrees of stiffness, slowness, tremor and gait and balance problems. Over the past few years, it has become increasingly recognized that non-motor features can also be a part of PD. In fact, in some patients these non-motor features can be more troublesome than the motor symptoms and may predate the motor features by years. It therefore becomes important to identify and treat the non-motor features in order to maintain optimal quality of life. The possible non-motor features include difficulties with sleep, mood, cognition, autonomic nervous system problems, and abnormal sensations, among others. Due to space limitations, in this article we will focus on only some of the major non-motor features in PD.
Sleep can be disrupted in a variety of ways in PD. Excessive daytime sleepiness can result from changes in normal sleep cycles or as a side effect from Parkinson's medications. A common sleep disorder seen in PD is REM Sleep Behavior Disorder (RSBD) which occurs when the REM stage of sleep, which is the deepest, most restorative stage of sleep, is disrupted. In RSBD, a person may "act out" their dreams in their sleep, thrashing and striking their bed partner. RSBD can predate the onset of motor signs of PD in approximately 40% of people with this sleep disorder. Another common sleep disorder in PD is known as periodic limb movements of sleep (PLS), where a patient may have excessive, repetitive movements of the lower extremities. Restless Legs Syndrome (RLS) occurs in many patients with PD and results in abnormal sensations in the lower extremities when lying still, but disappears with activity. RLS is typically most symptomatic in the evening or at night. Sleep apnea is also a common source of sleep disruption and may not always be accompanied by snoring. Sleep specialists (neurologists or pulmonologists) are trained to diagnose and treat sleep disorders and should be consulted for their expertise with these problems.
Mood problems associated with PD can be manifested by depression, apathy, and anxiety, among others. In fact, some studies have shown that up to 80% of PD, patients may experience depression during the course of their illness. It is important for the person with PD as well as for their families and caregivers, to understand that mood changes can be a part of the PD symptoms and requires attention in order to maintain quality of life. Since the depression can often have a biochemical basis related to neurotransmitter changes in the brain, medication management can be very effective and should be discussed with your doctor. Additionally, coping with the diagnosis of PD may result in a "reactive" depression where counseling or psychotherapy can be helpful. It should also be noted here that the PD medications can sometimes be responsible for other psychiatric symptoms such as paranoia, hallucinations, delusions and compulsive behaviors. A careful evaluation of the entire patient's medical status is essential in identifying the causes of the mood changes in each patient. It is important to remember that these mood disorders are treatable and should not be ignored.
Cognitive issues have been recognized as a part of the PD symptom spectrum. There is evidence that in some patients, even early in the course of PD, there are problems with executive functions. Executive functions are those that allow us to plan ahead, organize our activities, multitask, and control goal-directed activities. Executive dysfunction is different from dementia. Dementia, if it occurs in PD patients, usually occurs in the advanced stages of the disease. Studies have shown that 10-40% of patients may experience Parkinson's disease dementia (PDD). PDD evolves gradually and patients can show signs of a specific type of memory disturbance, personality changes, slowed thinking and impaired problem solving. A neuropsychologist is trained to test patients and objectively diagnose PDD. Fortunately, we now have several medications that can be helpful in PDD (cholinesterase inhibitors) and these should be considered if this diagnosis is made. Additionally, it is good for patients to stay as engaged and involved in activities that "exercise" their cognitive skills, including using word games (e.g. crossword puzzles, Scrabble, etc.) and participating in social events.
Autonomic Nervous System (ANS) dysfunction includes a number of symptoms some patients may experience. These symptoms can be frustrating, but treatment is available for most of them. The autonomic nervous system is responsible for the automatic regulation of important involuntary body processes that are vital to the quality of life. When PD impacts the ANS, a patient may experience some of the following challenges:
- Blood pressure changes- low blood pressure when standing up (orthostatic hypotension) can cause dizziness or lightheadedness and if severe enough, may even result in fainting. PD itself, as well as the medicines used to treat PD can contribute to this problem. Proper evaluation can determine the cause and appropriate treatment options that can be used. Genitourinary dysfunction urinary frequency or urgency occurs commonly in PD. If PD related, a "neurogenic" bladder may be responsible (the bladder is smaller and is unable to hold as much urine). Urologists should always be consulted to rule out other causes. If PD-related, there are effective treatment options available.
- Constipation - slowed gastric motility is commonly related to the disease process. Some studies have shown that constipation occurs in up to 70-80% of PD patients. Constipation must be taken seriously, as severe cases can result in serious illness or even death. With proper attention, constipation can be well-managed using the effective treatments that are now available. A common problem contributing to constipation is dehydration, and PD patients should be attentive to their level of fluid intake.
- Sexual dysfunction decreased libido and erectile dysfunction are relatively common in PD. Erectile dysfunction is a common problem in males with PD, occurring in up to 60% of males at some point in the course of the illness. Interestingly, studies suggest decreased libido is significantly more common in females. There may be many other causes for these problems, including psychological factors, prostate and urinary issues, etc., and therefore a thorough evaluation should be undertaken. Specialists are available for consultation in the fields of urology and psychology and should be consulted. Physical intimacy is an important part of a relationship quality of life and with proper treatment can be maintained.
- Temperature regulation feeling very cold or warm (despite normal room temperature) as well as inappropriate sweating can occur in PD. Less common is the troublesome phenomenon of "acute drenching sweats" requiring patients to change clothes. As with all of the non-motor symptoms, all other causes (including endocrine dysfunction) need to be evaluated.
Other Non-Motor Problems
- Sensory complaints- numbness, tingling, burning and pain can be related to PD. The sensory disturbances may mimic other pathological processes (e.g., a herniated disc causing radiating nerve pain). A thorough workup is required, but if no cause is found and if PD medicines relieve the sensations, it is likely that the problem is a non-motor feature of PD. It should be noted that a common finding in PD patients is anosmia, or loss of smell. Interestingly, anosmia may predate the onset of motor symptoms by many years and may now be considered a risk factor for the future development of PD.
- Dermatological problems- oily, red and flaky skin, also known as seborrheic dermatitis, is common in PD patients. Seborrheic dermatitis is commonly found on the face and scalp, where many oil glands are located. A variety of treatments and shampoos are available to manage this problem. For unknown reasons, malignant melanoma, the most lethal form of skin cancer, appears to have a 2-4% increased incidence in people with PD compared to the general population. It is therefore important to see a dermatologist regularly for "melanoma screening," since early detection can be curative.
As one can see from the above paragraphs, treating PD is no longer a matter of only addressing the well-known motor features of the disease, but also recognizing and aggressively managing the non-motor symptoms. It is incumbent upon the patient to bring to light complaints that may previously have been considered non-specific or unrelated to PD. In the same way the neurologist should now question the PD patient about these non-motor features so that if they are present, appropriate treatment can be instituted.
With the many effective treatments we have available today, optimal quality of life can be attained by addressing and managing all of the symptoms that arise from PD.