Complications

Parkinson's disease (PD) is not fatal, but it can reduce longevity. The disease progresses more quickly in older than younger patients, and may lead to severe incapacity within 10 - 20 years. Older patients also tend to experience freezing and greater declines in mental function and daily functioning than younger people. If PD starts without signs of tremor, it is likely to be more severe than if tremor had been present. Having other family members with PD does not appear to have any effect on the severity of the disease.

Parkinson's disease can seriously impair the quality of life in any age group. The physical and emotional impact on the family should not be underestimated as the patient becomes increasingly dependent on their support.

Treatment advances are increasingly effective in alleviating symptoms and even slowing progression of the disease. Taking many of the medications over time, however, can produce significant side effects. Newer drugs may help reduce these occurrences.

Motor Impairment

The negative effect of overall motor and muscle impairment on daily life can be considerable. Some motor complications can be life-threatening.

• Disturbed gait and unstable posture are common and serious problems in elderly patients, since they increase the risk for falling and injury. Some studies have suggested that the appearance of these symptoms early in the course of the disease predict a faster decline than having tremor as the predominant symptom.
• Swallowing problems (dysphagia). The presence of dysphagia is associated with shorter survival time. Motor impairment of the muscles in the throat not only impairs swallowing but it also poses a risk for aspiration pneumonia.
• Constipation is a major problem and occurs both as a result of the disease and a side effect of its treatment. Laxatives, stool softeners, and other medications may be prescribed.
• Bladder control and urinary incontinence are also important complications of PD.
• Speech problems occur in more than 70% of patients, by some estimates. Speech difficulty can be caused by rigidity of the facial muscles, loss of motor control, and impaired breath control. Tone can become monotonous, words may be repeated over and over, or the rate of speech may even be very fast.

Impact on Emotions

Depression is extremely common, affecting up to 40% of patients with Parkinson's. PD poses multiple threats on the emotional health:

• The disease process itself causes changes in chemicals in the brain that affect mood and well-being.
• The complications of its symptoms have a profound impact on daily life that can be emotionally devastating without help and support.
• Some drug treatments (levodopa combined with a dopamine agonist) can cause compulsive behavior, such as gambling, shopping, and increased sexuality. Patients who have pre-existing tendencies to novelty-seeking behavior, or a family or personal history of alcohol abuse, may be more likely to develop compulsive gambling. Deep brain stimulus (DBS) surgery may also increase the risk for compulsive gambling in patients who have a history of gambling.

Effects on Thinking and Mental Status

Impaired Thinking (Cognitive Impairment). Defects in thinking, memory, language, and problem solving skills may occur early on in untreated patients or late in the course of the disease. Medications may play a role in thinking problems. In one study, for example, patients with PD were slower in detecting associations, although (unlike in Alzheimer's disease) once they discovered them they were able to apply this knowledge to other concepts. After they were taken off medication, however, they had no problems with the tasks.

Dementia. Dementia is three to six times more common in the elderly Parkinson patient than in the average older adult. It is most likely to occur in older patients who have had major depression. PD marked by muscle rigidity (akinesia), rather than tremor, and early hallucinations also increase the risk for dementia. (Visual hallucinations can also occur in about a third of patients from PD medication.) Unlike in Alzheimer's, language is not usually affected in Parkinson's related dementia.

Other Problems that Impair Daily Life

A number of other problems associated with Parkinson's disease affect daily life:

Vision Problems. Vision is also affected, including impaired color perception and contrast sensitivity. These problems progress and can impair motor functioning.

Sleep Disorders. Excessive daytime sleepiness and other sleep disorders are common in PD, both from the disease itself and from the drugs that treat it. In general, patients have a 25% higher risk for daytime sleepiness, including suddenly falling asleep, than patients with other neurologic diseases.

Restless legs syndrome, an irresistible urge to move the calves, which often occurs at night, affects many patients. However, Parkinson's disease itself does not seem to increase the risk for RLS. Nor does RLS early in life predispose to Parkinson's later on. The common connection between RLS and Parkinson's disease may derive from iron deficiencies that can play a role in both conditions.

Many patients also suffer from nighttime leg cramps. And, some of the medications cause vivid dreams as well as waking hallucinations.

Impaired Sexuality. Although Parkinson's disease and its treatments can cause compulsive sexual behavior, the disease can also affect patients' self-esteem and inhibit sexuality. This is an area not often studied but which is important for many patients' well-being. A 2000 study reported that not only did sexual dysfunction occur, but also affectionate touching and expression of feelings were reduced, even though both partners maintained a desire for intimacy.

Worsened Sense of Smell. The sense of smell is impaired in about 70% of patients.

Increased Risk for Other Medical Conditions

Osteoporosis. Parkinson’s disease may increase the risk for low bone density and osteoporosis. Both men and women are at risk. Experts recommend that patients with Parkinson’s disease get tested for osteoporosis, especially if they have problems with walking.