Parkinson's Parkinson disease


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Parkinson's Parkinson disease

Abbreviation: PD
A common, chronic degenerative disease of the central nervous system that produces progressive movement disorders and changes in cognition and mood. Its hallmarks include a pill-rolling tremor of the hands, muscular rigidity, loss of facial expression, difficulty initiating movements (akinesia, bradykinesia), and gait disturbances (esp. shuffling gait, festination, and sometimes difficulty initiating forward movements). Parkinson's disease is usually found in people over the age of 65. Its underlying cause is unknown; it is clear, however, that dopamine production by brain cells in the substantia nigra is diminished in the disease. Although PD often clusters in families, it is uncertain whether this is the result of genetics or of exposure to common precipitating agents (viruses, toxins, or drugs). In the U.S. about 1.5 million people have PD, with about 50,000 new cases diagnosed each year.

Symptoms

Most patients report gradual onset of fatigue, or malaise, followed by evidence of a tremor in one or more extremities, typically a hand when it is at rest. Such tremors increase during periods of anxiety or stress but decrease during purposeful motion or sleep. Other common symptoms include difficulty getting up from a chair or turning over in bed, a change in vocal quality (a softer, less audible, more monotonous voice), shuffling gait that becomes faster after a few steps (festination), and a stooped posture. As the years pass, frequent falls may occur. Occasionally a tendency to fall backward (retropulsion) replaces festination. Facial expressiveness may diminish (patients are said to have masklike facies), swallowing often becomes impaired, and handwriting may become smaller or more cramped (micrographia).

Treatment

The goal of treatment is to maintain function for as long as possible and relieve symptoms. Medical therapies include selegiline, levodopa/carbidopa; dopamine agonists (e.g., bromocriptine); inhibitors of catechol-o-methyltransferase (e.g., entacapone), and monoamine oxidase-B inhibitors (e.g., deprenyl). Surgical therapy, which is performed at a small number of hospitals, may involve transplantation of dopamine-secreting cells (fetal brain tissue, nerve cells from other parts of the patient's body) into affected areas of the brain or insertion of electrical brain stimulators into the subthalamic nucleus, globus pallidus internus, or ventral intermediate nucleus. Physical therapy is a very important part of the treatment, helping to maintain muscle tone and function.

Patient care

Teamwork benefits the PD patient, who may require a social worker, nurses, primary care providers, a neurologist, registered dietitian, physical therapist, occupational therapist, and speech therapist. Patients should be monitored for the efficacy and safety of drug therapy, particularly when a new drug is prescribed. Drug-drug interactions are common but may be avoided with careful dose titration and prescribing. Elderly patients are at increased risk for adverse effects because of reduced drug tolerance and should be assessed for postural hypotension, pulse irregularities, blepharospasm, and anxiety and confusion. Drug dosages should be reduced if adverse side effects occur. If patients have periods of immobility alternating with periods of severely impaired mobility, they may need changes in their medication schedule or new, additional medications. The patient and family are taught safety measures to prevent injury caused by falling, as well as swallowing techniques to deal with dysphagia. Prescribed drugs are administered and evaluated for desired effects and adverse reactions; the patient is instructed in their use and potential side effects so that the dosage can be adjusted to minimize the side effects. The nurse, physician, or occupational or physical therapist teaches the patient and family about safety measures to prevent injury, about drug-related dietary restrictions, and about the need for frequent small feedings to provide needed fluids, calories, and dietary bulk. Drinking at least 2 L/day of liquids and eating a high-fiber diet help to establish a regular bowel routine; an elevated toilet seat and frame can help the patient in moving from sitting to standing position. Independence is encouraged. The patient should plan daily activities for when he or she feels rested to prevent fatigue, but even so, the patient needs to exercise regularly (active and passive range of motion, walking, massage, baths, carrying out activities of daily living) to help relax muscles and prevent contractures and muscle atrophy. Education about progression of the disease and emotional support are provided; the family is assisted to recognize and fulfill the patient's need for intellectual stimulation and recreation. The patient is also referred to national organizations (e.g., the National Parkinson Foundation, Inc.; www.parkinson.org) for additional information.