DEAR DR. GOTT: My father has recently been diagnosed with Parkinson's disease. Because we know so little about the condition, we would like to know what we might expect.

DEAR READER: Parkinson's disease (PD) is a progressive neurological disorder that occurs when neurons located in a portion of the brain become impaired or die. In healthy individuals, these cells produce a chemical known as dopamine that allows smooth, coordinated functioning of muscles and movement. When approximately 80 percent of the dopamine-producing cells are damaged, symptoms of Parkinson's appear.

This is the second most common neurodegenerative condition, following Alzheimer's. About 4 million people worldwide are affected, with the disorder being more common in men.

Early symptoms are subtle, may occur slowly, and often include a decreased or total lack of the ability to smell. As the disease progresses, complications may escalate. Handwriting may appear cramped and difficult to read. Rigidity, lack of facial expression, postural instability, slowed thinking, memory loss, sleep disorders, constipation, urinary incontinence, visual hallucinations, dyskinesia (involuntary movements) and emotional changes may occur. Depression affects quality of life and may be present in up to 70 percent of all sufferers. Difficulty swallowing affects about 75 percent of all individuals with moderate to advanced PD. Oddly enough, we've been led to believe that the condition is always associated with a tremor when, in actuality, almost one-third of all PD patients fail to have that symptom. When it occurs, it most frequently begins in a hand, although it can appear in a foot or the jaw.

Treatment includes new drugs that may assist in avoiding the complications associated with the long-term use of levodopa, which was introduced in the 1960s and considered the first effective medication for control. Debate remains regarding when to begin initial treatment. Delaying treatment until symptoms become severe is common practice since levodopa is effective only for a period of a few years, but there is a growing consensus that supports early treatment.

As a patient ages, he or she will likely experience difficulty with remembering to take medication. This contributes to a decrease in adherence to drug schedules. In this instance, a pill container listing the days of the week and times of day may come in handy. And it goes without saying that a caregiver will be required to set out and monitor the specific amount of medication prescribed.

Caregivers are an extremely important part of the picture, yet a great deal of auxiliary assistance may be needed at the appropriate time. A patient may benefit from medication; physical, occupational and speech therapy; exercise; massage; acupuncture; and herbs. In fact, almost 50 percent of patients admit to using alternatives such as grape-seed extract and vitamin B50 for control of tremors. Caregivers should realize that a coordinated, successful individual who may have been the primary breadwinner in the family will have difficulty adapting to something over which he or she has no control. Frustration, anger and a feeling of hopelessness may result. The patient must remain as independent and active as possible for as long as possible. The services of an outside counselor might be appropriate.

If he isn't already, your father should be under the care of a neurologist with appropriate knowledge of Parkinson's. Ask his primary-care physician for a referral.