Parkinson's disease and antioxidants

Parkinson's disease occurs when certain nerve cells, or neurons, in an area of the brain known as the substantia nigra die or become impaired. Normally, these neurons produce an important brain chemical known as dopamine. Dopamine is a chemical messenger responsible for transmitting signals between the substantia nigra and the next "relay station" of the brain, the corpus striatum, to produce smooth, purposeful muscle activity. Loss of dopamine causes the nerve cells of the striatum to fire out of control, leaving patients unable to direct or control their movements in a normal manner. Studies have shown that Parkinson's patients have a loss of 80 percent or more of dopamine-producing cells in the substantia nigra. The cause of this cell death or impairment is not fully understood.

One theory holds that highe levels of free radicals - unstable and potentially damaging molecules generated by normal chemical reactions in the body - may contribute to nerve cell death thereby leading to Parkinson's disease. Free radicals are unstable because they lack one electron. With missing electron, free radicals are very reactive, attatching to electrons on molecules in their proximity (especially metals such as iron), in a process called oxidation. Oxidation is thought to cause damage to tissues, including brain neurons. Free radical damage is kept under control by antioxidants, chemicals that protect cells from this damage. Evidence that oxidative mechanisms may cause or contribute to Parkinson's disease includes the finding that patients with the disease have increased brain levels of iron, especially in the substantia nigra, and decreased levels of ferritin, which serves as a protective mechanism by chelating or forming a ring around the iron, and isolating it. The normal, age-related deterioration of dopamine-producing neurons accelerates in certain individuals. A loss of antioxidative protective mechanisms is associated with both Parkinson's disease and increasing age, so here again is another serious disease with links to low antioxidant levels in the body.

In some cases, a toxin may be the cause of the disease. There may also be genetic factors involved.

Parkinson's disease is a disease of late middle age, usually affecting people over the age of 50. The average age of onset is 60 years. However, some physicians have reportedly noticed more cases of "early-onset" Parkinson's disease in the past several years, and some have estimated that 5 to 10 percent of patients are under the age of 40.

 Major symptoms of the Parkinson's disease

In the early stage of this disease, patients may feel tired. They may feel a little shaky or have difficulty getting out of a chair. Sometimes they may speak too softly or their handwriting becomes cramped and spidery. They may lose track of a word or thought, or they may feel irritable or depressed for no apparent reason. This very early period may last a long time before the more classic and obvious symptoms appear.

Friends or family members may notice that the person's face lacks expression and animation (known as "masked face") or that the person remains in a certain position for a long time or does not move an arm or leg normally. They may notice that the person seems stiff, unsteady, and unusually slow.

Parkinson's disease affects people in different ways. Sometimes the disease progresses quickly, while in other cases it does not. Some people may become severely disabled, while others experience only minor motor disruptions. Tremor is the major symptom for some patients, while for others tremor is only a minor complaint and different symptoms are more troublesome.

• Tremor.
• The tremor associated with Parkinson's disease has a characteristic appearance. Typically, the tremor takes the form of a rhythmic back-and-forth motion of the thumb and forefinger at three beats per second. This is sometimes called "pill rolling." Tremor usually begins in a hand, although sometimes a foot or the jaw is affected first. It is most obvious when the hand is at rest or when a person is under stress. In three out of four patients, the tremor may affect only one part or side of the body, especially during the early stages of the disease. Later it may become more general. Tremor is rarely disabling and it usually disappears during sleep or improves with intentional movement.
• Rigidity.
• Rigidity, or a resistance to movement, affects most Parkinsonian patients. A major principle of body movement is that all muscles have an opposing muscle. Movement is possible not just because one muscle becomes more active, but because the opposing muscle relaxes. In Parkinson's disease, rigidity comes about when, in response to signals from the brain, the delicate balance of opposing muscles is disturbed. The muscles remain constantly tensed and contracted so that the person aches or feels stiff or weak. The rigidity becomes obvious when another person tries to move the patient's arm, which will move only in ratchet-like or short, jerky movements known as "cogwheel" rigidity.
• Bradykinesia.
• Bradykinesia, or the slowing down and loss of spontaneous and automatic movement, is particularly frustrating because it is unpredictable. One moment the patient can move easily. The next moment he or she may need help. This may well be the most disabling and distressing symptom of the disease because the patient cannot rapidly perform routine movements. Activities once performed quickly and easily - such as washing or dressing - may take several hours.
• Postural instability.
• Postural instability, or impaired balance and coordination, leads to patients developing a forward or backward lean and to fall easily. Such patients may have a stooped posture in which the head is bowed and the shoulders are drooped. As the disease progresses, walking may be affected. Patients may halt in mid-stride and "freeze" in place, possibly even toppling over. Patients may walk with a series of quick, small steps as if hurrying forward to keep balance.
• Other symptoms include: Depression, emotional changes, difficulty in swallowing and chewing, speech changes, urinary problems, constipation, skin problems and sleep problems.

The above information is abstracted from http://www.medicinenet.com/parkinsons_disease/index.htm . Refer to this site for a more detailed review.