Parkinson’s disease is named after the doctor who first identified it in the early nineteenth century. It is also known as paralysis agitans and shaking palsy. The disease, which affects the nervous system, has a slow onset and usually occurs in people over sixty, although some cases occur as early as forty.
Parkinson’s disease is caused by a degeneration of the basal ganglia of the brain, and particularly the corpus striatum and the substantia nigra. These areas of the brain regulate voluntary movement and in Parkinson’s disease there is a lack of the neurotransmitter dopamine. Debilitating symptoms appear when only twenty to thirty percent of dopamine neurons remain.
The sufferer may first notice mild tremors in the hands and involuntary nodding of the head. Bodily movements become slower and more difficult. As the disease progresses, stiffness and tremors increase until walking is reduced to a shuffle and the facial muscles become set in a fixed expression. While the intellect remains unaffected, mood swings do occur. Parkinson’s disease is more common in men than in women. The disease was either unknown or undiagnosed before the industrial revolution and its incidence has risen markedly in the last 170 years. The disease does not seem to have a genetic aspect, and the fact that it is more common in industrialised countries than developing nations has led some to believe that it may be caused or exacerbated by chemical pollution. Others claim that iodine deficiency and excessive sodium intake may be causal factors.
The treatment of Parkinson’s disease is essentially symptomatic. The drug Levodopa is administered to increase dopamine levels in the brain and thus reduce tremor. Because Levodopa has some potentially harmful side-effects, treatment with the drug is often only intermittent. Vitamin E is recommended to slow the progress of the disease and antioxidants are considered to be beneficial.