Environmental roots to parkinsonism.Environmental roots to parkinsonism New support for the theory that Parkinson's disease Parkinson's disease or Parkinsonism, degenerative brain disorder first described by the English surgeon James Parkinson in 1817. When there is no known cause, the disease usually appears after age 40 and is referred to as Parkinson's disease. is caused by environmental factors has come from six Canadian families. Each family has several members who developed the disorder within less than five years of one another, despite large are differences, say Donald B. Calne of the University of British Columbia Locations Vancouver The Vancouver campus is located at Point Grey, a twenty-minute drive from downtown Vancouver. It is near several beaches and has views of the North Shore mountains. The 7. in Vancouver and his colleagues. The appearance of the neurological disorder among only a portion of the parents and their children undermines a purely genetic explanation, say the researchers. "Whatever the environmental factors were, they must have been transient,' says Calne. "There may be a range of environmental toxins stimulating Parkinson's disease, including some in the diet, but at the moment this is very speculative.' In one family, for instance, the only healthy member was also the only one who had abstained from a rigorous "health food' diet that included large quantities of sunflower seeds. Whether that diet contained toxic elements is unclear, says Calne. Parkinson's disease usually occurs among people over 40 years of age and is marked by tremors, muscle rigidity and weakness and a shuffling gait shuffling gait short, uncertain steps, with minimal flexion and toes dragging. shuffling gait Neurology A gait in which the foot is moving forward at the time of initial contact, with the foot either flat or at heel strike, or during midswing Etiology . In the Canadian families, an average of only 4.6 years separated the onset of symptoms in different generations, while the average age difference between children and parents who contracted the disorder was 25 years. Two of the families contained identical twins identical twins pl.n. Twins derived from the same fertilized ovum that at an early stage of development becomes separated into independently growing cell aggregations, giving rise to two individuals of the same sex, identical genetic makeup, and , and only one member of each pair developed Parkinson's disease, report Calne and his coworkers in the August CANADIAN JOURNAL OF NEUROLOGICAL SCIENCES. The children, whose symptoms developed by age 40, had generally lived apart from their parents for two or more decades. Any common environmental causes must have occurred before they left home, conclude the researchers. This inference is in line with a previous hypothesis that environmental hazards first cause "clinically silent damage' to the brain early in life, followed by normal cell loss with aging that triggers Parkinson's disease (SN: 10/5/85, p.212). Their data dovetail dovetail (dov´tāl), n a widened or fanned-out portion of a prepared cavity, usually established deliberately to increase the retention and resistance form. with a report that an amino acid amino acid (əmē`nō), any one of a class of simple organic compounds containing carbon, hydrogen, oxygen, nitrogen, and in certain cases sulfur. These compounds are the building blocks of proteins. found in the seeds of the false sago palm sago palm cycasrevoluta. produces parkinsonism in monkeys and may have caused an increases in neurological diseases on two west Pacific islands (SN: 8/8/87, p.94). |
|
||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion