Research Roundup updates as of June 2005
Long-ago residence on Guam is likely ALS risk factor
In a study that included 140 people with ALS and another 140 without the disease, those with ALS were found to be eight times more likely to have lived on Guam, even for a few months, than were those who didn’t have ALS.
Only one person from the non-ALS (control) group had ever lived on Guam, while nine of the ALS-affected subjects had lived on this island in the Pacific for between one and 15 months. The nine hadn’t lived there for an average of 43 years when they learned they had ALS. (The time between living on Guam and an ALS diagnosis ranged from 27 to 57 years.)
The findings, published in the May 24 issue of Neurology, and reported by Lewis Rowland of the MDA ALS Center at Columbia University in New York; Ruth Ottman, also at Columbia; and investigators at Erasmus Medical Center in Rotterdam, the Netherlands, shed new light on the ALS-Guam connection, a subject that has been under scrutiny for decades.
In 2002, researchers proposed that the unusually high incidence of ALS on Guam seen between 1940 and 1965 probably had to do with the islanders’ tradition of eating fruit bats (see “Bats and Nuts,” May 2002). These bats eat cycad nuts that contain a known toxin and then concentrate the toxin in their tissues.
The investigators on the new study say their findings “could indicate that one of the key characteristics of the exposure occurring during the period of endemic ALS on Guam is the long delay in clinical expression [outward signs of disease].” They say their data “support the vision that exposure to slow-acting toxic agents is important in the pathogenesis of ALS, most likely in combination with a genetic predisposition.”
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Studies examine genetic and environmental factors
|Genetic background and exposures to toxins in the natural and industrial worlds probably combine to produce ALS.
Several studies are now probing genetic and environmental factors that contribute to ALS.
One, open to people who either have ALS, are a sibling or parent of someone with ALS, or have neither ALS nor a family history of the disease, is being conducted at Northwestern University in Chicago and Massachusetts General Hospital in Boston. No travel is necessary. You can contact Nailah Siddique in Chicago at (312) 503-2712 or firstname.lastname@example.org. Or contact Diana McKenna-Yasek in Boston at (617) 726-5750 or email@example.com.
The Massachusetts General Hospital group is also conducting a study to identify more genes that directly cause ALS. The investigators are seeking participants whose family contains at least two people, living or deceased, who have or had ALS.
In New York, an MDA-funded study of environmental and genetic factors in ALS is under way at Columbia University Medical Center. This study, which prefers to accept participants from the New York area, seeks people whose ALS has been diagnosed within the past year, parents and siblings of those with ALS, and married-in family members.
Contact Ani Sara Thankachan in New York at (212) 305-4746.
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Four with ALS use thought to control computer cursor
Using brain waves, signals from brain cells that resemble electrical discharges, to control a computer cursor or other electronic device has long been a dream of people who can’t use their voluntary muscles. But until now, the relevance to ALS of this approach has been far from certain, since the motor cortex, the part of the brain from which movement signals originate, is damaged in this disease. (The cortex is usually intact in people paralyzed by spinal cord injuries.)
Now, researchers at the State University of New York at Albany, the New York State Department of Health, and centers in Italy and Germany, describe four people severely disabled by ALS who learned to direct a cursor to a target with greater than 75 percent accuracy, using a brain-computer interface (BCI) method. With training, they learned to use thought alone to move the cursor, and electrodes placed over the cortex showed that thinking changed their brain waves.
The findings of this pilot study, published in the May 24 issue of Neurology, show that people with ALS can use thoughts to control electronic devices, although the researchers say increasing users’ speed and accuracy is necessary for the application to be practical. They also caution that control may wane as ALS progresses.
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