Study confirms increased MS rates 15 November 2006
The recently released findings of a new study appear to confirm long-held suspicions that local communities Morrison and Paw Paw have higher-than-average rates of multiple sclerosis - particularly among women.
The study found Morrison in particular had 21 confirmed cases of MS - all of them women - which represents about 218 cases for every 100,000 people. That's about 2 1/2 times the average diagnosis rate, which is about 85 diagnoses for every 100,000 people, according to a national survey.
Multiple sclerosis or MS is a disease that affects the brain and spinal cord resulting in loss of muscle control, vision, balance, sensation or thinking ability, according to the medical Web site WebMD. The exact cause of the disease is unknown.
Studies typically have found about two or three women are diagnosed with MS for every man with the disease, but in the communities studied locally, the rate was much higher - 11 women diagnosed for every man.
"It boils down to about one out of every 300 women in the areas that we studied (have multiple sclerosis)," said Joel Cowen, principal investigator at Health Systems Research of the University of Illinois College of Medicine at Rockford. "The key message I think is the Morrison area is predisposed (to MS). It has this big female excess. That is a really high level, probably highest in any of the known literature."
The study was able to verify three cases of MS for Paw Paw, representing more than 2 1/2 times the average rate because of Paw Paw's small population. Lewiston also had a higher rate, but Savanna and DePue were not elevated, the study found.
Although the study confirmed long held rumours of high rates of MS for Morrison, Paw Paw and Lewistown, the researchers could not find any environmental factors to explain why the numbers were elevated, Cowen said.
"We really don't have an answer to say why it is so high," Cowen said. "We can really just say it is so high and that women with a northern European background in northern Illinois should be on the lookout for this."
That particular ancestry appears to be a factor in all the communities studied. Of the 37 individuals diagnosed with multiple sclerosis, all 37 had a northern European background, Cowen said. Morrison is know to have strong Dutch and German roots.
"I think women need to be aware in this area that being of northern European ancestry is a risk factor," Cowen said.
Genetics are also thought to play a part in the disease. Eleven of the study participants had a blood relative with MS. Because small towns "may have many related persons," genetic predisposition could also be one of the factors for the elevated levels of the disease, the study found.
The results for Morrison mirror a 1993 study also done by the University of Illinois College of Medicine in Rockford at the behest of the Whiteside County Health Department.
In the 1993 study, 23 people said they had multiple sclerosis in the Morrison ZIP code. That study was different because the findings were based on self-designation, meaning the 23 people simply told the researchers they had MS; the diagnosis was not verified medically, Cowen said.
This time around participants agreed to have their medical records reviewed by an expert at Texas Tech University who verified whether participants actually had MS, Cowen said.
Verification is important because MS was once a "disease of exclusion," meaning doctors would sometimes diagnose patients with the disease simply because the patient's symptoms didn't match any other illness. Cowen said Monday that the study identified several people in the five communities who were either misdiagnosed with MS or whose diagnoses couldn't be confirmed.
The researchers in the current study also looked at the background of all the study participants, searching for commonalties in past living locations, jobs or other factors. Cowen said he'd heard local rumours blaming water supplies or industrial pollution for the high rate of MS, but his study found no evidence supporting any particular environmental cause.
The study - one of five conducted in the United States to better understand MS and ALS, also known as Lou Gehrig's Disease - was funded with a grant given in October 2002 by the Agency for Toxic Substances and Disease Registry. Cowen recently sent the completed study's data to the agency, where it will be compiled with the four other studies in hopes of better understanding the disease.
While the results may not have been a breakthrough in discovering an environmental cause or trigger for MS, Cowen said the results were unique in finding a generally high rate in several of the towns, especially among women.
Eventually, Cowen hopes the medical community creates a national database for MS, similar to the current database for cancer victims. That way researchers could better study the disease, Cowen said. He said he'd would also like to sponsor a future conference on MS in Rockford.
Source: Sauk Valley.com Copyright © 2006 Sauk Valley Newspapers - All Rights Reserved