Dear Friends,
The following came my way; RLS can trouble some folks with PD and I
thought the article might be of interest. Best, Kathrynne
======================================================

Study suggests cause for restless leg syndrome
http://www.eurekalert.org/pub_releases/2003-06/ps-ssc060503.php

Underdiagnosed syndrome may affect 5 percent to 10 percent of U.S.
population
Restless legs syndrome (RLS) may sound like something right out of a
1950s horror flick. And for some sufferers, it is. This affliction
causes an irresistible urge to move the legs often accompanied by
creepy-crawly sensations in the legs. The sensations are only relieved
by movement, and become worse as the sun goes down. Night after night
this sleeplessness occurs for the millions who suffer with RLS and their
partners.

Because little is known about what causes RLS, researchers at Penn State
College of Medicine and Johns Hopkins University went looking for
answers. The team, led by James Connor, Ph.D., professor and interim
chair, Department of Neuroscience and Anatomy, Penn State College of
Medicine, performed the first-ever autopsy analysis of the brains of
people with RLS. This research, presented today (June 5, 2003) at the
Association of Professional Sleep Societies meeting in Chicago,
uncovered a possible explanation for this syndrome.

“We found that, although there are no unique pathological changes in the
brains of patients with RLS, it appears that cells in a portion of the
mid-brain aren’t getting enough iron,” Connor said. “It was a relief to
many that there was no neurodegeneration, or loss or damage of brain
cells, like we see in Parkinson’s and Alzheimer’s disease.”

The discovery of a physical cause for this disorder establishes it as a
sensory motor rather than a psychological disorder. Because cells aren’t
lost or damaged but rather iron-deficient, there is more hope that
treatments can be developed.

For the study, Connor examined brain tissue acquired through the
Restless Legs Syndrome Foundation’s brain collection at the Harvard
Brain Bank. Tissue from seven people with RLS was examined and five
samples from people with no neurological conditions served as controls.
Cross-sectional slides of the substantia nigra, the portion of the
middle brain thought to play a role in RLS, allowed the research team to
thoroughly examine the cells’ structures and functions. To avoid bias,
during examination, the investigator did not know whether the sample was
that of a patient with or without RLS.

Although it’s been long-suspected that iron deficiency had something to
do with RLS, Connor’s study found that a specific receptor for iron
transport is lacking in patients with RLS. When that mechanism
malfunctions, enough iron gets into the brain cells to keep them alive,
but not enough so that they function optimally. That missing iron may
cause a misfiring of neural signals to the legs creating the
creepy-crawly feelings.

“This doesn’t necessarily mean that a person has dietary iron-deficiency
and needs supplements,” Connor said. “It means only that these receptors
aren’t packaging and delivering an adequate amount of iron to the
specific cells in this portion of the brain.”

This explains why some patients find temporary relief from iron
supplements, but it is important that any supplementation therapy be
managed by a physician.

Although not FDA-approved for the treatment of RLS, a few prescription
drugs, which have been approved for other conditions, have temporarily
relieved symptoms in some patients. One such drug is that used in
Parkinson’s disease to calm tremors. The cells in the brain in RLS that
are iron deficient are the cells that make the neurotransmitter
dopamine. Dopamine synthesis requires iron and this is the likely reason
that small amounts of the drugs that are used to treat Parkinson’s
patients can be effective in RLS.

Connor’s next step is to continue to pinpoint other potential breakdowns
in the iron packaging and transport system to this part of the brain,
including the genes that regulate the iron transport proteins.

“We hope these discoveries lead to a test that could diagnose this
syndrome, and a potential target for a therapy to bring long-term relief
to those suffering with restless legs syndrome,” Connor said.

###

This study was funded in part by grants from the National Institutes of
Health and the Restless Legs Syndrome Foundation.

Other members of the research team were: P.J. Boyer, M.D., Ph.D.,
Departments of Neuroscience and Anatomy, and Pathology, S. L. Menzies,
Department of Neuroscience and Anatomy, and B. Dellinger, Department of
Pathology, Penn State College of Medicine, Penn State Milton S. Hershey
Medical Center; R.P. Allen, Ph.D., Department of Neurology, Johns
Hopkins Bayview Medical Center; W.G. Ondo, M.D., Department of
Neurology, Baylor College of Medicine, Houston; C.J. Earley, M.D.,
Ph.D., Department of Neurology, Johns Hopkins Bayview Medical Center.
--
Kathrynne Holden, MS, RD
"Ask the Parkinson Dietitian"  http://www.parkinson.org/
"Eat well, stay well with Parkinson's disease"
"Parkinson's disease: Guidelines for Medical Nutrition Therapy"
http://www.nutritionucanlivewith.com/

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