Johns Hopkins researchers believe they may have discovered
an explanation for the sleepless nights associated with restless legs syndrome
(RLS), a symptom that persists even when the disruptive, overwhelming nocturnal
urge to move the legs is treated successfully with medication.
Neurologists have long believed RLS is related to a
dysfunction in the way the brain uses the neurotransmitter dopamine, a chemical
used by brain cells to communicate and produce smooth, purposeful muscle
activity and movement. Disruption of these neurochemical signals,
characteristic of Parkinson’s disease, frequently results in involuntary
movements. Drugs that increase dopamine levels are mainstay treatments for RLS,
but studies have shown they don’t significantly improve sleep. An estimated 5
percent of the U.S. population has RLS.