The overwhelming urge to move your legs while trying to sleep and relax keeps about 5% of the United States up at night For years, scientists have thought abnormal levels of dopamine could be the reason behind the movements. Dopamine is a neurotransmitter which communicates with brain cells to produce smooth muscle activity. Drugs that increase dopamine levels have been used to treat these symptoms.
Professor Richard P. Allen at Johns Hopkins University recently found that glutamate, not dopamine, may be at fault. Glutamate is a neurotransmitter in the thalamus associated with arousal.
MRIs of 48 individuals, 28 with restless leg syndrome and 20 without, found that increased glutamate levels are congruent with sleepless nights. Also, glutamate results in hyperarousal (day or night), which may be why individuals suffering with restless leg syndrome may not sleep but also not feel tired during the day.
But, does it matter what the cause is, as long as the dopamine medications are working? Well they do…at first. As the body becomes adapted and doses are increased, the symptoms can actually get worse.
There are medications that can lower glutamate levels, such as anticonvulsive gabapentin enacarbil, but they have not been used to treat restless leg syndrome yet. This research can also help explain other problems associated with insomnia.
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