There are several clues that light therapy might help people with
Parkinson's disease. Experiments have shown that blocking
melatonin might reduce the severity of the muscle rigidity that's
characteristic of the disease — and light therapy seems to reduce
Light therapy may also help with the depression that besets
people with Parkinson's. Australian researchers enrolled a dozen
Parkinson's patients in a light therapy study. They exposed them
to bright fluorescent light (1,000 to 1,500 lux) for an about
hour each day shortly before they went to sleep.
Then they assessed the effect of the treatment at regular
intervals. Within two weeks they observed improvement in
bradykinesia (slow movements) and rigidity. Tremors were not
affected, but the researchers did document improvements in mood,
sleep, and appetite. Light therapy also permitted the reduction
of L-dopa and other medicines without a worsening of Parkinson's
disease, according to the results published last year in a
journal called Chronobiology International.
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