Energy crisis in brain may trigger Parkinson's

WASHINGTON - Parkinson's disease may stem from an energy crisis in the brain, years before symptoms appear.

If the research pans out, it points to a possible new approach for Parkinson's: Giving a boost to a key power switch in brain cells in hope of slowing the disease's inevitable march, instead of just treating symptoms.

"This is an extremely important and interesting observation that opens up new therapeutic targets," said Dr. Flint Beal of Weill Cornell Medical College in New York, who wasn't involved with the new study. Beal said scientists already are planning first-stage tests to see whether a drug used for diabetes might help Parkinson's, too, by targeting one of the implicated energy genes.

At issue are little power factories inside cells, called mitochondria. Increasingly, scientists suspect that malfunctioning mitochondria play some role in a list of degenerative brain diseases. Brain cells make up about 2 percent of body weight yet consume about 20 percent of the body's energy. So a power drain could trigger some serious consequences.

"It could be a root cause" of Parkinson's, said Dr. Clemens Scherzer of Brigham and Women's Hospital in Boston and Harvard University.

About 5 million people worldwide, and 1.5 million in the United States, have Parkinson's, characterized by increasingly severe tremors and periodically stiff or frozen limbs. Patients gradually lose brain cells that produce dopamine, a chemical key to the circuitry that controls muscle movement. There is no cure, although dopamine-boosting medication and an implanted device called deep brain stimulation can help some symptoms.

No one knows what causes Parkinson's. To find genetic clues, Scherzer gathered an international team of researchers to comb studies of more than 300 samples of brain tissue - from diagnosed Parkinson's patients, from symptom-free people whose brains showed early Parkinson's damage was brewing, and from people whose brains appeared normal.

The team found 10 sets of genes that work at abnormally low levels in Parkinson's patients, genes that turned out to play various roles in the mitochondria's energy production, Scherzer reported recently in the journal Science Translational Medicine.