The human brain is a powerful and resilient organ. But it has many enemies and a dramatic vulnerability. When under attack—from ischemic stroke, head trauma or degenerative diseases—a small cluster of affected brain cells basically commits suicide and, in so doing, releases toxins that kill off neighboring cells in droves. Neurons tumble like dominoes to their death in a process that can take hours (in a stroke or a head trauma) or years (in Alzheimer’s or Parkinson’s disease). The physical symptoms of that cell death may vary from disease to disease, but the result is the same: disability that can make the simplest of human tasks difficult or impossible. The medical profession has struggled to combat each of the brain’s enemies separately and limit the damage and disability they wreak. But prevention is hard, and cures are elusive. It has been a war with few successes. But what if there were a simple way to fortify human neurons against the brain’s enemies? What if some safe, readily available compound, taken before or just after a stroke or injury or even long before a neurodegenerative disease takes hold, could protect the brain against insults and injuries? This idea is called neuroprotection. Although the quest for it has a history of disappointment, some glimmers of hope are on the horizon. “It’s a little bit like the search for the Holy Grail,” says Dr. Walter Koroshetz, deputy director of the National Institute of Neurological Disease and Stroke. “But I don’t think there’s anybody who doesn’t believe eventually we’re going to be able to do this. We need a success that we can build on.” To that end, the US government launched a nationwide trial in March to investigate whether creatine—a dietary supplement safely taken by bodybuilders at lower doses than those being tested—can slow the die-off of neurons in early-stage Parkinson’s disease. A second promising neuroprotectant, the dietary supplement co-enzyme Q10, is set to enter clinical trials next year for early-stage Parkinson’s disease, as well. This summer, the National Institute of Neurological Diseases and Stroke is expected to fund a national clinical trial to see if high doses of progesterone—the hormone that surges during pregnancy but is present in all human brains—can help disrupt the rapid death of brain cells in head trauma. Scientists at the University of California, Los Angeles, are studying whether magnesium sulfate—long used to stave off early labor and delivery — can break the chain of destruction that leaves stroke patients disabled. And a common antibiotic, minocycline, is being tested in humans as a way to slow Lou Gehrig’s disease and Huntington’s disease, a degenerative genetic disorder. “The biology of the neuroprotection has just exploded. It’s just amazing,” Koroshetz says. “There are so many different pathways people have identified that could potentially save brain cells from dying, it really piques your interest.” Researchers are wary. They have been here before and come up empty-handed. “The graveyard of neuroprotectants is absolutely full. It’s depressing,” says Dr. David Wright, a professor of medicine at Emory University Medical School in Atlanta and a leader in testing progesterone for head injury. But his hopes have been buoyed by studies suggesting that quickly elevating levels of progesterone, a steroid, may help save many with traumatic head injury and improve their outcomes.Melissa Healy, (Los Angeles Times)
