66 Scientifi c American, February 201266 Scientifi c American, February 2012SCOTT CUNNINGHAM Getty ImagesTHE COLLISION SYNDROMEFootball players diagnosed with Lou Gehrig’s disease may suff er from the eff ect of repeated blows to the head, controversial new research says By Jeff rey BartholetBRAIN SCIENCEIN BRIEFKevin Turner, a former professional foot ball player, suff ered at least two concussions during his career and has been diagnosed with ALS, or Lou Geh-rig’s disease. Some scientists believe that he has a distinct type of ALS caused by repeated concussions and that other players have suff ered a similar fate.The fi ndings, which stem from re-search connecting concussions to an-other brain disease, are controversial. Proponents compare their eff orts to show a link between brain trauma and an ALS-like disease to the battle to prove a connection between smoking and lung cancer; others say that the science does not justify that analogy. There is widespread agreement, how-ever, that repeated blows to the head, such as those sustained during a foot-ball player’s career, can result in brain damage.sad0212Bar74p.indd 66 12/14/11 5:35 PMsad0212Bar74p.indd 67 12/14/11 5:36 PM68 Scientific American, February 2012Now Turner can’t button his shirt. When we met recently at a California Pizza Kitchen in Birmingham, Ala., the first sign of physical impairment came when he put his small backpack into the booth where he would be sitting. His arm was Frankenstein-straight, and his shoulder was stiff as he swung the pack away from his body. Other issues soon became apparent. His fingers were curled up and his thumbs almost useless, so he drank from a glass by holding it in his palms. After he had trouble removing the little paper ring from his napkin, he took a furtive glance at the nearby tables before ducking his head down to rip it off with his teeth.“I can’t tell you how frustrating it is to open a box of cereal,” the 42-year-old father of three told me as we left the restaurant. “Open-ing a box of cereal is an event.” Turner needs someone to help him pull his pants on in the morning. His then 11-year-old daughter performed that duty the day I met him. She also helped him shave.In 2010 Turner was diagnosed with amyotrophic lateral scle-rosis (ALS), commonly known as Lou Gehrig’s disease. Nobody knows what causes ALS. In 5 to 10 percent of cases, the disease is inherited; otherwise, it is a random death sentence. Its arrival is a mystery, and there is no cure.Now a group of scientists in Boston believes that Turner, de-spite suffering symptoms of ALS, may not really have the disease. Around the same time he was diagnosed, these researchers discov-ered what they say could be a separate disorder with exactly the same clinical syndrome as ALS. It is also incurable. The only real difference is that this disease seems to have a clear cause: repeated blows to the head, like those that often occur on the football field.The finding is hugely controversial. Many specialists in ALS have been critical of the science behind the new study and worry that it has confused their patients. They maintain that decades of research trying to find a link between head trauma and ALS have been inconclusive at best. They have been particularly in-censed by the suggestion, made in press interviews, that Lou Gehrig might not have had Lou Gehrig’s disease. In a letter to the editor of the Journal of Neuropathology & Experimental Neurol-ogy, more than a dozen doctors and researchers questioned the science in the findings and complained that “many patients have understandably been frightened and confused by these state-ments and are now wondering if their diagnoses are correct.” Ann McKee, a neuropathologist at Boston University and the Bedford VA Medical Center in Massachusetts, is the primary sci-entist behind the study. She says she re-grets the controversy stirred up by the speculation regarding Gehrig but stands firmly behind the science. Her original study was based on three cases, and she now has five more, as well as three other suspected cases awaiting confirmation. McKee and her colleagues liken their bat-tle to the one waged by scientists trying to show that smoking causes cancer. There has been a lot of re-sistance, but ultimately, they believe, they will prevail in showing that repetitive concussions cause a motor neuron disease with ALS-like symptoms. Already findings about the potential for repetitive concus-sions to cause other forms of mental impairment have spurred the NFL to change some of its rules on flagrant hits to the head, and many states have passed legislation to ensure that young athletes do not return to the field too quickly after a concussion. Even some scientists critical of certain details in McKee’s re-search, or the way in which it was presented to the press, believe her findings are significant. “The core observations of her work are very important,” says Robert Brown, chair of neurology at the University of Massachusetts Medical School, “and the public policy implications are staggering.”HAVOC IN THE BRAINto grasp the controversy, it helps to first understand what hap-pens inside the brain when someone suffers a concussion. Our current knowledge is based largely on animal models—experi-ments on rodents and cats—as well as the monitoring of human patients in intensive care with severe brain injuries and magnet-ic resonance imaging of people with mild concussions. Part of this picture is uncertain, but the science is improving. “Previous-ly there was no way to get some of the necessary data without drilling a hole in somebody’s head,” says Christopher Giza, an as-sociate professor of pediatric neurology and neurosurgery at the University of California, Los Angeles, who has done a review of the scientific literature. “We now have advanced imaging that has provided us with some of this information.”What is clear is that when the head, moving at significant speed, comes to an abrupt stop, the brain cells inside get stretched, squeezed and twisted. In their normal state, these cells function by transmitting electric current. A part of the cell called the axon acts somewhat like a wire, conducting current between the cells. Ions shift back and forth along the axons in a controlled fashion, trans-mitting messages from one part of the brain to the other and to the rest of the body. When a
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