In a major medical breakthrough, scientists studying amyotrophic lateral sclerosis (ALS) -- popularly known as Lou Gehrig's disease -- believe they have idenfitied the cause of all forms of the disease.

A team of neuroscientists at Northwestern University's Feinberg School of Medicine discovered a faulty cellular mechanism in the brain and spinal chord of ALS patients believed to be responsible for the breakdown of communication between the brain and the muscular system, which causes increasing paralysis that ultimately kills most ALS victims.

The results of this research, which are published in the Aug. 22 issue of the journal Nature, could prove to be a historic and lifesaving breakthrough for the 30,000 Americans diagnosed with ALS each year -- 50 percent of them are expected to die within three years of developing the disease.

The 23 contributing researchers, led by Northwestern neurological researchers Han-Xiang Deng and Wenjie Chen, idenitifed a malfunction of the protein Ubiquilin 2, which, when functioning properly, disposes or repairs other damaged proteins in brain and spinal cells. When Ubiquilin 2 is ineffective, damaged proteins can clog the cells and interfere with the normal transmission of brain signals, resulting in paralysis.

This is the first time we could connect [ALS] to a clear-cut biomedical mechanism, Northwestern researcher Dr. Teepu Siddique told the Los Angeles Times. It has really made the direction we have to take very clear and sharp. We can now test for drugs that would regulate this protein pathway or optimize it, so it functions as it should in a normal state.

ALS first became well known in the U.S. when beloved New York Yankee first baseman Lou Gehrig developed the disease and ultimately succumbed to it. Gehrig died in 1941 at the age of 37, a year after he retired from baseball because of his condition. ALS has since been commonly known as Lou Gehrig's disease. In 1942, RKO Pictures released the film The Pride of the Yankees, which chronicled Gehrig's career and heroic struggle, and includes a dramatization of his famous farewell speech at Yankee Stadium.

More recently, New York City-based author and historian Tony Judt died of ALS on Aug. 7, 2010.  Judt, who taught at New York University and was one of the country's most polarizing and outspoken critics of the Jewish occupation of Israel, continued to lecture and publish after his diagnosis in 2008.

In January 2011, he published an essay in The New York Review of Books about his experience with the disease, describing ALS as progressive imprisonment without parole.

In contrast to almost every other serious or deadly disease, Judt wrote, one is thus left free to contemplate at leisure and in minimal discomfort the catastrophic progress of one's own deterioration.