This was then followed by a paper on a second case in 2006 describing similar pathology, based on findings in the brain of former NFL player Terry Long.In 2008, the Center for the Study of Traumatic Encephalopathy at the BU School of Medicine (now the BU CTE Center) started the VA-BU-CLF Brain Bank at the Bedford Veterans Administration Hospital to analyze the effects of CTE and other neurodegenerative diseases on the brain and spinal cord of athletes, military veterans, and civilians. To date, the VA-BU-CLF Brain Bank is the largest CTE tissue repository in the world, with over 1000 brain donors.On 21 December 2009, the National Football League Players Association announced that it would collaborate with the BU CTE Center to support the centers study of repetitive brain trauma in athletes. Additionally, in 2010 the National Football League gave the BU CTE Center a $1 million gift with no strings attached. In 2008, twelve living athletes (active and retired), including hockey players Pat LaFontaine and Noah Welch as well as former NFL star Ted Johnson, committed to donate their brains to VA-BU-CLF Brain Bank after their deaths.
A tendency towards low 5-HIAA may be hereditary. A putative hereditary component to low CSF 5-HIAA and concordantly possibly to impulsive violence has been proposed. Other traits that correlate with IED are low vagal tone and increased insulin secretion. A suggested explanation for IED is a polymorphism of the gene for tryptophan hydroxylase, which produces a serotonin precursor; this genotype is found more commonly in individuals with impulsive behavior.IED may also be associated with damage or lesions in the prefrontal cortex, with damage to these areas, including the amygdala and hippocampus, increasing the incidences of impulsive and aggressive behavior and the inability to predict the outcomes of an individuals own actions. Lesions in these areas are also associated with improper blood sugar control, leading to decreased brain function in these areas, which are associated with planning and decision making. A national sample in the United States estimated that 16 million Americans may fit the criteria for IED.