I have previously reported on the BIAA white paper authored by Brent Masel, M.D. describing traumatic brain injury as a chronic disease.  The Federal Register has published a proposed rule of the Department of Veteran Affairs (VA) which is proposing an amendment to its adjudication regulations concerning service connection.  The amendment ,according to the summary of the rule, states,“this amendment is necessary to act upon a report of the National Academy of Sciences, Institute of Medicine, Gulf War and Health Volume 7: Long-term consequences of traumatic brain injury regarding the association between traumatic brain injury and five diagnosable illnesses.  The intended effect of the amendment is to establish that if a veteran who has a service-connected TBI also has one of these diagnosable illnesses, that that illness will be considered service connected as secondary to the TBI.  
The five diagnosable illnesses are: Parkinsonism; dementias (which includes:  (a) pre senile dementia of the Alzheimer type and (b) post-traumatic dementia); depression (also associated with mild TBI), and diseases of hormone deficiency that may result from hypothalamo-pituitary changes.   
A copy of the proposed rule change can be found here.