And MIT Technology Review also reports that the general state of TBI research isn't much better:

Yet much about brain injuries remains unknown. Despite decades of research, no treatments yet target the underlying pathophysio­logical cause of progressive brain damage. For patients so severely injured that they are in a minimally conscious state, medical knowledge is particularly lacking; in such cases, we are just beginning to understand the damage and the possibility of treatment (see "Raising Consciousness").
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Finding treatments for those injuries that do occur will depend on better understanding the complex cellular events triggered by a brain injury. In TBI, a rapid mechanical deformation of the brain both physically disrupts and mechanically stimulates cells. Some cell damage is immediate, but most of the damage develops over days, weeks, and even months. The delayed and progressive nature of the neurodegenerative cascade represents a critical therapeutic opportunity: targeted intervention could halt the progression of cell damage and death. However, no therapeutic strategies yet exist that target the degeneration mechanisms.