Figuring out how science can help answer many of the unresolved questions about brain injuries — and how to make contact sports like football safer — remains a major problem for neuroscientists to tackle. Understanding impacts, concussions and their effects, both immediately and through the course of a person’s life, remains one of the most tangled questions in neuroscience. The short-term and long-term effects of subconcussive impacts are currently poorly understood and difficult to study.
Further, diagnoses themselves are somewhat subjective, and based in part on a patient’s description of his or her injury. There are no definitive biomarkers of concussion — no way to definitely diagnose it by looking for telltale signs in drawn blood, for instance, or in CT scans or MRIs of the brain. Some scientists argue that what we currently call a concussion is actually a spectrum of injuries. Animal models may help researchers develop diagnostic tests and point the way toward therapies and preventative measures, but current models are imperfect.