Processes and materials are provided for the detection, diagnosis, or determination of the severity of a neurological injury or condition, including traumatic brain injury, multiple-organ injury, stroke, Alzeimer's disease, Parkinson disease and Chronic Traumatic Encephalopathy (CTE). The processes and materials include biomarkers detected or measured in a biological sample such as whole blood, serum, plasma, or CSF. Such biomarkers include Tau and GFAP proteins, their proteolytic breakdown products, brain specific or enriched micro-RNA, and brain specific or enriched protein directed autoantibodies. The processes and materials are operable to detect the presence of absence of acute, subacute or chronic brain injuries and predict outcome for the brain injury.