Methods, compositions and kits useful in the detection, assessment, diagnosis, prognosis and/or treatment of neurological injury or disease or brain injury, such as traumatic brain injury (TBI), are provided in which certain newly discovered protein biomarkers are detected in a biological sample of a subject undergoing testing or evaluation. The methods allow for detection of changes in levels, amounts, or concentrations of the protein biomarkers in a subject compared with those of controls. Detection of the protein biomarkers, and/or levels thereof, provides an indication of biological and biochemical events, e.g., at a cellular level, that are occurring in the subject who is undergoing testing or analysis for the neurological injury or brain injury.