The present invention provides systems and methods for detection and diagnosis of concussion and/or acute neurologic injury comprising a portable headwear-based electrode array and computerized control system to automatically and accurately detect cortical spreading depression and acute neurological injury-based peri-infarct depolarization (CSD/PID). The portable headwear-based electrode system is applied to a patient or athlete, and is capable of performing an assessment automatically and with minimal user input. The user display indicates the presence of CSD/PID, gauges its severity and location, and stores the information for future use by medical professionals. The systems and methods of the invention use an instrumented DC-coupled electrode/amplifier array which performs real-time data analysis using unique algorithms to produce a voltage intensity-map revealing the temporally propagating wave depressed voltage across the scalp that originates from a CSD/PID on the brain surface.