Methods for aiding in the diagnosis and determination of the extent of traumatic brain injury in a human subject using the early biomarker ubiquitin carboxy-terminal hydrolase L1

A method comprising:

• performing an assay for ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) in a sample obtained from a human subject after a head injury or suspected head injury;
• and
• treating the subject for a moderate to severe TBI when the level of UCH-L1 in the sample is greater than or equal to about 550 pg/mL, or for a mild TBI when the level of UCH-L1 in the sample is less than about 550 pg/mL;
• wherein the sample is whole blood, serum, or plasma obtained within about 24 hours after the head injury or suspected head injury.

A method comprising:

• performing an assay for ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) in at least a first sample taken at a first time point and a second sample taken at a second time point and obtained from a human subject after a head injury or suspected head injury;
• and
• performing a head computed tomography (CT) scan on the subject when the level of UCH-L1 in the second sample exhibits a fold-change of less than about 1.81 as compared to the level of UCH-L1 in the first sample;
• and
• wherein the sample is whole blood, serum, or plasma obtained wherein the first time point is within about 24 hours after the head injury or suspected head injury and the second time point is within about 3 to about 6 hours after the first sample is taken.