Overview
Head injuries, especially mild ones, are among the hardest injuries to document. NINDS states that current imaging, blood tests and other measures “can’t always detect damage from mild, concussive injuries,”[1] and the CDC notes that some symptoms may not appear for hours or days.[2] In claims, the injury is usually shown through a combination of medical records, imaging, testing, expert opinion and observations from people who know the injured person.
Why proof is difficult
A 2020 study in the Journal of Neurotrauma reports that fewer than 10% of people who come to the emergency department with a mild TBI have abnormalities on head CT.[3] Many concussion symptoms, such as headaches, trouble concentrating, irritability and sleep changes, are reported by the person rather than measured.[2] Those two facts are the core of most disputes.
- Why head injuries are disputedThe common arguments in head injury claims
- A normal CT scanWhat a normal scan does and doesn’t mean
- Delayed symptomsWhen symptoms appear after the first visit
Medical evidence
- Medical recordsYour HIPAA right to get copies
- MRI and advanced imagingMRI, DTI, SWI and how courts treat them
- Blood tests for brain injuryGFAP and UCH-L1 biomarker tests
- Neuropsychological testingCognitive testing and validity measures
Evidence in the legal process
- Expert witnessesRule 702, Daubert and Frye
- Everyday evidenceWitnesses, journals, and work and school records
- Pre-existing conditionsPrior concussions and the eggshell skull rule
- Independent medical examsCourt-ordered exams under Rule 35
- Social media and surveillanceWhat the other side can request
This page provides general information from the sources listed below. It is not legal or medical advice, and reading it does not create an attorney-client or provider-patient relationship. Laws vary by state and change over time. See our legal disclaimer.
Sources
- National Institute of Neurological Disorders and Stroke. “Traumatic Brain Injury (TBI).” https://www.ninds.nih.gov/health-information/disorders/traumatic-brain-injury-tbi
- Centers for Disease Control and Prevention. “Symptoms of Mild TBI and Concussion.” https://www.cdc.gov/traumatic-brain-injury/signs-symptoms/index.html
- Okonkwo DO, et al. “Point-of-Care Platform Blood Biomarker Testing of Glial Fibrillary Acidic Protein versus S100 Calcium-Binding Protein B for Prediction of Traumatic Brain Injuries: A TRACK-TBI Study.” Journal of Neurotrauma, 2020. https://pmc.ncbi.nlm.nih.gov/articles/PMC7698990/
Sources last checked: October 11, 2026
