Build a converging record and let each source answer only the question it can support.

Identify the force and preserve the physical or digital source: vehicle and event data, scene, equipment, helmet, object, fall geometry, blast evidence, security or body-camera video, emergency calls, phone photographs, and witnesses. Record custody, time zone, export, edits, and whether the file is native. A clip may show movement or behavior without capturing impact, assistance, or what happened outside the frame.

Collect exact acute observations: consciousness or altered awareness, amnesia, confusion, repeated questions, speech, balance, vomiting, vision, seizure, headache, behavior, and change. Use the observer's own words and time. Do not assign a medical score retrospectively. Explain conditions that affected observation—sedation, intoxication, shock, pain, stress, language, hearing, developmental status, or other trauma.

Preserve source medical data. Obtain trauma flowsheets, nursing checks, physician notes, consultations, laboratory results, original computed tomography and magnetic resonance imaging, electroencephalography if performed, operative and intensive-care records, medication, discharge instructions, and follow-up. Identify copied-forward text and differences between preliminary, final, and later interpretations. A report is not a substitute for the complete study when imaging is contested.

Neuropsychological testing can assess cognitive and behavioral patterns using standardized methods. Review referral question, qualifications, language, culture, education, estimated prior ability, test selection, administration, scoring, validity measures, pain, sleep, medication, mood, sensory or motor limitations, and interval from injury. A low score does not identify cause by itself. A validity concern requires careful interpretation and is not a universal synonym for intentional deception.

Imaging methods answer different structural or research questions. Routine clinical computed tomography and magnetic resonance imaging can be essential in appropriate circumstances. Advanced imaging, biomarkers, eye tracking, balance, electrophysiology, computerized cognition, and other emerging tools require method-specific evidence of validation, clinical role, timing, controls, error, interpretation, and admissibility. A marketing claim or research association should not become an individual forensic conclusion without support.

The differential should address prior brain injury, migraine, attention or learning issues, neurological disease, sleep, pain, medication, depression, anxiety, post-traumatic stress, substance use, vision, vestibular or hearing conditions, and other injuries where relevant. Compare pre-event and post-event course. Experts should explain why the evidence supports trauma, aggravation, another cause, or multiple contributors and what remains uncertain.

For work, collect duties, pace, accuracy, work product, email, errors, supervision, attendance, leave, accommodations, safety, customer interaction, earnings, benefits, evaluations, and return attempts. Protect confidential business information and distinguish ordinary variation from post-event change. A supervisor may describe function but should not diagnose brain injury.

For home and community, document scheduling, finances, medication, cooking, navigation, driving, household tasks, childcare, relationships, impulse control, sleep, fatigue, recreation, and safety. Natural, consistent diaries and family observations may help. Social media offers isolated snapshots and rarely shows symptoms, assistance, recovery, or the rest of the day; authenticate and contextualize it.

For school, preserve attendance, assignments, grades, testing, nurse and teacher observations, accommodations, formal evaluations, and developmental history. For children, apply age-valid methods and privacy. For adults, educational history can help estimate prior ability and interpret testing. Function does not replace medical causation, but it tests whether the claimed cognitive or behavioral effect appears in environments that demand it.

Map disputed propositions to reconstruction, engineering, biomechanics, radiology, neurology, rehabilitation, neuropsychology, mental health, sensory, sleep or pain specialties, vocational review, life-care planning, and economics. Confirm qualifications for each method, materials, assumptions, alternative causes, peer-reviewed basis, uncertainty, and scope limits.

Keep treating and retained roles clear. Treaters may know the contemporaneous course without evaluating legal causation, long-term work, or every alternative. Retained experts should not edit history or ignore disagreement. The legal team may provide facts and focused questions without ghostwriting medical conclusions. Demonstratives should reflect evidence without amplifying certainty.

Connect injury evidence to the claim. Identify the responsible party, duty or defect, breach, mechanism, medical causation, comparative issues, and damages. Work, public entities, products, professional care, schools, sports, assault, Tribal governments or entities, federal parties, and minors may alter procedure and defenses. Admissibility, preservation, spoliation, privilege, confidentiality, discovery, limitations, and notice require current court- or tribunal-specific review.