Why a Past Concussion Does Not Weaken Your Brain Injury Claim in Newport Beach
Key Takeaways: CACI 3928, the "Unusually Susceptible Plaintiff" instruction, directs California juries to award full damages caused by a defendant’s wrongful conduct even when the injured person was more vulnerable to harm. Rooted in the eggshell skull rule, it shapes damages calculation once liability and causation are established. CACI 3927 allows recovery for aggravation of pre-existing conditions, though not for the prior condition itself. Newport Beach brain injury victims with concussion history must prove aggravation through pre-injury records, physician testimony, neuropsychological testing, and qualified causation opinions. Evidence Code Section 801.1 limits opposing expert causation testimony, while defense counsel may scrutinize prior claims and treatment gaps. Acting quickly, disclosing full history, documenting symptoms, and requesting correct jury instructions protect repeat head injury claims.
If you suffered a concussion years ago and a negligent driver just gave you another one, California law does not penalize you for that history. Under CACI 3928, juries may award full damages caused by the defendant’s wrongful conduct even if you were more susceptible to injury than a healthy person. This instruction can be the difference between a fair verdict and an insurance adjuster’s low offer built on "you were already damaged." For Newport Beach brain injury victims with documented concussion history, understanding how this instruction works and what proof it demands matters enormously.
If you or a family member sustained a repeat head injury in Orange County, the team at Bisnar Chase is available to review your medical records and explain your options. Call 800-561-4887 or reach out to our Newport Beach personal injury attorneys to discuss what happened.
What the CACI 3928 Unusually Susceptible Plaintiff Instruction Actually Says
CACI 3928 is titled "Unusually Susceptible Plaintiff" and sits within the CACI Series 3900 damages instructions, approved by the Judicial Council. Because it lives in the damages series rather than the liability series, it does not help establish negligence. It addresses how juries measure compensation once negligence and causation are established.
The instruction directs jurors to award full damages the defendant’s conduct caused, even where the plaintiff was more susceptible to harm than a normally healthy person. A defendant who rear-ends a driver with two prior concussions cannot argue the driver should recover less because a person with no concussion history would have walked away unhurt. Whether the instruction is given depends on the evidence presented, and a judge may decline where the record does not support susceptibility.
The Eggshell Skull Rule Behind the Instruction
The "eggshell skull rule" is the common-law foundation for CACI 3928. California appellate authority, including Rideau v. Los Angeles Transit Lines (1954) 124 Cal.App.2d 466 and Ng v. Hudson (1977) 75 Cal.App.3d 250, reflects the principle that a tortfeasor takes the victim as found. The fact that a healthier person would have suffered less injury does not excuse liability or reduce damages attributable to the defendant’s conduct.
This principle carries particular weight in traumatic brain injury litigation. Repeat head trauma is widely recognized in medical literature as producing worse and longer-lasting deficits than a first concussion, so the person most protected by the rule is often the person insurers most aggressively target.
How CACI 3927 Works Alongside CACI 3928
CACI 3928 rarely stands alone. Its companion is CACI 3927, the aggravation of pre-existing condition instruction, and experienced trial counsel generally request both where evidence supports them. CACI 3927 tells jurors that plaintiffs are not entitled to damages for conditions that existed before the defendant’s conduct, but should be compensated for the effect of that condition being worsened by the wrongful conduct.
Read together, the two instructions frame recoverable harm precisely. You are not asking a jury to pay for the concussion you had in 2019. You are asking for compensation for how the new crash worsened it, made a dormant condition symptomatic, or made it materially harder to treat.
Full Recovery for a Worsened Condition
California courts confirm that plaintiffs may recover to the full extent that a condition has worsened as a result of the tortious act, a rule restated in Sanchez v. Kern Emergency Medical Transportation Corp. (2017) 8 Cal.App.5th 146, 168. The degree of aggravation is generally a question of fact for the jury, and plaintiffs typically bear the burden of proving the subsequent act aggravated the pre-existing condition.
Citing Vecchione v. Carlin (1980) 111 Cal.App.3d 351, 358, the CACI 3927 directions indicate the aggravation instruction is intended for cases where the injured person is the claimant, and is generally not given in wrongful death actions.
Why Requesting the Right Instruction Matters
Generic causation instructions may not be enough when a prior condition flares up. In Ng v. Hudson (1977) 75 Cal.App.3d 250, 256, the court concluded that general proximate cause instructions were inadequate on aggravation of a preexisting condition. If your attorney does not affirmatively request the aggravation instruction, the jury may never be told how to handle your prior concussion.
This is one of many reasons why case-specific guidance matters. Our brain injury legal resources cover related questions Orange County TBI clients raise throughout litigation.
Proving Aggravation: What the Medical Evidence Must Show
The plaintiff generally carries the burden of showing the new incident worsened the condition, made it symptomatic, or made it harder to treat. In repeat head injury cases, this is a medical question that typically requires qualified expert testimony rather than argument.
Under Evidence Code Section 801.1(a), operative January 1, 2024, when the party bearing the burden of proof offers expert testimony that a matter is medically caused by an act or omission, an expert offered by the opposing party to controvert that testimony must, if opining that a matter has an alternative cause, opine that each alternative cause is probable to a reasonable medical probability. Defense physicians cannot simply speculate that the old concussion produced the symptoms.
| Evidence Type | What It Establishes |
|---|---|
| Pre-injury medical records | Baseline function before the new trauma |
| Treating physician testimony | Change in condition attributable to the incident |
| Retained neurological witness | Causation to a reasonable medical probability |
| Neuropsychological testing | Objective cognitive deficits post-injury |
| Before-and-after lay witnesses | Observable changes in personality, memory, work capacity |
| Life care plan | Future medical needs and lifetime cost exposure |
💡 Pro Tip: Ask your physician to review pre-injury records before rendering any causation opinion. An opinion that a previously asymptomatic condition became symptomatic after new trauma is far more persuasive when the reviewer has seen the baseline.
Anticipating the Defense Playbook
Defense counsel in aggravated injury cases may examine prior claims and prior courses of medical treatment. The goal is to argue symptoms predated the crash entirely. Expect possible subpoenas to old providers, review of previous injury claims, and close scrutiny of treatment gaps.
Thorough documentation can help. Consistent follow-up care, contemporaneous symptom journals, and non-party witnesses who can describe your functioning before and after the collision may blunt this strategy.
Practical Steps for Orange County TBI Victims With a Concussion History
What you do in the first weeks after a repeat head injury can shape the entire case. Severe brain injuries can involve long-term or permanent disability requiring lifetime care, and damages analysis may need to account for future medical expenses, lost earning capacity, and noneconomic harm.
- Seek immediate neurological evaluation, even if imaging appears normal
- Disclose full concussion history to treating physicians and your attorney
- Request copies of pre-injury records to establish baseline early
- Track symptoms daily, including headaches, light sensitivity, sleep disruption, and mood changes
- Identify family, coworkers, or friends who can describe changes in your functioning
- Preserve crash scene evidence and avoid recorded statements before consulting counsel
💡 Pro Tip: Never minimize a prior concussion when speaking with a doctor. Concealment may give the defense a credibility argument, while full disclosure allows your physician to document aggravation properly.
Timing also matters. California’s two-year personal injury deadline under Code of Civil Procedure Section 335.1 generally governs negligence claims. Exceptions, tolling provisions, delayed discovery principles, and shorter government claim deadlines may apply. Claims against public entities generally require presenting an administrative claim, often within six months, before a lawsuit may be filed.
Frequently Asked Questions
1. Can an insurance company reduce my settlement because I had a concussion before?
Insurers frequently attempt this, but the eggshell skull rule and CACI 3928 exist to counter it. Under California law, a defendant takes the victim as found. What is not recoverable is the pre-existing condition itself, only its worsening, which is why medical proof of aggravation is critical.
2. What if my prior concussion caused no symptoms before the crash?
An asymptomatic pre-existing condition that becomes symptomatic after new trauma presents a classic aggravation scenario. A treating physician or neurological witness who has reviewed pre-injury records may opine on that change. The degree of aggravation remains a question of fact for the jury.
3. Does the caci 3928 unusually susceptible plaintiff instruction apply to wrongful death claims?
The companion aggravation instruction is intended for cases where the injured person is the claimant, per Vecchione v. Carlin (1980) 111 Cal.App.3d 351, 358. Families pursuing fatal brain injury claims should discuss alternative damages instructions with counsel.
4. Are there caps on what I can recover for an aggravated brain injury?
In ordinary car accident, truck accident, and premises liability brain injury cases, California does not impose a general cap on noneconomic damages. A statutory cap exists under Civil Code Section 3333.2(b) only for claims against health care providers based on professional negligence. Separate limits may apply to certain claims, such as those against public entities.
5. Do I need a life care plan for a repeat head injury case?
In serious TBI cases involving long-term deficits, a life care plan is often important to quantify future medical costs and attendant care. Whether one is warranted depends on the severity and permanence of your injuries.
Protecting Your Right to Full Brain Injury Compensation
A prior concussion is not necessarily a liability in your case. It is a medical fact that California’s jury instructions were written to accommodate, and in some instances it may support the argument that a second impact caused disproportionate harm. Much of the critical work happens early: establishing a documented baseline, retaining qualified medical witnesses who can testify to a reasonable medical probability, and requesting correct damages instructions at trial.
If you are navigating a repeat head injury claim, a caci 3928 unusually susceptible plaintiff lawyer at Bisnar Chase can evaluate how your concussion history fits into your claim. Call 800-561-4887 or contact us now for a free consultation.
Disclaimer: This content is for informational purposes only and is not legal advice. Every case is unique, and results may vary. Consult an attorney about your specific circumstances.