Written and reviewed by Josh Kohanim, Esq., California Bar No. 328609 · Reviewed
In this guide
Between three weeks and a year after a Los Angeles crash, fall, or assault, unresolved concussion symptoms have a definition, a published rate, a set of risk factors, and a documentation standard that makes the claim credible. The first two weeks are covered in our guide to concussion after a car accident.
When post-concussion syndrome is diagnosed
Post-concussion syndrome, written PCS in the charts, is the cluster of symptoms that continues after a mild traumatic brain injury. The StatPearls article on postconcussive syndrome, published on the National Library of Medicine's Bookshelf and last updated August 28, 2023, describes it as a constellation of physical, cognitive, behavioral, and emotional symptoms occurring after traumatic brain injury. It lists headache, fatigue, vision changes, disturbances in balance, confusion, dizziness, insomnia, and difficulty concentrating among the common ones.
The two definitions differ, and that matters in a claim. StatPearls explains that two clinical criteria are in use and that they can give different results applied to the same population. ICD-10, one diagnostic manual, defines PCS as those symptoms persisting longer than three weeks. DSM-IV, a second manual, requires cognitive deficits in attention or memory plus at least three further symptoms persisting for three months or longer. The article also notes that concussion refers to the condition that resolves within 30 days of injury, before a PCS diagnosis is made.
| Marker | Threshold | What it signals |
|---|---|---|
| Typical recovery | 10 to 14 days | The window most concussions close in |
| ICD-10 definition of PCS | Longer than 3 weeks | The earliest point a chart may carry the label |
| DSM-IV definition of PCS | 3 months or longer | The stricter standard a defense doctor will prefer |
| Persistent PCS | Past 3 months | The point at which future care enters the case |
How often symptoms persist
StatPearls reports that approximately 90 percent of concussion symptoms are transient, with symptoms resolving within 10 to 14 days, though they may linger for weeks. It states that 15 percent of mild TBI patients will suffer from PCS, and that in 85 to 90 percent of cases mild TBI is self-limited and does not progress to PCS. On the far end, it describes a minority of patients, 10 to 15 percent, with symptoms that persist for more than a year.
The article adds a caveat that answers an insurance adjuster who cites the 15 percent figure as proof you are unusual. Because of limited diagnostic tools, permanent changes in executive function can go undocumented, so the 15 percent incidence is an underestimation of the true incidence. Read together, those numbers say two things at once. Most people recover, and being in the group that does not is neither rare nor suspicious.
Who still has symptoms at month three
StatPearls separates mild TBI into two kinds, and the distinction runs through these claims. Complicated mild TBI means concussion symptoms with abnormalities on the head CT scan, such as a hematoma, a subarachnoid or subdural bleed, midline shift, or a fracture. Uncomplicated mild TBI presents with a normal head CT. Patients with uncomplicated mild TBI are more likely to resolve in under three months. Patients with complicated mild TBI, or with more than one TBI, are more likely to develop PCS or persistent PCS.
The other listed risk factors are female gender, age, a psychiatric history, and a history of chronic pain syndromes. The defense will read each of those back as an alternative explanation. In California, each is a reason the defendant pays more rather than less. California's jury instruction CACI No. 3928 requires the full award even where the plaintiff was more susceptible to injury than a normally healthy person, and CACI No. 3927 makes the aggravation of a preexisting condition compensable.
Why the insurer stops believing you
Up to about ninety days, an adjuster will carry a concussion file without much argument. Past that point the reserve, the money the insurer has set aside for the claim, gets reviewed, and the file needs a reason to stay open. What follows is predictable: a request for every medical record going back ten years, an independent medical examination by a doctor the insurer chooses, and a first offer built on the emergency department discharge rather than on anything that happened since.
What defeats that is a record with no holes in it. Treatment continues without a three week silence, treating physicians write down function rather than pain scores, and formal neuropsychological testing follows when a doctor orders it. People from before the injury describe, in writing, one specific thing you used to do and no longer do.
Treatment that also proves your claim
StatPearls describes physical and cognitive rest for at least the first 24 to 48 hours after injury, notes that patients should return to usual activity only once symptom-free at rest, and cites studies in which patients who rested two days returned to baseline more quickly than those who rested five. The National Institute of Neurological Disorders and Stroke (NINDS) separately describes cognitive rehabilitation therapy, an individualized training program aimed at regaining function and at teaching strategies for coping with persistent memory, problem solving, and thinking difficulties.
In practice, the referrals that matter in these files are to neurology, to neuropsychology, to vestibular therapy for balance and dizziness, and to vision therapy for the tracking and focusing problems that make screens intolerable. Each referral produces a dated chart, and that sequence of dates is what an adjuster cannot argue with. Our attorneys get clients treated before anyone discusses a number.
When a post-concussion claim breaks down
- Nothing in the first month. If the first documented complaint is at week six, the defense gets to argue that something else happened in between, and often it can name it.
- An intervening event. A second crash, a fall at home, a new job stressor, or a surgery on something unrelated all give the other side a competing cause with its own date.
- Self-report with no objective measure. Symptoms alone, with no formal testing and no observer, is the file the defense wants. Testing is not always indicated, but when a doctor orders it and the patient does not go, that shows.
- A prior record that looks identical. If neuropsychological testing from before the crash shows the same profile, the case shifts from injury to aggravation, and the value shifts with it.
What to do past three months
Roughly one in seven people with a mild traumatic brain injury develops post-concussive syndrome, and a minority of those still have symptoms a year later. That is a documented minority, and the literature says the count is probably low.
Keep treating without gaps, and ask the treating physician to write down function as well as symptoms. If the injury came from a fall on someone else's property, our Los Angeles slip and fall page explains that side of the claim. For how the medical proof is assembled, read how a mild traumatic brain injury is proved, and for the claim as a whole, our Los Angeles brain injury attorney page.