Post-Concussion Syndrome and Ontario's Limitation Periods: Why Waiting Can Cost You Your Legal Rights

August 14, 2026, Kitchener, Ontario

Posted by: Robert Deutschmann, Personal Injury Lawyer

A concussion can be difficult to understand, even for the person experiencing it.

You may have headaches, dizziness, fatigue, memory problems, anxiety or difficulty concentrating, yet still expect to recover. You may return to work, continue with your normal responsibilities and assume that things will eventually improve.

But what happens when they don't?

A recent decision from the Ontario Court of Appeal provides an important warning for people suffering from ongoing concussion symptoms: you should not necessarily wait until your prognosis is certain before getting legal advice.

In Lloyd v. Baker, 2026 ONCA 434, the Court of Appeal dismissed a personal injury claim because the lawsuit was commenced after the applicable limitation period had expired. (Law Times)

What happened in Lloyd v. Baker?

The plaintiff was injured in a November 2015 motor vehicle collision. She suffered a concussion after the vehicle in which she was travelling was struck.

Importantly, she had previously suffered a concussion in a workplace accident.

Although she initially expected to recover, her symptoms continued. Medical records documented ongoing physical and cognitive difficulties. She returned to work in January 2016, but only with reduced hours and modified duties, and she never returned to her previous full-time work. (OBA)

The significant legal issue was when she knew, or reasonably ought to have known, that she had a claim.

She did not commence her lawsuit until November 2021.

The Court of Appeal ultimately concluded that the claim was discoverable more than two years before the lawsuit was started and dismissed the action as statute-barred. (minicounsel)

What is a limitation period?

A limitation period is a legal deadline for commencing a lawsuit.

For many Ontario personal injury claims, the basic limitation period is two years from the date the claim was discovered, subject to important exceptions and rules.

The concept of "discoverability" is particularly important.

The law does not necessarily ask only:

"When did you receive your final diagnosis?"

Instead, it can ask when you knew—or when a reasonable person in your circumstances ought to have known—that you had suffered an injury for which another person may be legally responsible.

That distinction can be extremely important in concussion cases.

You don't have to wait until you know your final prognosis

One of the biggest misconceptions following a concussion is that you should wait until treatment is finished before speaking with a personal injury lawyer.

That can be risky.

Concussion symptoms can evolve over time. A person may initially believe they will make a complete recovery, only to discover months or years later that symptoms are interfering with work, relationships, daily activities and quality of life.

But waiting for complete medical certainty can create a limitation-period problem.

Lloyd v. Baker demonstrates that the legal analysis can focus on what the injured person knew, or reasonably ought to have known, based on the circumstances and available medical information. (Rogers Partners LLP)

What should you do after a concussion caused by an accident?

If you have suffered a concussion in a motor vehicle accident or another incident caused by someone else's negligence:

• Seek appropriate medical attention.
• Follow your healthcare provider's recommendations.
• Keep records of your symptoms and treatment.
• Document changes to your ability to work and perform everyday activities.
• Keep track of expenses related to your injury.
• Do not assume that ongoing symptoms are simply something you have to live with.
• Consider obtaining legal advice early.

Speaking with a personal injury lawyer does not necessarily mean that you must immediately start a lawsuit.

It means understanding your rights and the deadlines that may apply to your circumstances.

Concussion injuries can be more serious than they appear

A person with a concussion may look perfectly healthy while struggling with significant cognitive, emotional or physical symptoms.

Post-concussion syndrome can affect employment, education, family relationships, sleep, concentration and the ability to participate in activities that were previously routine.

That is why these cases can require careful medical and legal analysis.

Don't let uncertainty become a missed deadline

If you have been injured in an Ontario motor vehicle accident and continue to experience concussion or post-concussion symptoms, do not assume you should wait until you have a final prognosis before seeking legal advice.

The recent Lloyd v. Baker decision is a reminder that limitation periods can become a critical issue before an injured person feels completely certain about the future. (Law Times)

Deutschmann de Koning Law represents people suffering serious injuries throughout Kitchener-Waterloo, Cambridge, Woodstock and surrounding Southwestern Ontario communities.

If you or someone you love has suffered a concussion or brain injury in an accident, contact Deutschmann de Koning Law to discuss your circumstances.

About Deutschmann de Koning Law

Deutschmann de Koning Law serves South-Western Ontario with offices in Kitchener-Waterloo, Cambridge, Woodstock, Brantford, Stratford and Ayr. The law practice of Robert Deutschmann and Nick de Koning focuses almost exclusively in personal injury and disability insurance matters. For more information, please visit www.ddinjurylaw.com or call us at 1-519-742-7774.