When someone gets injured in an accident, any claim for damages must stem from injuries that resulted from the accident in question. In Heyward v. Young, a Nova Scotia Supreme Court case decided in 2011, the Plaintiff, who was injured after the defendant driver t-boned his car, suffered from severe migraine headaches, and an MRI of his head post-accident revealed residual scarring to the inferior frontal lobe. At trial, the Defendant produced evidence to support, on a balance of probabilities, the fact that the sustained brain injury had resulted from an unrelated assault on the Plaintiff 15 years prior to the accident.
The Plaintiff’s pre-existing susceptibility to brain injury, making him a “thin-skulled” plaintiff in legal jargon, removed the causation element required to prove that, but-for the motor vehicle accident, he would not have suffered the brain injury. However, the Plaintiff’s migraine headaches, which did materialize after the accident, and developed into long-term chronic pain syndrome, were recognized to be directly attributed to the accident in question. Despite the fact that a pre-existing condition may have exacerbated the chronic pain, the Plaintiff was still awarded a sizeable general damage award, as well as a modest future care award.


