How is a claim for compensation affected if you suffer from pre-existing injuries and as a result of the fault of another have your injuries aggravated? If your injuries would have deteriorated eventually without the intervening event your claim for damages can be adjusted accordingly. This is sometimes referred to as the ‘crumbling skull’ principle and reasons for judgment were released today by the BC Supreme Court, New Westminster Registry, applying this point of law.
In today’s case (Jopling v. Bradowich) the Plaintiff was injured in a 2004 BC Car Crash. The Plaintiff’s accident related injuries included headaches, disturbed sleep, depression and chronic pain. However, the Plaintiff suffered from pre-existing problems which were summarized by Mr. Justice Rice as follows: “ I am satisfied that the plaintiff suffered from pre-existing injuries to her lower back prior to the motor vehicle accident, and that there was a general degeneration of her spine, all of which were likely to lead her to the condition that she now experiences, although probably not as soon as it did because of the accident.”
The Court valued the Plaintiff’s non-pecuniary loss (pain and suffering) at $75,000 but then reduced this award by 20% to ‘reflect the contingencies that her back and shoulder pain would have manifested regardless of the accident‘.
In reaching this conclusion Mr. Justice Rice made the following observations of the law of causation in BC personal injury claims:
29] The principal issue in this action is whether the plaintiff’s individual injuries were caused by the accident, or whether they were only aggravations of pre-existing injuries.
 Proof of causation is determined by the “but for” test: Athey v. Leonati,  3 S.C.R. 458, at para. 14; Hanke v. Resurfice, 2007 SCC 7,  1 S.C.R. 333, at para. 21). If I find that “but for” the defendant’s conduct the plaintiff would not have been injured, then the defendant is liable for all the damages flowing from those injuries. If the conduct of the defendant is unrelated to the alleged loss, then the defendant is not liable.
 It is no answer to a plaintiff’s claim for damages that he or she would have suffered less injury or no injury at all had he or she been less susceptible. If an individual has a pre-existing condition, the person who injures that individual must take him or her as found: Athey, at para. 34.
 However, if the plaintiff’s injuries would have manifested themselves on their own in the future regardless of the defendant’s conduct, the court must apply a contingency factor to address that possibility. Such a contingency does not have to be proven to a certainty. Rather, it should be given weight according to its relative likelihood: Athey, at para. 35.