Court of Appeals Clarifies When a Pre-Existing Condition is Compensably Exacerbated

By Monica A. Nassar, Attorney at Law

The Oregon Court of Appeals recently clarified what standard applies to claims involving a pre-existing condition that was exacerbated or rendered symptomatic by a work injury. In Barnes v. Cache Valley Electric, 339 Or App 371 (2025), the court held that a preexisting condition exacerbated by a work injury can be compensable as a standalone condition if the work injury was the major contributing cause of an actual, pathological worsening of that condition. Following the landmark decision in Carrillo, the courts have been finding preexisting conditions independently compensable if the evidence shows the work injury rendered them merely symptomatic or simply exacerbated the condition. In other words, the courts have been applying a material causation standard to requests for acceptance of standalone preexisting conditions (i.e., preexisting conditions requested separately and not as a combined condition).

These decisions have been somewhat at odds with ORS 656.225, which provides that, in accepted injury or occupational disease claims, disability solely caused by, or medical services directed solely to, a preexisting condition are not compensable unless one of the following applies:

1. The work conditions or injury were the major contributing cause of a pathological worsening of the preexisting condition (unless the claim involves a preexisting mental disorder);
2. In mental health cases, the work conditions or injury were the major contributing cause of an actual worsening of the preexisting condition and not just of its symptoms; or
3. In medical service claims, the service is prescribed to treat a change in the preexisting condition and not merely as an incident to the treatment of a compensable injury or disease.

Barnes reconciles this and brings the causation standard for standalone preexisting conditions firmly under ORS 656.225.

In Barnes, the claimant was injured when a plexiglass window hatch fell onto his head. This resulted in a concussion and neck pain. The carrier accepted a head contusion, concussion, and post-concussion syndrome. Following a request for acceptance of new/omitted conditions, the carrier added a cervical strain to the claim but denied the request for “cervical spondylosis.” The carrier then processed a combined condition of the cervical strain/sprain with preexisting osteoarthritis of the cervical spine and denied the major contributing cause of claimant’s disability and need for treatment thereof. Claimant challenged both the partial denial of “cervical spondylosis” and the major contributing cause denial.

The ALJ upheld both denials, finding that the medical evidence supported compensability of claimant’s symptomatic but preexisting spondylosis on a “combined condition” basis but did not persuasively show the spondylosis was compensable as a standalone condition. The Board affirmed and claimant appealed. The Court upheld the denials, citing Schleiss v. SAIF, 354 Or 637 (2013), wherein the Supreme Court found that “a preexisting condition that is exacerbated by a work injury can be compensable, but only if the work injury is the major contributing cause of a ‘pathological worsening of the preexisting condition.’” Id. at 644 n 2.

In practice, this means we can push for the higher, major contributing cause standard for requested new/omitted conditions which the evidence establishes are preexisting conditions (such as those for arthritis or degenerative issues). While we do not think this will be the last we hear from the courts regarding this standard, in the meantime, it could be useful for defense of preexisting condition denials! As always, we recommend contacting the attorneys at Reinisch Wilson P.C. to further discuss how these developments apply to your current cases.