A new investigation by CBS News attempts to clear up some of the confusion plaguing the long-running, fiery debate over whether there are links between autism and childhood vaccinations.

The issue has long pitted parents of affected children searching for answers against the vast majority of medical professionals who have argued that there are no links between vaccines and autism — and that suspicions parents raise about vaccine programs undermine public health efforts to protect children.

However, CBS’s investigation points out that, in rare instances, vaccines do cause life-altering brain-damage, known as “encephalopathy.” The government is not tracking how many families have brought cases based on such brain damage with autism-like symptoms, but in the past 20 years, CBS reports, more than 1,300 families have been compensated for vaccine-related cases of encephalopathy by the federal Vaccine Injury Compensation Program, called the vaccine court for short.

Symptoms common to autistic children can be among the problems caused by encephalopathy, a point conceded even by pro-vaccine experts. But establishment medical opinion remains steadfast that attempts to link vaccines and autism are unfair.

“The fact that a person suffers autism and encephalopathy does not mean that the vaccine caused both of them,” says Dr. Brian Strom, a University of Pennsylvania doctor who spoke with CBS. “Even if it caused the encephalopathy, that may or may not have been the cause of the autism–those are two different questions.”

That sort of defense comes across as insensitive to distraught parents, who see it as glossing over the fact that, whatever you call the medical problem, their children suffer from significant cognitive problems that may ruin their lives.

The distinction between autism and encephalopathy can make all the difference in the world in the vaccine court. Attempts to win cases by directly blaming a vaccine for a child’s autism have been almost universally unsuccessful.

However, claiming that a vaccine caused encephalopathy typically brings better results. One attorney who represented the family of a girl who was diagnosed with brain damage and autism after receiving a vaccine, who spoke with CBS under the condition of anonymity, said:

“I purposely avoided mentioning ‘autism’ in the claim. Using [the child’s] autism diagnosis would have dragged out the lawsuit for years. The point wasn’t to try to win the autism debate, it was to get this family the compensation they need to take care of their injured child.”

And, in fact, his clients won.