The whole grey area here is about the brain-damaged people not being able to correctly evaluate the value of the document they are signing.
Even if 100% of the brain-damaged people were black, that still wouldn't make it OK to include their race in the title, because the article is not about that. It's about brain-damaged people.
Now, it would be different if the article was directly about blacks, about how they were specifically selected, but it's not.
Here's an example headline to show the difference:
"An individual robbed a bank this afternoon"
VS
"A black man robbed a bank this afternoon"
The important event here is the bank robbery, not the race of the person who did it.
You could have a study that showed that 90% (or 10%...) of all bank robbery were caused by black men and THEN including the race in the title would be warranted, because that's what the study is about.