"brain disease" is a correct and usable phrase in written English.
For example, you could write, "Alzheimer's Disease is an example of a common brain disease."
"Addiction is a brain disease," she said.
It is, he says, a "brain disease".
Have they not yet contracted the brain disease?
1732 Scrapie, the brain disease, is first recorded in sheep.
Parkinson's is completely a brain disease, unlike, say, multiple sclerosis, which causes more widespread damage.
Flying foxes are now rare, and few people under 40 now suffer from the brain disease.
Brain change is the foundation of all learning: it doesn't equal brain disease.
For decades the medical profession has largely treated addiction as as a chronic brain disease.
Being diagnosed with a chronic brain disease is hardly something to celebrate.
Those experiments left both Shane and Léo's wife, Coré, afflicted with the same brain disease.
The drug had led to two deaths and caused serious brain disease in another patient.
