What are the dangers of opening the blood brain barrier?

We know in the animal world, whether it’s in Parkinson’s animals, Alzheimer’s animals or even healthy animals, that when you open the blood-brain barrier with focused ultrasound, it looks like it’s safe. It looks like we don’t cause any bleeding, swelling or the introduction of anything bad into the brain. A lot of that has to do with the fact that it’s a temporary opening for only a few hours. In the human research, we’ve now shown that it also appears to be safe. We don’t see any bleeding or swelling in the brain—even microscopic bleeds that we can detect on an MRI scan. Patients themselves appear to do well too. We haven’t seen any evidence of inflammation, infection or anything negative when we’ve followed them after the trial.