New Ultrasound Technique Could Help Treat Alzheimer’s Disease
An experimental technique called “focused ultrasound (FUS)” can safely overcome the defense mechanisms of the blood-brain barrier to deliver targeted doses of medication to precise locations in the brain.
This low-ultrasound technique holds out the hope drugs can be delivered to those parts of the human brain responsible for the progression of Alzheimer’s disease, Parkinson’s disease and other currently incurable brain diseases.
Apart from finding a safe and non-invasive way past the blood-brain barrier, FUS will also aid in delivering life-saving medicine to a precise location in the brain and ensure the drug doesn’t spread to the rest of the brain.
The blood-brain barrier prevents pathogens and potentially harmful substances crossing over from the bloodstream into the parenchyma or functional tissue of the brain. It consists of a mass of blood vessels that feed the brain and the rest of the central nervous system (CNS).
FUS employs ultrasound beams and microbubbles for the non-invasive delivery of drugs safely to specific locations in the brain. It will open the door to the successful delivery of thousands of drugs that can treat a range of brain conditions if they could only cross the blood-brain barrier.
Scientists at Columbia University in New York City have announced the development of an FUS device. Their initial tests have the FUS device help curb early Parkinson's disease progression and improve brain function in mice.
In a study published recently in the Journal of Controlled Release, researchers said their FUS technique temporarily opens the blood-brain barrier in a specific part of the brain to allow drugs to reach just that part.
The FUS technique beams ultrasound pulses through the skull to a precise location in the brain. When the pulses hit the microbubbles injected into the bloodstream, they force the microbubbles to oscillate or vibrate between the walls of tiny blood vessels.
The vibrating microbubbles cause a reversible increase in the permeability of the blood-brain barrier in that location. When the FUS beams are switched off, the microbubbles stop oscillating. The temporary access through the blood-brain barrier then closes.
The recent study that focused on Parkinson's disease proved FUS could be used to deliver brain-altering genes and proteins across the blood-brain barrier.
Once clear of the blood-brain barrier, the genes and proteins partly restored dopamine-releasing pathways in the brain. An early feature of Parkinson's disease is the loss of ability to make dopamine, which is a chemical messenger important for controlling movement.
The researchers saw reductions in some of the behavioral symptoms of Parkinson's disease in the mice, as well.
"We found both behavioral and anatomical neuronal improvements in the brain," said Prof. Elisa Konofagou, one of the senior study authors.
Konofagou believes she and her team are the first to use available drugs to restore a dopamine-releasing pathway in early Parkinson's disease.
