Focused Ultrasound Foundation Working on New Brain Treatment
Nov 11 2015
Canadian scientists have discovered a non-invasive way to deliver medication into previously unreachable parts of the brain, meaning more advanced treatment for Alzheimer's, Parkinson's and other brain-related illnesses. After the ultrasound treatment succeeded in breaching the blood-brain barrier, the tumor was surgically removed, and the scientists are using pathology to measure the differences between the concentration of chemotherapy in the regions targeted by sound waves and those in areas where the blood-brain barrier was not breached.
The blood-brain barrier is a layer of tightly packed cells that prevent infections and toxins from getting into the blood vessels in the brain, and this barrier makes it almost impossible to deliver drugs directly into brain cells to treat brain diseases such as tumors among others. Gadolinium cannot normally cross the barrier, says Mainprize. As researcher Kullervo Hynynen put it, "It will revolutionize the way we treat brain disease completely".
"The blood-brain barrier (BBB) has been a persistent obstacle to delivering valuable therapies to treat disease such as tumors", says Dr. Todd Mainprize, principal investigator of the study and neurosurgeon in the Hurvitz Brain Sciences Program at Sunnybrook Health Sciences Centre in a media release.
According to BBC, gas-filled bubbles guided by ultrasound were used to punch holes in the barrier and deliver chemotherapy drugs without damaging the barrier or the brain. When in the presence of ultrasounds, air bubbles rapidly compress and expand, vibrating in a way that loosens junctions between cells.
The procedure involves three steps.
The bubbles themselves do not cross the BBB, and are eventually absorbed in the lungs. The microbubbles and the drug spread throughout their body, including into the blood vessels that serve the brain.
The appearance of bright spots, the size of pinkie fingerprints, on the MRI images of Bonny Hall's brain allowed Mainprize to immediately see that he had accomplished what he set out to do.
In the days ahead, Hall, 56, of Tiny, Ont., was anxious yet eager to be the first patient to undergo the procedure.
"If you just give a general dose, you could do a lot of damage in the patient that is treated", Bethune said. Hall is a mother, grandmother and business owner who recently learned that the benign brain tumor she has lived with for eight years had begun to grow quickly and was malignant.
Although the tumor caused no pain, Hall experienced what she described as "little blips", or small 10- to 20-second seizures during which she would feel "spaced out".
The next day, doctors performed traditional surgery on the patient to remove the tumor. The team will analyze the tissue to calculate how much of the drug reached its intended target. The tumor will be analyzed over the next week to determine how much of the chemotherapy effectively passed through the blood-brain barrier. "Essentially, whatever you can think of is a potential study that may help in the future".