NEW PARADIGMS FOR ULTRASOUND: ALZHEIMER’S DISEASE
Last month, I wrote a guest-blog based on my learning experience attending a program studying neuropsychiatry at Harvard last summer. Thank you for the kind words of encouragement and support many of you have given me thus far. It seeded the courage for me to complete this follow-up.
Because, for me, ultrasound science is ‘the family business’ I had a natural desire to understand more about emerging technologies and applications in the field of medicine. One area, in particular, that piqued my interest was the potential use of focused ultrasound therapy to improve the lives of patients with Alzheimer’s disease. Admittedly, my interest was in large part personal as my grandfather suffers from this affliction. I am fortunate that my grandparents live with us for six months of the year which allows me and my siblings to spend valuable time with them, but it has also brought to the forefront how devastating this cognitive decline can be.
Research into possible treatment or a ‘cure’ for Alzheimer’s disease is hampered by a lack of certainty understanding the actual cause of the disease. The scientist for whom the disease is named, early 20th century German psychiatrist Dr. Aloysius Alzheimer, believed its cause to be intimately related to brain anomalies, described then as ‘senile plaques’, which he identified during autopsy of his affected patient, Mrs. Auguste Deter.
Modern researchers have more varied opinions, and even less certainty than Dr. Alzheimer. Potential causes theorized and under study include any one, or potential combinations of the following conditions: nutritional deficiencies, toxic (metallic) exposure, prior head injuries, infections, inflammation from disease, or that Alzheimer’s may be a natural deterioration in brain functionality.
Still, the prevalence of these senile plaques strongly correlates to the onset of Alzheimer’s symptoms, and many researchers theorize these plaques as being triggered by deposits of beta amyloid. Using that premise as a starting point, medical researchers hoped that if there were a way to dissolve or dissipate amyloid plaques within living brain tissue, it might result in a reversal of progressive Alzheimer’s disease.
The execution of this theory had one big problem to overcome: The impenetrability of the blood–brain barrier (BBB). This is an amazing semipermeable membrane that serves to insulate the brain from most unwanted pathogens, while allowing essential substances for brain functionality (i.e. glucose, water and amino acids) to penetrate. Treatments that would involve invasive surgical destruction of the integrity of the blood-brain barrier are universally considered to be an unacceptable risk.
However, as previously referenced, the transformative paradigm of ultrasound treatment versus invasive medical procedures rests in the ability of sound waves to penetrate membrane without damaging its physiological integrity. Based on this premise, researchers at the University of Queensland (Australia) in 2015 pioneered the use of ultrasound waves to dissipate (interior) beta amyloid deposits and flush them outward through the BBB in the brains of mice, while maintaining the membrane’s integrity. The initial research seemingly showed some degree of reversal in the cognitive degeneration associated with Alzheimer’s disease. While actual treatments may be on the distant horizon, Phase 1 clinical trials have begun and Phase 2 trials on human subjects have been green-lighted for this year.
Another area of research is the potential of focused ultrasound to augment the delivery of therapeutic drugs or antibodies across the BBB. Focused ultrasound allows for more precise targeting of delivery, minimizing damage to healthy, non-targeted brain tissue. Although these treatments will not be realized for my grandfather, I follow the progress of clinical trials with great interest as the reality that this disease may impact other family members is real.
Gina Miele is the daughter of Frank Miele, MSEE , President of Pegasus Lectures, Inc. and Carol Miele, RN, RVT, RDCS, FSVU, Vice President. She attends high school in Dallas, Texas as a Junior at The Hockaday School.
*** A Special ‘Thank You‘ to Focused Ultrasound Foundation for use of images, statistical and industry research.