Should we be concerned that ultrasound is capable of effecting changes in the brain? Ultrasound is one of those "safe" medical operations that you don't think too much about because it's not chemical, radioactive, or built out of superconductors.
For example, 3D fetal ultrasounds bombard a baby but they are really only done out of pure vanity for parents. They don't tell doctor's anything they don't already know from the boring standard ultrasound.
The long-term effects of tissue heating and cavitation are not known. Therefore, ultrasound scans should be done only when there is a medical need, based on a prescription, and performed by appropriately-trained operators.
In the article I didn't see what type of ultrasound they are using. I don't know a great deal about ultrasound, but I do know that there is a difference between diagnostic (imaging) and therapeutic ultrasound systems. It's likely they were using a therapeutic system for this test.
I was having chronic muscle spasms in my right shoulder blade area, and the physical therapist used therapeutic ultrasound on me. It melted the spasms like butter. Several months of terrible pain gone in an instant. I was never so tempted to steal a machine in my life.
Ultrasound is not without risk. The general advice is to follow the ALARA principle (as low exposure as reasonably achievable). In the early 90's the FDA under pressure from manufacturers approved a 7-fold increase in the power output of ultrasound. Part of that approval was that ultrasound machines show feedback to technicians on estimated amount of tissue heating. That's one of the main concerns. E.g., in a fetus, heating tissue above 4 degrees or so causes damage and that level of heating is possible, especially around areas of bone.
From the paper - they don't use ultrasound itself to generate the effect, they use ultrasound to activate injected 'micro-bubbles' in the brain which disrupt the blood-brain barrier.
There's a news article about the paper that Science wrote up, which goes into some of the history of the work and has a broad sampling of views on the relevance of this paper within the broader context. http://news.sciencemag.org/biology/2015/03/ultrasound-therap...
I guess you could say it that way. When some researchers say plaque is a "symptom," they might just mean that there is an underlying mechanism that is broken and causing plaque to build up. No one thinks the plaque is good or normal. The real question is why some people get it in the first place and others don't.
By analogy, broken bones are a symptom of osteoporosis (chronic brittle bones). No one is saying a broken bone doesn't hurt or shouldn't be fixed, but we've had more success historically by ALSO treating the underlying cause to prevent damage from coming back.
No, he's referring to the fact that some researchers have questioned the mainstream adoption of the amyloid/tau hypotheses -- that the plaques and/or tangles are the cause of the dementia.
It's mainstream, but it is not proven, and there have been some studies that cast at least a little doubt on them.
So the OP isn't using an off-the-wall phrasing, it is very much a question of whether the plaques and tangles are the cause or the effect of some yet-to-be-established mechanism.
There is no better phrasing.
This makes it clear that the mechanism is still a matter of hypothesis:
Anyway, the apparent success of the ultrasound does indeed seem to be evidence that the plaque/tangle hypotheses are correct in assuming these things to be causal and not merely correlated symptoms.
We don't know that for sure yet. A few phase III trials were conducted in the past years, and while they succeeded at reducing the amount of plaque, they completely failed on the cognitive side.
On Alzheimer's front, does anyone know what happened to "Young blood reverses age-related impairments in cognitive function and synaptic plasticity in mice" (2014)?
Life science research runs slowly. It's darkly funny to expect any meaningful update a year after something is published. Raising grants for step two can take a year, or several years if yours is not a very hot topic indeed, animal studies can take a couple of years, and so the iterative loop is not particularly short.
If you're not involved, it makes sense to check every five years or so on any particular thread in early stage medical research.
This killed my grandfather, and my father is starting to show symptoms too. Having Alzheimer's one of my biggest fears. I'd suck a cock for a definite way to prevent/cure it.
These results may out may not apply to humans. I wonder what frequencies were used in the experiment. While anything higher than 20 kHz is beyond humans hearing range and is called ultrasound, mice can hear sounds as high as 79kHz.
I'm not entirely sure I understand your concern. Hearing the sound doesn't stimulate change, so whether or not we can hear it doesn't seem to matter. The crux is whether or not ultrasound also stimulates microglia production in humans, and whether or not ultrasound is irreparably harmful to the brain.
Ultrasound is typically in the megahertz range. Calling it "sound" is really kind of a misnomer.
From the article:
Parameters for the ultrasound delivery were 0.7-MPa peak rarefactional pressure, 10-Hz pulse repetition frequency, 10% duty cycle, 1 MHz center frequency, and 6-s sonication time per spot.
For example, 3D fetal ultrasounds bombard a baby but they are really only done out of pure vanity for parents. They don't tell doctor's anything they don't already know from the boring standard ultrasound.