We all know that using a cell phone can stimulate the brain to work a bit harder. “Mr. Skerrett? This is Dr. LeWine’s office. Do you have a minute to talk about your test results?” or “Dad, a bunch of kids are going to Casey’s house after the dance. Can I go?” But a new study published in JAMA is making me wonder what the energy emitted by the phone itself — not just the information it delivers — is doing to my brain.
Here’s the study in a nutshell. Dr. Nora Volkow and her colleagues recruited 47 volunteers to have their brain activity measured twice by a PET scanner. Both times the volunteer had a cell phone strapped to each ear. During one measurement, both phones were turned off. During the other, one phone was turned on but muted so the volunteer didn’t know it was on; the other was left off. Each session lasted about an hour. The scans showed a small increase in the brain’s use of glucose (blood sugar) when the phone was on, but only in parts of the brain close to the antenna.
It was an elegant study. The researchers took pains to anticipate sources of error. They used a control (both phones off) against which to compare the effect of a “live” cell phone. They used cell phones on each ear, one on and one off, to see if the effect was localized. They muted the phone that was on to eliminate the possibility that any brain activation was due to listening to the sound of a voice coming through the phone’s speaker. So the result is probably a real one, not an artifact or measurement error.
What does this brain activation mean? No one really knows. As Dr. Volkow told NPR, “I cannot say if it is bad that they [cell phones] are increasing glucose metabolism, or if it could be good.” Read more »
*This blog post was originally published at Harvard Health Blog*
Data presented at the International Conference on Alzheimer’s Disease in Honolulu this week indicated that exercise and adequate vitamin D levels could help reduce risk for the disorder. Framingham Heart Study researchers found that risk for dementia was halved in “moderate to heavy exercisers” compared with more sedentary people, while researchers on a separate study found that vitamin D deficiency can greatly increase risk for mental impairment.
Another study found that injecting the compound florbetapir into the brain of patients with dementia and then performing a PET scan could help pinpoint the size and location of plaques.
Researchers also reported that tea consumption was linked to a slower rate of cognitive decline in older adults without cognitive impairment, but there was no dose response and more studies will need to be done to determine a definitive link. (CBS News, Wall Street Journal, Medscape)
*This blog post was originally published at ACP Internist*
It’s well known that the use of imaging scans, like CTs, MRIs and PET scans, have been growing at an alarming rate. But a recent study provides some stark numbers. According to a recent CDC report, “MRI, CT or PET scans were done or ordered in 14 percent of ER visits in 2007.” That’s four times as often as in 1996. Although a physician called that growth “astounding,” it’s really no surprise.
Emergency departments are becoming more crowded, and with patient satisfaction scores becoming more influential in financial incentives for physicians, sometimes just ordering a test is the path of least resistance. Factor in the spector of defensive medicine which, according to a survey from the Massachusetts Medical Society, accounts for up to 28 percent of tests ordered, it’s a wonder that more scans weren’t ordered.
Imaging scans are a clear cost driver in healthcare, contributing $12 billion to Medicare’s bill. But costs won’t resonate with patients requesting the tests or the doctors ordering them. One encouraging sign is the recent trend of publicizing the harms of scans, like radiation from CTs. I’m finding that patients are becoming increasingly aware of the risk, and making a more informed decision after I explain it to them. It’s a small step forward.
*This blog post was originally published at KevinMD.com*