Blood Supply to Brain is Linked to Dementia

Low blood flow to the brain may lead to dementia in older people, researchers are reporting. The findings, which appear this week in the journal Radiology, suggest that doctors may be able to reduce the risk of patients’ developing dementia by monitoring how well blood is flowing to their brains and giving treatment if there is a problem, the researchers said.

Blood flow to the brain can be restricted by an array of problems, said Dr. Aart Spilt of the Leiden University Medical Center in the Netherlands, the lead author of the study.

High blood pressure is one; it can lead to stiffening and narrowing of the arteries. So, on the other hand, is low blood pressure, if the body is unable to compensate for the problem. Heart failure can also be a cause.

For the study, researchers made MRI scans of the brains of 17 people over 75 who had dementia associated with Alzheimer’s or Parkinson’s diseases. They compared the results with brain scans of people the same age who had normal mental functioning, as well as scans from much younger people.

The incidence of both dementia and problems of the blood vessels in the brain increase significantly after age 70, the researchers said.

The connection between the two problems, if any, has been harder to establish.

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DO YOU HEAR WHAT I HEAR? People who are tone deaf not your run-of-the-mill bad shower singers but those who truly cannot hear or produce musical tones are actually processing the sounds differently in their brains, researchers reported.

The researchers, writing online in Annals of Neurology, said they found the problem in the right side of the brain. The study was led by Isabelle Peretz of the University of Montreal.

The researchers, using an EEG to measure brain activity, said they could instantly detect an abnormal response when a tone-deaf person heard a note.

Tone-deafness, formally known as amusia, may occur in as much of 4 percent of the population, the study said. A person can be born tone-deaf or develop the problem as a result of injury or illness.

Amusia is related to speech and reading disorders like dyslexia and dysphasia. A better understanding of it may help doctors devise treatments for people with the other problems, the researchers said.

For the study, eight tone-deaf adults and 10 others were connected to an EEG and asked to listen to a series of musical tones. Half the time, one of the notes was pitched up or down. The volunteers were asked to say when they heard a change.

The study found that the brains of amusic volunteers did not respond to small changes in pitch that caused changes among the other volunteers.

When the pitch changes were bigger, the study found, the amusic brains “overreacted.”

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WHO’S RIDING SHOTGUN? The roadways might be a lot safer if there were fewer teenage boys in, yes, the passenger seat.

That is the message of a new study in the United States suggesting that when a teenage boy is the front-seat passenger, a teenage driver, whether boy or girl, becomes more careless. The study appears online in the journal Accident Analysis & Prevention.

The study, by researchers from the National Institute of Child Health and Human Development, also found that when a teenage boy was driving and a teenage girl was in the passenger seat, he drove more safely.

The lead author of the study, Bruce Simons-Morton, said it was unclear how passengers were affecting drivers.