Alzheimer’s spares brain’s music regions

Parts of the brain that respond to music seem to withstand the ravages of Alzheimer’s disease. These neural bastions, described June 3 in Brain, may help explain why music is sometimes able to move people suffering from advanced dementia.

The study is “thorough and meticulous,” says neurologist Oliver Sacks. “I thought their results fascinating,” suggesting an anatomical explanation for why music therapy can sometimes help patients.

Researchers began their study after noticing that music seemed to have a special influence on family members with Alzheimer’s, says University of Amsterdam neuroscientist Jörn-Henrik Jacobsen, who conducted the research at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany. A mother-in-law of one of the authors was still leading songs at her church despite her Alzheimer’s.

The disease wreaks havoc on the brain, but its destruction isn’t indiscriminate. Jacobsen and his colleagues wondered whether brain regions involved in recognizing long-known songs might be relatively spared in Alzheimer’s. So the researchers looked for brain areas involved in responding to songs that a person has known for a long time. Healthy volunteers listened to snippets of familiar songs, songs they had just heard for the first time and songs they had never heard before while undergoing a functional MRI scan.

The scans identified two adjacent areas in the brain that that seem to respond to familiar songs: the caudal anterior cingulate and the ventral presupplementary motor area. Neither area had been known to have big roles in musical memory, Jacobsen says.

Next, 20 elderly people with Alzheimer’s underwent brain scans that looked for brain thinning, low metabolism and deposits of amyloid-beta, a sticky protein linked to Alzheimer’s.

The music-related brain areas scored surprisingly well on two measures, the team found. Unlike most other places in the brain, this region didn’t show much thinning and didn’t show big declines in metabolism. A-beta, however, was present, consistent with the idea that the protein is an early marker for the disease, whereas thinning and reduced activity are more advanced markers.

The results are very valuable, says psychologist Mohamad El Haj of University of Lille 3 in France. “It highlights the neuroanatomical basis for the response to music” in people with Alzheimer’s, he says. El Haj recently found that familiar music seemed to boost autobiographical memories in people with Alzheimer’s. While listening to familiar music, volunteers described richer accounts of their life memories, El Haj and colleagues reported May 28 in International Psychogeriatrics.  

Scientists don’t yet know how musical memory relates to other memories, Jacobsen says. It’s possible that music, especially songs from when a person was young, could serve as a lifeline that, once summoned, can bring up other aspects of their lives. “I can imagine that once you remember the songs, it triggers more stuff,” Jacobsen says. “It’s a very rich stimulus.”