Shrinking brain in dementia prompts overeating

SYDNEY - Researchers have discovered that a shrinkage in the brain is the reason why some people with dementia are compulsive overeaters, paving the way for better diagnosis and new treatment for the disease.

The research, led by Olivier Piguet from Neuroscience Research Australia, shows for the first time that some people with dementia have deterioration in the brain region that controls hunger.

“We think the cells in this brain region lose the ability to tell these individuals when they’ve had enough to eat,” says Piguet, according to the journal Annals of Neurology.

These people become unable to control their urge to eat, gorging on sweet and carbohydrate-rich foods and eating in socially inappropriate ways, according to a statement of Neuroscience Research Australia.

“They may steal food from people’s plates or go looking for a bowl of sugar and eat the whole thing,” says Piguet. “Some people will even eat inedible objects, like a pen.”

“Because we now know the exact site of this problem, we can work on understanding the mechanism and designing a treatment to target this symptom,” he says.

Frontotemporal dementia (FTD) is a type of dementia that can affect people in their 50s and 60s, and as young as 30 years of age. There are currently no treatments for FTD.

A Neuroscience Research Australia study looked at MRI brain scans of a group of people with FTD as well as post-mortem brain tissue of another group with the disease.

“We found that the more pronounced their eating problem, the more severe the shrinkage in the back section of the hypothalamus,” Piguet says.

He also found that people with particularly severe shrinkage in this region also tended to have unusual deposits of a type of protein in their brains called TDP-43.

“This suggests to us that someone with FTD who has severe eating problems is likely to have this type of abnormal protein in their brain,” the researcher said.