Researchers at Washington University School of Medicine in St. Louis have received a $3.7 million grant to investigate the link between manganese and cognitive problems. Understanding how the metal harms the brain could lead to better ways to prevent or treat some forms of cognitive impairment, including in Parkinson’s disease.
The grant, from the National Institute of Environmental Health Sciences of the National Institutes of Health (NIH), will focus on welders, many of whom have high levels of manganese exposure.
Manganese is an essential mineral, but too much of it can lead to parkinsonism, or movement difficulties similar to Parkinson’s disease: tremor, stiffness, slow movement, and problems with balance and walking. Overexposure to the metal also is linked to cognitive issues such as memory and attention lapses, slow thinking, irritability, aggression and confusion.
The connection between the metal and movement problems is well understood: Excess manganese collects in an area of the brain devoted to movement and damages a kind of neuron there. But the cognitive effects are more puzzling.
“People think of Parkinson’s disease as a movement disorder, and it is, but cognitive problems are also very common among people with Parkinson’s disease,” said principal investigator Susan Criswell, MD, an associate professor of neurology. “The cognitive issues you see in people exposed to manganese are very similar to mild cognitive impairment and dementia in Parkinson’s disease. Understanding the causes of these cognitive issues is going to be very helpful in ultimately finding better treatments for people exposed to manganese and people with dementia linked to Parkinson’s.”