For approximately a third of individuals worldwide diagnosed with Distal Symmetric Polyneuropathy, or DSP, there isn’t one specific cause for the disorder. Michigan State University College of Osteopathic Medicine professor Michelle Kvalsund is hoping to fix that.
Kvalsund, a global health neurologist in the Department of Neurology and Ophthalmology, has received a $750,000 National Institutes of Health grant for her work in Zambia identifying potential causes of DSP, which is prevalent among certain clinical populations in the region.
DSP is a disorder that usually starts in the toes and slowly spreads to nearby parts of the body causing tingling, numbness and/or pain.
It is commonly associated with diabetes in the United States and in Zambia, is most commonly linked to HIV. Other known associations include alcohol use, B12 deficiency and kidney disease. But in two prior studies, Kvalsund’s research showed that nutritional deficiencies also could be a very common treatable and avoidable cause of neuropathies among clinic patients in Zambia. Through the grant, Kvalsund aims to collect population-based data on this phenomenon.
“We know that food insecurity and low dietary diversity are common in sub-Saharan Africa, so we suspect that this may be a problem that exists in communities,” Kvalsund said. “And addressing it at that level may be much more impactful.”
This research has roots dating back to the peak of the HIV pandemic in the early 2000s, when Kvalsund was an epidemiology student taking part in HIV neuropathy research.
“Even then, we saw the signals that we were missing other potentially treatable or avoidable causes of neuropathy in these populations,” she said.
Zambia also has unique environmental and toxic exposures that may help researchers understand more about DSP.
“We know that a lot of micronutrients are involved in detoxification processes. So, we will look to see if toxic and nutritional, or environmental and nutritional interactions may precipitate the onset of these neuropathies,” Kvalsund added.
The goal of the project is to eventually develop an intervention that addresses these nutritional problems either at the community, educational or clinical level.
After the initial planning stage of the grant, Kvalsund plans to potentially start enrolling patients in the study in May 2021, COVID-permitting, and at the end of Zambia’s rainy season, which often can make it difficult for researchers to reach some communities by road.
This research has global implications in regions with low dietary diversity, as well as closer to home.
“Even though we don't think of nutritional deficiency as common in the U.S., it is often an undiagnosed micronutrient deficiency that is found to be the underlying cause of symptoms in subspecialty clinics,” Kvalsund said.
But even with diabetic neuropathy, which is the most common cause of DSP in the U.S., there aren’t high quality regenerative treatments. Instead, treatment usually focuses on preventing progression and treating symptoms.
“Ultimately, I hope that conducting this study in an area with unique exposures might lead to insights that could result in new therapies or new diagnostics that would improve outcomes or diagnosis for patients,” Kvalsund said. “Maybe we can start to have effective therapies for this condition.”
Given the current world climate, Kvalsund feels especially passionate about this work.
“There has never been a better time in history to explain how health inequities from around the globe can affect our own communities, land on our own front door and affect our individual health,” she said. “In addition to the potential for new scientific advancements and discoveries that could benefit populations around the world, understanding health disparities and addressing them in distant populations is certainly an investment worth making.”