As populations get older, the number of debilitating age-related neurodegenerative diseases has increased. In this article, we look at three recent developments in the field of neurology.

1. Parkinson’s disease may stem from the intestines

Swedish scientists have recently discovered a possibility that Parkinson’s disease may actually start in the gut and spread to the brain via the vagus nerve. They compared 9,430 individuals who underwent a surgical vagotomy to 377,000 other people, and discovered that 19 individuals who underwent a “truncal vagotomy” – the removal of the main trunk of the vagus nerve – were 40% less likely to develop Parkinson’s disease.

"We were not largely surprised, as other research has also shown evidence for a link between the gut and Parkinson's disease," said Karin Wirdefeldt, study author and associate professor of medical epidemiology and biostatistics at the Karolinska Institute in Stockholm.

"Other evidence for this hypothesis is that people with Parkinson's disease often have gastrointestinal problems such as constipation, that can start decades before they develop the disease,” added co-author Bojing Liu.

However, the study findings are only an association, and further research and evidence are required to confirm the link.

"But it's interesting that this connection seems to be persisting," said chief scientific officer of the National Parkinson Foundation, James Beck. "It's not causal, but it underscores something potentially going on in the gut and how that may influence Parkinson's disease."

2. Repurposing drugs as potential therapy for neurodegenerative disorders

Certain antidepressants and anti-cancer drugs may have protective effects against Alzheimer’s disease, dementia and other degenerative brain diseases according to researchers from the University of Cambridge, University of Nottingham and the Medical Research Centre Toxicology Unit in Leicester.

Since 2013, the team tested over 1,000 available drugs and found that “two drugs were markedly neuroprotective”. The antidepressant trazodone hydrochloride and anti-cancer compound dibenzoylmethane were found to restore protein production in the brains of mice and reduced brain shrinkage.

"We could know in two to three years whether this approach can slow down disease progression, which would be a very exciting first step in treating these disorders," said project leader Professor Giovanna Mallucci. Adding that trazodone is already approved for use in the elderly, "we now need to find out whether giving the drug to patients at an early stage could help arrest or slow down the disease through its effects on this pathway," he said.

Though the drugs “represent potential new disease-modifying treatments for dementia", a definitive cure has yet to be discovered and further clinical trials are necessary to prove these findings.

"If these studies were replicated in human clinical trials, both trazodone and DBM could represent a major step forward,” added Dr David Dexter from Parkinson’s UK.

3. Detecting early signs of Alzheimer’s disease with a simple graphic test

The graphic characters called Greebles may be a potential tool in detecting signs of Alzheimer’s disease. Photo credit: Science Daily/ Michael J. Tarr, Center for the Neural Basis of Cognition and Department of Psychology, Carnegie Mellon University
The graphic characters called Greebles may be a potential tool in detecting signs of Alzheimer’s disease. Photo credit: Science Daily/ Michael J. Tarr, Center for the Neural Basis of Cognition and Department of Psychology, Carnegie Mellon University

A unique but simple test with graphic characters may be used as a tool to detect early signs of Alzheimer’s disease in the future, a new study suggests.

According to findings, individuals with a genetic predisposition for Alzheimer’s face more difficulties distinguishing the characters – known as Greebles – compared to individuals with lower risks. Participants aged 40 to 60 years were divided into two groups: the first comprised of individuals who were considered at-risk, while the other had no family history of Alzheimer’s.

"We were able to find a significant difference between the at-risk group and the control group. Both groups did get better with practice, but the at-risk group lagged behind the control group throughout the process,” said researcher Emily Mason, from the University of Louisville (UofL).

According to Brandon Ally, senior author and assistant professor of neurological surgery at UofL, though not a definitive marker, Greebles can act as a cost-effective tool to identify early stages of Alzheimer’s disease, and may improve diagnostic acumen in high-risk individuals when paired with biomarkers and a complete clinical history.

“Right now, by the time we can detect the disease, it would be very difficult to restore function because so much damage has been done to the brain,” she added.

“We want to be able to look at really early, really subtle changes that are going on in the brain. One way we can do that is with cognitive testing that is directed at a very specific area of the brain.” MIMS

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