Motor neuron disease can be noticed more than a decade before the condition sets in, scientists say.
Experts at Aberdeen University believe they can spot the neurodegenerative disorder simply by looking at stool samples.
The condition, which causes muscle weakness, slurred speech and weight loss, is thought to be caused by unusual clumps of proteins.
These can be found in the gut before tell-tale symptoms even begin, the study revealed.
The findings come from a study of 13 MND patients between the ages of 40 and 85.
They had all had biopsies taken before for other reasons, including one who had had a lymph node sample taken 14 years earlier.
It can take years to be diagnosed with MND because there is no single test, forcing doctors to order a battery of tests to rule out other diseases.
Study author Dr Jenna Gregory said early detection of MND ‘could be a critical missing step in our efforts to cure this disease’.
Researchers from the University of Aberdeen studied samples from a dozen patients who suffered from the rare condition that damages the brain and nerves. They found that half of the patients had markers of the disease in biopsies up to 14 years before they developed telltale grasping, walking and speech problems. The results show that six patients had the protein in their digestive system, lymph nodes or skin
WHAT IS MOTOR NEUR DISEASE?
Motor neuron disease is caused when nerves in the brain and spinal cord — which are needed to walk, speak, and breathe — stop working properly.
As the condition progresses, patients find that all of these actions become more difficult or impossible.
It is not clear what causes the condition and there is currently no test or cure of any kind.
But it’s thought to be related to the buildup of proteins in the brain that clump together and cause problems with moving, breathing and thinking.
Symptoms of the condition begin gradually over weeks and months, usually on one side of the body before getting worse.
These include a weakened grip, dragging of the left leg, and slurred speech.
About 5,000 people have MND in the UK at any one time.
Patients live an average of three to five years after being diagnosed. Byt some can live up to 10 years.
The condition, also known as amyotrophic lateral sclerosis (ALS), came to the fore in 2014 after the “ice bucket challenge” flooded social media.
It causes the rapid degeneration of nerves and brain cells, leading to weakness and muscle wasting. Patients also have difficulty walking, talking, using their arms and hands, eating and breathing.
Over time, it can lead to paralysis and eventual death, although some can live with it for decades.
About 5,000 people in the UK and 30,000 in the US have the condition.
It is not clear what causes the condition.
But it’s thought to be related to the buildup of TDP-43 proteins in the brain that clump together.
However, Aberdeen researchers noted that people with MND often have symptoms that affect their gut, such as altered bowel habits and weight loss.
In an effort to detect early signs of the disease, the team studied historically stored tissue biopsies and stool samples taken from 13 people over 40 in Scotland, who later developed MND.
The researchers had a total of 68 samples taken from eight different organ systems, including the digestive, muscular and lymphatic systems.
The samples were tested for TDP-43.
The results, published in The Journal of Pathology: Clinical Research, show that six patients had the protein in their digestive system, lymph nodes or skin.
These samples were taken an average of 12 months before patients developed telltale symptoms and an average of two years before the condition was diagnosed.
And in one case, the protein was detected in a patient’s lymph nodes 14 years before their MND was confirmed.
The findings suggest that MND can be detected “many years” before people develop known neurological symptoms, the team said.
Detecting MND earlier would not only enable the development of better drugs, but “lead to a rethink of neurodegenerative disorders” from end-stage diseases to conditions that can be screened long before brain-related symptoms develop, the researchers wrote.
Dr Gregory, a clinical researcher at the university, said: ‘I believe this is an important finding for our broader understanding of this disease.
“The early detection of disease could be a critical missing step in our efforts to cure this disease – if disease markers are present outside the brain, it could pave the way for non-invasive early detection.”
As it stands, there is only one approved drug that has been shown to extend the lifespan of people with MND — but only by a few months.
The researchers said one of the reasons why anti-MND drugs are difficult to develop is that by the time someone has visible symptoms of the disease, it may be too late for a successful intervention.
dr. Fergal Waldron, a researcher at the University of Aberdeen and co-author of the study, said: ‘Potentially effective treatments have been identified from a wide range of experimental studies.
‘However, in these studies they were often only effective, or most effective, when applied before the onset of the disease – early detection in this way is a huge step forward in our search for a cure.
“We hope this will mean that the chances of treatment success are higher and that the onset of the disease can be delayed or even prevented if caught and treated early enough.”
dr. Mathew Horrocks, a biophysicist at the University of Edinburgh who also worked on the study, said: ‘MND is a devastating disease, with those diagnosed surviving an average of three to five years.
‘This work shows that it is possible to observe features of the disease in readily accessible tissue more than a decade prior to the onset of symptoms.
“This could pave the way for an earlier diagnosis, expanding the therapeutic window, ultimately leading to a cure for MND.”