If you have spinal muscular atrophy (SMA), you may have experienced a test called electromyography on a clinical trial or during diagnosis. It tracks the loss of motor units, the links between the muscle and the nervous system which are gradually lost for people with SMA. But electromyography can be both painful and it is limited in how well it can monitor change.

And with treatments like Spinraza now being developed, the need for effective testing to ensure patients get the right support at the right time has never been clearer.

A new technique – discovered by accident

A new research grant from Muscular Dystrophy UK (MDUK) will help develop a technique using MRI scanners to monitor motor units in a pain-free and more effective way.

And like so many of science’s best discoveries, it was found by accident.

Professor Andrew Blamire, at Newcastle University, has spent much of his research career trying to get scanners to take new measurements. But even he was surprised at the results of a recent test.

He said: “A few years ago we were running tests using a technique that’s generally used to measure the structure of the brain.

“We were looking at the muscles of those with Duchenne muscular dystrophy, but when we got back the scans, we found we had some bad images.

“They were described by others we were working with as ‘annoying artefacts’, a problem with the data. But we showed them to some colleagues who specialise in neurophysiology, and that was the Eureka moment – they told us they were motor units.”

The MDUK research grant will fund Professor Blamire to fully examine how motor units could be monitored with MRI, and how it can be translated into a technology that can be easily deployed for people with muscle-wasting conditions.

Crucially, the new technique could also be used as a way to track loss in clinical trials, helping to see how treatments work and finding the best ways to deploy them.

Questions that still need answering

The new technique – dubbed by the team as MUMRI, for motor unit magnetic resonance imaging – holds a lot of promise.

Professor Blamire will now look at taking the initial idea and seeing if his team can turn it into something workable by answering some key questions.

To start with, what precisely did Professor Blamire see in the scans? Were they single motor units, or was it several motor units firing at once?

And how exactly will the team be able to isolate motor units to test them in a systematic way that will be helpful for clinicians? That second question could involve some new kit being developed so that individuals being scanned make precise movements that can be examined in a concise, systematic way.

Using existing technology to tackle new problems

While we think of MRI scanners as really large machines, there are some scanners designed just for limbs. Professor Blamire’s team will be looking to see if a new type of scanner could be set up to work in a clinic.

Professor Blamire said: “The sense from clinicians is that it would be great to have it as a device in their clinic.

“It could be a game changer for the way we work – they say there’s been no development in electrophysiological techniques in the last 50 years.”

If a scanner can be built, it could have use for any condition involving the loss of motor nerves, or even the decline of muscle function in ageing.

Dr Kate Adcock, Director of Research and Innovation at Muscular Dystrophy UK, said: “We are in such an exciting time for research into SMA.

"But to really get the most from emerging treatments, we need to understand how the condition progresses and how effectively we can manage it.

"This project is so exciting because it makes use of existing technology to do just that; it could mean the end of painful existing techniques and a new era in effective scanning. We look forward to seeing the results.”

Professor Blamire added: “We are very delighted to have been chosen to develop this and appreciate all the support from fundraisers, families and the charity. We do believe we are going to make a difference using the funding we’ve been given.”

Press release with thanks to Musculr Dystrophy UK