BRC Clinical Fellow
Development of a novel imaging method “Motor Unit Magnetic Resonance Imaging” (MUMRI) to investigate motor unit activity in ageing.
Matthew Birkbeck
Developing Magnetic Resonance Imaging (MRI) techniques to study functional muscle activity in ageing.
The Study
Sarcopenia is a condition affecting people over the age of 50 and is a progressive disease which gets worse later in life. Sarcopenia leads to loss of muscle mass and function, increasing the risk of falls and admission to hospital.
One of the causes of sarcopenia is damage to the motor units (MU) which are connected to each individual muscle fibre in your body. Each motor unit consists of a motor nerve and fibres, which allows the brain to control how the muscle contracts. A loss of motor units in sarcopenia causes changes in in the muscle itself, reducing muscle size and preventing muscles from working normally. Therefore measuring the number and size of MUs is an important diagnostic test for some patients with sarcopenia. This assessment is normally made using a technique called electromyography (EMG) which uses either electrodes placed on the skin or a needle electrode which must be carefully inserted into the muscle.
We have created a new type of magnetic resonance imaging (MRI) scan which takes pictures of the muscle and can see the MUs when they contract or twitch. We call this method “Motor Unit MRI” (MUMRI), which allows us, for the very first time to see how MUs are positioned within the living muscle. We have taken pictures with our new scans in healthy muscles and have done a small test in patients with motor neuron disease which although is not linked to sarcopenia has confirmed that we can see the effect of motor neuron damage.
This project will make technological developments to transform our preliminary MUMRI method into a tool for pain free and non-invasive clinical monitoring of sarcopenia. We aim to use this tool to investigate the effect of physical exercise on muscle condition in volunteers in different age ranges.
In the future, this will allow us to provide specific treatments on a patient by patient basis, increasing the quality of life of patients with sarcopenia.
Project milestones
- Complete construction of an isometric force rig and volitional activation protocol
- Complete image quality, sequence and analysis optimisation. Trial the sequence in a number of healthy volunteers.
- Obtain ethical approval for the studies of MU activity in healthy volunteers (first - comparison of MU activity between older and younger volunteers).
- Perform study in 60 volunteers aged 45 – 85 to gain information about MU activity with ageing.