Motor neuron disease (MND) causes profound weakness that typically affects the arms and legs but it may also affect the tongue. This causes problems with speaking and swallowing food. Assessment of tongue involvement is important as there are few conditions which cause both limb and tongue weakness. This means that when tongue involvement is seen doctors can be more confident in diagnosing MND. Unfortunately, the present assessment for tongue involvement is difficult to do when compared with the standard electrical tests that are used on arms and legs.
If a new means of assessing the tongue could be devised then the time to diagnosis could be quicker, meaning more support can be put in place for the patient. In addition, having a measurement that could be easily repeated would help doctors know if new treatments were working. Measurements of the electrical properties of muscle can be made using a technique called electrical impedance myography (EIM). The test is quick and painless as it uses a tiny electrical current that is so small it is not felt. Measurements on how the current is changed by tissue can be used to assess the health of the muscle. In this study, tiny electrical pulses will be delivered to and recorded from the tongue using a novel device. If successful in identifying differences between patients with MND and healthy volunteers over time it could be used alongside currently available investigations for diagnostic purposes, as well as to track disease progression in clinical trials.