IMNDA Research Webinar Recording with Dr Roisin McMackin - IMNDA

IMNDA Research Webinar Recording with Dr Roisin McMackin

April 18th, 2023

On Wednesday 5th of April we were treated to an excellent interactive talk with Dr. Roisin Mc Mackin on some of the ongoing research of MND/ALS in Dublin on how MND affects activity in the brain. Roisin discussed how the research is done, who can take part, why it may improve medical care and testing of possible treatments and gave a quick overview of some of the most recent results.

Here is a look back over that in-depth discussion. Below she gives a summary of what was discussed. If you have any questions, on the information provided please contact 

Motor neuron disease (MND) is an umbrella term, which covers a number of different diseases which affect the motor neurons. Motor neurons are signalling cells which allow our brain to tell our muscles what to do. There are two main types: the upper motor neurons that carry signals from our brain to our spine, which they then relay on to the lower motor neurons, which carry the signal to a muscle, to cause it to move. Amyotrophic lateral sclerosis (ALS) is the most common type of MND, and is the type in which both upper and lower motor neurons fail to work, and ultimately are lost. There are other types of MND such as primary lateral sclerosis (PLS), where only the upper motor neurons are declining, and progressive muscular atrophy (PMA), where only the lower motor neurons declining. However, despite the name MND, we now know that these diseases do not only, specifically, affect these motor neurons. There are many other types of signalling cells (neurons) in our brain and spine that work with the motor neurons to control movement, as well as neurons which control other functions.

All of these neurons cannot work on their own, they must form complicated links to one another to form networks (“neural networks”). It is the way that the neurons send signals around different routes in these networks which is how our brain and spine perform different jobs. So, it is very unlikely that one specific type of neuron, such as the motor neurons, would stop working without it having knock-on effects on the other neurons connected to them in these networks. If we want to fully understand MND and how to find good treatments, we should not focus only on the motor neurons, but also look at the wider neural networks which our brain needs to work. In this blog/webinar, I’ll talk about ALS specifically, but there is evidence that in other MND types, such as PLS, that the disease does not only affect motor neurons. Our research aims to find out how ALS affects neural networks across the brain, and not only the motor neurones. This could help us diagnose the disease earlier, predict how it will affect each person and allow us to design and test new drugs more effectively.

What evidence is there that ALS causes problems outside the motor neurons?

We know that some people with ALS not only experience problems with movement, but also with things like thinking clearly, planning tasks or paying attention (I’ll refer to these “non-movement” issues going forward). This tells us that the networks of neurons which are needed to perform these functions are also affected by ALS. We can also see in MRI scan studies that the size of brain areas containing these other networks are affected by ALS. Also, the chemical changes that happen in ALS are found to not only happen in the motor neurons, but also other types of neurons in other parts of the brain.

Why is understanding the effects of ALS on these networks important? Should we not just focus on the motor neurons for now, since they control movement?

In this webinar, I cover in more detail why this is important, but in short, there are a few reasons:

  1. We know that people with ALS who have certain non-movement issues can have worse movement changes, so the problem(s) causing movement issues in ALS is probably not only harming the motor neurons. If we focus just on motor neurons, we might miss important information needed to understand, detect and treat these problems. (More information in the webinar on why detecting the disease earlier is important)
  2. Understanding the bigger picture of how ALS affects the brain can help us to understand why different people with ALS have different problems or symptoms that are more or less severe. At the moment, we have no way to foreseeing how each single person with ALS will be affected. This causes distress to people with ALS and it causes problems when testing if new drugs are working (see the webinar for more details on this)
  3. Understanding the effect of ALS across neural networks and not only the motor neurons can help us understand how to treat non-movement issues caused by ALS, which can make life hard for people with ALS and their friends and families.
  4. It may be the case that problems in neurons other than the motor neurons are driving the disease. If so, we need to understand these problems so we can develop treatments to target those neurons.
  5. It may be the case that individual people with ALS have different types of ALS, where the neural networks are affected in different patterns. Different people with different types may require a different medical approach.

How do you perform the research to test how ALS is affecting these neural networks?

Thankfully, to measure these networks we don’t need to cross the skin at all – There are no needles and there is no blood involved! Because the neural networks signal by electricity, we can measure this electrical signal on top of your head, over the brain. To do this we use two methods:

One is called electroencephalography (EEG) (which is not the same as needle electromyography, or needle EMG, which is a very different test sometimes used to diagnose ALS). To do an EEG, we just need to put recording sensors on top of the head and they can record what the neural networks are doing underneath.

The other is called transcranial magnetic stimulation (TMS). We use TMS to apply magnetic pulses over the scalp. These pulses can activate electrical signals in the neurons underneath. This will allow us to test if those neurons are working as expected.

Have you found anything interesting yet?

Yes – We have already made a number of exciting findings and learned valuable information about ALS from this research (see webinar for more information). For example, we have learned important information about how ALS affects neural networks outside of the motor neurons, such as those related to the non-movement problems caused by ALS. We have also learned more information about how ALS affects neurons which are connected to the motor neurons, which may be contributing to the movement problems caused by ALS. We have also found that different subgroups of people with ALS have different patterns of neural network problems. This suggests that there are subtypes of ALS that we should investigate further.

Are you still doing this work?

Yes – And we’d be delighted if you’d like to hear more information about it and/or volunteer. Anyone over the age of 18, with or without MND, can volunteer. Feel free to contact me by emailing me at

Or contact the IMNDA directly. There is no commitment involved in getting in touch, we will simply provide you with more information about the study.


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