Understanding a Child's Brain
It has been a strange week here at Thinktank Birmingham Science Museum. Without necessarily planning it this way, I seem to have spent a significant amount of time working with neuroscientists and psychologists, which inevitably leads to lots of discussions about the human brain. I have also been electrocuted and attacked by a giant millipede but it is the neuroscience that is actually more interesting.
This month's Birmingham Café Scientifique hosted Dr Caroline Witton from Aston University talking about her work with magnetoencephalography (MEG) which Aston has been pioneering over the last few decades and the rest of the world is only just starting to catch up on. Many people are familiar with the sorts of images that MRI scans can give of the body, high resolution reconstructions of how your body looks inside.
To a brain surgeon, the MRI scan can show them exactly where different parts of the brain are in relation to each other and other parts of the body. This is all very well, if you know exactly which part of the brain needs operating upon, but how do you get that information? MRI can be used to a certain extent, but the detail of an MRI scan actually comes from the water in the body, and when we are talking about the brain, it is actually the flow of blood and how that changes with different tasks, that gives this information. This means that there is always going to be a slight delay (approx 5-6 seconds) as blood flow changes in the brain in response to activity levels. EEG is another alternative; this is the technique where electrodes are attached to the scalp (sometimes in the form of a rather attractive hair net), and the brain's electrical activity is measured as it performs various tasks. This can tell you which parts of the brain are active - which is the sort of information that you want - but the data is a bit 'fuzzy' due to the nature of electricity and the shape of the head; it cannot pinpoint activity to anything like the sort of accuracy that a surgeon would trust.
This is where MEG scanning comes in, since it gives a much more accurate interpretation of the brain's activity, in real time. The device itself, looks a bit like a like a hair drying machine that, as a gentleman, I have only ever seen in ladies' hairdressing salons. The key difference is that this machine has a vat of liquid helium sitting above it at approx minus 269 degrees Celsius. This is very close to absolute zero and is important for the superconductors that are inside and give the scanner its power. Whereas EEG measures electrical signals from the brain, MEG scanners measure the magnetism that these electrical signals possess. The superconductors (or more accurately Superconducting Quantum Interference Devices - SQUIDs) can detect these tiny magnetic fields and some clever maths converts this into positions in the brain where they came from - the neuroscience equivalent of how the police determine where a bullet was fired from. Not only is the MEG scanner very sensitive (the level of magnetism it measures is on the scale of millionths of times smaller than a fridge magnet), but it also has some beautiful benefits over other methods. EEG can at its best measure around 100 different signals at once and this takes hours to achieve. The Aston MEG scanner - which is still just a prototype - can measure over 300 signals at the same time. If you have ever been in an MRI scanner, you are likely to have been strapped down so that you cannot move, but with MEG, you can move around freely (within reason) which is very good news when you are studying children.
But what is it that the Aston team are using this equipment for? The Aston Brain Centre is registered as a Hospital in its own right, but it works exclusively in the realms of diagnostics and research. From the brief time that I have spent with Caroline and the head of the facility, Prof Paul Furlong, there are two main areas that are of particular interest; epilepsy and brain development.
Around 90% of people with epilepsy can manage their condition with drugs, but the remaining 10% do not respond to drugs and therefore have a very limited range of treatments options left. In some cases, there might be a surgical approach, in which the surgeon removes the part of the brain that is triggering the epilepsy. Clearly this carries a significant amount of risk in terms of damaging other areas of the brain, but I am assured that the brain does have a certain ability of flexibility in recovering from damage. I am very careful in how I choose my words here and do not refer to healing, but if you think of the neurons that form the 'thinking' part of your brain as being in pathways, then the brain has a wonderful way of finding another path around many of the problems that it encounters. Indeed, I am told that potentially an entire hemisphere of the brain can be removed or damaged and a person can potentially survive. For the surgeon removing parts of the brain, this offers a certain element of reassurance I presume, but you are still going to want to be as careful as you can, if you are a surgeon!
Without MEG however, the method involves something a bit like the following. You have an MRI scan to give a very detailed structure of the brain. You then have an EEG to work out the approximate area of the brain where the epilepsy starts (the focal point). Next you have the appropriate part of your skull removed and another EEG taken by directly applying a series of electrodes to your brain - this gives a much more accurate indication of the focal point. This information is combined with the MRI data to give a good idea of which part of the brain needs removing. The final check is to put the patient under a general anaesthetic, remove the skull again and then wake them up so that they can tell you what it feels like when the surgeon pokes and prods other parts of the brain nearby to they can work out what they might be damaging if they get it wrong. Now this all sounds fairly horrific for an adult, but imagine how it might be for a child - especially the part about waking up mid-surgery to have your brain poked.
With MEG however, you can get all of the same information about function, without laying a finger on the child. This is currently what the Aston team are working on and they are 3 years into a trial to make this a mainstream technique.
The other main area of interest is brain development & behaviour and what happens when the brain develops in an atypical manner. There are many conditions that involve the brain and the variety of ways in which it develops. Epilepsy is one example, but others such as autism, dyslexia and possibly even things like migraines, all have one thing in common - the brain. By using techniques such as MEG, in combination with other techniques, we are starting to probe these conditions and hopefully one day be able to work out how they might be treated.
One of the things that I love most about working with real scientists - as opposed to pretend scientists - is their brutal honesty. Both Caroline and Paul openly admit that we (as a species) really don't know how the brain works. Real scientists are also often extremely passionate about their work, although I should add as a caveat here that it might just be the ones who like talking to the public about their work who show this passion! This makes them such a joy to work with. In these times of austerity, it strikes me that there are fewer and fewer people who actually enjoy their work and it is so nice to meet some of them and share their passion, even just for a few short hours.