SMILES STUDY ~ EMMA JACKSON’S REPORT
One of our wonderful Patron’s, Emma Jackson, has been spending time with Vicky, Andy and Dominic at the Smiles Study. Here is her report:
The money raised by Smiles With Grace is funding exciting research being carried out by Victoria Jones on Spinal Lipomas. This is a serious condition present from birth that affects one in every 4,000 children. You may have heard of lipomas – harmless fatty lumps that can occur anywhere in the body. They are relatively common and one in every 100 people may develop them. However, when they grow in the spinal cord, the outcome can be devastating. These spinal lipomas are found attached to the base of the spinal cord and are visible from the outside as a fatty lump.
Why are spinal lipomas harmful?
As a child develops, its bones, tissues and organs mature and enlarge. However, their rate of growth differs. For example, in normal development, the vertebral column grows more quickly than the spinal cord. As a result, the spinal cord ascends during childhood and remains free and floating in the Cerebrospinal Fluid (CSF) within the spine to prevent damage as we move, stretch and bend.
Spinal lipomas stick to the bottom of the spinal cord and so prevent this ascension. As a result, the nerves are stretched and damaged as they are pulled upwards but still remain attached at the base. Due to the positioning of these lipomas, nerves that control the lower limbs and bladder function are affected. Patients may lose neurological function at worst within the first few weeks of birth, but usually the condition deteriorates over the following months and years. This includes loss of bowel and bladder control, muscle weakness and pain. If left untreated, patients can eventually lose complete control of their lower limbs.
In the past, most children born with such a lipoma had it surgically detached from the cord, an operation known as ‘untethering’. This has its risks, as the surgeon must cut directly through the vertebral column and expose the cord. For example, the CSF (the fluid surrounding the brain and spinal cord) may leak out; bacteria may enter and cause an infection; and some nerves may be damaged accidentally, which leads to pain and further neurological decline. Unfortunately this operation only prevents the condition from worsening. Once the nerves are damaged they rarely heal.
Initially, this operation was carried out for all children with spinal lipomas, including symptomless patients, to prevent any damage that might occur. However, surgeons wondered whether all children with a spinal lipoma did in fact develop symptoms. To test this, they closely monitored those born with the condition and found that not everyone deteriorated and experienced neurological symptoms. This led to the conclusion that not all children need surgery, as some do not experience symptoms. So, for some children the stress and risks of such dangerous surgery could be avoided.
Despite this, surgeons are still faced with a dilemma. Once a child develops symptoms, all they can do is perform the surgery and prevent any further damage – the initial damage remains. Is it worth operating on all children straight away to stop symptoms from occurring, even though some do not need the surgery, or should they wait and see who deteriorates and then operate?
What would solve this problem is a test to see who will develop symptoms and who will remain healthy. This is what the Smiles study aims to do. If successful, they will develop a simple blood or urine test to indicate if the child will deteriorate. The test will determine whether a patient is high or low risk: Those who are high risk will receive immediate surgery, whereas the low risk patients will be monitored and may have the operation at a later date, or not at all. This would prevent many unnecessary operations and will avoid the associated stress and dangers. In addition, it will give families some peace of mind, as they will have a better idea how their child will progress.
How will this test be developed?
Since the lipoma is made of fat, some of these molecules are likely to break off and enter the blood stream. If this is the case then an examination of the blood, or urine, may show elevated levels of certain fats. To test this theory, the researcher Victoria Jones is comparing the fat molecules in the blood, urine and CSF of patients with lipomas and without. The aim is to find a specific fat that is more prevalent in sufferers, and use it to form the basis of a diagnostic test.
To identify these molecules, a machine called a ‘mass spectrometer’ is used. In all samples there are hundreds of different types of fats, but the researchers ideally want to focus on just one. The question is, which one? To answer this, first they must look at all the molecules present in a patient with a lipoma, and then compare that to a patient without. The mass spectrometer separates all the compounds within a sample and orders them, so we can more easily examine their concentrations.
What does the research involve?
Before identifying the fats, the Smiles team have to collect the samples. Recall that samples from both patients with and without spinal lipomas are required. This study needs at least 30 sets of samples to increase the validity of the results, and finding this many presents a challenge on its own! Despite Great Ormond Street being at the forefront of spinal lipoma operations, they still only see a few per month.
Blood is usually taken at the time of surgery, since a butterfly needle must be inserted as part of the usual procedure, so using this a vial of blood can be extracted. However, this is a challenge with young children. Not only because the veins are tiny, so they are difficult to find and enter, but also because the flow rate is incredibly low. The blood is therefore collected in drops, and sometimes not enough blood is collected. If this is the case then that sample cannot be used.
CSF is also taken during the operation. To treat a spinal lipoma, surgeons cut through the surrounding bone and tough membranes to expose the spinal cord that floats in this fluid. When exposed, the surgeon extracts a sample to give to Victoria. It has been challenging to collect CSF from enough patients without spinal lipomas because very few other operations give access to the fluid. However, it is collected during operations such as insertion of a shunt (a tube that directs excess CSF from one part of the body to another).
Collecting urine is relatively easy as a catheter is inserted into most patients who have operations so a sample can easily be taken. Or, urine can be directly collected before or after the operation. For young children a gauze is inserted into the nappy, and from that a sample is collected.
Finally, collecting any of these samples requires the approval of the parents. Sometimes this is not achieved so Victoria will need to find another patient.
Despite all of this, so far the research has been on track and promising. She has obtained over 30 samples and is in the process of analysing the fats.
Another issue that Victoria faces is that is still not clear how these lipomas develop and why. So, in addition to creating a test, this research may shine some light onto how spinal lipomas form in the first place. At the moment there are various theories, but each has its downfalls. By using mice embryos and tissue samples Victoria can look for clues that might pave the way towards an answer.
How are the samples analysed?
Blood has many components, and to extract the fats these must be separated. To do this, a centrifuge is used. This results in a layer of red blood cells and plasma that are placed into individual vials. The four resulting solutions- red blood cells, plasma, CSF and urine- can then be prepared and run through the mass spectrometer.
The research is now at the stage where the fats are being compared. As I mentioned, there are hundreds of fats to choose from that are organised into a table, and Victoria is only looking for one. She is looking for a fat that is in highly concentrated in children with symptoms, and in lower concentrations for children who have this condition but do not suffer from symptoms.
So far various fats are being looked at, but as with everything there are always complications. For example, in one lipoma sample a specific fat was identified that was not present in the controls. Victoria followed this lead, and it proved to be a plant fat – something you would not expect. Scientific discoveries are full of unexpected results so it was investigated in more detail. However, after consulting a specialist, the most likely source of this fat was hand cream! It probably entered the samples through minute contamination, so Victoria had to return to the very long list of fats, in the hope of finding another one to focus on.
What have I been doing?
Thanks to Smiles With Grace for the past few months I have been at Great Ormond Street following Victoria’s research. I arrived expecting to be the annoying student watching from the side, but I soon realised my time would be much more interesting than that. So far, I have dissected mice embryos, helped prepare microscope slides, joined in with some of her lab work and much more. This has shown me the journey Victoria must take each time she collects a new set of samples, starting with obtaining permission from the parents and ending with the mass spectrometer. Now, when I see her list of hundreds of lipids, I know just how much time and effort was needed to form that table! I also had the opportunity to meet some of the children who suffer from spinal lipomas.
The other half of my time has been spent in the hospital itself, where I have shadowed Dominic Thompson and his colleagues and watched some of the amazing surgical work they perform every day. The operations have ranged from spinal cord untethering to foramen magnum decompressions (surgery that relieves pressure caused by a build up of fluid within the brain), and of course spinal lipoma surgery.
Watching surgery, learning about spinal lipomas and observing what goes on inside a research laboratory has been fascinating and has helped me to see what a difference the money that Smiles With Grace will make on the lives of these children. For families, not knowing whether their child will deteriorate is stressful to say the least, so too are the constant visits to the hospital.
So, this test will not only prevent pointless operations from taking place, which are risky and could do more damage than good, but the prediction of how a child will progress will also give families much needed comfort during these stressful times.
Emma Jackson June 2017