After a seemingly innocuous fall during a trip to north Wales last August, five-year-old Olivier Roberts started limping on his left leg.
As he'd always been a very active and energetic young boy, his parents Richard and Marina had no reason to suspect anything was seriously wrong.
But that all changed when he also began holding his left arm and hand in an unusual position. When asked what was wrong, he replied: "They're stuck."
Read more: For more health-related content please go here
"We asked him to carry out a range of hand movements and we could see that they were very limited," recalled his dad, Richard.
"We then asked him to move his arm above his head and he could only go as far as the shoulder. We also asked him to grip our fingers in his hand and there was clearly a reduction in strength.
"We found it very odd that this came on all of a sudden, and was on the same side as the leg he'd been limping on. Just days before he was hiking up hills in Snowdonia with us and running on ahead as he always wanted to be first.
"He loves trampolining and going on his scooter. He was just a very energetic five-year-old boy."
During a visit to their GP surgery in Cwmbran, the doctor asked Olivier to do something his parents had not previously considered.
"He asked Olivier to raise his eyebrows. When he noticed that he didn't have the same movement on the left side as the right, he immediately felt it was neurological. It was almost as if he'd had a stroke, " Richard added.
"He said we needed to take him straight to A&E."
Olivier was given CT and MRI scans at The Grange University Hospital in Cwmbran. Just 48 hours later, following further analysis from medics at the Noah's Ark Children's Hospital for Wales, doctors informed Richard and Marina that their youngest son had a cancerous brain tumour known as a diffuse intrinsic pontine glioma, or DIPG for short.
Not only is the very aggressive tumour inoperable as it is wrapped around vital nerves in his brain stem used for movement and breathing, the life expectancy is typically between nine and 11 months after diagnosis.
"You read about children with cancer and these poor families having to suffer, but it is one of those things you never really think will happen to you and your family," Richard admitted.
Mum Marina Roberts added: "I'm still sometimes, in a way, denying it. I think I'm still trying to process everything that has happened. When the business of the day is over and I'm lying in bed at night I start to think about it more - and that's when it hits me most."
Olivier started his first of 30 radiotherapy treatments at Velindre Cancer Centre in Cardiff on September 27 which aim to reduce the size of the tumour and alleviate his symptoms.
"Because of the the delicate area in which the tumour is located - and given that the tumour is wrapped and intertwined among various nerves in the brain stem - it needs to be done with extreme accuracy and so he has to be put under a general anaesthetic every day," Richard added.
"The hope is that the radiotherapy will reduce the size of the tumour and effectively relieve some of the symptoms for a period of time."
DIPG, which is diagnosed in just 30 to 40 children each year in the UK, commonly causes patients to experience double vision, reduced eye movement, facial weakness and arm and leg weakness.
The condition also leads to problems with walking, coordination, speech, chewing, and swallowing. As the tumour progresses it also interferes with breathing and the heart which ultimately results in the child's death.
Olivier's heartbroken parents, along with his three siblings Aline, seven; Nicole, 10; and Matthew, 16, are now exploring further treatment options not available on the NHS that they hope will give them as much time as possible with their "golden boy" - a nickname given to him because of his bright blonde hair.
"While there is no known cure for DIPG, there are a number of medical trials that have shown some promise in slowing the progression of the tumour," Richard explained.
"As DIPG affects so few children in the UK each year there is very little funding for trials and research to find a cure for this disease in this country. The majority of the trials are in the United States and a small number in Europe.
"Because of this, any potential treatment which may extend Olivier's life is highly expensive and difficult to access."
In addition to enrolment on clinical trials, Richard said there is also the possibility of obtaining expensive medicines "off trial" from private doctors in Europe.
He added: "The main issue we will face in getting further help for Olivier is the cost of treatment. We have been told that some of the clinical trials can cost as much as £750,000 for non-US patients to access. Other trials in the US and Europe can cost in excess of £250,000. Just one of the 'off trial' medicines or supplements that we may be able to use can cost several thousand pounds per week.
"We understand that the trial drugs and treatments that are available have not yet been proven to be a fully effective cure to DIPG, but the end of Olivier's radiotherapy treatment puts us at a crossroads. Do we seek further treatment that might extend our little boy's life, do we try to do something to help him, anything that might help even a little, or do we sit back, do nothing but make memories and hope for the best?"
To date, tens of thousands of pounds has been raised for Olivier and his family through two fundraising pages - one for his treatment (which can be found here ), and the other to allow the family to make precious memories (which can be found here ).
Richard added: "We're just so, so grateful to everyone who has been donating and contacting us and offering to help. The kindness of people has just been amazing."
Marina added: "Olivier hasn't complained once [during his ordeal]. He's said a couple of times that it's not fair that his sisters can have breakfast and he can't because he needs an empty stomach for his treatment, but other than that he's been incredible.
"What we've also found incredible is his resilience and his ability to adapt to the situation, even if he doesn't really understand it."
To get the latest news from WalesOnline sent to your email inbox click here
