Changing lives with laser surgery


Since February 2019, Great Ormond Street Hospital for Children (GOSH) has been carrying out cutting edge laser ablation surgery for children with rare and difficult to treat forms of epilepsy.

What is Hypothalamic Hamartoma?

Hypothalamic hamartoma (HH) is a type of rare, benign brain tumour arising from the hypothalamus deep in the brain. It is responsible for many ‘automatic’ brain functions such as controlling hunger, thirst, emotions and regulating hormones. These often-small tumours can cause seizures that present as laughing (gelastic) seizures or crying (dacrystic) seizures.

This type of epilepsy is a form of focal epilepsy, which means the seizures are arising from a specific part of the brain. Some patients respond very well to drugs, but for many others, surgery provides the only chance of reasonable seizure control.

Complex surgery reduces recovery times

Surgery for HH epilepsy is very complex as the tumours are located deep in the brain. Laser ablation is a technique designed to destroy abnormal brain tissue in an extremely targeted manner, while causing minimal damage to surrounding healthy tissues. Using a state-of-art laser surgeons can directly target the lesion in a minimally invasive way whilst protecting vital structures around the lesion.

Because the surgery is minimally invasive, patients recover from the operation much quicker and only normally spend 2-4 days in hospital as opposed to 10-14 days for traditional open neurosurgical techniques.

32 patients at GOSH have so far received surgery using this technique and we are the only centre in the UK currently offering this type of surgery for control of epilepsy in either children or adults. In October 2022 NHS England announced that they would be commissioning a national service to widen access to this surgery for children and adults across the UK with difficult to treat forms of focal epilepsy.

Ellie's mum, Lynnette, explains the difference this surgery has made to their lives:

“Ellie had been having short episodes of laughing and crying since she was about 6 months old, but at the time we thought they were just her expressing her emotions. It wasn’t until she was three when we realised something was wrong. We were having breakfast and she laughed, seemingly out of nowhere, so I asked her what had tickled her. But she said she felt unwell and sad after laughing which was strange. I looked into this online and as soon as I read about HH and discussed it with my husband it just clicked to us that that was what she had.

"Ellie was having at least ten seizures a day and up to ten through the night, but at times this was as high as 50 and Ellie had to be hospitalised. The seizures were having a huge impact on her life as they left her exhausted and disoriented. We used to have to plan to do things with her in the morning only, as we knew by lunchtime, she would be so tired from the seizures."

Five-year-old Ellie from Royal Wootton Bassett is one of the children who has benefited from this surgery. She had a Hypothalamic hamartoma treated with laser ablation in May 2022. Before surgery she was having up to 50 seizures a day.


Immediately after the surgery the difference was clear – and she hasn’t had a seizure since.

"We tried very hard in those early days to not get our hopes up too much, as the team warned us anaesthetic can suppress seizures and that the surgery may only reduce and not completely stop the seizures. We were hopeful, but always touching wood!

"Six months after surgery our lives are so different. Ellie has just started school and it’s so wonderful to see her enjoying it. We were always watching her for signs of seizures because if they were different, we had to call an ambulance. We can now relax a lot more and she can now do all the normal things that children her age do without being interrupted by seizures or being exhausted. She loves swimming and playing with her little brother and her friends and has so much more confidence.”

Leading innovation

We’ve been running our laser ablation service for two and a half years now and we are very pleased with the outcomes so far. The majority of our patients have seen vast improvements in their seizure activity which allows them and their families to live more normal lives.

GOSH is uniquely placed to take innovations in surgery like this and scale them up thanks our large patient cohorts, expert subspecialised clinicians and our multi-disciplinary teams.

Mr Martin Tisdall, Consultant Paediatric Neurosurgeon at GOSH


The surgeries at GOSH have been possible thanks to a generous donation from The Gerald and Gail Ronson Family Foundation to GOSH Charity. In October 2022 NHS England announced that they would be commissioning a national service to widen access to this surgery for children and adults across the UK with difficult to treat forms of focal epilepsy.


We are really grateful to GOSH Charity and its donors including The Gerald and Gail Ronson Family Foundation for helping us to establish this novel therapy. We strongly welcome the commitment from NHSE to create specialist centres for this treatment in the UK and we look forward to working with our partners to share our expertise and allow more people across the UK to access this life changing surgery.

  Mr Martin Tisdall

We are very grateful to the team at GOSH who have championed and trialled the laser since 2019, and to the Gerald and Gail Ronson Family Foundation who secured funding for the equipment and for the pilot surgical series.  We are delighted that this cutting-edge surgical technology will now improve the lives and life chances of many NHS patients with epilepsy, not just those with hypothalamic hamartoma.

 Emma Nott, Trustee of patient charity Hope for Hypothalamic Hamartoma UK, who have worked with medics in the UK and USA to support the development of the laser surgery