The family of a teenager struck down by a devastating brain disease fear it may have been caused by a brutal assault he suffered at school.

Samuel Thorne was beaten unconscious at the Spires Academy and had to be taken to hospital in an ambulance, where he underwent brain scans.

Now, the 17-year-old has been diagnosed with white matter disease - an illness normally associated with ageing but also linked to brain trauma.

In just four months he has gone from a fit, active teenager to being wheelchair-bound, suffering loss of vision and speech and having to be fed by a tube.

It is heartbreaking for his family, who are at his bedside at the London hospital where he is currently undergoing neurological tests.

The teenager, of South Road, Herne Bay, was studying for his GCSEs at the Spires Academy when the assault happened in April 2015.

Two 15-year-old boys subsequently appeared at Canterbury Youth Court in July that year, charged with assault.

They both pleaded guilty to causing actual bodily harm and were ordered to pay Samuel £500 compensation.

Now school principal Nicki Mattin said she had not been made aware of Samuel’s illness but the boys involved in the assault had been expelled promptly as a result of the incident.

She added: “We take the safety of our students very seriously and the incident was dealt with robustly at the time.”

Samuel’s sister Kellyann Eskisan, 29, says doctors are looking into a potential connection between the assault and the brain deterioration he has now developed.

“They know he has a form of white matter disease which is normally associated with ageing but can be brought on by injury,” she said.

“They can’t say for sure if it is the cause but hope more tests will help and they are also examining his original scans.

“It was an frightening experience for Sam at the time. He is so gentle and wouldn’t hurt a fly.

“To see him in such a terrible state now is heartbreaking and to think it might have been brought on as a result of the attack makes it even worse.”

“He appeared to return to being a perfectly normal, active teenager after the assault.

“But in March this year it became apparent that things weren’t right and the following month he went to his doctor with what appeared to be stroke-like symptoms.”

"Apparently there is no cure but we are hoping they can do something to stop it getting any worse" - Kellyann Eskisan

Samuel underwent tests and MRI scans in Margate and Canterbury but was transferred to London’s King’s College Hospital after his condition deteriorated.

He is now in the Queen Square Hospital, where he is due to have a brain biopsy.

Kellyann said: “Apparently there is no cure but we are hoping they can do something to stop it getting any worse.”

Samuel’s rapid decline has forced him to give up his involvement with the 1st Herne Bay Scouts and his weekend work at Jumping Monkey in Herne Bay, where he was a mascot and Spider-Man character.

Family members, including mum and dad Linda and Darren, are regularly at his hospital beside.

He also has another sister, Katie, 24 and brother, Billy, 28 and six nephews and nieces who are visiting him.

“Sam has always been a bit of a joker and tries to make people laugh. Even now he is trying to keep his spirits up,” added Kellyann.

Samuel was completing a carpentry course at Canterbury College at the time he was taken ill, which he is now unlikely to return to.

His family has launched an appeal to raise money so he can enjoy a bucket list of experiences while he is still able.

Already he is going to see his comedy hero Michael McIntyre, which the star’s management offered free tickets and transport for after hearing of his plight.

Also on his list is a visit to Madame Tussauds and the London Eye, and leaders of the 1st Herne Bay Scouts have asked Bear Grylls if he can come and visit him in hospital.

On Sunday, a fun run/walk has also been organised which will set out from Herne Bay clocktower at 1pm and finish at Hampton.

Kellyann says participants are being encouraged to dress as super heroes and there will be collection buckets.

• To donate to the appeal visit gf.me/u/kcrd4g