A mother, from Ballyclare, County Antrim, says her young son became “possessed by the devil” after a throat infection triggered a rare neurological condition, known as “exorcist syndrome.”

Cameron Lindsay (14) was diagnosed with this rare disorder, which caused violent rages and attacks, having contracted the common Streptococcal infection and scarlet fever. The teenager went from a normal young man to one who grabbed knives from the kitchen to harm himself or his family and wanted his parents dead. His family say his rare neurological condition has even caused him to hallucinate that Adolf Hitler was at his window.

Approximately one in 2,000 children are affected by the syndrome though the diagnosis may be overlooked due to some of the common symptoms associated with the disease.

Cameron’s mother, Nastasha (44), has suffered a black eye, bruised ribs and broken fingers at the hands of her son. She has also suffered a brain injury from one of his attacks.

She told the Daily Mail “At first I was worried about taking him to the doctor because I thought they would lock him up for being psychotic.

“It may manifest itself like a mental illness but this is caused by his body fighting strep.

“It was an incredible shock to the system to have a healthy normal, functioning 11-and-a-half-year old to then suddenly watch that child completely disappear before your eyes.

“It's like someone kidnapped him but he never left the house. It was very very, very frightening because it really felt like the devil had taken possession of my child.”

Natasha continued “He does things like throw himself down the stairs or puts his hands on the grill and when I try to stop him, he'll say things like "I hope you die in a fiery car crash and come back to the house in a coffin". It's just heartbreaking.”

Their child become anxious and in 2013 Cameron started to develop nervous tics. His parents put this down to the health child being worried about school. After the spring break Cameron started to suffer from body contortion, violent tics and severe bouts of anxiety.

He was rushed to hospital in an attempt to find out what could be wrong. They were transferred to the Royal Victoria Children's Hospital, in Belfast, where they were told he had rapid onset Tourette's syndrome.

The Belfast team then noticed the raised levels of streptococcal bacteria in his blood and he was diagnosed with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS). This is caused by the body trying to fight an infection. In doing so it also destroys some of the cells in the brain that of a similar makeup to the infection.

PANDAS was described in the late 1990s after investigators identified a subgroup of children who developed a sudden onset of obsessive-compulsive disorder (OCD) symptoms, vocal and motor tics, and other behavioral changes.

Cameron spent the last three years going in and out of hospitals in a bid to control his symptoms. His tonsils, where the bacteria was rife, were removed in an effort to prevent violent rages. He had four rounds of intravenous immunoglobulin, which involves pumping antibodies directly into his bloodstream.

Despite various forms of treatment his symptoms continue and any time he catches any sort of bug, the condition flares up and causes him to suffer more violent rages.

At home Cameron has to be restrained to prevent him from harming himself or others.

His little sister, Annie, now 12, often has to leave the family home and stay with friends for her own safety.

Her mother said “She's been impacted so much for this. He can just go for her when he's really bad and he's a 14-year-old lad, who is much bigger than her. He frightens her terribly.”

As well as the violent rages Cameron also suffers from severe headaches, obsessive compulsive disorder and his short term memory is deteriorating, similar to that seen in dementia suffers. Currently he is only able to attend school for six to nine hours a week, with fulltime support.

What Natasha says was most frightening was that there were no signs of Cameron’s health deteriorating and then it was just like an earthquake.

“I find it very hard to find the words to convey what that felt like to watch,” said Natasha.

“When he asks me what has happened to him, I use the earthquake analogy - there are aftershocks and it takes a long time to rebuild a city after that.

“While that happens, the city runs on reduced power, alternative routes have to be taken and normal life is not possible.”

Natasha has taken a three-year career break to help care for her son she has also launched a fundraising campaign to raise $49,150 so Cameron can undergo more tests and drug therapy in the United States.

In March 2015, Cameron had plasma therapy treatment in the US and his symptoms disappeared for six weeks. Doctors have since told the family that this treatment would no longer benefit Cameron as his brain has been too injured.

“I don't know what the future holds for Cameron but when he had the treatment in America, we got our son back for six weeks and I think more would help,” said Natasha.

“I want to do all I can to make the experiences of other families easier. This has been utter hell for us but there has to be a positive legacy.

“Even if he never gets better, I need to know I have helped raise awareness of this terrible condition.”

The family are establishing the PANDAS foundation in Northern Ireland to help raise awareness about Cameron’s condition and be of support to other parents in similar situations.

To donate to their fund visit their GoFundMe page.

Here’s a video made by a New York mother and daughter on PANDAS: