Within one month, the 12-year-old was in intensive care in John Hunter Hospital unable to speak, move and in a state of extreme psychosis.

The Lambton High student was struck down by a rare form of encephalitis, which is an inflammation of the brain, and doctors are still not sure exactly what made him ill.

Maddy has been in the intensive care unit for 64 days on a cocktail of steroids and other drugs, and on Sunday stood up for the first time since getting sick.

His mother Katt allowed the Newcastle Herald into his room to warn other parents to watch for the unique symptoms that mark the condition and encourage them to advocate for their children’s health.

Maddy has NMDA Receptor Encephalitis, a condition only properly identified in 2007.

Read more about NDMA Receptor Encephalitis here.

Since then, there has been about 1000 recorded cases worldwide but doctors suspect it is much more common than acknowledged.

Maddy’s doctor, paediatric neurologist Dr Rob Smith, said in children it was sometimes confused with behaviour problems and not treated as a medical condition.

Maddy’s problems began when he suffered a series of seizures in October and was taken to the emergency department.

He was initially treated for epilepsy and sent home but within a week had developed psychosis – hallucinations, screaming and thrashing – and was readmitted.

His sleep cycle reversed, so he slept during the day, and it wasn’t until doctors performed a second spinal tap that they were able make a diagnosis.

Dr Smith said in most cases a virus triggered this type of encephalitis in children and suspect that was the case with Maddy, who had recently had a severe sore throat.

He said researchers think that affected patients’ immune systems had underlying vulnerabilities that reacted to certain viruses, causing the illness.

In this case, the antibodies in patients attack the brain’s nerve receptors.

Dr Smith’s message to parents was to have all seizures assessed by a doctor immediately and if it was followed by psychosis or an obvious change in behaviour, insist on tests.

He emphasised the condition was not contagious.

‘‘This was unusually severe, we had a lot more trouble getting Maddy’s behaviours under control,’’ he said.

‘‘He’s actually making some exciting progress, which is wonderful news.’’

Doctors said Maddy had a long road ahead of him and had to learn to do everything again.

Maddy is aware of people in the room, shows eye movements and has stood up. 

His mother Katt said early detection was vital and encouraged parents to always persist when it came to their children’s health.

She said the only sign something was wrong prior to the seizures was Maddy complaining of short-term numbness and twitching in his leg.

‘‘A healthy boy one day can end up in this situation with no notification,’’ she said.

Ms Coffey thanked John Hunter Hospital staff.

‘‘He’s been making a remarkable recovery since Christmas,’’ she said.

Sore throat linked to sickness

MADDY’s rare form of encephalitis is a variety of encephalitis lethargica, thought to have caused an epidemic of ‘‘sleepy sickness’’ in the 1920s.

It is thought to have killed a million people, many women, and it left millions more frozen inside their bodies in institutions.

For a long time researchers linked the condition to the Spanish flu that wiped out up to 50 million after  World War I, thinking the virus triggered the condition.

In 2003 researchers found a probable cause of the condition was diplococcus, a strep bacteria that causes sore throats, and that some patients’ immune systems reacted to the bacteria.

They dug up medical reports from the era and found the patients all had a bad sore throat before developing sleepy sickness.

NMDA-RECEPTOR ANTIBODY ENCEPHALITIS

Condition: The NMDA receptor is a protein in the brain that helps control the electrical activity of nerves. The body produces antibodies that attack these receptors.

Causes: Not known. Researchers suspect a virus triggers the antibodies.

Symptoms: Seizures, confusion and memory loss followed    by a movement disorder, psychosis, loss of consciousness and changes in blood pressure, heart rate and temperature.