What is idiopathic transverse myelitis, the neurological condition Helen Haines’ alleged attacker has?

Key points

• Brendan Nugent appeared in court charged with dangerous driving causing serious injury, intentionally causing serious injury, and causing harm to a Commonwealth public official, as well as cultivating and processing cannabis. Independent MP Helen Haines has lost both legs, her husband Phil Haines said, and is in stable condition in hospital.
• Nugent's lawyer, Chirag Patel, said his client had a concussion and idiopathic transverse myelitis. Transverse myelitis is a rare neurological condition caused by inflammation of the spinal cord.
• It can cause weakness, numbness, paralysis and pain, and there is no cure, though treatments can help.