What is encephalitis? Viral illness Shane MacGowan was diagnosed with that swells brain

Encephalitis is an uncommon but serious condition in which the brain becomes inflamed or swollen

The Pogues frontman Shane MacGowan has died aged 65, following his health battle with viral encephalitis.

Confirming his death in a social media post on Thursday, his wife Victoria Mary Clarke said in a statement: “Shane will always be the light that I hold before me and the measure of my dreams and the love of my life”.

Last year, he revealed he was diagnosed with encephalitis in a video posted to social media on New Year’s Eve.

The Irish singer had been receiving care at St Vincent’s Hospital in Dublin after being diagnosed with the condition last year.

Shane MacGowan has died aged 65 (PA Archive)

Just one week ago, Ms Clarke updated fans that the Fairytale of New York singer had been released from hospital.

While Mr MacGowan’s exact cause of death has not been confirmed yet, here is some information on the condition he fought for the final year of his life:

What is viral encephalitis?

Encephalitis is an uncommon but serious condition in which the brain becomes inflamed or swollen.

It can be life-threatening and requires urgent treatment in hospital. Anyone can be affected, but the very young and very old are most at risk.

It is not always clear what causes encephalitis, but it can be caused by viral infections, a problem with the immune system, or bacterial and fungal infections.

Members of the Pogues in 1984: Pictured are Shane MacGowan, Cait O'Riordan, Andrew Rankin, Jem Finer (Getty Images)

What are the symptoms?

Symptoms usually start with flu-like symptoms, such as a high temperature and headache.

More serious symptoms develop over hours, days or weeks. These can include confusion or disorientation, seizures or fits, changes in personality and behaviour, difficulty speaking, weakness or loss of movement in some parts of the body, and loss of consciousness

What is the treatment?

Encephalitis needs to be treated in a hospital and treatment can last from a few days to even months.

Treatment depends on the underlying cause, but may include antiviral medicines, steroid injections, antibiotics or antifungal medicines, painkillers to reduce discomfort, medicine to control seizures or fits or support with breathing.

The earlier treatment is started, the more successful it’s likely to be.