ANE Awareness Day Date in the current year: July 31, 2025

Encephalopathy is a general term for brain diseases or disorders that can have various causes. Acute necrotizing encephalopathy (ANE) is one type of encephalopathy that occurs following a viral infection. The term “necrotizing” in the name indicates that ANE can cause the death of brain tissue (necrosis), resulting in severe neurological damage.

ANE most commonly develops following an influenza A or B infection. Other viruses known to trigger this condition include human herpesvirus 6, enteroviruses, SARS-CoV-2 (the virus that causes the disease COVID-19), and the measles virus. ANE can be familial, linked to genetic changes in one of several genes, or sporadic.

ANE typically develops in infants or young children, though some people may develop it as adolescents or adults. The disease progresses rapidly and can cause significant neurological damage. Approximately one-third of those affected die from the illness, and about half of those who survive experience permanent brain damage and neurological impairment. However, some patients appear to make a full recovery.

ANE usually begins with symptoms of a common viral infection, such as fever, cough, congestion, fatigue, and sometimes diarrhea and/or vomiting. Then, neurological problems develop as lesions form in the brain. These neurological problems may include double vision, coordination problems, seizures, vomiting, hallucinations, and abnormal muscle tone. Eventually, most patients fall into a coma that can last for weeks.

There is no standard treatment protocol for ANE. Physicians may use corticosteroids, cytokine regulators (such as TNF inhibitors and IL-6 blockers), plasmapheresis, therapeutic hypothermia, or a medically induced coma to prevent brain swelling. They may also prescribe anticonvulsant medications for seizures, antipsychotic drugs to treat behavioral symptoms associated with brain damage, and antiviral drugs to treat the underlying infection.

Patients who survive ANE may experience difficulties with walking, speech, and other basic functions due to brain tissue damage. They require rehabilitation to regain neurological function, which may include physical therapy, occupational therapy, vision therapy, orthotics, and other therapies and treatments.

Some individuals who have survived ANE experience recurrent episodes following new infections. These episodes result in further neurological deterioration as more brain tissue is damaged. Genetic (familial) ANE is thought to be prone to recurrence.

ANE Awareness Day was created by ANE International, an organization that works to raise awareness of ANE and support affected families. The main goals of this day are to educate medical professionals and the general public about acute necrotizing encephalopathy and to advocate for further research and genetic testing when ANE is suspected.