Acute hemorrhagic leukoencephalitis (AHLE) is a rare, severe central nervous system disorder. With AHLE, the body’s immune response damages the myelin that coats and protects nerve fibers.

Doctors also refer to AHLE as Hurst disease. AHLE progresses quickly, typically after a person acquires a viral or bacterial infection. It often has a poor outlook. However, receiving treatment quickly sometimes improves the outlook for those with AHLE.

Read on to learn about the symptoms and causes of AHLE. This article also looks at treatments, outlook, and more.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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AHLE symptoms can include:

  • fever
  • a stiff neck
  • extreme tiredness
  • headaches
  • nausea
  • vomiting
  • seizures
  • coma

Lesions and brain bleeding can damage the white matter of the brain. The white matter is the network of nerve fibers that help the brain’s processing centers communicate.

The symptoms of AHLE appear and progress very rapidly. They commonly develop between 2 days and 2 weeks after an initial illness.

According to a 2020 systematic review, AHLE symptoms can progress to death within days. This results from increased pressure inside the skull.

The exact cause of AHLE is unclear. However, researchers consider AHLE to be an autoimmune response. This is when the immune system mistakenly attacks the body’s healthy tissue.

According to a 2022 review, 32–35% of people with AHLE experienced a viral upper respiratory tract infection (URTI) before diagnosis. Bacterial infections can also occur before AHLE progression.

Less frequently, people developed AHLE after vaccinations against measles or rabies. One 2022 case study also found that AHLE developed after taking the COVISHIELD vaccine against COVID-19. However, these are rare causes of an extremely rare disorder. Additionally, COVID-19 has possible links to lesions that resemble those in AHLE.

Risk factors

According to a 2020 review, AHLE is most common in adult males, accounting for around 67% of cases.

The review also suggests that 12% of people who developed AHLE had an underlying autoimmune condition. These included conditions such as psoriasis, multiple sclerosis, and rheumatoid arthritis.

Diagnosing AHLE is challenging, and,due to limited evidence, no formal guidelines are available. However, doctors can diagnose AHLE using the following methods:

  • Brain imaging: This can detect hemorrhagic lesions, fluid buildup, and other clinical signs, using tests such as an MRI scan.
  • Blood tests: These help doctors check for signs of inflammation.
  • Cerebrospinal fluid (CSF) analysis: This involves removing and testing cerebrospinal fluid.
  • Brain biopsies: These involve removing brain tissue where possible and sending it for examination under a microscope.

These tests can help a doctor assess the scale of any brain damage. They can also help them determine whether an immune reaction is largely responsible.

Treatment for AHLE aims to:

  • reduce the autoimmune activity that may be causing AHLE
  • limit brain damage due to increased pressure inside the skull
  • prevent complications, such as pneumonia

Although successful treatment for AHLE is rare, it is possible. Treatment most commonly involves the use of glucocorticoid medications, which reduce the activity of the immune system.

Less commonly, doctors may try plasmapheresis. This involves transporting blood out of the body, removing or cleaning it, then returning it to the individual.

Intravenous immunoglobulin (IVIG) treatment may also help to suppress immune activity and limit further white matter damage.

AHLE is so rare that there is no data on how many people develop the condition. Reports are often based on individual case studies. However, existing data suggests that AHLE is more common in males.

AHLE generally has a very poor outlook. A 2020 review found that people with the condition had a mortality rate of 46.5%.

Those who survive AHLE often live with psychiatric symptoms, seizures, and reduced mental function. Overall, these cases accounted for 39.5% of those who received an AHLE diagnosis.

In 14% of cases, people achieved complete remission. This means they recovered and returned to their normal function.

Acute hemorrhagic leukoencephalitis (AHLE) is an extremely rare inflammatory brain condition. It is often fatal. Researchers are not sure what causes AHLE, but it commonly develops after a viral infection. In rare cases, it can occur following measles or rabies vaccination.

Treatment with glucocorticosteroids may help to reduce a person’s immune response and limit brain damage. Other, less common treatments for AHLE include plasmapheresis and IVIG.

AHLE develops rapidly, and outlook for the condition is generally poor. Those who survive often live with reduced mental function or psychological problems.