This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Acute hemorrhagic leukoencephalitis (AHLE) is a very rare form of acute disseminated encephalomyelitis that frequently results in death. It is characterized by a brief but intense attack of inflammation in the brain and spinal cord that damages the myelin (the protective covering of the nerve fibers). It may also cause bleeding in the brain, leading to damage of the white matter. Symptoms usually come on quickly and may include fever, neck stiffness, fatigue, headache, nausea, vomiting, seizures, and coma. AHLE has a very poor prognosis, with rapid deterioration and death usually occurring within days to one week after onset of symptoms. Although the exact cause is unclear, AHLE usually follows a viral or bacterial infection, or less often, vaccination for measles or rabies. Some researchers think that an infection or vaccination can initiate an autoimmune process in the body thus leading to AHLE. While favorable outcomes are uncommon, timely treatment with immunosuppressant medications and plasma exchange may lead to an improved outlook.
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