While it proves that an autoimmune reaction can cause inflammation in the white matter, the analogy stops there. It may also follow a variety of other viral and nonviral infections or vaccinations. Sometimes it appears without a preceding infection. It is a monophasic disease that usually runs a mild course with recovery but sometimes may be severe or fatal. Clinically, it presents with drowsiness, headache, stiff neck, focal deficits, paraplegia and sensory loss.
ADE following varicella often presents with ataxia.
Severe ADE with confluent lesions causes cerebral edema and herniations. Pathologically, ADE is characterized by microscopic perivenous demyelination and mononuclear cells in the brain and spinal cord. ADE is not an infection. It is thought to be an immune reaction triggered by the preceding viral infection or vaccination. Old rabies vaccines were prepared from brains of inoculated rabbits.