Encephalitis is a life-threatening condition in which inflammation of the brain tissue occurs. Although it is relatively rare, misdiagnosis or delays in recognition and treatment can have devastating consequences for patients, and there is a high mortality rate. People who survive are often left with neuropsychological impairment.

This article describes the pathophysiology of the condition, as well as clinical presentation and treatment, and explains why it can be easily missed. It includes a case study that describes a situation in which the condition was not considered initially as a differential diagnosis, and considers implications for practice.