Encephalitis is a complex illness, difficult to diagnose and easy to confuse with other diseases of the brain or with psychiatric illness.  This is because the symptoms are similar to other conditions which are much more common than encephalitis.


The signs and symptoms of encephalitis can range from very mild symptoms to potentially life threatening ones.  Encephalitis is suspected in people with unexplained alterations in mental status.  These can be poor responsiveness, altered behaviour and personality changes, memory loss, seizures, and loss of consciousness.

This information is taken from the Book “Understanding Encephalitis” by Elaine Dowell.  The book is available from Amazon Understanding Encephalitis.



Links are to a pdf if the article is free and to the Pubmed page is the article is not free

Diagnosis and management of acute encephalitis Encephalitis results in considerable morbidity and mortality in the United States and worldwide. Neurologists are often consulted or directly care for patients with encephalitis admitted to the hospital and must be able to discriminate between encephalitis and the many conditions that mimic it. Moreover, neurologists must be familiar with the myriad causes of encephalitis in order to develop a practical approach to diagnostic testing and treatment. An understanding of recent advances in management, particularly with respect to autoimmune etiologies and critical care approaches, is equally important. Here, we summarize a general approach to the care of adult patients with encephalitis. 

Encephalitis Hospitalization Rates and Inpatient mortality in the United States   In the U.S. from 2000-2010, there were 7.3±0.2 encephalitis hospitalizations per 100,000 population. Encephalitishospitalization rates were highest among females and those <1 year and >65 years of age.  Etiology was unknown for approximately 50% of cases. Among patients with identified etiology, viral causes were most common (48.2%), followed by Other Specified causes (32.5%), which included predominantly autoimmune conditions. The most common infectious agents were herpes simplex virus, toxoplasma, and West Nile virus. Comorbid HIV infection was present in 7.7% of hospitalizations. Average length of stay was 11.2 days with mortality of 5.6.

The spectrum of acute encephalitis: causes, management, and predictors of outcome. Abstract – To describe and analyze etiologies, clinical presentations, therapeutic management, and outcomes of patients with acute encephalitis and identify outcome predictors.

Encephalitis of unclear origin diagnosed by brain biopsy: a diagnostic challenge. Brain biopsy specimens that exhibit encephalitis without specific histopathologic features pose a diagnostic challenge to neuropathologists and neurologists. Such cases are generally referred to pathologically as encephalitis, not otherwise specified (ENOS). A systematic approach to diagnostic evaluation in such patients is challenging, and currently there is no generally accepted algorithm.  CONCLUSIONS AND RELEVANCE:  ENOS is the most common initial type of encephalitis diagnosed by brain biopsy. In such patients, it may be worth having the biopsy materials reviewed again in a comprehensive fashion by a neuropathologist because additional review led to a more specific categorization in one-third of our cases. Ancillary testing, clinical correlation, and clinical follow-up establish more specific diagnoses in some patients. ENOS still remains a diagnostic challenge after all these efforts in many cases. Current algorithms are of limited value. More advanced methods and better diagnostic algorithms are needed to characterize these patients.

Two different presentations, one diagnosis. Abstract- Acute confusion and hyponatraemia are common presentations in acute medicine. We report two cases of anti-voltage gated potassium channel (VGKC) antibody-related limbic encephalitis highlighting the variable presentation of this condition. Both patients were thoroughly investigated with MRI scan of brain, lumbar puncture, EEG as well as infective and autoimmune screens for encephalitis. Anti-VGKC antibodies were positive for both patients and prompt treatment with immunotherapy yielded good recovery. Patients presenting with confusion and seizures who have no demonstrable infectious or metabolic cause should have investigation for an autoimmune cause expedited. In addition, psychiatric presentations with atypical features such as drowsiness should prompt similar investigations. The outcome of anti-VGKCrelated limbic encephalitis is improved with early treatment employing steroids or immunotherapy.