Send to

Choose Destination
Neurology. 2015 Jan 27;84(4):359-66. doi: 10.1212/WNL.0000000000001190. Epub 2014 Dec 24.

The spectrum of acute encephalitis: causes, management, and predictors of outcome.

Author information

From the Department of Neurology, Mayo Clinic, Rochester, MN.
From the Department of Neurology, Mayo Clinic, Rochester, MN.



To describe and analyze etiologies, clinical presentations, therapeutic management, and outcomes of patients with acute encephalitis and identify outcome predictors.


We conducted a retrospective review of patients diagnosed with acute encephalitis at Mayo Clinic Rochester between January 2000 and December 2012. On the basis of the final diagnosis, the patients were categorized into 3 groups: viral encephalitis, autoimmune encephalitis, and encephalitis of unknown/other etiology. Multivariate logistic regression analysis was used to analyze factors associated with good (modified Rankin Scale scores of 0-2) or poor (scores of 3-6) outcome at hospital discharge.


We identified 198 patients (100 [50.5%] men and 98 [49.5%] women) with a median age of 58 years (range 41.8-69). Etiologies included viral infection (n = 95, 48%), autoimmune (n = 44, 22%), and unknown/others (n = 59, 30%). Good outcome at discharge was achieved by 48 patients (50.5%) with viral encephalitis, 17 (40.5%) with autoimmune encephalitis, and 32 (54.2%) with unknown/other etiologies. Mortality rates were 8%, 12%, and 5% in each of the 3 categories, respectively. On multivariate regression analysis, the factors that were associated with poor outcome were age 65 years or older (p = 0.0307), immunocompromised state (p = 0.0153), coma (p = 0.0062), mechanical ventilation (p = 0.0124), and acute thrombocytopenia (p = 0.0329). CSF polymorphonuclear cell count was also strongly associated with poor outcome in viral encephalitis (p = 0.0027).


Advanced age, immunocompromised state, coma, mechanical ventilation, and acute thrombocytopenia portend a worse prognosis in acute encephalitis. In contrast, the etiology of encephalitis, development of seizures or focal neurologic deficit, and MRI findings were not associated with clinical outcomes.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center