Table 1.
Identified Infectious and Noninfectious Etiologies of Temporal Lobe Encephalitis (N = 251)
| Etiology | Cases, No. (% of Total) | Cases With Confirmed/ Probable Infectious Etiology, % |
|---|---|---|
| Infectious | 108 (43) | 82 |
| Herpes simplex virus 1 | 57 (22.7) | 91 |
| Herpes simplex virus 2 | 3 (1.2) | 100 |
| Tuberculosis | 8 (3.2) | 88 |
| Varicella zoster virus | 7 (2.8) | 71 |
| Mycoplasma pneumoniae | 5 (2.0) | 20 |
| Enterovirus | 4 (1.6) | 75 |
| Balamuthia mandrillaris | 4 (1.6) | 100 |
| Human herpesvirus 6 | 4 (1.6) | 100 |
| Creutzfeldt-Jakob disease | 3 (1.2) | 100 |
| West Nile virus | 2 (0.8) | 100 |
| Rocky Mountain spotted fever | 2 (0.8) | 50 |
| Influenza | 2 (0.8) | 0 |
| Other infectiousa | 7 (2.8) | 57 |
| Noninfectious | 40 (16) | … |
| Glioma/lymphoma/other malignancy | 9 (3.6) | … |
| Central nervous system vasculitis | 6 (2.4) | … |
| Paraneoplastic | 5 (2.0) | … |
| Toxic-metabolic | 4 (1.6) | … |
| Vascular | 4 (1.6) | … |
| NMDA receptor–associated limbic encephalitis | 3 (1.2) | … |
| ADEM | 3 (1.2) | … |
| Dementia | 2 (0.8) | … |
| Other noninfectiousb | 4 (1.6) | … |
| No etiology identified | 103 (41) | … |
Abbreviations: ADEM, acute disseminated encephalomyelitis; NMDA, N-methyl-d-aspartate.
a Other infectious etiologies: syphilis, Chlamydia pneumoniae, coccidioidomycosis, Nocardia, adenovirus, human metapneumovirus, Aspergillus.
b Other noninfectious etiologies: systemic lupus erythematosus, neurosarcoidosis, and Hashimoto's steroid responsive encephalopathy.