| Intracranial infection |
| Meningitis |
| Bacterial |
| Fungal |
| Viral |
| Lymphocytic |
| Encephalitis |
| Brain abscess |
| Subdural empyema |
| Systemic infection |
| Bacterial infection |
| Viral infection |
| HIV/AIDS |
| Other systemic infection |
| Other causes |
| Familial hemiplegic migraine |
| Pituitary apoplexy |
| Rhinosinusitis |
| Subarachnoid hemorrhage |
| Malignancy of central nervous system |
