Box 1.

Differential diagnosis

  • Viral infections

  • Sporadic viral infections such as Herpes simplex virus (HSV), Varicella zoster virus, adenovirus and enteroviruses

  • Epidemic viral infections such as Japanese encephalitis virus (JEV), dengue virus, rabies virus and enterovirus 71

  • Bacterial infections including rickettsial diseases, tuberculosis, or bacterial abscess

  • Parasitic infections such as cerebral malaria or neurocysticercosis

  • Other space-occupying lesions