Charles Bonnet syndrome after herpes simplex encephalitis.

Visual impairment associated with Charles Bonnet syndrome is rarely reported in childhood. We describe a child who presented with visual hallucinations and postinfectious bilateral retrobulbar optic neuritis. The patient had undergone acyclovir therapy for 3 weeks because of herpes encephalitis. Four days after therapy was completed, he experienced visual impairment in both eyes. He manifested a bilateral decrease in visual acuity, with normal funduscopic findings. The patient experienced visual hallucinations for about 1 week, and then experienced total loss of vision. During his hallucinations, the patient did not exhibit behavioral changes or cognitive impairment. The visual hallucinations included unfamiliar children hiding under his bed, and he spoke to someone whom he did not know. Magnetic resonance imaging indicated bilateral optic nerve hyperintensity on T(2)-weighted and contrast-enhanced images. The patient received corticosteroid therapy for his retrobulbar optic neuritis, and his vision returned to normal after 1 month. Although rare, visual impairment can be associated with complex visual hallucinations indicative of Charles Bonnet syndrome.