[A case of encephalitis with hyperfamiliarity for faces].

A 21-year-old right-handed woman was admitted to our hospital with fever, headache, and seizures. On admission, she showed anterograde and retrograde amnesia. These features, together with mild pleocytosis in the cerebrospinal fluid, led to the diagnosis of encephalitis. Brain MRI was normal. EEG revealed small spike waves in the left temporal lobe. There were no recurrent convulsions. Five days later, she stated she had hyperfamiliarity for faces of people she had never met before. She reported that many people appeared familiar regardless of age, sex, and profession; however, feelings of likes and dislikes did not accompany these symptoms. This symptom lasted for 20 days. Her ability to recognize known faces was normal, and prosopagnosia was not present. Neuropsychological tests indicated that her verbal memory was impaired. The retrograde amnesia remained until discharge. Considering the psychological findings attributable to left temporal lobe dysfunction, as well as previous reports on similar cases, our case suggests a possible relationship between lesions of the left temporal lobe and hyperfamiliarity for faces.