Developmental Process of an Infant with Bilateral Temporal Lobe Lesions Caused by Infantile Herpes Simplex Encephalitis: with Special Reference to Development of Auditory Functions

Abstract

The present paper reports on a four-year follow-up study on a male infant with bilateral temporal lobe lesions.
The patient had no abnormal developmental history before the onset of this disease. When he was six months old, he suffered from herpes simplex encephalitis, at which time he behaved as deaf. His development of auditory functions was compared with that observed in a hearing brain-damaged infant who was initially diagnosed as having deafness.
From the observation of this infant until the present, the following results were obtained:
1) Although the auditory thresholds for pure tones were gradually lowered, a developmental test of auditory functions demonstrated that there was no progress beyond the level of a normal eight-month-old infant.
Therefore the discrepancy of development between auditory functions and visual functions as well as mental development was gradually diminishing.
2) The development of higher auditory functions was completely inhibited, while lower auditory function integrated at the subcortical level was in development.
3) Because language acquisition through the auditory channel seemed to be difficult, we attempted to educate the patient through the visual channel, but with little success.