CHRONIC AUDITORY AGNOSIA FOLLOWING LANDAU-KLEFFNER-SYNDROME - A 23 YEAR OUTCOME STUDY

We report a 27-year-old woman with chronic auditory agnosia following Landau-Kleffner Syndrome (LKS) diagnosed at age 4 1/2. She grew up in the hearing/speaking community with some exposure to manually coded En glish and American Sign Language (ASL). Manually coded (signed) Englis h is her preferred mode of communication. Comprehension and production of spoken language remain severely compromised. Disruptions in audito ry processing can be observed in tests of pitch and duration, suggesti ng that her disorder is not specific to language. Linguistic analysis of signed, spoken, and written English indicates her language system i s intact but compromised because of impoverished input during the crit ical period for acquisition of spoken phonology. Specifically, althoug h her sign language phonology is intact, spoken language phonology is markedly impaired. We argue that deprivation of auditory input during a period critical for the development of a phonological grammar and au ditory-verbal short-term memory has limited her lexical and syntactic development in specific ways, (C) 1998 Academic Press.