Prosodic preservation in Landau-Kleffner syndrome: a case report

Landau-Kleffner syndrome (LKS) is a rare acquired condition of auditory ver bal agnosia and convulsive disorder in children. It has been proposed that there is a functional relationship between electrical disturbance and the s peech defect. Prosody or the melody of language, as described by Monrad-Kro hn (1947), is one aspect of non-verbal communication which is distributed b ilaterally in the brain. Prosodic parameters of expression and perception i n one 7.5-year-old child were tested to see if they were preserved as a mea ns of communication. The child was observed during video-electroencephalogr am (EEG) monitoring over a 48-hour period. All utterances were recorded and subject to analysis for the salience and variation of acoustic correlates of prosody. Prosodic comprehension was measured using specific perceptual t asks previously presented to normal children between the ages of 5.5 and 8. 5. Despite being unable to meaningfully use or perceive phonemes, the child was able to use variations in fundamental frequency, duration and intensit y of utterances, to convey both emotional and propositional intent. Similar ly, the child was able to discriminate prosodic contours of a male adult vo ice to an age equivalent to 5.5 to 6.5 years. This argues in favour of the notion for educating such children not only through the visual channel but also through the auditory channel. Eur J Neurol 6:227-234 (C) 1999 Lippinco tt Williams & Wilkins.