A novel prosody assessment test: Findings in three cases of Landau–Kleffner syndrome

Abstract

Landau–Kleffner syndrome (LKS) is a rare childhood neurological disorder characterized by subacute aphasia, auditory agnosia and abnormal EEG. Prosody structures utterances, indicates sentence modality (linguistic prosody) and expresses the speaker’s intention, attitude and emotions (affective prosody). It not only functions as (para-) linguistic features but also provides social explanations. It has been shown that infants can perceive, distinguish and use prosodic features for communication. Since patients with LKS have no more means of verbal communication, we suppose they use some “primitive” cues in an attempt to understand what is said to them. Based on the fact that aphasia does not mean loss of social capacity/functionality, and the precociousness and functions of prosody, the present study investigated prosodic capacity outcomes (possible preservation of prosody) in three individuals - two children and one adolescent - with LKS compared with 7–8 yearold healthy children and healthy adults. A set of perceptual tests of linguistic and affective prosody was elaborated and used for this study. Results revealed that affective prosody is better used in a child with LKS than in the control group under the conditions such as relatively late age at onset, short duration of epilepsy/medication and persistent comprehension problems. Given that prosody appears to be helpful for better oral comprehension, prosody should be used in speech therapy for children with LKS.