Processing of nonlinguistic auditory stimuli in Landau–Kleffner Syndrome: A case study

Abstract

‘‘Acquired aphasia with convulsive disorder’’ or Landau–Kleffner Syndrome (LKS) was first described in 1957 [W. M. Landau and F. R. Kleffner, Neurology 7, 523–530 (1957)]. This language disorder typically manifests as a decline in verbal expression and comprehension in children who had been developing normally. EEG is always abnormal, although clinical seizures are not always observed. This report presents a 26-yr-old right-handed female who was diagnosed with LKS at age 4 with an abnormal EEG and seizure activity. Her EEG, MRI, and audiogram are now normal, but PET demonstrates bilateral temporal lobe hypometabolism. A detailed linguistic comparison of her limited spoken English and relatively good signed English is reported elsewhere [K. Baynes etal., Int. Neuropsychol. Soc. (submitted)]. Interestingly, she listens to and enjoys several types of music. This discrepancy motivates our initial investigation of her ability to perform nonlinguistic auditory tasks. Despite easy recognition of environmental sounds, discrimination thresholds of pitch and rhythm are greatly exaggerated. Such data can clarify which brain processes are specific to language, and which correspond to more general auditory or hierarchical processing. [Work supported by NIH.]