title: Serial auditory-evoked potentials in the diagnosis and monitoring of a child with Landau-Kleffner syndrome.
abstract: BACKGROUND
  A boy, aged 2 1/2 yr, experienced sudden deterioration of speech and language abilities. He saw multiple medical professionals across 2 yr. By almost 5 yr, his vocabulary diminished from 50 words to 4, and he was referred to our speech and hearing center.
  
  
  OBJECTIVE
  The purpose of this study was to heighten awareness of Landau-Kleffner syndrome (LKS) and emphasize the importance of an objective test battery that includes serial auditory-evoked potentials (AEPs) to audiologists who often are on the front lines of diagnosis and treatment delivery when faced with a child experiencing unexplained loss of the use of speech and language.
  
  
  METHODS
  Clinical report.
  
  
  RESULTS
  Interview revealed a family history of seizure disorder. Normal social behaviors were observed. Acoustic reflexes and otoacoustic emissions were consistent with normal peripheral auditory function. The child could not complete behavioral audiometric testing or auditory processing tests, so serial AEPs were used to examine central nervous system function. Normal auditory brainstem responses, a replicable Na and absent Pa of the middle latency responses, and abnormal slow cortical potentials suggested dysfunction of auditory processing at the cortical level. The child was referred to a neurologist, who confirmed LKS. At age 7 1/2 yr, after 2 1/2 yr of antiepileptic medications, electroencephalographic (EEG) and audiometric measures normalized. Presently, the child communicates manually with limited use of oral information.
  
  
  CONCLUSIONS
  Audiologists often are one of the first professionals to assess children with loss of speech and language of unknown origin. Objective, noninvasive, serial AEPs are a simple and valuable addition to the central audiometric test battery when evaluating a child with speech and language regression. The inclusion of these tests will markedly increase the chance for early and accurate referral, diagnosis, and monitoring of a child with LKS which is imperative for a positive prognosis.
authors.affiliation: Department of Audiology and Speech Pathology, University of Tennessee Health Science Center.
authors.forename: Erin
authors.initials: E
authors.lastname: Plyler
authors.forename: Ashley W
authors.initials: AW
authors.lastname: Harkrider
mesh_terms: D000161:Acoustic Stimulation; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D000927:Anticonvulsants / Q000627:therapeutic use*; D001299:Audiometry / Q000379:methods*; D001308:Auditory Perceptual Disorders / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D001309:Auditory Threshold / Q000502:physiology; D001321:Autistic Disorder / Q000175:diagnosis*; D002675:Child, Preschool; D003937:Diagnosis, Differential; D042241:Early Diagnosis; D004569:Electroencephalography / Q000379:methods; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D006801:Humans; D018887:Landau-Kleffner Syndrome / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology; D011241:Prednisone / Q000627:therapeutic use; D012017:Referral and Consultation; D012022:Reflex, Acoustic / Q000502:physiology; D012813:Sign Language; D013070:Speech Therapy; D016896:Treatment Outcome
chemical_list: D000893:Anti-Inflammatory Agents; D000927:Anticonvulsants; D011241:Prednisone