title: Correlation of augmented startle reflex with brainstem electrophysiological responses in Tay-Sachs disease.
abstract: OBJECTIVE
  To clarify the evolution of an augmented startle reflex in Tay-Sachs disease and compare the temporal relationship between this reflex and brainstem evoked potentials.
  
  
  METHODS
  Clinical and electrophysiological data from 3 patients with Tay-Sachs disease were retrospectively collected.
  
  
  RESULTS
  The augmented startle reflex appeared between the age of 3 and 17 months and disappeared between the age of 4 and 6 years. Analysis of brainstem auditory evoked potentials revealed that poor segregation of peak I, but not peak III, coincided with the disappearance of the augmented startle reflex. A blink reflex with markedly high amplitude was observed in a patient with an augmented startle reflex.
  
  
  CONCLUSIONS
  The correlation between the augmented startle reflex and the preservation of peak I but not peak III supports the theory that the superior olivary nucleus is dispensable for this reflex. The blink reflex with high amplitudes may represent augmented excitability of reticular formation at the pontine tegmentum in Tay-Sachs disease, where the pattern generators for the augmented startle and blink reflexes may functionally overlap.
authors.affiliation: Department of Child Neurology, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan. Electronic address: nsadao@ncnp.go.jp.
authors.forename: Sadao
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Department of Child Neurology, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Saito
authors.affiliation: Department of Child Neurology, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Ishiyama
authors.affiliation: Department of Child Neurology, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugai
authors.affiliation: Department of Clinical Laboratory Medicine, NCNP, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Iso
authors.affiliation: Department of Developmental Disorders, National Institute of Mental Health, NCNP, Tokyo, Japan.
authors.forename: Masumi
authors.initials: M
authors.lastname: Inagaki
authors.affiliation: Department of Child Neurology, National Center of Neurology and Psychiatry (NCNP), Tokyo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sasaki
mesh_terms: D001933:Brain Stem / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D006801:Humans; D007223:Infant; D008297:Male; D013216:Reflex, Startle / Q000502:physiology*; D013661:Tay-Sachs Disease / Q000503:physiopathology*
keywords: Blink reflex; Brainstem auditory evoked potentials; Brainstem electrophysiological responses; Startle reflex; Tay–Sachs disease