title: Normal pressure hydrocephalus: Increase of utricular input in responders to spinal tap test.
abstract: OBJECTIVE
  To investigate whether there is a change in ocular (oVEMP) and cervical (cVEMP) vestibular evoked myogenic potentials in patients with normal pressure hydrocephalus (NPH) before and after spinal tap test (STT).
  
  
  METHODS
  In 25 patients (6 females, age 62-83years) c/oVEMP were measured before and after STT. Patients with an increase of >20% of walking velocity were classified as responders (n=10). VEMP were also measured in a control group of 13 non-NPH patients.
  
  
  RESULTS
  All patients had reproducible oVEMP; 68% had cVEMP. There was a significant increase of the peak-to-peak (pp) oVEMP amplitude after STT in responders (8.5±2.7 to 18.9±7.5μV (p=0.010)). No significant changes were found in non-responders (13.4±7.6 to 15.3±8.6μV) or controls (12.4±7.6 to 12.5±6.8μV). There were no significant differences in cVEMP before and after spinal tap test (STT).
  
  
  CONCLUSIONS
  One third of patients with suspected NPH had impaired otolith function. Responders to STT only had a significant increase of oVEMP and thereby utricular input, probably due to a decrease of pressure.
  
  
  CONCLUSIONS
  Both findings indicate that otolith dysfunction may contribute to imbalance in NPH and that increased utricular function after STT may be relevant for gait improvement.
authors.affiliation: German Center for Vertigo and Balance Disorders, Ludwig-Maximilians University, Munich, Germany; Dept. of Neurology, University Hospital Munich, Munich, Germany. Electronic address: nicolina.boettcher@med.uni-muenchen.de.
authors.forename: N
authors.initials: N
authors.lastname: Böttcher
authors.affiliation: German Center for Vertigo and Balance Disorders, Ludwig-Maximilians University, Munich, Germany; Graduate School of Systemic Neurosciences, Ludwig-Maximilians University, Munich, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Bremova
authors.affiliation: German Center for Vertigo and Balance Disorders, Ludwig-Maximilians University, Munich, Germany; Dept. of Neurology, University Hospital Munich, Munich, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Feil
authors.affiliation: German Center for Vertigo and Balance Disorders, Ludwig-Maximilians University, Munich, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Heinze
authors.affiliation: German Center for Vertigo and Balance Disorders, Ludwig-Maximilians University, Munich, Germany; Dept. of Neurology, University Hospital Munich, Munich, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Schniepp
authors.affiliation: German Center for Vertigo and Balance Disorders, Ludwig-Maximilians University, Munich, Germany; Dept. of Neurology, University Hospital Munich, Munich, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Strupp
mesh_terms: D000161:Acoustic Stimulation; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010037:Otolithic Membrane / Q000503:physiopathology*; D013129:Spinal Puncture; D058585:Vestibular Evoked Myogenic Potentials / Q000502:physiology*; D016138:Walking / Q000502:physiology
keywords: Clinical neurology; Normal pressure hydrocephalus; Otolith function; VEMP; Vestibular evoked myogenic potentials