title: Peripheral vestibular dysfunction in patients with primary ciliary dyskinesia: abnormal otoconial development?
abstract: OBJECTIVE
  Patients with primary ciliary dyskinesia (PCD) have absent or reduced otoconial function compared to the normal population.
  
  
  BACKGROUND
  Investigations in zebrafish show that ciliation is important for the development of the otolith organs, but this has never been evaluated in humans. PCD is a congenital defect of ciliary structure. We undertook a pilot study to determine whether patients with PCD have absent or reduced otoconial function compared to the normal population.
  
  
  METHODS
  Vestibular function testing, including utricular centrifugation (UCF) testing, vestibular evoked myogenic potentials (VEMPs), and electronystagmography, was undertaken in five patients with known PCD. Patients also completed validated questionnaires regarding subjective balance function and symptoms.
  
  
  RESULTS
  There were markedly reduced or unobtainable VEMPs bilaterally in three of the five subjects and unilaterally in the remaining two subjects. No subject had a pathological UCF asymmetry, but three subjects showed utricular abnormalities. The vestibulo-ocular reflex (VOR) at 0.25 Hz sinusoidal rotation was normal in all subjects. There were no subjective dizzy symptoms or balance issues.
  
  
  CONCLUSIONS
  We speculate that the reduced saccular and utricular function in PCD patients observed in this pilot study suggests a relationship between cilia structure and/or motility, and otoconia seeding and/or positioning. Further investigation is warranted.
authors.affiliation: *Department of Otolaryngology and Audiological Medicine, Charing Cross Hospital, and †Division of Brain Sciences, Imperial College London, Charing Cross Hospital, London, United Kingdom; and ‡Department of Respiratory Medicine, Royal Brompton Hospital, London, United Kingdom.
authors.forename: Joanne
authors.initials: J
authors.lastname: Rimmer
authors.forename: Mitesh
authors.initials: M
authors.lastname: Patel
authors.forename: Kiran
authors.initials: K
authors.lastname: Agarwal
authors.forename: Claire
authors.initials: C
authors.lastname: Hogg
authors.forename: Qadeer
authors.initials: Q
authors.lastname: Arshad
authors.forename: Jonny
authors.initials: J
authors.lastname: Harcourt
mesh_terms: D000293:Adolescent; D000368:Aged; D004244:Dizziness / Q000503:physiopathology; D004584:Electronystagmography; D005260:Female; D006801:Humans; D007619:Kartagener Syndrome / Q000150:complications*; D008297:Male; D008875:Middle Aged; D010037:Otolithic Membrane / Q000002:abnormalities*; D010865:Pilot Projects; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology; D015837:Vestibular Diseases / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D058585:Vestibular Evoked Myogenic Potentials / Q000502:physiology; D014724:Vestibular Function Tests