title: The Chiari I malformation and the neurotologist.
abstract: OBJECTIVE
  The first objective of this paper is to report the clinical symptoms of 77 patients and the results of their neurologic, vestibular, and audiological evaluations done with magnetic resonance imaging, which confirmed Chiari I malformations. The second objective is to report how the results of a vestibular evaluation can help neurosurgeons decide on the need for surgical treatment.
  
  
  METHODS
  Retrospective chart review of 77 patients seen between 1988 and 2000.
  
  
  METHODS
  Tertiary care center.
  
  
  METHODS
  The clinical data of patients under diagnoses of Chiari I malformation, which was filed in the vestibular laboratory computer, was analyzed.
  
  
  METHODS
  The cases included in this study were derived from a population of patients who were evaluated for dizziness, hearing loss, and tinnitus in the Torok Vestibular Laboratory.
  
  
  METHODS
  Occurrence of central vestibular findings in the patients with Chiari I malformation.
  
  
  RESULTS
  In this group of 77 patients, 10 had bilateral sensorineural hearing loss and 22 had unilateral sensorineural hearing loss of varying severities. Horizontal spontaneous nystagmus was noted in 27 patients, vertical upbeat nystagmus in 3, and downbeat nystagmus in 4 others. Saccadic dysmetria was noted in 4 patients, optokinetic nystagmus was impaired in 3, and smooth-pursuit impairment was noted in 12 of the group. Positional nystagmus was noted in 9 patients. The Torok monothermal caloric test showed normal responses in 19 patients, hyperactive responses in 43, decruitment in 45, and rebound caloric nystagmus in 20. Surgical decompression of the Chiari I malformation was completed in 33 patients.
  
  
  CONCLUSIONS
  From this study it is clear that the results of the basic vestibular function-test battery reflect the functional deficit in the vestibulocerebellum that is presumed by its ectopic position. These tests results have given our neurosurgeons a stronger foundation on which to base surgical decisions for this disease.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, University of Illinois at Chicago, 60612, USA. arvindku@uic.edu
authors.forename: Arvind
authors.initials: A
authors.lastname: Kumar
authors.forename: Aftab Hakim
authors.initials: AH
authors.lastname: Patni
authors.forename: Fady
authors.initials: F
authors.lastname: Charbel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001139:Arnold-Chiari Malformation / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D002150:Caloric Tests; D002648:Child; D019299:Decompression, Surgical; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000175:diagnosis / Q000209:etiology; D010036:Otolaryngology / Q000379:methods; D012189:Retrospective Studies; D013116:Spinal Cord / Q000473:pathology / Q000601:surgery; D013595:Syringomyelia / Q000473:pathology / Q000601:surgery; D014724:Vestibular Function Tests