title: Inferior cerebellar peduncular lesion causes a distinct vestibular syndrome.
abstract: OBJECTIVE
  The inferior cerebellar peduncle (ICP) contains various fibres to and from the cerebellum relating to the integration of the proprioceptive and vestibular functions. However, the full clinical features of isolated unilateral ICP lesions have not been defined in humans.
  
  
  METHODS
  Eight consecutive patients with isolated unilateral ICP lesions at the pontine level (six with stroke, one with multiple sclerosis and one with brainstem encephalitis) received bedside neurological and neuro-otological evaluations and underwent laboratory tests including measurements of the subjective visual vertical (SVV) and ocular torsion, bithermal caloric tests and pure tone audiometry.
  
  
  RESULTS
  All patients developed isolated acute vestibular syndrome (AVS) with ipsilesional spontaneous nystagmus (n = 7) and contralesional ocular tilt reaction (OTR) and/or SVV tilt (n = 7). In view of the normal head impulse test in all patients and skew deviation in one, our patients met the criteria for AVS from central lesions. Five patients showed a directional dissociation between the OTR/SVV tilt and body lateropulsion that fell to the lesion side whilst the OTR/SVVtilt was contraversive.
  
  
  CONCLUSIONS
  A unilateral ICP lesion at the pontine level leads to the development of isolated AVS. However, a negative head impulse test and directional dissociation between OTR/SVV tilt and body lateropulsion may distinguish lesions involving unilateral ICP at the pontine level from those affecting other vestibular structures.
authors.affiliation: Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea.
authors.forename: J-H
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Neurology, Bonhospital, Busan, Korea.
authors.forename: J-D
authors.initials: JD
authors.lastname: Seo
authors.affiliation: Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, Korea.
authors.forename: Y R
authors.initials: YR
authors.lastname: Choi
authors.affiliation: Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, Korea.
authors.forename: M-J
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Biomedical Laboratory Science, Kyungdong University, Goseong, Korea.
authors.forename: H-J
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Biomedical Research Institute and Department of Neurology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: J S
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, Korea.
authors.forename: K-D
authors.initials: KD
authors.lastname: Choi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002526:Cerebellar Diseases / Q000150:complications / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008526:Medulla Oblongata / Q000473:pathology*; D008875:Middle Aged; D013577:Syndrome; D015837:Vestibular Diseases / Q000209:etiology / Q000503:physiopathology*; D066127:White Matter / Q000473:pathology*
keywords: acute vestibular syndrome; body lateropulsion; inferior cerebellar peduncle; ocular tilt reaction; stroke