title: Horizontal nystagmus and multiple sclerosis using 3-Tesla magnetic resonance imaging.
abstract: BACKGROUND
  Nystagmus in patients with multiple sclerosis (MS) is generally attributed to brainstem disease. Lesions in other regions may result in nystagmus. The identification of these other sites is enhanced by using 3-Tesla magnetic resonance imaging (3TMRI) due to increased signal-to-noise ratio.
  
  
  OBJECTIVE
  We sought to evaluate the distribution of structural lesions and disruption of tracts in patients with horizontal nystagmus secondary to MS using 3TMRI.
  
  
  METHODS
  Twenty-four patients (20 women, 4 men; age range 26-55 years) with horizontal nystagmus secondary to MS underwent 3TMRI brain scans; and 18 patients had diffusion tensor imaging (DTI) for tractography.
  
  
  RESULTS
  Nystagmus was bidirectional in 11, right-sided in 6 and left-sided in 7. We identified 194 lesions in 20 regions within the neural integrator circuit in 24 patients; 140 were within the cortex and 54 were within the brainstem. Only two patients had no lesions in the cortex, and 9 had no lesions in the brainstem. There was no relationship between side of lesion and direction of nystagmus. Thirteen of 18 (72 %) had tract disruption with fractional anisotropy (FA) values below 0.2. FA was significantly lower in bidirectional compared to unidirectional nystagmus (p = 0.006).
  
  
  CONCLUSIONS
  In MS patients with horizontal nystagmus, lesions in all cortical eye fields and their descending connections were evident. Technical improvements in tractography may help identify the specific site(s) resulting in nystagmus in MS.
authors.affiliation: Department of Neurology, St. James's Hospital, Dublin 8, Ireland.
authors.forename: P M
authors.initials: PM
authors.lastname: Iyer
authors.affiliation: Centre for Advanced Medical Imaging, St James's Hospital, Dublin, Ireland.|School of Medicine, Trinity College, University of Dublin, Dublin, Ireland.
authors.forename: A J
authors.initials: AJ
authors.lastname: Fagan
authors.affiliation: Centre for Advanced Medical Imaging, St James's Hospital, Dublin, Ireland.|School of Medicine, Trinity College, University of Dublin, Dublin, Ireland.|Department of Diagnostic Imaging, St. James's Hospital, Dublin, Ireland.
authors.forename: J F
authors.initials: JF
authors.lastname: Meaney
authors.affiliation: School of Medicine and Medical Science, and School of Electrical, Electronic and Mechanical Engineering, University College Dublin, Dublin, Ireland.
authors.forename: N C
authors.initials: NC
authors.lastname: Colgan
authors.affiliation: School of Medicine and Medical Science, and School of Electrical, Electronic and Mechanical Engineering, University College Dublin, Dublin, Ireland.
authors.forename: S D
authors.initials: SD
authors.lastname: Meredith
authors.affiliation: Department of Diagnostic Imaging, St. James's Hospital, Dublin, Ireland.
authors.forename: D O
authors.initials: DO
authors.lastname: Driscoll
authors.affiliation: School of Medicine and Medical Science, and School of Electrical, Electronic and Mechanical Engineering, University College Dublin, Dublin, Ireland.
authors.forename: K M
authors.initials: KM
authors.lastname: Curran
authors.affiliation: Department of Neurology, St. James's Hospital, Dublin 8, Ireland.
authors.forename: D
authors.initials: D
authors.lastname: Bradley
authors.affiliation: Department of Neurology, St. James's Hospital, Dublin 8, Ireland. jredmond@stjames.ie.
authors.forename: J
authors.initials: J
authors.lastname: Redmond
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000000981:diagnostic imaging*; D009759:Nystagmus, Pathologic / Q000000981:diagnostic imaging*
keywords: 3-Tesla MRI; Digital tensor imaging; Horizontal nystagmus; Multiple sclerosis