title: White matter involvement in idiopathic normal pressure hydrocephalus: a voxel-based diffusion tensor imaging study.
abstract: The aim of this study was to characterise the white matter damage involved in idiopathic normal pressure hydrocephalus (INPH) using diffusion tensor imaging (DTI) and the relationship between this damage and clinical presentation. Twenty patients with INPH, 20 patients with Alzheimer's disease and 20 patients with idiopathic Parkinson's disease (as disease control groups) were enrolled in this study. Mean diffusivity (MD) and fractional anisotropy (FA) were determined using DTI, and these measures were analysed to compare the INPH group with the control groups and with certain clinical correlates. On average, the supratentorial white matter presented higher MD and lower FA in the INPH group than in the control groups. In the INPH group, the mean hemispheric FA correlated with some of the clinical measures, whereas the mean hemispheric MD did not. On a voxel-based statistical map, white matter involvement with high MD was localised to the periventricular regions, and white matter involvement with low FA was localised to the corpus callosum and the subcortical regions. The total scores on the Frontal Assessment Battery were correlated with the FA in the frontal and parietal subcortical white matter, and an index of gait disturbance was correlated with the FA in the anterior limb of the left internal capsule and under the left supplementary motor area. DTI revealed the presence of white matter involvement in INPH. Whereas white matter regions with high MD were not related to symptom manifestation, those with low FA were related to motor and cognitive dysfunction in INPH.
authors.affiliation: Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan. s-kanno@med.tohoku.ac.jp
authors.forename: Shigenori
authors.initials: S
authors.lastname: Kanno
authors.forename: Nobuhito
authors.initials: N
authors.lastname: Abe
authors.forename: Makoto
authors.initials: M
authors.lastname: Saito
authors.forename: Masahito
authors.initials: M
authors.lastname: Takagi
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Nishio
authors.forename: Akiko
authors.initials: A
authors.lastname: Hayashi
authors.forename: Makoto
authors.initials: M
authors.lastname: Uchiyama
authors.forename: Risa
authors.initials: R
authors.lastname: Hanaki
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kikuchi
authors.forename: Kotaro
authors.initials: K
authors.lastname: Hiraoka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamasaki
authors.forename: Osamu
authors.initials: O
authors.lastname: Iizuka
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takeda
authors.forename: Yasuto
authors.initials: Y
authors.lastname: Itoyama
authors.forename: Shoki
authors.initials: S
authors.lastname: Takahashi
authors.forename: Etsuro
authors.initials: E
authors.lastname: Mori
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000473:pathology; D016880:Anisotropy; D001921:Brain / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000473:pathology*; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D010300:Parkinson Disease / Q000473:pathology