title: Diffusion tensor imaging in elderly patients with idiopathic normal pressure hydrocephalus or Parkinson's disease: diagnosis of gait abnormalities.
abstract: BACKGROUND
  Gait abnormalities in the elderly, characterized by short steps and frozen gait, can be caused by several diseases, including idiopathic normal pressure hydrocephalus (INPH), and Parkinson's disease (PD). We analyzed the relationship between these two conditions and their association with gait abnormalities using laboratory test data and findings from diffusion tensor imaging (DTI).
  
  
  METHODS
  The study involved 10 patients with INPH, 18 with PD, and 10 healthy individuals (control group). Fractional anisotropy (FA) of five brain areas was measured and compared among the three groups. In addition, the association of INPH and PD with gait capability, frontal lobe function, and FA of each brain area was evaluated.
  
  
  RESULTS
  The INPH group had significantly lower FA for anterior thalamic radiation (ATR) and forceps minor (Fmin) as compared to the PD group. The gait capability correlated with ATR FA in the INPH and PD groups. We found that adding DTI to the diagnosis assisted the differential diagnosis of INPH from PD, beyond what could be inferred from ventricular size alone.
  
  
  CONCLUSIONS
  We expect that DTI will provide a useful tool to support the differential diagnosis of INPH and PD and their respective severities.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan. k.maru5081@gmail.com.
authors.forename: Kohei
authors.initials: K
authors.lastname: Marumoto
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Koyama
authors.forename: Masashi
authors.initials: M
authors.lastname: Hosomi
authors.forename: Norihiko
authors.initials: N
authors.lastname: Kodama
authors.forename: Hiroji
authors.initials: H
authors.lastname: Miyake
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Domen