title: A new scale for assessment of severity and outcome in iNPH.
abstract: OBJECTIVE
  To present a new, continuous, calibrated and norm-based scale for the grading of severity and assessment of treatment outcome in idiopathic normal pressure hydrocephalus (iNPH).
  
  
  METHODS
  A scale designed for the assessment of the four domains, gait, neuropsychology, balance and continence, using ordinal ratings and continuous measures, was developed. Data from a series of 181 consecutive iNPH patients were used to calibrate the continuous parts of the scale and to describe the distributional properties of the ordinal ratings. Data from normative studies were used to determine the limits for normal scores.
  
  
  RESULTS
  The construction of the scale made it well equipped to separate iNPH patients at baseline, and the total scores assumed a bell-shaped, approximately normal distribution. All four domain scores correlated significantly with each other, underscoring the well-known syndromatic nature of iNPH, and justifying the use of a total score to describe the patients. Reliability [Cronbach's α for the total score = 0.74, and for the domains of gait and neuropsychology, 0.86 and 0.89, respectively) and validity estimates (convergent validity evaluated by Spearman rank correlations for the scale and the modified Rankin scale (ρ = -0.61) and the mini mental state examination (ρ = 0.57)] are satisfying.
  
  
  CONCLUSIONS
  The iNPH scale covers the four most important symptom domains and the full range of severity of the iNPH syndrome. The scale is sensitive, reliable, valid and feasible. We recommend that it should be used in future iNPH research.
authors.affiliation: Hydrocephalus Research Unit, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Hellström
authors.forename: P
authors.initials: P
authors.lastname: Klinge
authors.forename: J
authors.initials: J
authors.lastname: Tans
authors.forename: C
authors.initials: C
authors.lastname: Wikkelsø
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D032763:Behavior Control; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D017063:Outcome Assessment, Health Care / Q000379:methods*; D004856:Postural Balance; D015203:Reproducibility of Results; D012647:Self-Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D001750:Urinary Bladder, Neurogenic / Q000209:etiology; D016138:Walking