title: Trunk sway in idiopathic normal pressure hydrocephalus-Quantitative assessment in clinical practice.
abstract: In diagnosis and treatment of patients with idiopathic normal pressure hydrocephalus (iNPH), there is need for clinically applicable, quantitative assessment of balance and gait. Using a body-worn gyroscopic system, the aim of this study was to assess postural stability of iNPH patients in standing, walking and during sensory deprivation before and after cerebrospinal fluid (CSF) drainage and surgery. A comparison was performed between healthy elderly (HE) and patients with various types of hydrocephalus (ventriculomegaly (VM)).
  
  
  
  Trunk sway was measured in 31 iNPH patients, 22 VM patients and 58 HE. Measurements were performed at baseline in all subjects, after CSF drainage in both patient groups and after shunt surgery in the iNPH group.
  
  
  
  Preoperatively, the iNPH patients had significantly higher trunk sway compared to HE, specifically for the standing tasks (p<0.001). Compared to VM, iNPH patients had significantly lower sway velocity during gait in three of four cases on firm support (p<0.05). Sway velocity improved after CSF drainage and in forward-backward direction after surgery (p<0.01). Compared to HE both patient groups demonstrated less reliance on visual input to maintain stable posture.
  
  
  
  INPH patients had reduced postural stability compared to HE, particularly during standing, and for differentiation between iNPH and VM patients sway velocity during gait is a promising parameter. A reversible reduction of visual incorporation during standing was also seen. Thus, the gyroscopic system quantitatively assessed postural deficits in iNPH, making it a potentially useful tool for aiding in future diagnoses, choices of treatment and clinical follow-up.
authors.affiliation: Department of Radiation Sciences, Biomedical Engineering, Umeå University, Umeå, Sweden. Electronic address: tomas.backlund@vll.se.
authors.forename: Tomas
authors.initials: T
authors.lastname: Bäcklund
authors.affiliation: Department of Radiation Sciences, Radiation Physics, Umeå University, Umeå, Sweden. Electronic address: jennifer.frankel@umu.se.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Frankel
authors.affiliation: Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden; Vrinnevi Hospital, Norrköping, Sweden. Electronic address: hanna.israelsson@umu.se.
authors.forename: Hanna
authors.initials: H
authors.lastname: Israelsson
authors.affiliation: Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden. Electronic address: jan.malm@umu.se.
authors.forename: Jan
authors.initials: J
authors.lastname: Malm
authors.affiliation: Department of Radiation Sciences, Biomedical Engineering, Umeå University, Umeå, Sweden. Electronic address: nina.sundstrom@vll.se.
authors.forename: Nina
authors.initials: N
authors.lastname: Sundström
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000503:physiopathology*; D008297:Male; D004856:Postural Balance / Q000502:physiology*; D011446:Prospective Studies; D012683:Sensory Deprivation / Q000502:physiology*; D060726:Torso / Q000502:physiology*; D016138:Walking / Q000502:physiology*
keywords: Balance; Gait; Gyroscope; Idiopathic normal pressure hydrocephalus; Trunk sway