title: Reversed aqueductal cerebrospinal fluid net flow in idiopathic normal pressure hydrocephalus.
abstract: OBJECTIVE
  The changes of CSF flow dynamics in idiopathic normal pressure hydrocephalus (iNPH) are not fully elucidated. Most previous studies took the whole cardiac cycle as a unit. In this work, it is divided into systole and diastole phase and compared between iNPH patients and normal elderly and paid special attention to the change of netflow direction.
  
  
  METHODS
  Twenty iNPH patients according to international guideline and twenty healthy volunteers were included in this study and examined by MRI. Three categories of CSF flow parameters were measured: peak velocity (Vpeak), stroke volume (SV), and minute flow volume (MinV) covering the whole cycle; peak velocity (Vpeak-s, Vpeak-d) and flow volume (Vols, Vold) of the systole and diastole, respectively; net flow. Evans index (EI) was also measured and compared statistically between the two groups.
  
  
  RESULTS
  EI, Vpeak, SV, MinV, Vols, Vold, and Vpeak-dsignificantly increased in iNPH group (P<0.05). Vpeak-sof the two groups were not significantly different (P>0.05). The net flow of 16 iNPH patients (16/20) was in the caudo-cranial direction, while 15 volunteers (15/20) were in the opposite direction, which showed statistically significant differences (P=.001).
  
  
  CONCLUSIONS
  INPH patients present hyperdynamic flow with increased velocity and volume both in systole and diastole phase. Degree of rising in diastole phase exceeds that of systole phase. The resulting reversal of netflow direction may play a key role in the occurrence of ventriculomegaly in iNPH patients.
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: L K
authors.initials: LK
authors.lastname: Yin
authors.affiliation: Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: J J
authors.initials: JJ
authors.lastname: Zheng
authors.affiliation: Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: L
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: X Z
authors.initials: XZ
authors.lastname: Hao
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: X X
authors.initials: XX
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: J Q
authors.initials: JQ
authors.lastname: Tian
authors.affiliation: Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: K
authors.initials: K
authors.lastname: Zheng
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Y M
authors.initials: YM
authors.lastname: Yang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002535:Cerebral Aqueduct / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002552:Cerebral Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000134:cerebrospinal fluid* / Q000000981:diagnostic imaging / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged
keywords: cerebrospinal fluid; magnetic resonance imaging; normal pressure hydrocephalus; phase contrast