title: Evaluation of autonomic malfunction in idiopathic normal pressure hydrocephalus.
abstract: OBJECTIVE
  The autonomic nervous system plays an important role in urinary disturbance which is one of the main symptoms of idiopathic normal pressure hydrocephalus (iNPH); thus, the focus of the present study was to identify the autonomic function parameters that would be useful as clinical indicators of iNPH.
  
  
  METHODS
  The subjects consisted of 18 iNPH patients (group N) and 31 normal controls (group C). Before and after a lumbar puncture test, they were examined for CVR-R and total heart rate. A power spectral analysis of R-R interval variability of their 24-hour Holter ECGs was also done. High frequency (HF) was an indicator of parasympathetic activity, while the low to high frequency ratio (L/H) was used as an indicator of sympathetic activity. Urinary incontinence was evaluated using the overactive bladder symptom score (OABSS) questionnaire and bladder capacity. Correlations between the above indicators and clinical indicators of iNPH, such as the mini-mental state examination and the Evans index, were examined.
  
  
  RESULTS
  The HF values (ms(2)) were 190.3 in group C and 237.2 in group N; the difference was statistically significant. In group N, the HF value after the lumbar puncture test was lower (160.3) than the value before the lumbar puncture test, confirming that the increased parasympathetic state returned to a near normal level after CSF drainage. A significant positive correlation was noted only between the pre-lumbar puncture HF value and the OABSS.
  
  
  CONCLUSIONS
  iNPH is associated with increased parasympathetic activity, and the lumbar puncture test and shunt surgery may correct this autonomic imbalance to near normal levels.
authors.affiliation: Dept. of Neurology and Gerontology, Kyoto Prefectural University of Medicine, 465 Kawaramachi-hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan. nkuriyam@koto.kpu-m.ac.jp
authors.forename: Nagato
authors.initials: N
authors.lastname: Kuriyama
authors.forename: Takahiko
authors.initials: T
authors.lastname: Tokuda
authors.forename: Masaki
authors.initials: M
authors.lastname: Kondo
authors.forename: Junichi
authors.initials: J
authors.lastname: Miyamoto
authors.forename: Kei
authors.initials: K
authors.lastname: Yamada
authors.forename: Yo
authors.initials: Y
authors.lastname: Ushijima
authors.forename: So
authors.initials: S
authors.lastname: Ushijima
authors.forename: Natsuko
authors.initials: N
authors.lastname: Takayasu
authors.forename: Fumitoshi
authors.initials: F
authors.lastname: Niwa
authors.forename: Masanori
authors.initials: M
authors.lastname: Nakagawa
mesh_terms: D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology*; D002557:Cerebrospinal Fluid Shunts; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000503:physiopathology*; D008297:Male; D013129:Spinal Puncture; D011795:Surveys and Questionnaires; D053201:Urinary Bladder, Overactive / Q000503:physiopathology*