title: Mechanism of bladder dysfunction in idiopathic normal pressure hydrocephalus.
abstract: OBJECTIVE
  To elucidate the mechanism of bladder dysfunction in idiopathic normal pressure hydrocephalus (iNPH) by a urodynamic study.
  
  
  METHODS
  Forty-two patients with possible iNPH, who were diagnosed by clinical symptoms/signs (gait, cognitive, and urinary disorders) with typical imaging features (ventricular enlargement) and normal cerebrospinal fluid pressure, were enrolled. The subjects included 36 men and 6 women; mean age, 72 years (62-83 years). All patients underwent a urodynamic test according to the definitions and methods proposed by the International Continence Society.
  
  
  RESULTS
  Lower urinary tract symptoms were seen in 93% of the patients, with storage symptoms (93%) being more common than voiding symptoms (71%); and urinary urgency (overactive bladder) (64%)/frequency (64%) being more common than urinary incontinence (57%). The mean values for the maximum flow rate and post-void residual (PVR) volume were 11.7 ml/sec and 42.1 ml, respectively. PVR >100 ml was noted in six patients (three men, three women; range, 100-228 ml). Although the majority of patients had normal bladder volume at the first sensation (mean 134 ml), bladder capacity was small (mean 200 ml) and detrusor overactivity was seen in 95% of patients.
  
  
  CONCLUSIONS
  While incontinence can result secondarily from gait disturbance or dementia, detrusor overactivity mostly underlies urinary urgency/frequency and incontinence in iNPH.
authors: Neurology Division, Department of Internal Medicine, Sakura Medical Center, Toho University, Sakura, Japan. sakakibara@sakura.med.toho-u.ac.jp
authors: Ryuji
authors: R
authors: Sakakibara
authors: Takemasa
authors: T
authors: Kanda
authors: Tetsutoshi
authors: T
authors: Sekido
authors: Tomoyuki
authors: T
authors: Uchiyama
authors: Yusuke
authors: Y
authors: Awa
authors: Takashi
authors: T
authors: Ito
authors: Zhi
authors: Z
authors: Liu
authors: Tatsuya
authors: T
authors: Yamamoto
authors: Tomonori
authors: T
authors: Yamanishi
authors: Tatsuhiko
authors: T
authors: Yuasa
authors: Koji
authors: K
authors: Shirai
authors: Takamichi
authors: T
authors: Hattori
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015170:Cerebrospinal Fluid Pressure; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000150:complications* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D001743:Urinary Bladder / Q000503:physiopathology*; D053201:Urinary Bladder, Overactive / Q000209:etiology* / Q000503:physiopathology; D014549:Urinary Incontinence / Q000209:etiology* / Q000503:physiopathology; D014563:Urodynamics