title: Characteristics and reversibility of dementia in Normal Pressure Hydrocephalus.
abstract: Studies of the cognitive outcome after shunt insertion for treatment of Normal Pressure Hydrocephalus have reported widely mixed results. We prospectively studied performance of 60 patients with Normal Pressure Hydrocephalus on a comprehensive battery of neuropsychological tests before and after shunt surgery to determine which cognitive functions improve with shunt insertion. We also administered a subset of cognitive tests before and after temporary controlled drainage of cerebrospinal fluid to determine if change on this brief subset of tests after drainage could predict which patients would show cognitive improvement three to six months after shunt insertion. There was a significant improvement in learning, retention, and delayed recall of verbal memory three to six months after surgery (using paired t-tests). The majority (74%) of patients showed significant improvement (by at least one standard deviation) on at least one of the memory tests. Absence of improvement on verbal memory after temporary drainage of cerebrospinal fluid had a high negative predictive value for improvement on memory tests at 3-6 months after surgery (96%; p=0.0005). Also, the magnitude of improvement from Baseline to Post-Drainage on few specific tests of learning and recall significantly predicted the magnitude of improvement after shunt surgery on the same tests (r2=0.32-0.58; p=0.04-0.001). Results indicate that testing before and after temporary drainage may be useful in predicting which patients are less likely to improve in memory with shunting.
authors.affiliation: Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
authors.forename: Priyanka
authors.initials: P
authors.lastname: Chaudhry
authors.forename: Siddharth
authors.initials: S
authors.lastname: Kharkar
authors.forename: Jennifer
authors.initials: J
authors.lastname: Heidler-Gary
authors.forename: Argye E
authors.initials: AE
authors.lastname: Hillis
authors.forename: Melissa
authors.initials: M
authors.lastname: Newhart
authors.forename: Jonathan T
authors.initials: JT
authors.lastname: Kleinman
authors.forename: Cameron
authors.initials: C
authors.lastname: Davis
authors.forename: Daniele
authors.initials: D
authors.lastname: Rigamonti
authors.forename: Paul
authors.initials: P
authors.lastname: Wang
authors.forename: David N
authors.initials: DN
authors.lastname: Irani
authors.forename: Michael A
authors.initials: MA
authors.lastname: Williams
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology; D003704:Dementia / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000150:complications* / Q000601:surgery*; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000209:etiology; D009483:Neuropsychological Tests; D011184:Postoperative Period; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D017287:Ventriculoperitoneal Shunt