Use of cerebrospinal fluid flow rates measured by phase-contrast MR to predict outcome of ventriculoperitoneal shunting for idiopathic normal-pressure hydrocephalus.
OBJECTIVE
To determine whether favorable clinical response and magnitude of improvement are associated with increased aqueductal cerebrospinal fluid (CSF) flow rates in patients who undergo ventriculoperitoneal shunting (VPS) for idiopathic normal-pressure hydrocephalus (NPH).


METHODS
Between January 1995 and June 2000, 49 patients (14 men and 35 women; mean age, 72.9 years; range, 54-88 years) underwent magnetic resonance quantification of aqueductal CSF flow followed by VPS for presumed idiopathic NPH at the Mayo Clinic, Rochester, Minn. Logistic regression models for the odds of any improvement in score as a function of aqueductal CSF flow and separate models for any improvement in gait, incontinence, cognition, and total score were constructed.


RESULTS
Forty-two patients (86%) had improvement in gait at postoperative follow-up (mean, 10 months). Of the 32 patients with incontinence, 27 (69%) improved. Of the 36 patients with cognitive impairment, 16 (44%) improved. In univariate and fully adjusted models, increased CSF flow through the aqueduct was not significantly associated with improvement or the magnitude of improvement in gait, cognition, or incontinence. Thirty-six patients underwent high-volume lumbar puncture preoperatively, of whom 5 (14%) had no response. The aqueductal CSF flow rates of these 5 patients were significantly higher than those of the patients who improved after lumbar puncture. Postoperative complications occurred in 15 patients. The aqueductal CSF flow rates in these 15 patients were not significantly different from those of patients who experienced no complications.


CONCLUSIONS
Among patients who underwent VPS for the treatment of NPH, measurement of CSF flow through the cerebral aqueduct did not reliably predict which patients would improve after shunting or the magnitude of improvement.
Dixon
Geoffrey R
GR
Department of Neurologic Surgery, Mayo Clinic, Rochester, MN 55905, USA.
Friedman
Jonathan A
JA
Luetmer
Patrick H
PH
Quast
Lynn M
LM
McClelland
Robyn L
RL
Petersen
Ronald C
RC
Maher
Cormac O
CO
Ebersold
Michael J
MJ
D000368:Aged; D000369:Aged, 80 and over; D002535:Cerebral Aqueduct / Q000473:pathology; D002552:Cerebral Ventricles; D002555:Cerebrospinal Fluid; D003071:Cognition; D005069:Evaluation Studies as Topic; D005260:Female; D005684:Gait; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000134:cerebrospinal fluid / Q000503:physiopathology* / Q000601:surgery*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011673:Pulsatile Flow; D012680:Sensitivity and Specificity; D013997:Time Factors; D016896:Treatment Outcome; D014549:Urinary Incontinence; D017287:Ventriculoperitoneal Shunt