Assessment of a quick reference table algorithm for determining initial postoperative pressure settings of programmable pressure valves in patients with idiopathic normal pressure hydrocephalus: SINPHONI subanalysis.
BACKGROUND
Management of overdrainage complications in shunted patients with idiopathic normal pressure hydrocephalus (INPH) remains a difficult task despite the use of programmable pressure valves.


OBJECTIVE
To assess the usefulness of a quick reference table (QRT) algorithm for achieving a suitable initial programmable pressure valve setting in INPH patients who participated in the Study for INPH on Neurological Improvement (SINPHONI).


METHODS
One hundred registered patients diagnosed with probable INPH were treated with ventriculoperitoneal shunts using Codman-Hakim programmable valves (CHPVs). In this series, the initial CHPV setting was decided prospectively according to the QRT algorithm. Shunt effectiveness, complications, and the number of CHPV readjustments during follow-up periods were investigated.


RESULTS
Eighty patients were considered better than shunt responders (more than 1 point improvement in modified Rankin scale at any follow-up period). Readjustments of CHPVs within 3 months after treatment with ventriculoperitoneal shunt were performed 56 times in 44 cases (44%, 0.56 times/patient). Low-pressure headache occurred in 9 patients, all of whom improved by readjustment alone. Nontraumatic subdural fluid collections and chronic subdural hematomas occurred in 15 cases (15%); however, most of the cases were subclinical and improved after CHPV readjustments alone. Burr hole irrigation was necessary in only 1 case.


CONCLUSIONS
Use of the QRT algorithm was associated with a decrease in postoperative CHPV readjustments and serious overdrainage complications during the follow-up period. The QRT algorithm is an easy, safe, and effective method for determining the initial CHPV pressure setting in INPH patients.
Nishinomiya Kyoritsu Neurosurgical Hospital, Imazuyamanakacho, Nishinomiya, Hyogo, Japan. miyake@nk-hospital.or.jp
Hiroji
H
Miyake
Yoshinaga
Y
Kajimoto
Hisayuki
H
Murai
Sadahiro
S
Nomura
Shigeki
S
Ono
Yuji
Y
Okamoto
Yoshihiro
Y
Sumi
D000368:Aged; D000465:Algorithms; D015170:Cerebrospinal Fluid Pressure; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000601:surgery*; D008297:Male; D017287:Ventriculoperitoneal Shunt / Q000295:instrumentation*