[Significance of shunt efficacy decision of SPECT on idiopathic normal pressure hydrocephalus].
OBJECTIVE
The purpose of this study was to investigate the significance of the shunt-effect evaluation of SPECT in idiopathic normal pressure hydrocephalus (iNPH).


METHODS
The subjects were 15 patients with possible iNPH, aged 62-83 (mean 75.3, the ratio of males to females to 6:9), who were treated at our department during the period from June to September, 2004. All patients received the lumbar tap test (LTT) at the outpatient section before surgery. An L-P shunt was conducted on patients whose the LTT positive or negative with cerebrospinal fluid outflow resistance value (Ro) was 10 mmHg/ml/min. or higher patients. As for SPECT, a 3D-SSP Z-score, as well as an mCBF, was conducted before and after the LTT and within one month after surgery. Comparisons were made for (1) the shunt effect, (2) mCBF before and after the LTT and after surgery, (3) mean cerebral blood flow increase rate (mIR) after the LTT, and (4) 3D-SSP before and after surgery.


RESULTS
(1) The shunt was effective for all the patients. (2) The mCBF levels was 30.8 +/- 4.02 ml/100 g/min. before the LTT, 37.1 +/- 100 g/min. after the LTT, and 38.6 +/- 3.4 ml/100 g/min. after surgery. A significant increase in mCBF was observed both after the LTT and after surgery (p < 0.05). (3) The mean mIR after the LTT was 21.2 +/- 8.01%, with all the patients showing 10% or higher. (4) The ischemic patterns in the SD-SSP Z-score before surgery were the frontal type (F: 10 cases, 66.7%), the occipitotemporal type (OT: 3 cases, 20%), and the mixed type (M: 2 cases, 13.3%), but not the parietal localized type. The post-operative course showed no-change in 4 cases, disappearance-reduction in 9 cases, and shift to OT in 2 cases.


CONCLUSIONS
The evaluation factors in the measurement of the cerebral blood flow for evaluation of the shunt effect were the following two items. (1) The mIR of mCBF after the LIT was 10% or higher. (2) As for the preoperative cerebral ischemic patterns, there were many F cases and no parietial localized types found.
Takeuchi
Totaro
T
Department of Neurosurgery, The Southern Tohoku High Degree Medical Center, Southern Tohoku Research Institute for Neuroscience, Japan.
Ishihara
Tetsuya
T
Kubo
Hitoshi
H
Izawa
Naoki
N
Watanabe
Chikako
C
Tanno
Yoshihiro
Y
Abe
Yoshinori
Y
Katayama
Soichi
S
Goto
Hiromi
H
Izaki
Kenji
K
Kokubu
Kohei
K
Oda
Masaya
M
Ohmae
Tomoya
T
Sasanuma
Jin-ichi
J
Maeno
Kazushige
K
Kikuchi
Yasuhiro
Y
Koizumi
Jin-ichi
J
Watanabe
Zen-ichiro
Z
Ito
Yasunobu
Y
Ohara
Hiroo
H
Kowada
Masayoshi
M
Watanabe
Kazuo
K
D000368:Aged; D000369:Aged, 80 and over; D015170:Cerebrospinal Fluid Pressure / Q000502:physiology*; D002557:Cerebrospinal Fluid Shunts; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015899:Tomography, Emission-Computed, Single-Photon