[Reinvestigation of CSF outflow resistance value in idiopathic normal pressure hydrocephalus--comparing epidural pressure monitoring with lumbar subarachnoid cerebrospinal fluid pressure monitoring].
OBJECTIVE
To compare the cerebrospinal fluid (CSF) outflow resistance values (Ro) with epidural pressure (EDP) monitoring and lumbar subarachnoid CSF pressure (L-CSFP) monitoring.


METHODS
The subjects were 14 patients with possible iNPH (age: 59-74 years old, ratio of male and female 8:6). All the patients were subjected to an infusion test by a single bolus injection method (1 ml/sec., deltaV: 5 ml, t2: 2 min) as prescribed in the Standard of SINPHONI. EDP was monitored by continuous monitoring and the L-CSFP values By intermittent simple glass tube method (SINPHONI) were measured simultaneously. The Ro (RoEDP, RoL-CSFP) calculated from both methods, (1) the correlation of Ro and (2) the Ro threshold in a shunt effective group (E: nine cases) and a non effective group (NE, five cases) were compared.


RESULTS
(1) Although a favorable correlation was found between both Ro measurements (r=0.784), the RoEDP was always higher than the RoL-CSFP. (2) The mean Ro values in the E and NE groups were 36.8 +/- 15.7 mmHg/ml/min, and 10 +/- 2.05 mmHg/ml/min for Ro-EDP, 22.1 +/- 13.95 mmg/ml/min and 6.4 +/- 1.7 mmHg/ml/min for RoL-CSFP, respectively. The approximate thresholds in the E and NE groups were 15 mmHg/ml/min for RoEDP and 10 mmHg/ml/min for RoL-CSFP.


CONCLUSIONS
(1) Although the RoEDP is always higher than the RoL-CSFP, a favorable correlation is found between the RoEDP and RoL-CSFP, (2) The Ro thresholds of the E and NE groups in the infusion test are about 15 mmHg/ml/min for RoEDP and 10 mmHg/ml/min for RoL-CSFP. (3) After this, Ro calculation ought to execute by standard of SINPHONI and the Ro threshold of the E and NE groups is about 10 mmHg/ml/min.
Takeuchi
Totaro
T
Department of Neurosurgery, The Southern TOHOKU High Degree Medical Center, Southern TOHOKU Research Institute for Neuroscience, Koriyama City, Fukushima 963-8052, Japan.
Goto
Hiromi
H
Izaki
Kenji
K
Kokubu
Kohei
K
Oda
Masaya
M
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; D015170:Cerebrospinal Fluid Pressure / Q000502:physiology*; D004824:Epidural Space; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000503:physiopathology* / Q000601:surgery; D007427:Intracranial Pressure / Q000502:physiology*; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D017287:Ventriculoperitoneal Shunt