Changes in the volumes of the brain and cerebrospinal fluid spaces after shunt surgery in idiopathic normal-pressure hydrocephalus.
OBJECTIVE
To investigate volumetric changes of the brain and cerebrospinal fluid (CSF) spaces after shunt surgery in shunt-responsive idiopathic normal-pressure hydrocephalus (iNPH), and correlations between the changes and postoperative clinical improvements.


METHODS
Twenty-one patients with shunt-responsive iNPH were studied. Magnetic resonance imaging (MRI) of the brain was performed before and 1year after surgery, and clinical symptoms were assessed by the iNPH Grading Scale, a validated assessment tool of the triad of iNPH, the Modified Rankin Scale, the Timed Up and Go Test, and neuropsychological tests including the Mini-Mental State Examination. The volumes of the left cerebral hemisphere, infratentorial brain, ventricles, and suprasylvian and infrasylvian subarachnoid CSF spaces were measured using an MRI-based volumetric technique.


RESULTS
The volumes of the cerebral hemisphere and infratentorial brain did not change significantly after shunt surgery (p=0.231, 0.109, respectively). The volumes of the ventricles and infrasylvian subarachnoid CSF spaces were significantly decreased (p<0.0001, <0.05, respectively), with a mean change rate of -26.1% and -4.5%, respectively. The volumes of the suprasylvian subarachnoid CSF spaces increased significantly (p<0.0001), with a mean change rate of 43.5%. The decrease in ventricular volumes was significantly correlated with clinical improvement.
Hiraoka
Kotaro
K
Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan. khiraoka@mail.tains.tohoku.ac.jp
Yamasaki
Hiroshi
H
Takagi
Masahito
M
Saito
Makoto
M
Nishio
Yoshiyuki
Y
Iizuka
Osamu
O
Kanno
Shigenori
S
Kikuchi
Hirokazu
H
Kondo
Takeo
T
Mori
Etsuro
E
D000368:Aged; D001921:Brain / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000134:cerebrospinal fluid* / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D011183:Postoperative Complications / Q000134:cerebrospinal fluid* / Q000473:pathology*; D015203:Reproducibility of Results; D016896:Treatment Outcome; D017287:Ventriculoperitoneal Shunt / Q000009:adverse effects*