scholarly journals Prospective estimation of mean axon diameter and extra-axonal space of the posterior limb of the internal capsule in patients with idiopathic normal pressure hydrocephalus before and after a lumboperitoneal shunt by using q-space diffusion MRI

2015 ◽  
Vol 26 (9) ◽  
pp. 2992-2998 ◽  
Author(s):  
Masaaki Hori ◽  
Kouhei Kamiya ◽  
Atsushi Nakanishi ◽  
Issei Fukunaga ◽  
Masakazu Miyajima ◽  
...  
2016 ◽  
Vol 124 (6) ◽  
pp. 1850-1857 ◽  
Author(s):  
Geir Ringstad ◽  
Kyrre Eeg Emblem ◽  
Per Kristian Eide

OBJECT The objective of this study was to assess the net aqueductal stroke volume (ASV) and CSF aqueductal flow rate derived from phase-contrast MRI (PC-MRI) in patients with probable idiopathic normal pressure hydrocephalus (iNPH) before and after ventriculoperitoneal shunt surgery, and to compare observations with intracranial pressure (ICP) scores. METHODS PC-MRI at the level of the sylvian aqueduct was undertaken in patients undergoing assessment for probable iNPH. Aqueductal flow in the craniocaudal direction was defined as positive, or antegrade flow, and net ASV was calculated by subtracting retrograde from antegrade aqueductal flow. Aqueductal flow rate per minute was calculated by multiplying net ASV by heart rate. During the same hospital admission, clinical examination was performed using NPH score and overnight continuous ICP monitoring. Twelve patients were followed prospectively 12 months after shunt placement with clinical assessment and a second PC-MRI. The study also included 2 healthy controls. RESULTS Among 21 patients examined for iNPH, 17 (81%) received a shunt (shunt group), and 4 were treated conservatively (conservative group). Among the patients with shunts, a clinical improvement was observed in 16 (94%) of the 17. Net ASV was negative in 16 (76%) of 21 patients before shunt placement and in 5 (42%) of 12 patients after shunt placement, and increased from a median of −5 μl (range −175 to 27 μl) to a median of 1 μl (range −61 to 30 μl; p = 0.04). Among the 12 patients with PC-MRI after shunt placement, 11 were shunt responders, and in 9 of these 11 either a reduced magnitude of retrograde aqueductal flow, or a complete reversal from retrograde to antegrade flow, occurred. Net ASV was significantly lower in the shunt group than in the conservative group (p = 0.01). The aqueductal flow rate increased from −0.56 ml/min (range −12.78 to 0.58 ml/min) to 0.06 ml/min (range −4.51 to 1.93 ml/min; p = 0.04) after shunt placement. CONCLUSIONS In this cohort of patients with iNPH, retrograde net aqueductal flow was observed in 16 (76%) of 21 patients. It was reversed toward the antegrade direction after shunt placement either by magnitude or completely in 9 (75%) of 12 patients examined using PC-MRI both before and after shunt placement (p = 0.04); 11 of the 12 were shunt responders. The study results question previously established concepts with respect to both CSF circulation pathways and CSF formation rate.


2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Mitsuaki Ishii ◽  
Toshio Kawamata ◽  
Ichiro Akiguchi ◽  
Hideo Yagi ◽  
Yuko Watanabe ◽  
...  

We aimed to investigate the characteristics of Parkinsonian features assessed by the unified Parkinson's disease rating scale (UPDRS) and determine their correlations with the computed tomography (CT) findings in patients with idiopathic normal pressure hydrocephalus (iNPH). The total score and the scores for arising from chair, gait, postural stability, and body hypokinesia in the motor examination section of UPDRS were significantly improved after shunt operations. Stepwise multiple regression analysis revealed that postural stability was the determinant of the gait domain score of the iNPH grading scale. The canonical correlation analysis between the CT findings and the shunt-responsive Parkinsonian features indicated that Evans index rather than midbrain diameters had a large influence on the postural stability. Thus, the pathophysiology of postural instability as a cardinal feature of gait disturbance may be associated with impaired frontal projections close to the frontal horns of the lateral ventricles in the iNPH patients.


2021 ◽  
pp. 1-12
Author(s):  
Kaito Kawamura ◽  
Masakazu Miyajima ◽  
Madoka Nakajima ◽  
Mitsuyasu Kanai ◽  
Yumiko Motoi ◽  
...  

Background: The amyloid-β oligomers, consisting of 10–20 monomers (AβO10–20), have strong neurotoxicity and are associated with cognitive impairment in Alzheimer’s disease (AD). However, their role in patients with idiopathic normal pressure hydrocephalus (iNPH) is poorly understood. Objective: We hypothesized that cerebrospinal fluid (CSF) AβO10–20 accumulates in patients with iNPH, and its clearance after CSF shunting contributes to neurological improvement. We measured CSF AβO10–20 levels before and after CSF shunting in iNPH patients evaluating their diagnostic and prognostic role. Methods: We evaluated two iNPH cohorts: “evaluation” (cohort-1) with 32 patients and “validation” (cohort-2) with 13 patients. Comparison cohorts included: 27 neurologically healthy controls (HCs), and 16 AD, 15 Parkinson’s disease (PD), and 14 progressive supranuclear palsy (PSP) patients. We assessed for all cohorts CSF AβO10–20 levels and their comprehensive clinical data. iNPH cohort-1 pre-shunting data were compared with those of comparison cohorts, using cohort-2 for validation. Next, we compared cohort-1’s clinical and CSF data: 1) before and after CSF shunting, and 2) increased versus decreased AβO10–20 levels at baseline, 1 and 3 years after shunting. Results: Cohort-1 had higher CSF AβO10–20 levels than the HCs, PD, and PSP cohorts. This result was validated with data from cohort-2. CSF AβO10–20 levels differentiated cohort-1 from the PD and PSP groups, with an area under receiver operating characteristic curve of 0.94. AβO10–20 levels in cohort-1 decreased after CSF shunting. Patients with AβO10–20 decrease showed better cognitive outcome than those without. Conclusion: AβO10–20 accumulates in patients with iNPH and is eliminated by CSF shunting. AβO10–20 can be an applicable diagnostic and prognostic biomarker.


2017 ◽  
Vol 7 (2) ◽  
pp. 98-108 ◽  
Author(s):  
Shigeki Yamada ◽  
Masatsune Ishikawa ◽  
Masakazu Miyajima ◽  
Madoka Nakajima ◽  
Masamichi Atsuchi ◽  
...  

AbstractBackground:The 3-meter Timed Up and Go test (TUG) is a reliable quantitative test for assessment of gait and balance. We aimed to establish an optimal threshold of TUG at the tap test for predicting outcomes 12 months after shunt surgery in patients with idiopathic normal pressure hydrocephalus (iNPH).Methods:The TUG was measured in a total of 151 patients with possible iNPH before and after a tap test and 12 months after shunt surgery. Among them, 81 patients underwent ventriculoperitoneal shunt implantation (SINPHONI) and 70 underwent lumboperitoneal shunt implantation (SINPHONI-2). The areas under the curve (AUCs), sensitivities, and specificities for predicting shunt effectiveness were assessed.Results:The simple differences of time on TUG at the tap test were significantly more accurate for predicting shunt effectiveness than percent improvement of time. The highest AUC for the synchronized moving cutoff point of TUG time was 0.81 (sensitivity 81.0%; specificity 81.6%) at the threshold of 5 seconds in the SINPHONI-2. For predicting improvements of ≥10 seconds 12 months after lumboperitoneal shunt implantation, the AUC was 0.90, and the sensitivity and specificity at the threshold of 5.6 seconds were 83.3% and 81.0%. Only for patients with a <5-second improvement at the tap test, ventriculoperitoneal shunt implantation conveyed significantly better improvements in TUG time 12 months after surgery than lumboperitoneal shunt implantation.Conclusions:An improvement of 5 seconds was a useful threshold of TUG time at the tap test for predicting a ≥10-second improvement 12 months after shunt surgery, rather than the percent improvement of TUG time.


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