The Significance of Outflow Resistance Measurements in the Prediction of Outcome After CSF-Shunting in Patients with Normal Pressure Hydrocephalus

Reproducibility of the aqueductal CSF signal intensity on a gradient echo cine-MR sequence exploiting through plane inflow enhancement was tested in 11 patients with normal or dilated ventricles. Seven patients with normal pressure hydrocephalus (NPH) syndrome were investigated with the sequence before and after CSF shunting. Two patients exhibiting central flow void within a hyperintense aqueductal CSF improved after surgery and the flow void disappeared after shunting. One patient with increased maximum and minimum aqueductal CSF signal as compared to 18 healthy controls also improved and the aqueductal CSF signal was considerably decreased after shunting. Three patients with aqueductal CSF values similar to those in the controls did not improve, notwithstanding their maximum aqueductal CSF signals decreasing slightly after shunting. No appreciable aqueductal CSF flow related enhancement consistent with non-communicating hydrocephalus was found in the last NPH patient who improved after surgery. Cine-MR with inflow technique yields a reproducible evaluation of flow-related aqueductal CSF signal changes which might help in identifying shunt responsive NPH patients. These are likely to be those with hyperdynamic aqueductal CSF or aqueductal obstruction.

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CEREBROSPINAL FLUID DRAINAGE AND DYNAMICS IN THE DIAGNOSIS OF NORMAL PRESSURE HYDROCEPHALUS

Neurosurgery ◽

10.1227/01.neu.0000341902.44760.10 ◽

2009 ◽

Vol 64 (5) ◽

pp. 919-926 ◽

Cited By ~ 39

Author(s):

Graeme F. Woodworth ◽

Matthew J. McGirt ◽

Michael A. Williams ◽

Daniele Rigamonti

Keyword(s):

Cerebrospinal Fluid ◽

Normal Pressure Hydrocephalus ◽

Normal Pressure ◽

Waveform Analysis ◽

Csf Shunt ◽

Symptom Improvement ◽

Wave Characteristics ◽

Csf Drainage ◽

Ventriculoperitoneal Shunting ◽

Csf Shunting

Abstract INTRODUCTION Because of the difficulty in distinguishing idiopathic normal pressure hydrocephalus (INPH) from other neurodegenerative conditions unrelated to cerebrospinal fluid (CSF) dynamics, response to CSF shunting remains highly variable. We examined the utility of CSF drainage and CSF pressure (Pcsf) dynamics in predicting response to CSF shunting for patients with INPH. METHODS Fifty-one consecutive INPH patients underwent continuous lumbar Pcsf monitoring for 48 hours followed by 72 hours of slow CSF drainage before ventriculoperitoneal shunting. Response to CSF drainage and B-wave characteristics were assessed via multivariate proportional-hazards regression analysis. RESULTS Improvement in 1, 2, or all 3 INPH symptoms was observed in 35 (69%), 28 (55%), and 11 (22%) patients, respectively, after CSF shunt implantation by 12 months after surgery. A positive response to CSF drainage was found to be an independent predictor of shunt responsiveness (relative risk, 0.30; 95% confidence interval, 0.09–0.98; P = 0.05). There was no difference in Pcsf wave characteristics between the shunt-responsive and -nonresponsive groups, regardless of whether 1-, 2-, or 3-symptom improvement was used to define response to CSF shunting. CONCLUSION In this study of 51 INPH patients who underwent Pcsf monitoring with waveform analysis and CSF drainage followed by shunt surgery, there was no correlation between specific Pcsf wave characteristics and objective symptomatic improvement after shunt placement. Pcsf monitoring with B-wave analysis contributes little to the diagnostic dilemma with INPH patients. Clinical response to continuous CSF drainage over a 72-hour period suggests a high likelihood of shunt responsiveness.

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Characterization of periventricular edema in normal-pressure hydrocephalus by measurement of water proton relaxation times

Journal of Neurosurgery ◽

10.3171/jns.1990.73.6.0864 ◽

1990 ◽

Vol 73 (6) ◽

pp. 864-870 ◽

Cited By ~ 21

Author(s):

Norihiko Tamaki ◽

Takayuki Shirakuni ◽

Kazumasa Ehara ◽

Satoshi Matsumoto

Keyword(s):

Relaxation Time ◽

White Matter ◽

Gray Matter ◽

Normal Pressure Hydrocephalus ◽

Relaxation Times ◽

Normal Pressure ◽

Water Proton ◽

Proton Relaxation ◽

Csf Shunting ◽

Significant Difference

✓ The magnetic resonance longitudinal relaxation time (T1) and transverse relaxation time (T2) of the water proton of the periventricular white and cortical gray matter were measured for 17 control patients and 21 patients with suspected normal-pressure hydrocephalus (NPH). Of the latter group, 14 showed good response to shunting (true-NPH group) and seven showed no response (false-NPH group). In the true-NPH group, both the T1 and the T2 of the periventricular white matter were significantly prolonged compared to the control values, and slowly shortened after cerebrospinal fluid (CSF) shunting. The true-NPH group showed significantly longer T1 and T2 of the white matter than did the false-NPH group. The T1 and T2 of the white matter were longer than those of the gray matter in this group, which was the reverse of the relationship observed in the control patients. In the white matter of the false-NPH group, there was a significant prolongation of T1 only; no difference was seen in the T2 compared to control values. There was no change in either T1 or T2 of this region after CSF shunting. The false-NPH group showed no significant difference in either T1 or T2 between the white and the gray matter. There was no difference in either T1 or T2 of the gray matter between the false-NPH and control groups or between preshunt and postshunt measurements in each patient group. It is suggested that a distinction between true- and false-NPH, which cannot be made from the radiographic appearance alone, may be possible from measurement of relaxation times. The mechanism of varied relaxation behavior between two entities may be explained by a difference in properties of the biological water and its environment.

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Quantitative electroencephalography in idiopathic normal pressure hydrocephalus: relationship to CSF outflow resistance and the CSF tap-test

Acta Neurologica Scandinavica ◽

10.1111/j.1600-0404.1994.tb02641.x ◽

2009 ◽

Vol 89 (5) ◽

pp. 317-322 ◽

Cited By ~ 4

Author(s):

T. Sand ◽

G. Bovim ◽

R. Gimse

Keyword(s):

Normal Pressure Hydrocephalus ◽

Normal Pressure ◽

Idiopathic Normal Pressure Hydrocephalus ◽

Outflow Resistance ◽

Quantitative Electroencephalography ◽

Tap Test

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Impaired pulsation absorber mechanism in idiopathic normal pressure hydrocephalus

Journal of Neurosurgery ◽

10.3171/2012.9.jns121227 ◽

2012 ◽

Vol 117 (6) ◽

pp. 1189-1196 ◽

Cited By ~ 13

Author(s):

Eun-Hyoung Park ◽

Per Kristian Eide ◽

David Zurakowski ◽

Joseph R. Madsen

Keyword(s):

Heart Rate ◽

Transfer Function ◽

Frequency Dependence ◽

Normal Pressure Hydrocephalus ◽

Inverse Relationship ◽

Animal Experiments ◽

Normal Pressure ◽

High Amplitude ◽

Frequency Dependent ◽

Csf Shunting

Object The pathophysiology of normal pressure hydrocephalus (NPH), and the related problem of patient selection for treatment of this condition, have been of great interest since the description of this seemingly paradoxical condition nearly 50 years ago. Recently, Eide has reported that measurements of the amplitude of the intracranial pressure (ICP) can both positively and negatively predict response to CSF shunting. Specifically, the fraction of time spent in a “high amplitude” (> 4 mm Hg) state predicted response to shunting, which may represent a marker for hydrocephalic pathophysiology. Increased ICP amplitude might suggest decreased brain compliance, meaning a static measure of a pressure-volume ratio. Recent studies of canine data have shown that the brain compliance can be described as a frequency-dependent function. The normal canine brain seems to show enhanced ability to absorb the pulsations around the heart rate, quantified as a cardiac pulsation absorbance (CPA), with properties like a notch filter in engineering. This frequency dependence of the function is diminished with development of hydrocephalus in dogs. In this pilot study, the authors sought to determine whether frequency dependence could be observed in humans, and whether the frequency dependence would be any different in epochs with high ICP amplitude compared with epochs of low ICP amplitude. Methods Systems analysis was applied to arterial blood pressure (ABP) and ICP waveforms recorded from 10 patients undergoing evaluations of idiopathic NPH to calculate a time-varying transfer function that reveals frequency dependence and CPA, the measure of frequency-dependent compliance previously used in animal experiments. The ICP amplitude was also calculated in the same samples, so that epochs with high (> 4 mm Hg) versus low (≤ 4 mm Hg) amplitude could be compared in CPA and transfer functions. Results Transfer function analysis for the more “normal” epochs with low amplitude exhibits a dip or notch in the physiological frequency range of the heart rate, confirming in humans the pulsation absorber phenomenon previously observed in canine studies. Under high amplitude, however, the dip in the transfer function is absent. An inverse relationship between CPA index and ICP amplitude is evident and statistically significant. Thus, elevated ICP amplitude indicates decreased performance of the human pulsation absorber. Conclusions The results suggest that the human intracranial system shows frequency dependence as seen in animal experiments. There is an inverse relationship between CPA index and ICP amplitude, indicating that higher amplitudes may occur with a reduced performance of the pulsation absorber. Our findings show that frequency dependence can be observed in humans and imply that reduced frequency-dependent compliance may be responsible for elevated ICP amplitude observed in patients who respond to CSF shunting.

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Cerebral Autoregulation, CSF outflow resistance and outcome following CSF diversion in Normal Pressure Hydrocephalus

10.1101/223867 ◽

2017 ◽

Cited By ~ 2

Author(s):

Afroditi Despina Lalou ◽

Marek Czosnyka ◽

Joseph Donnelly ◽

John D. Pickard ◽

Eva Nabbanja ◽

...

Keyword(s):

Cerebrospinal Fluid ◽

Normal Pressure Hydrocephalus ◽

Cerebral Autoregulation ◽

Normal Pressure ◽

Reactivity Index ◽

Outflow Resistance ◽

Cardiovascular Comorbidity ◽

Csf Circulation ◽

Csf Diversion ◽

The Relationship

AbstractIntroductionNormal pressure hydrocephalus (NPH) is not simply the result of a disturbance in cerebrospinal fluid (CSF) circulation, but often includes cardiovascular comorbidity and abnormalities within the cerebral mantle. In this study, we have examined the relationship between the global autoregulation pressure reactivity index (PRx), the profile of disturbed CSF circulation and pressure-volume compensation, and their possible effects on outcome after surgery.Materials and methodsWe studied a cohort of 131 patients, investigated for possible NPH. Parameters describing CSF compensation and circulation were calculated during the cerebrospinal fluid (CSF) infusion test and PRx was calculated from CSF pressure and arterial pressure recordings. A simple scale was used to mark the patients’ outcome 6 months after surgery (improvement, temporary improvement, and no improvement).ResultsPRx was negatively correlated with Rout (R=−0.18; p=0.044); patients with normal CSF circulation tended to have worse autoregulation. The correlation for patients who were surgically-managed (N=83) was: R=−0.28; p=0.03, and stronger in patients who improved after surgery (N=64; R=−0.36; p=0.03). In patients who did not improve, the correlation was not significantly different from zero (N= 19; R=0.17; p=0.15). There was a trend towards higher values for PRx in non-responders than in responders (PRx =0.16+/− 0.04 vs 0.09 +/−0.02 respectively; p=0.061), associated with higher MAP values (107.2+/−8.2 in non-responders vs 89.5+/−3.5 in responders; p=0.195). The product of MAP* (1+PRx), proposed as a measure of combined arterial hypertension and deranged autoregulation, showed a significant association with outcome (greater value in non-responders; p=0.013).ConclusionAutoregulation proves to associate with cerebrospinal fluid circulation, and appears strongest in shunt responders. Outcome following CSF diversion is possibly most favorable when CSF outflow resistance is increased and global cerebral autoregulation is intact, in combination with arterial normotension.

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Cerebrospinal Fluid Amyloid-β Oligomer Levels in Patients with Idiopathic Normal Pressure Hydrocephalus

Journal of Alzheimer s Disease ◽

10.3233/jad-210226 ◽

2021 ◽

pp. 1-12

Author(s):

Kaito Kawamura ◽

Masakazu Miyajima ◽

Madoka Nakajima ◽

Mitsuyasu Kanai ◽

Yumiko Motoi ◽

...

Keyword(s):

Cerebrospinal Fluid ◽

Normal Pressure Hydrocephalus ◽

Characteristic Curve ◽

Amyloid Β ◽

Normal Pressure ◽

Idiopathic Normal Pressure Hydrocephalus ◽

Cognitive Outcome ◽

Neurological Improvement ◽

Csf Shunting ◽

Before And After

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.

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