Shunt surgery in patients with hydrocephalus and white matter changes

Symptoms and signs did not predict outcome after surgery: a prospective study of 143 patients with idiopathic normal pressure hydrocephalus

OBJECTIVE

To determine the utility of symptoms, signs, comorbidities and background variables for the prediction of outcome of treatment in iNPH.

METHODS

A prospective observational study of consecutively included iNPH patients, who underwent neurological, physiotherapeutic and neuropsychological assessments before and after shunt surgery. The primary outcome measure was the total change on the iNPH scale, and patients were defined as improved postoperatively if they had improved by at least five points on that scale.

RESULTS

143 iNPH patients were included, and 73% of those were improved after surgery. None of the examined symptoms or signs could predict which patients would improve after shunt surgery. A dominant subjective complaint of memory problems at baseline was predictive of non-improvement. The reported comorbidities, duration of symptoms and BMI were the same in improved and non-improved patients. Each of the symptom domains (gait, neuropsychology, balance, and continence) as well as the total iNPH scale score improved significantly (from median 53 to 69, p < 0.001). The proportions of patients with shuffling gait, broad-based gait, paratonic rigidity and retropulsion all decreased significantly.

DISCUSSION

This study confirms that the recorded clinical signs, symptoms, and impairments in the adopted clinical tests are characteristic findings in iNPH, based on that most of them improved after shunt surgery. However, our clinical data did not enable predictions of whether patients would respond to shunt surgery, indicating that the phenotype is unrelated to the reversibility of the iNPH state and should mainly support diagnosis. Absence of specific signs should not be used to exclude patients from treatment.

CWH43 Variants Are Associated With Disease Risk and Clinical Phenotypic Measures in Patients With Normal Pressure Hydrocephalus

Background and Objectives

Variants in the CWH43 gene have been associated with normal pressure hydrocephalus (NPH). We aimed to replicate these findings, identify additional CWH43 variants, and further define the clinical phenotype associated with CWH43 variants.

Methods

We determined the prevalence of CWH43 variants by whole-genome sequencing (WGS) in 94 patients with NPH. The odds of having CWH43 variant carriers develop NPH were determined through comparison with 532 Mayo Clinic Biobank volunteers without a history of NPH. For patients with NPH, we documented the head circumference, prevalence of disproportionate enlargement of subarachnoid hydrocephalus (DESH), microvascular changes on MRI quantified by the Fazekas scale, and ambulatory response to ventriculoperitoneal shunting.

Results

We identified rare (MAF <0.05) coding CWH43 variants in 15 patients with NPH. Ten patients (Leu533Terfs, n = 8; Lys696Asnfs, n = 2) harbored previously reported predicted loss-of-function variants, and combined burden analysis confirmed risk association with NPH (OR 2.60, 95% CI 1.12-6.03, p = 0.027). Additional missense variations observed included Ile292Thr (n = 2), Ala469Ser (n = 2), and Ala626Val (n = 1). Though not quite statistically significant, in single variable analysis, the odds of having a head circumference above the 75th percentile of normal controls was more than 5 times higher for CWH43 variant carriers compared with that for noncarriers (unadjusted OR 5.67, 95% CI 0.96-108.55, p = 0.057), and this was consistent after adjusting for sex and height (OR 5.42, 95% CI 0.87-106.37, p = 0.073). DESH was present in 56.7% of noncarriers and only 21.4% of carriers (p = 0.016), while sulcal trapping was also more prevalent among noncarriers (67.2% vs 35.7%, p = 0.030). All 8 of the 15 variant carriers who underwent ventriculoperitoneal shunting at our institution experienced ambulatory improvements.

Discussion

CWH43 variants are frequent in patients with NPH. Predicted loss-of-function mutations were the most common; we identified missense mutations that require further study. Our findings suggest that congenital factors, rather than malabsorption or vascular dysfunction, are primary contributors to the CWH43-related NPH clinical syndrome.

Normal Pressure Hydrocephalus Following Cranial Radiation: Identification of Shunting Responders

BACKGROUND

We examined cognitive, brain MRI, and lumbar infusion test (LIT) features to identify predictors of response to ventriculoperitoneal shunting (VPS) in long-term cancer survivors with suspected normal pressure hydrocephalus (NPH) following cranial radiotherapy (RT).

METHODS

Patients who completed cranial RT at least 2 years before with clinically suspected NPH and an Evans' index (EI) ≥ 0.30 underwent a cognitive and a cerebrospinal fluid (CSF) volumetric (MRI) analysis (n = 36). For those in whom VPS was placed (n = 14), we explored whether adding a CSF volumetric analysis to classical MRI and LIT (Tap Test) features would better identify VPS responders.

RESULTS

Nearly 80% exhibited cognitive impairment. The CSF volume at NPH diagnoses was significantly larger in the group of VPS responders (p = 0.04). The addition of CSF volume to NPH diagnoses increased accuracy to 93%, with a positive and negative predictive value of 91% and 100%, respectively.

CONCLUSION

The addition of a quantitative MRI analysis of CSF volume to classical MRI and LIT NPH criteria, along with a high clinical suspicion of NPH, may help to identify VPS responders, thus improving the clinical management and prognosis of long-term survivors.

White matter hyperintensity mediating gait disorders in iNPH patients via neurofilament light chain

Purpose

This study aimed to analyze the differences in regional white matter hyperintensities (WMH) volume and cerebrospinal fluid biomarker levels between idiopathic normal pressure hydrocephalus (iNPH) patients with or without gait disorder.

Methods

Forty-eight iNPH patients undergoing bypass surgery and 20 normal senile individuals were included. The LST toolkit was used to segment all MRI fluid attenuation inversion images and quantify the WMH volume in each brain region. Cerebrospinal fluid was collected from all individuals and measured for concentrations of Aβ, t-tau, p-tau, and neurofilament light chain (NfL). Patients with iNPH were followed up for 1 year and divided categorized into a gait disorder improvement group and no improvement group according to the 3 m round-trip test time parameter improvement by more than 10%.

Results

We found that WMH in all areas of iNPH patients was higher than that in the control group. CSF levels of Aβ, t-tau, and p-tau were lower than those in the control group, while NfL levels were higher than those in the control group. The gait (+) group NfL level was higher than that in gait (−), and there were no statistical differences in Aβ, t-tau, and p-tau levels. The gait (+) group of frontal and parietal lobe WMH volume PVH above the gait (−) group. The mediating effect model analysis showed that PVH might affect the gait disorder of iNPH patients through NfL. A 1-year follow-up of the patients after the bypass surgery found that 24 of the 35 patients in the gait (+) group had improvements, while 11 had no significant improvements. The comparison of CSF marker levels between the two groups showed that the CSF NfL level in the improved group was lower than that in the non-improved group. The WMH volume and PVH in the frontal–parietal lobe of the improved group were lower than those of the non-improved group.

Conclusion

iNPH patients have more serious frontoparietal and periventricular white matter lesions, and WMH volume in the frontoparietal may mediate the occurrence of gait disorder in iNPH patients through the increase of NfL level.

Placebo-Controlled Effectiveness of Idiopathic Normal Pressure Hydrocephalus Shunting: A Randomized Pilot Trial

BACKGROUND

Multiple prospective nonrandomized studies have shown 60% to 70% of patients with idiopathic normal pressure hydrocephalus (iNPH) improve with shunt surgery, but multicenter placebo-controlled trial data are necessary to determine its effectiveness.

OBJECTIVE

To evaluate the effectiveness of cerebrospinal fluid shunting in iNPH through comparison of open vs placebo shunting groups at 4 months using a pilot study.

METHODS

Patients were randomized to a Codman Certas Plus valve (Integra LifeSciences) set at 4 (open shunt group) or 8 ("virtual off"; placebo group). Patients and assessors were blinded to treatment group. The primary outcome measure was 10-m gait velocity. Secondary outcome measures included functional scales for bladder control, activities of daily living, depression, and quality of life. Immediately after 4-month evaluation, all shunts were adjusted in a blinded fashion to an active setting and followed to 12 months after shunting.

RESULTS

A total of 18 patients were randomized. At the 4-month evaluation, gait velocity increased by 0.28 ± 0.28 m/s in the open shunt group vs 0.04 ± 0.17 m/s in the placebo group. The estimated treatment difference was 0.22 m/s ([ P = .071], 95% CI -0.02 to 0.46). Overactive Bladder Short Form symptom bother questionnaire significantly improved in open shunt vs placebo ( P = .007). The 4-month treatment delay did not reduce the subsequent response to active shunting, nor did it increase the adverse advents rate at 12 months.

CONCLUSION

This multicenter, randomized pilot study demonstrates the effectiveness, safety, and feasibility of a placebo-controlled trial in iNPH, and found a trend suggesting gait velocity improves more in the open shunt group than in the placebo group.

Idiopathic normal pressure hydrocephalus: historical context and a contemporary guide

Idiopathic normal pressure hydrocephalus (NPH) was described in 1965 as a syndrome in which hydrocephalus develops but with a normal cerebrospinal fluid (CSF) pressure, causing shunt-responsive gait apraxia, cognitive impairment and urinary incontinence. Not all patients respond to shunting despite having the clinical syndrome with appropriate radiological features. This has led to considerable debate over subsequent decades regarding idiopathic NPH. It is now understood that asymptomatic communicating hydrocephalus can develop in many healthy older people, and that over time this can develop into a symptomatic state that sometimes responds to CSF shunting, but to a variable extent. This review looks at the historical background of NPH, the use of predictive tests, the current state of clinical evidence for the diagnosis and treatment of idiopathic NPH and the possible underlying causes, to provide a contemporary practical guide for assessing patients with the radiological features of idiopathic NPH.

White matter changes should not exclude patients with idiopathic normal pressure hydrocephalus from shunt surgery

Introduction

White matter changes (WMC) on brain imaging can be classified as deep white matter hyperintensities (DWMH) or periventricular hyperintensities (PVH) and are frequently seen in patients with idiopathic normal pressure hydrocephalus (iNPH). Contradictory results have been reported on whether preoperative WMC are associated with outcome after shunt surgery in iNPH patients. The aim of this study was to investigate any association between DWMH and PVH and shunt outcome in patients with iNPH, using magnetic resonance volumetry.

Methods

A total of 253 iNPH patients operated with shunt surgery and clinically assessed before and 12 months after surgery were included. All patients were investigated preoperatively with magnetic resonance imaging of the brain. The volumes of DWMH and PVH were quantified on fluid-attenuated inversion recovery images using an in-house semi-automatic volumetric segmentation software (SmartPaint). Shunt outcome was defined as the difference in symptom score between post- and preoperative investigations, measured on the iNPH scale, and shunt response was defined as improvement with ≥ 5 points.

Results

One year after shunt surgery, 51% of the patients were improved on the iNPH scale. When defining improvement as ≥ 5 points on the iNPH scale, there was no significant difference in preoperative volume of WMC between shunt responders and non-responders. If outcome was determined by a continuous variable, a larger volume of PVH was negatively associated with postoperative change in the total iNPH scale (p < 0.05) and negatively associated with improvement in gait (p < 0.01) after adjusting for age, sex, waiting time for surgery, preoperative level of symptoms, Evans’ index, and disproportionately enlarged subarachnoid space hydrocephalus. The volume of DWMH was not associated with shunt outcome.

Conclusions

An association between outcome after shunt surgery and volume of PVH was seen, but there was no difference between shunt responders and non-responders in the volumes of DWMH and PVH. We conclude that preoperative assessment of WMC should not be used to exclude patients with iNPH from shunt surgery.

Shunting for idiopathic normal pressure hydrocephalus

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To determine the effect of cerebrospinal fluid (CSF) shunting versus no CSF shunting in people with idiopathic normal pressure hydrocephalus (iNPH).

To determine the frequency of adverse effects of CSF shunting in iNPH

Shared CSF Biomarker Profile in Idiopathic Normal Pressure Hydrocephalus and Subcortical Small Vessel Disease

Introduction

In this study, we examine similarities and differences between 52 patients with idiopathic normal pressure hydrocephalus (iNPH) and 17 patients with subcortical small vessel disease (SSVD), in comparison to 28 healthy controls (HCs) by a panel of cerebrospinal fluid (CSF) biomarkers.

Methods

We analyzed soluble amyloid precursor protein alpha (sAPPα) and beta (sAPPβ), Aβ isoforms −38, −40, and −42, neurofilament light protein (NFL), glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), matrix metalloproteinases (MMP −1, −2, −3, −9, and −10), and tissue inhibitors of metalloproteinase 1 (TIMP1). Radiological signs of white matter damage were scored using the age-related white matter changes (ARWMC) scale.

Results

All amyloid fragments were reduced in iNPH and SSVD (p &lt; 0.05), although more in iNPH than in SSVD in comparison to HC. iNPH and SSVD showed comparable elevations of NFL, MBP, and GFAP (p &lt; 0.05). MMPs were similar in all three groups except for MMP-10, which was increased in iNPH and SSVD. Patients with iNPH had larger ventricles and fewer WMCs than patients with SSVD.

Conclusion

The results indicate that patients with iNPH and SSVD share common features of subcortical neuronal degeneration, demyelination, and astroglial response. The reduction in all APP-derived proteins characterizing iNPH patients is also present, indicating that SSVD encompasses similar pathophysiological phenomena as iNPH.

Cerebrospinal Fluid Biomarkers Predict Gait Outcomes in Idiopathic Normal Pressure Hydrocephalus

Background and Objectives

The assessment of biomarkers in selecting patients with idiopathic normal pressure hydrocephalus (iNPH) for shunt surgery has been limited to small cohort studies and those with limited follow-up. We assessed the potential for CSF biomarkers in predicting immediate response to CSF tap test (TT) and long-term response after shunt surgery.

Methods

CSF was obtained from patients with iNPH referred for CSF TT after baseline assessment of cognition and gait. CSF neurofilament light (NfL), β-amyloid 42 (Aβ_1–42), β-amyloid 40 (Aβ_1–40), total tau (tTau), and phosphorylated tau 181 (pTau181) and leucine-rich alpha-2-glycoprotein-1 (LRG1) were measured by ELISA. The ability of these measures to predict immediate improvement following CSF TT and long-term improvement following shunt surgery was compared by univariate and adjusted multivariate regression.

Results

Lower NfL, pTau181, tTau, and Aβ_1–40 were individually predictive of long-term improvement in gait outcomes after shunt surgery. A multivariate model of these biomarkers and MRI Evans index, adjusted for age, improved prediction (area under the receiver operating curve 0.76, 95% confidence interval 0.66–0.86). tTau, pTau181, and Aβ_1–40 levels were statistically different in those whose gait improved after CSF TT compared with those who did not. Using a multivariate model, combining these markers with Evans index and transependymal flow did not significantly improve prediction of an immediate response to CSF TT.

Discussion

A combination of CSF biomarkers can predict improvement following shunt surgery for iNPH. However, these measures only modestly discriminate responders from nonresponders following CSF TT. The findings further suggest that abnormal CSF biomarkers in nonresponders may represent comorbid neurodegenerative pathology or a predegenerative phase that presents with an iNPH phenotype.

High Periventricular T1 Relaxation Times Predict Gait Improvement After Spinal Tap in Patients with Idiopathic Normal Pressure Hydrocephalus

PURPOSE

The diagnosis of idiopathic normal pressure hydrocephalus (iNPH) can be challenging. Aim of this study was to use a novel T1 mapping method to enrich the diagnostic work-up of patients with suspected iNPH.

METHODS

Using 3T magnetic resonance imaging (MRI) we prospectively evaluated rapid high-resolution T1 mapping at 0.5 mm resolution and 4 s acquisition time in 15 patients with suspected iNPH and 8 age-matched, healthy controls. T1 mapping in axial sections of the cerebrum, clinical and neuropsychological testing were performed prior to and after cerebrospinal fluid tap test (CSF-TT). T1 relaxation times were measured in 5 predefined periventricular regions.

RESULTS

All 15 patients with suspected iNPH showed gait impairment, 13 (86.6%) showed signs of cognitive impairment and 8 (53.3%) patients had urinary incontinence. Gait improvement was noted in 12 patients (80%) after CSF-TT. T1 relaxation times in all periventricular regions were elevated in patients with iNPH compared to controls with the most pronounced differences in the anterior (1006 ± 93 ms vs. 911 ± 77 ms; p = 0.023) and posterior horns (983 ± 103 ms vs. 893 ± 68 ms; p = 0.037) of the lateral ventricles. Montreal cognitive assessment (MoCA) scores at baseline were negatively correlated with T1 relaxation times (r < -0.5, p < 0.02). Higher T1 relaxation times were significantly correlated with an improvement of the 3‑m timed up and go test (r > 0.6 and p < 0.03) after CSF-TT.

CONCLUSION

In iNPH-patients, periventricular T1 relaxation times are increased compared to age-matched controls and predict gait improvement after CSF-TT. T1 mapping might enrich iNPH work-up and might be useful to indicate permanent shunting.

Gait characteristics and effects of the cerebrospinal fluid tap test in probable idiopathic normal pressure hydrocephalus

OBJECTIVES

To evaluate gait characteristics and investigate changes pre- and post- cerebrospinal fluid tap test (CSF TT) in gait parameters in patients with probable idiopathic normal pressure hydrocephalus (iNPH).

METHODS

Sixty patients were sequential circuited and diagnosed with possible iNPH according to Japanese second iNPH guidelines at our hospital from December 2016 to March 2021. All patients underwent the CSF TT. Gait parameters, cognitive and urinary function were assessed pre- and post-CSF TT. Patients who were unable to ambulate to take the tests or could not walk independently or walked normally were excluded.

RESULTS

Twenty-six patients were diagnosed with probable iNPH using the CSF TT. After CSF TT, the Boon sum score improved from 20.0 ± 7.7-16.6 ± 8.0 (p < 0.001), the Boon walking score improved from 8.9 ± 3.5-7.8 ± 4.4 (p = 0.008), the Boon step score improved from 6.3 ± 2.3-5.2 ± 2.1 (p < 0.001), the Boon time score improved from 4.9 ± 2.4-3.7 ± 2.3 (p < 0.001), tandem walking disturbance improved from 1.7 ± 0.7-1.4 ± 0.9 (p = 0.043), tendency toward falling improved from 1.7 ± 0.7-1.3 ± 1(p = 0.022), 3-meter timed up and go test (3-mTUG) improved from 21.9 ± 7.1-17.6 ± 5.1( p < 0.001), 10-meter walking (10-MWT) step improved from 31.1 ± 13.1-24.6 ± 7.5 (p < 0.001), velocity improved from 0.7 ± 0.2-0.8 ± 0.3 (p < 0.001) and stride length improved from 0.4 ± 0.1-0.46 ± 0.1(p < 0.001), compared with before the CSF TT.

CONCLUSION

These results suggest that many parameters in the Boon gait test were responsive to the CSF TT, and the Boon gait test may help objectify response to the CSF TT by combining the 10-MWT and 3-mTUG gait assessments.

N. BP, Mohamed Ibrahim N, Mustapha M. Aberrant Neurogliovascular Unit Dynamics in Cerebral Small Vessel Disease: A Rheological Clue to Vascular Parkinsonism

The distinctive anatomical assemble and functionally discrete multicellular cerebrovasculature dynamics confer varying rheological and blood-brain barrier permeabilities to preserve the integrity of cerebral white matter and its neural microenvironment. This homeostasis intricately involves the glymphatic system that manages the flow of interstitial solutes, metabolic waste, and clearance through the venous circulation. As a physiologically integrated neurogliovascular unit (NGVU) serving a particularly vulnerable cerebral white matter (from hypoxia, metabolic insults, infection, and inflammation), a likely insidious process over a lifetime could inflict microenvironment damages that may lead to pathological conditions. Two such conditions, cerebral small vessel disease (CSVD) and vascular parkinsonism (VaP), with poorly understood pathomechanisms, are frequently linked to this brain-wide NGVU. VaP is widely regarded as an atypical parkinsonism, described by cardinal motor manifestations and the presence of cerebrovascular disease, particularly white matter hyperintensities (WMHs) in the basal ganglia and subcortical region. WMHs, in turn, are a recognised imaging spectrum of CSVD manifestations, and in relation to disrupted NGVU, also include enlarged perivascular spaces. Here, in this narrative review, we present and discuss on recent findings that argue for plausible clues between CSVD and VaP by focusing on aberrant multicellular dynamics of a unique integrated NGVU-a crossroad of the immune-vascular-nervous system-which may also extend fresher insights into the elusive interplay between cerebral microvasculature and neurodegeneration, and the potential therapeutic targets.

Olfactory bulb volume in patients with normal-pressure hydrocephalus: an MRI evaluation

AIM

To investigate changes in olfactory bulb (OB) volume in patients with idiopathic normal-pressure hydrocephalus (NPH).

MATERIALS AND METHODS

This multicentric retrospective study included a test group of 23 patients with NPH (10 male and 13 female patients) and a control group of 27 healthy participants without hydrocephalus. The OB volume in all participants had been measured using cranial magnetic resonance imaging (MRI). In the NPH group, positivity for disproportionately enlarged subarachnoid space hydrocephalus (DESH) was also evaluated.

RESULTS

The OB volumes of the NPH group (R 38.29 ± 9.34 mm³ and L37.52 ± 9.59 mm³) were significantly lower than those of the control group (R 45.87 ± 7.33 mm³ and L48.41 ± 7.62 mm³) bilaterally. There were no significant differences between right and left OB volumes in the NPH group. Nine of the 23 patients were DESH positive and 14 were DESH negative. There were no significant differences between OB volumes of the DESH positive and DESH vpatients in the NPH group. In both groups, there was a positive correlation between right and left OB volumes. There were no significant correlations between OB volumes and age or gender. In the NPH group, there were no significant correlations between DESH positivity and OB volumes.

CONCLUSION

OB volume decrease and olfactory problems should be taken into account in idiopathic NPH patients. When expanded ventricles and decreased OB volume are observed at cranial MRI, a diagnosis of idiopathic NPH should be considered.

Early shunt surgery improves survival in idiopathic normal pressure hydrocephalus

BACKGROUND AND PURPOSE

To examine the effect of delayed compared to early planning of shunt surgery on survival, in patients with idiopathic normal pressure hydrocephalus (iNPH), a long-term follow-up case-control study of patients exposed to a severe delay of treatment was performed.

METHODS

In 2010-2011 our university hospital was affected by an administrative and economic failure that led to postponement of several elective neurosurgical procedures. This resulted in an unintentional delay of planning of treatment for a group of iNPH patients, referred to as iNPHDelayed (n = 33, waiting time for shunt surgery 6-24 months). These were compared to patients treated within 3 months, iNPHEarly (n = 69). Primary outcome was mortality. Dates and underlying causes of death were provided by the Cause of Death Registry. Survival was analysed by Kaplan-Meier plots and a Cox proportional hazard model adjusted for potential confounders.

RESULTS

Median follow-up time was 6.0 years. Crude 4-year mortality was 39.4% in iNPHDelayed compared to 10.1% in iNPHEarly (p = 0.001). The adjusted hazard ratio in iNPHDelayed was 2.57; 95% confidence interval 1.13-5.83, p = 0.024. Causes of death were equally distributed between the groups except for death due to malignancy which was not seen in iNPHDelayed  but in 4/16 cases in iNPHEarly (p = 0.044).

CONCLUSIONS

The present data indicate that shunt surgery is effective in iNPH and that early treatment increases survival.

Guidelines for Management of Idiopathic Normal Pressure Hydrocephalus (Third Edition): Endorsed by the Japanese Society of Normal Pressure Hydrocephalus

Among the various disorders that manifest with gait disturbance, cognitive impairment, and urinary incontinence in the elderly population, idiopathic normal pressure hydrocephalus (iNPH) is becoming of great importance. The first edition of these guidelines for management of iNPH was published in 2004, and the second edition in 2012, to provide a series of timely, evidence-based recommendations related to iNPH. Since the last edition, clinical awareness of iNPH has risen dramatically, and clinical and basic research efforts on iNPH have increased significantly. This third edition of the guidelines was made to share these ideas with the international community and to promote international research on iNPH. The revision of the guidelines was undertaken by a multidisciplinary expert working group of the Japanese Society of Normal Pressure Hydrocephalus in conjunction with the Japanese Ministry of Health, Labour and Welfare research project. This revision proposes a new classification for NPH. The category of iNPH is clearly distinguished from NPH with congenital/developmental and acquired etiologies. Additionally, the essential role of disproportionately enlarged subarachnoid-space hydrocephalus (DESH) in the imaging diagnosis and decision for further management of iNPH is discussed in this edition. We created an algorithm for diagnosis and decision for shunt management. Diagnosis by biomarkers that distinguish prognosis has been also initiated. Therefore, diagnosis and treatment of iNPH have entered a new phase. We hope that this third edition of the guidelines will help patients, their families, and healthcare professionals involved in treating iNPH.

Risk factors, comorbidities, quality of life, and complications after surgery in idiopathic normal pressure hydrocephalus: review of the INPH-CRasH study

OBJECTIVE

Idiopathic normal pressure hydrocephalus (INPH) is a dementia treatable by insertion of a shunt that drains CSF. The cause of the disease is unknown, but a vascular pathway has been suggested. The INPH-CRasH (Comorbidities and Risk Factors Associated with Hydrocephalus) study was a modern epidemiological case-control study designed to prospectively assess parameters regarding comorbidities and vascular risk factors (VRFs) for INPH, quality of life (QOL), and adverse events in patients with shunted INPH. The objective of this review was to summarize the findings of the INPH-CRasH study.

METHODS

VRFs, comorbidities, QOL, and adverse events were analyzed in consecutive patients with INPH who underwent shunt placement between 2008 and 2010 in 5 of 6 neurosurgical centers in Sweden. Patients (n = 176, within the age span of 60–85 years and not having dementia) were compared to population-based age- and gender-matched controls (n = 368, same inclusion criteria as for the patients with INPH). Assessed parameters were as follows: hypertension; diabetes; obesity; hyperlipidemia; psychosocial factors (stress and depression); smoking status; alcohol intake; physical activity; dietary pattern; cerebrovascular, cardiovascular, or peripheral vascular disease; epilepsy; abdominal pain; headache; and clinical parameters before and after surgery. Parameters were assessed through questionnaires, clinical examinations, measurements, ECG studies, and blood samples.

RESULTS

Four VRFs were independently associated with INPH: hyperlipidemia, diabetes, obesity, and psychosocial factors. Physical inactivity and hypertension were also associated with INPH, although not independently from the other risk factors. The population attributable risk percent for a model containing all of the VRFs associated with INPH was 24%. Depression was overrepresented in patients with INPH treated with shunts compared to the controls (46% vs 13%, p < 0.001) and the main predictor for low QOL was a coexisting depression (p < 0.001). Shunting improved QOL on a long-term basis. Epilepsy, headache, and abdominal pain remained common for a mean follow-up time of 21 months in INPH patients who received shunts.

CONCLUSIONS

The results of the INPH-CRasH study are consistent with a vascular pathophysiological component of INPH. In clinical care and research, a complete risk factor analysis as well as screening for depression and a measurement for QOL should probably be included in the workup of patients with INPH. The effect of targeted interventions against modifiable VRFs and antidepressant treatment in INPH patients should be evaluated. Seizures, headache, and abdominal pain should be inquired about at postoperative follow-up examinations.

Gaps, Controversies, and Proposed Roadmap for Research in Normal Pressure Hydrocephalus

Idiopathic normal pressure hydrocephalus is considered common but remains underinvestigated. There are no uniformly accepted diagnostic criteria and therapeutic guidelines. We summarize the accumulated evidence regarding the definition, pathophysiology, diagnosis, and treatment of idiopathic normal pressure hydrocephalus, highlighting the many gaps and controversies, including diagnostic challenges, the frequent association with neurodegeneration and vascular disease, and the many unknowns regarding patient selection and outcome predictors. A roadmap to fill these gaps and solve the controversies around this condition is also proposed. More evidence is required with respect to diagnostic criteria, the value of ancillary testing, prospective population-based studies and novel trial designs. Furthermore, a need exists to develop new advanced options in shunt technology. © 2020 International Parkinson and Movement Disorder Society.

Dopaminergic Degeneration and Small Vessel Disease in Patients with Normal Pressure Hydrocephalus Who Underwent Shunt Surgery

The diagnosis of idiopathic normal pressure hydrocephalus (iNPH) and the outcome of lumboperitoneal shunt treatment remains to be systematically explored. Here, we aim to evaluate whether the severity of dopaminergic degeneration and white matter small vessel disease could be predictors of outcome for iNPH patients subjected to lumboperitoneal shunt treatment. This is a single center retrospective study with 39 patients with probable iNPH undergoing programmable surgical lumboperitoneal shunt from June 2016 to March 2018 at Hualien Tzu Chi Hospital. In all patients, dopaminergic degeneration was determined with ^99mTc- TRODAT-1 SPECT scan, while white matter small vessel disease (Fazekas scale) was assessed with Brain MRI. The iNPH grading scale (iNPHGS) score and Karnofsky Performance Score (KPS) pre- and post-operation (6-month follow-up) were available for all patients. Linear regression was used to correlate the severities of dopaminergic degeneration and small vessel disease with lumboperitoneal shunt treatment outcomes. Their iNPHGS score improved significantly after surgery (pre-operatively, 7.8 ± 2.6; post-operatively, 5.7 ± 2.6 (26.9% improvement) (p < 0.05)). Moreover, the KPS was also improved significantly after surgery, by a mean of 24.6% from the baseline score (p < 0.05). A significant correlation was observed between the severity of dopaminergic degeneration and a poorer improvement of iNPHGS score (p = 0.03). However, improvement of the iNPHGS score was not correlated with white matter small vessel disease. Dopaminergic degeneration comorbidity neutralized the degree of improvement after surgery. Although white matter small vessel disease was correlated with iNPH incidence, it may not be a prognostic factor for shunt operation. These findings have implications for the use of dopaminergic imaging, as they might help predict the surgical outcome of patients with iNPH, while vascular mechanisms seem to be involved in iNPH pathophysiology.

Rheologically Essential Surfactant Proteins of the CSF Interacting with Periventricular White Matter Changes in Hydrocephalus Patients - Implications for CSF Dynamics and the Glymphatic System

Surfactant proteins (SP) are multi-systemic proteins playing crucial roles in the regulation of rheological properties of physiological fluids, host defense, and the clearance of potentially harmful metabolites. Hydrocephalus patients suffer from disturbed central nervous system (CNS) fluid homeostasis and exhibit remarkably altered SP concentrations within the cerebrospinal fluid (CSF). A connection between CSF-SPs, CSF flow, and ventricular dilatation, a morphological hallmark of hydrocephalus, has been reported previously. However, currently there are no studies investigating the link between rheologically active SPs and periventricular white matter changes caused by impaired CSF microcirculation in hydrocephalic conditions. Thus, the aim of this study was to assess their possible relationships. The present study included 47 individuals (27 healthy subjects and 20 hydrocephalus patients). CSF specimens were analyzed for concentrations of SP-A, SP-C, and SP-D by using enzyme-linked immunosorbent assays (ELISAs). Axial T2w turbo inversion recovery magnitude (TIRM) magnetic resonance imaging was employed in all cases. Using a custom-made MATLAB-based tool for quantification of magnetic resonance signal intensities in the brain, parameters related to disturbed deep white matter CSF microcirculation were estimated (TIRM signal intensity (SI)-mean, minimum, maximum, median, mode, standard deviation, and percentiles, p10th, p25th, p75th, p90th, as well as kurtosis, skewness, and entropy of the SI distribution). Subsequently, statistical analysis was performed (IBM SPSS 24™) to identify differences between hydrocephalic patients and healthy individuals and to further investigate the connections between CSF-SP changes and deep white matter signal intensities. SP-A (0.38 ± 0.23 vs. 0.76 ± 0.49 ng/ml) and SP-C (0.54 ± 0.28 vs. 1.27 ± 1.09 ng/ml) differed between healthy controls and hydrocephalus patients in a statistically significant manner. Also, corresponding quantification of white matter signal intensities revealed statistically significant differences between hydrocephalus patients and healthy individuals: SImean (370.41 ± 188.15 vs. 222.27 ± 99.86, p = 0.001), SImax (1115.30 ± 700.12 vs. 617.00 ± 459.34, p = 0.005), SImedian (321.40 ± 153.17 vs. 209.52 ± 84.86, p = 0.001), SImode (276.55 ± 125.63 vs. 197.26 ± 78.51, p = 0.011), SIstd (157.09 ± 110.07 vs. 81.71 ± 64.94, p = 0.005), SIp10 (229.10 ± 104.22 vs. 140.00 ± 63.12, p = 0.001), SIp25 (266.95 ± 122.62 vs. 175.63 ± 71.42, p = 0.002), SIp75 (428.80 ± 226.88 vs. 252.19 ± 110.91, p = 0.001), SIp90 (596.47 ± 345.61 vs. 322.06 ± 176.00, p = 0.001), skewness (1.19 ± 0.68 vs. 0.43 ± 1.19, p = 0.014), and entropy (5.36 ± 0.37 vs. 4.92 ± 0.51, p = 0.002). There were no differences regarding SP-D levels in hydrocephalus patients vs. healthy controls. In the acute hydrocephalic subgroup, correlations were as follows: SP-A showed a statistically significant correlation with SImax (r = 0.670, p = 0.024), SIstd (r = 0.697, p = 0.017), SIp90 (r = 0.621, p = 0.041), and inverse correlation with entropy (r = - 0.700, p = 0.016). SP-C correlated inversely with entropy (r = - 0.686, p = 0.020). For the chronic hydrocephalus subgroup, the following correlations were identified: SP-A correlated with kurtosis of the TIRM histogram (r = - 0.746, p = 0.021). SP-C correlated with SImean (r = - 0.688, p = 0.041), SImax (r = - 0.741, p = 0.022), SImedian (r = - 0.716, p = 0.030), SImode (r = - 0.765, p = 0.016), SIstd (r = - 0.671, p = 0.048), SIp25 (r = - 0.740, p = 0.023), SIp75 (r = - 0.672, p = 0.048), and SIp90 (r = - 0.667, p = 0.050). SP-D apparently does not play a major role in CSF fluid physiology. SP-A and SP-C are involved in different aspects of CNS fluid physiology. SP-A appears to play an essential compensatory role in acute hydrocephalus and seems less involved in chronic hydrocephalus. In contrary, SP-C profile and white matter changes are remarkably connected in CSF of chronic hydrocephalus patients. Considering the association between CSF flow phenomena, white matter changes, and SP-C profiles, the latter may especially contribute to the regulation of paravascular glymphatic physiology.

Background Risk Factors Associated with Shunt Intervention for Possible Idiopathic Normal Pressure Hydrocephalus: A Nationwide Hospital-Based Survey in Japan

Background:

Patients with idiopathic normal-pressure hydrocephalus (iNPH) are typically older adults with multiple comorbidities that are associated with a reduction in the efficacy of iNPH treatment via cerebrospinal fluid (CSF) shunt placement.

Objective:

The present study aimed to investigate the effectiveness of CSF shunt for iNPH using data from a nationwide epidemiological survey in Japan.

Methods:

We examined 1,423 patients (581 women) aged ≥60 years (median age [25%–75%]: 77 [73–80] years) who were diagnosed with iNPH following a hospital visit in 2012. Patients who experienced an improvement of at least one modified Rankin Scale (mRS) grade after the CSF shunt were classified as “improvement” while the remaining patients were classified as “non-improvement.” The efficacy of the shunt intervention (n = 842) was analyzed using a binomial logistic regression analysis.

Results:

An analysis of risk factors associated with shunt placement in patients with mRS grade 2 revealed an association between comorbid chronic ischemic lesions (odds ratio [OR], 2.28; 95% confidence interval [CI], 1.11–4.67; p = 0.025) and cervical spondylosis (OR, 3.62; 95% CI, 1.15–11.34; p = 0.027). Patients with mRS grade 3 at study entry had an association with comorbid Alzheimer’s disease (OR, 3.02; 95% CI, 1.44–6.31; p = 0.003).

Conclusions:

The results presented here showed that any age-related risk is minimal and should not be cause for rejection of surgical treatment options. Clinical decisions regarding CSF shunt should be individualized to each patient, with adequate consideration of the relative risks and benefits, including maximizing a healthy life expectancy.

Gait in normal pressure hydrocephalus: characteristics and effects of the CSF tap test

ABSTRACT Normal pressure hydrocephalus (NPH), described by Hakim and Adams in 1965, is characterized by gait apraxia, urinary incontinence, and dementia. It is associated with normal cerebrospinal fluid (CSF) pressure and ventricular dilation that cannot be attributed to cerebral atrophy. Objectives: To evaluate gait characteristics in patients with idiopathic NPH and investigate the effect of the CSF tap test (CSF-TT) on gait. Methods: Twenty-five patients diagnosed with probable idiopathic NPH were submitted to the CSF-TT. The procedure aimed to achieve changes in gait parameters. Results: Fifteen gait parameters were assessed before and after the CSF-TT. Five showed a statistically significant improvement (p < 0.05): walking speed (p < 0.001), cadence (p < 0.001), step length (p < 0.001), en bloc turning (p = 0.001), and step height (p = 0.004). Conclusion: This study demonstrated that gait speed was the most responsive parameter to the CSF-TT, followed by cadence, step length, en bloc turning, and step height.

Long-term effects of complications and vascular comorbidity in idiopathic normal pressure hydrocephalus: a quality registry study

Background

There is little knowledge about the factors influencing the long-term outcome after surgery for idiopathic normal pressure hydrocephalus (iNPH).

Objective

To evaluate the effects of reoperation due to complications and of vascular comorbidity (hypertension, diabetes, stroke and heart disease) on the outcome in iNPH patients, 2–6 years after shunt surgery.

Methods

We included 979 patients from the Swedish Hydrocephalus Quality Registry (SHQR), operated on for iNPH during 2004–2011. The patients were followed yearly by mailed questionnaires, including a self-assessed modified Rankin Scale (smRS) and a subjective comparison between their present and their preoperative health condition. The replies were grouped according to the length of follow-up after surgery. Data on clinical evaluations, vascular comorbidity, and reoperations were extracted from the SHQR.

Results

On the smRS, 40% (38–41) of the patients were improved 2–6 years after surgery and around 60% reported their general health condition to be better than preoperatively. Reoperation did not influence the outcome after 2–6 years. The presence of vascular comorbidity had no negative impact on the outcome after 2–6 years, assessed as improvement on the smRS or subjective improvement of the health condition, except after 6 years when patients with hypertension and a history of stroke showed a less favorable development on the smRS.

Conclusion

This registry-based study shows no negative impact of complications and only minor effects of vascular comorbidity on the long-term outcome in iNPH.

Therapeutic Interventions for Vascular Parkinsonism: A Systematic Review and Meta-analysis

Background

Vascular parkinsonism (VP) is defined as the presence of parkinsonian syndrome, evidence of cerebrovascular disease, and an established relationship between the two disorders. However, the diagnosis of VP is problematic, particularly for the clinician confronted with moving from diagnosis to treatment. Given the different criteria used in the diagnosis of VP, the effectiveness of available therapeutic interventions for this disease are currently unknown.

Methods

To assess the clinical response of all published therapeutic interventions for VP that have been reported in the literature, we conducted a systematic review looking for VP subjects treated with any therapeutic intervention. To clarify the prevalence of responsiveness to levodopa among VP subjects, we conducted a meta-analysis of 17 observational studies retrieved with the search criteria of our review. Also, four studies were included in a second analysis to explore if nigrostriatal lesion affected the prevalence of levodopa response in VP subjects. Relevant articles were identified from MEDLINE, Scopus, and Web of Science published until June 2017.

Results

436 non-duplicate citations were identified for screening, 107 articles were assessed for eligibility, and only 23 observational studies were included in this review. No randomized clinical trials were found. Four different therapies were found in the literature; among them, levodopa was the only one repetitively reported. The calculated event rate of levodopa response in VP subjects was of 0.304 [95% confidence interval (CI) of 0.230–0.388]. The overall odds ratio for good response to levodopa in VP with lesion in the nigrostriatal pathway vs. no lesion in the nigrostriatal pathway was 15.15 (95% CI: 5.2–44.17).

Conclusion

Despite the lack of randomized controlled trials, results of this systematic review and meta-analysis show that VP subjects, as operationally defined here, have a low response rate to levodopa; nigrostriatal lesion could be used as a proxy predictor of levodopa response in VP subjects. Other therapies seem to be co-adjuvant. Randomized controlled trials with a clear definition of VP are necessary to be able to assign positive or negative predictive values to available treatments and to recommend any of the therapeutic interventions for these subjects.

Association between shunt-responsive idiopathic normal pressure hydrocephalus and alcohol

OBJECTIVE Idiopathic normal pressure hydrocephalus (iNPH) is characterized by ventriculomegaly, gait difficulty, incontinence, and dementia. The symptoms can be ameliorated by CSF drainage. The object of this study was to identify factors associated with shunt-responsive iNPH. METHODS The authors reviewed the medical records of 529 patients who underwent shunt placement for iNPH at their institution between July 2001 and March 2015. Variables associated with shunt-responsive iNPH were identified using bivariate and multivariate analyses. Detailed alcohol consumption information was obtained for 328 patients and was used to examine the relationship between alcohol and shunt-responsive iNPH. A computerized patient registry from 2 academic medical centers was queried to determine the prevalence of alcohol abuse among 1665 iNPH patients. RESULTS Bivariate analysis identified associations between shunt-responsive iNPH and gait difficulty (OR 4.59, 95% CI 2.32-9.09; p < 0.0001), dementia (OR 1.79, 95% CI 1.14-2.80; p = 0.01), incontinence (OR 1.77, 95% CI 1.13-2.76; p = 0.01), and alcohol use (OR 1.98, 95% CI 1.23-3.16; p = 0.03). Borderline significance was observed for hyperlipidemia (OR 1.56, 95% CI 0.99-2.45; p = 0.054), a family history of hyperlipidemia (OR 3.09, 95% CI 0.93-10.26, p = 0.054), and diabetes (OR 1.83, 95% CI 0.96-3.51; p = 0.064). Multivariate analysis identified associations with gait difficulty (OR 3.98, 95% CI 1.81-8.77; p = 0.0006) and alcohol (OR 1.94, 95% CI 1.10-3.39; p = 0.04). Increased alcohol intake correlated with greater improvement after CSF drainage. Alcohol abuse was 2.5 times more prevalent among iNPH patients than matched controls. CONCLUSIONS Alcohol consumption is associated with the development of shunt-responsive iNPH.

Efficacy and safety of programmable shunt valves for hydrocephalus: A meta-analysis

OBJECTIVES

Shunt implantation is an option in the treatment of hydrocephalus. However, the benefits and adverse effects of programmable shunt valves have not been well assessed.

MATERIALS AND METHODS

Randomized controlled trials (RCTs) and observational studies assessing the efficacy and safety of programmable valves (PV) treatment for hydrocephalus were identified from electronic databases (PubMed, EMBASE, and Cochrane library). The meta-analysis was performed with the fixed-effect model or random-effect model according to heterogeneity.

RESULTS

Three RCTs and eight observational studies met the inclusion criteria including 2622 subjects. Compared with non-PV, PV treatment did not have a statistically significant effect on one-year shunt survival rate [relative risk (RR), 1.06; 95% confidence interval (CI), 0.84-1.35], Substantial heterogeneity was observed between studies (P = 0.09; I² = 65%). PV administration significantly reduced revision rate (RR, 0.56; 95% CI, 0.45-0.69; I² = 29%; P = 0.23) and over- or under-drainage complications rate (RR, 0.55; 95% CI, 0.32-0.96). PV was not associated with increased rates of other adverse events, including overall complications rate, infection rate and catheter-related complications rate.

CONCLUSIONS

PV treatment is safe and may reduce the revision rate and over- or under-drainage complication rate, especially in patients aged less than 18 years with hydrocephalus. PV treatment is not associated with decreased overall complication rates in patients with hydrocephalus, but the trial sequential analysis indicate more studies are needed to confirm this result.

Vascular risk factors in INPH: A prospective case-control study (the INPH-CRasH study)

OBJECTIVE

To assess the complete vascular risk factor (VRF) profile of idiopathic normal pressure hydrocephalus (INPH) using a large sample of representative patients with INPH and population-based controls to determine the extent to which vascular disease influences INPH pathophysiology.

METHODS

All patients with INPH who underwent shunting in Sweden in 2008-2010 were compared to age- and sex-matched population-based controls. Inclusion criteria were age 60-85 years and no dementia. The 10 most important VRFs and cerebrovascular and peripheral vascular disease were prospectively assessed using blood samples, clinical examinations, and standardized questionnaires. Assessed VRFs were hypertension, hyperlipidemia, diabetes, obesity, psychosocial factors, smoking habits, diet, alcohol intake, cardiac disease, and physical activity.

RESULTS

In total, 176 patients with INPH and 368 controls participated. Multivariable logistic regression analysis indicated that hyperlipidemia (odds ratio [OR] 2.380; 95% confidence interval [CI] 1.434-3.950), diabetes (OR 2.169; 95% CI 1.195-3.938), obesity (OR 5.428; 95% CI 2.502-11.772), and psychosocial factors (OR 5.343; 95% CI 3.219-8.868) were independently associated with INPH. Hypertension, physical inactivity, and cerebrovascular and peripheral vascular disease were also overrepresented in INPH. Moderate alcohol intake and physical activity were overrepresented among the controls. The population-attributable risk percentage was 24%.

CONCLUSIONS

Our findings confirm that patients with INPH have more VRFs and lack the protective factors present in the general population. Almost 25% of cases of INPH may be explained by VRFs. This suggests that INPH may be a subtype of vascular dementia. Targeted interventions against modifiable VRFs are likely to have beneficial effects on INPH.

Multimodal analysis to predict shunt surgery outcome of 284 patients with suspected idiopathic normal pressure hydrocephalus

OBJECTIVES

Optimal selection of idiopathic normal pressure hydrocephalus (iNPH) patients for shunt surgery is challenging. Disease State Index (DSI) is a statistical method that merges multimodal data to assist clinical decision-making. It has previously been shown to be useful in predicting progression in mild cognitive impairment and differentiating Alzheimer's disease (AD) and frontotemporal dementia. In this study, we use the DSI method to predict shunt surgery response for patients with iNPH.

METHODS

In this retrospective cohort study, a total of 284 patients (230 shunt responders and 54 non-responders) from the Kuopio NPH registry were analyzed with the DSI. Analysis included data from patients' memory disorder assessments, age, clinical symptoms, comorbidities, medications, frontal cortical biopsy, CT/MRI imaging (visual scoring of disproportion between Sylvian and suprasylvian subarachnoid spaces, atrophy of medial temporal lobe, superior medial subarachnoid spaces), APOE genotyping, CSF AD biomarkers, and intracranial pressure.

RESULTS

Our analysis showed that shunt responders cannot be differentiated from non-responders reliably even with the large dataset available (AUC = 0.58).

CONCLUSIONS

Prediction of the treatment response in iNPH is challenging even with our extensive dataset and refined analysis. Further research of biomarkers and indicators predicting shunt responsiveness is still needed.

A Review of Clinical Outcomes for Gait and Other Variables in the Surgical Treatment of Idiopathic Normal Pressure Hydrocephalus

BACKGROUND

Idiopathic normal pressure hydrocephalus (INPH) is a treatable cause of gait disturbance, cognitive impairment, and urinary incontinence. This clinical triad of symptoms occurs in association with ventriculomegaly and normal cerebrospinal fluid (CSF) pressure. Although the treatment outcomes after CSF shunting for INPH have improved significantly since its first description in 1965, shortcomings in our understanding still remain. Not all INPH patients exhibit clinical improvement after shunting, and it is challenging to identify patients who are more likely to benefit from shunting.

METHODS

The Cochrane Library, Medline, Embase, and PubMed databases were searched for English-language publications between 1965 and October 2015. Reference lists of publications were also manually searched for additional publications.

RESULTS

The findings of this review indicate that, despite efforts to improve patient selection, the degree of clinical improvement after shunting continues to demonstrate significant variability both within and between studies. These discrepancies in treatment outcomes are the result of controversies in 3 distinct but interrelated domains: the underlying pathophysiology of INPH, the diagnosis of INPH, and the identification of likely shunt-responders.

CONCLUSIONS

This review focuses on these 3 areas and their relation to surgical treatment outcomes. Despite the limitations of published outcome studies and limitations in our understanding of INPH pathophysiology, shunting is a safe and effective means of achieving meaningful clinical improvement in most patients with INPH.

NPH Log: Validation of a New Assessment Tool Leading to Earlier Diagnosis of Normal Pressure Hydrocephalus

Introduction:

Early treatment of normal pressure hydrocephalus (NPH) yields better postoperative outcomes. Our current tests often fail to detect significant changes at early stages. We developed a new scoring system (LP log score) to determine if this tool is more sensitive in detecting clinical differences than current tests.

Material and Methods:

Sixty-two consecutive new patients with suspected idiopathic NPH were studied. Secondary, previously treated and obstructive cases were not included. We collected age, pre- and post-lumbar puncture (LP) Tinetti, Timed Up and Go (TUG) Test, European NPH scale, and LP log scores. The LP log score is recorded at baseline and for seven consecutive days after removing 40 cc of cerebrospinal fluid (CSF) via LP. We studied the diagnostic accuracy of the tests for surgical indication.

Results:

The post-LP log showed improvement in 90% of people with good baseline gait tests and in 93% of people who did not show any pre-LP and post-LP change in gait tests. Sensitivity, specificity, and accuracy to detect intention to treat when positive post-LP improvements were 4%, 100%, and 24%, respectively, for TUG, 21%, 86%, and 34%, respectively, for the Tinetti Mobility Test, 66%, 29%, and 58%, respectively, for Medical College of Virginia (MCV) grade, and 98%, 33%, and 85%, respectively, for LP log score. Pre-LP and post-LP TUG improvement and pre-LP and post-LP Tinetti improvement were not associated with a surgical indication (p > 0.05). LP log improvement was associated with surgical indication odds ratio (OR): 24.5 95% CI (2.4-248.12) (p = 0.007).

Conclusions:

LP log showed better sensitivity, diagnostic accuracy, and association with surgical indication than the current diagnostic approach. An LP log may be useful detecting NPH patients at earlier stages and, therefore, yield better surgical outcomes.

Vascular factors in suspected normal pressure hydrocephalus: A population-based study

OBJECTIVE

We examined clinical and imaging findings of suspected idiopathic normal pressure hydrocephalus (iNPH) in relation to vascular risk factors and white matter lesions (WMLs), using a nested case-control design in a representative, population-based sample.

METHODS

From a population-based sample, 1,235 persons aged 70 years or older were examined with CT of the brain between 1986 and 2000. We identified 55 persons with hydrocephalic ventricular enlargement, i.e., radiologic findings consistent with iNPH. Among these, 26 had clinical signs that fulfilled international guideline criteria for probable iNPH. These cases were labeled suspected iNPH. Each case was matched to 5 controls from the same sample, based on age, sex, and study cohort. Data on risk factors were obtained from clinical examinations and the Swedish Hospital Discharge Register. History of hypertension, diabetes mellitus (DM), smoking, overweight, history of coronary artery disease, stroke/TIA, and WMLs on CT were examined. Risk factors associated with iNPH with a p value <0.1 in χ2 tests were included in conditional logistic regression models.

RESULTS

In the regression analyses, suspected iNPH was related to moderate to severe WMLs (odds ratio [OR] 5.2; 95% confidence interval [CI]: 1.5-17.6), while hydrocephalic ventricular enlargement was related to hypertension (OR 2.7; 95% CI: 1.1-6.8), moderate to severe WMLs (OR 6.5; 95% CI: 2.1-20.3), and DM (OR 4.3; 95% CI: 1.1-16.3).

CONCLUSIONS

Hypertension, WMLs, and DM were related to clinical and imaging features of iNPH, suggesting that vascular mechanisms are involved in the pathophysiology. These findings might have implications for understanding disease mechanisms in iNPH and possibly prevention.

Feasibility of radiological markers in idiopathic normal pressure hydrocephalus

BACKGROUND

Various radiological markers have been proposed for diagnostics in idiopathic normal pressure hydrocephalus (iNPH). We examined the usefulness of radiological markers in the diagnostics and prediction of shunt response in iNPH.

METHOD

In this retrospective cohort study, we evaluated brain CT or MRI scans of 390 patients with suspected iNPH. Based on a 24-h intraventricular pressure monitoring session, patients were classified into a non-NPH (n = 161) or probable iNPH (n = 229) group. Volumes of cerebrospinal fluid compartments (lateral ventricles, sylvian and suprasylvian subarachnoid spaces and basal cisterns) were visually assessed. Disproportionally enlarged subarachnoid spaces, flow void, white matter changes, medial temporal lobe atrophy and focally dilated sulci were evaluated. Moreover, we measured quantitative markers: Evans' index (EI), the modified cella media index, mean width of the temporal horns and callosal angle.

RESULTS

iNPH was more likely in patients with severe volumetric disproportion between the suprasylvian and sylvian subarachnoid spaces than in those without disproportion (OR 7.5, CI 95 % 4.0-14.1, P < 0.0001). Mild disproportion (OR 2.6, CI 95 % 1.4-4.6, P = 0.001) and narrow temporal horns (OR per 1 mm 0.91, CI 95 % 0.84-0.98, P = 0.014) were also associated with an iNPH diagnosis. Other radiological markers had little association with the iNPH diagnosis in the final combined multivariate model. Interestingly, EI was higher in non-NPH than iNPH patients (0.40 vs. 0.38, P = 0.039). Preoperative radiological markers were not associated with shunt response.

CONCLUSIONS

Visually evaluated disproportion was the most useful radiological marker in iNPH diagnostics. Narrower temporal horns also supported an iNPH diagnosis, possibly since atrophy was more pronounced in the non-NPH than iNPH group.

3D Modeling of the Lateral Ventricles and Histological Characterization of Periventricular Tissue in Humans and Mouse

The ventricular system carries and circulates cerebral spinal fluid (CSF) and facilitates clearance of solutes and toxins from the brain. The functional units of the ventricles are ciliated epithelial cells termed ependymal cells, which line the ventricles and through ciliary action are capable of generating laminar flow of CSF at the ventricle surface. This monolayer of ependymal cells also provides barrier and filtration functions that promote exchange between brain interstitial fluids (ISF) and circulating CSF. Biochemical changes in the brain are thereby reflected in the composition of the CSF and destruction of the ependyma can disrupt the delicate balance of CSF and ISF exchange. In humans there is a strong correlation between lateral ventricle expansion and aging. Age-associated ventriculomegaly can occur even in the absence of dementia or obstruction of CSF flow. The exact cause and progression of ventriculomegaly is often unknown; however, enlarged ventricles can show regional and, often, extensive loss of ependymal cell coverage with ventricle surface astrogliosis and associated periventricular edema replacing the functional ependymal cell monolayer. Using MRI scans together with postmortem human brain tissue, we describe how to prepare, image and compile 3D renderings of lateral ventricle volumes, calculate lateral ventricle volumes, and characterize periventricular tissue through immunohistochemical analysis of en face lateral ventricle wall tissue preparations. Corresponding analyses of mouse brain tissue are also presented supporting the use of mouse models as a means to evaluate changes to the lateral ventricles and periventricular tissue found in human aging and disease. Together, these protocols allow investigations into the cause and effect of ventriculomegaly and highlight techniques to study ventricular system health and its important barrier and filtration functions within the brain.

Lumboperitoneal shunt surgery for idiopathic normal pressure hydrocephalus (SINPHONI-2): an open-label randomised trial

BACKGROUND

Lumboperitoneal shunt surgery has the potential to alleviate symptoms of normal pressure hydrocephalus but the benefits of such surgery have not been tested in a randomised trial. The aim of this trial was to determine the safety and efficacy of the lumboperitoneal shunt surgery for this disorder.

METHODS

For the open-label randomised SINPHONI-2 trial, eligible participants (60-85 years of age) with idiopathic normal pressure hydrocephalus, with ventriculomegaly, and tightness of the high-convexity and medial subarachnoid spaces on MRI, were recruited from 20 neurological and neurosurgical centres in Japan. Enrolled participants were randomly assigned in a 1:1 ratio according to a random code generated by the trial statistician, with a permuted block design (using a block size of 4 or 6) within each centre, to receive lumboperitoneal shunt surgery within 1 month after randomisation, or to surgery postponed for 3 months. Patients and assessors were not masked to treatment assignment. The primary endpoint was favourable outcome, defined as an improvement of one point or more on the modified Rankin scale (mRS) at 3 months after randomisation, analysed by intention to treat, and the main secondary endpoint was the same outcome 12 months after surgery, analysed per protocol. This trial is registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR), number UMIN000002730.

FINDINGS

Between March 1, 2010, and Oct 19, 2011, 93 patients with idiopathic normal pressure hydrocephalus were enrolled and randomly assigned to the immediate treatment group (n=49) or the postponed treatment group (n=44). More patients in the immediate treatment group than in the postponed treatment group had an improvement of one point or more on the mRS at 3 months: 32 (65%) of 49 in the immediate group vs 2 (5%) of 44 in the postponed group (difference 61% [95% CI 42-68]; p<0·0001). The number of patients who had an improvement of one point or more on the mRS at 12 months after surgery was similar between the two groups: 30 (67%) of 45 patients in the immediate group vs 22 (58%) of 38 in the postponed group (difference 9% [95% CI -14 to 31]; p=0·496). The proportions of patients with serious adverse events did not differ significantly between the groups during the 3 months post-randomisation (7 [15%] of 46 in the immediate group vs 1 [2%] of 42 in the postponed group; p=0·060). During the 12 months after surgery, 19 (22%) of 87 patients had serious adverse events, the most common of which was cerebral infarction (six patients [7%]).

INTERPRETATION

Our results suggest that lumboperitoneal shunt surgery might be beneficial for patients with idiopathic normal pressure hydrocephalus and, if these findings are confirmed in larger studies, could be a first-line treatment option for this disease.

FUNDING

Johnson & Johnson and Nihon Medi-Physics.

Vascular parkinsonism--characteristics, pathogenesis and treatment

Parkinson disease is a primary degenerative disease of the brain, but parkinsonism can also result from a variety of vascular disorders. Vascular parkinsonism (VP) most frequently presents as lower body parkinsonism, a condition that is accompanied by the development of white matter lesions (WMLs) and lacunes in the brain. Patients with lower body parkinsonism exhibit gait impairment and go on to develop urinary incontinence, abnormal pyramidal responses and cognitive decline. However, WMLs and lacunes are also common observations among elderly individuals who do not have parkinsonism, which causes difficulty in determining the pathogenetic mechanisms that lead to VP. In addition, imaging studies suggest that many pathological and clinical features are common to VP and Binswanger disease, a type of small vessel vascular dementia. This Review summarizes current understanding of the clinical characteristics of VP, as well as knowledge gained from neuroimaging and nuclear imaging of the pathological features of VP. The lack of current treatment options, and the emergence of new therapies such as cerebrospinal fluid drainage, are also discussed. Finally, consideration is given to whether the overlap between VP and Binswanger disease means that these two disorders should be considered as part of the same disease entity.

A randomized controlled dual-center trial on shunt complications in idiopathic normal-pressure hydrocephalus treated with gradually reduced or “fixed” pressure valve settings

Object

This study was undertaken to investigate whether a gradual reduction of the valve setting (opening pressure) decreases the complication rate in patients with idiopathic normal-pressure hydrocephalus (iNPH) treated with a ventriculoperitoneal (VP) shunt.

Methods

In this prospective double-blinded, randomized, controlled, dual-center study, a VP shunt with an adjustable valve was implanted in 68 patients with iNPH, randomized into two groups. In one group (the 20–4 group) the valve setting was initially set to 20 cm H2O and gradually reduced to 4 cm H2O over the course of the 6-month study period. In the other group (the 12 group), the valve was kept at a medium pressure setting of 12 cm H2O during the whole study period. The time to and type of complications (hematoma, infection, and mechanical problems) as well as overdrainage symptoms were recorded. Symptoms, signs, and outcome were assessed by means of the iNPH scale and the NPH grading scale.

Results

Six patients in the 20–4 group (22%) and 7 patients in the 12 group (23%) experienced a shunt complication; 9 had subdural hematomas, 3 mechanical obstructions, and 1 infection (no significant difference between groups). The frequency of overdrainage symptoms was significantly higher for a valve setting ≤ 12 cm H2O compared with a setting > 12 cm H2O. The 20–4 group had a higher improvement rate (88%) than the 12 group (62%) (p = 0.032). There was no significant relationship between complications and body mass index, the use of an antisiphon device, or the use of anticoagulants.

Conclusions

Gradual lowering of the valve setting to a mean of 7 cm H2O led to the same rate of shunt complications and overdrainage symptoms as a fixed valve setting at a mean of 13 cm H2O but was associated with a significantly better outcome.

Natural course of idiopathic normal pressure hydrocephalus

OBJECTIVES

The natural course of idiopathic normal pressure hydrocephalus (iNPH) has not been thoroughly studied. The consequences of postponing shunt treatment are largely unknown. We aimed to describe the effects of waiting for more than 6 months before surgery and to compare the outcome with that seen in patients who waited for less than 3 months.

METHODS

33 patients (iNPHDelayed) underwent an initial investigation (Pre-op 1), followed by re-examination, just prior to surgery, after waiting for at least 6 months (Pre-op 2). Outcome was evaluated after 3 months of treatment. 69 patients who were surgically treated within 3 months after Pre-op 1 and who were also evaluated after 3 months of treatment constituted a comparison group (iNPHEarly). Evaluations were done with the iNPH scale and the modified Rankin Scale (mRS). iNPHDelayed patients were prospectively studied with regard to outcome, whereas the comparison group iNPHEarly was defined and analysed retrospectively.

RESULTS

iNPHDelayed patients deteriorated significantly during their wait for surgery, with progression of symptom severity ranging from +7 to -47 on the iNPH scale, and from 0 to +3 on the mRS (both p<0.001). The magnitude of change after surgery was similar in the groups, but since the symptoms of iNPHDelayed patients had worsened while waiting, their final outcome was significantly poorer.

CONCLUSIONS

The natural course of iNPH is symptom progression over time, with worsening in gait, balance and cognitive symptoms. This deterioration is only partially reversible. To maximise the benefits of shunt treatment, surgery should be performed soon after diagnosis.

Measurement of CSF dynamics with oscillating pressure infusion

INTRODUCTION

Infusion tests are used to diagnose and select patients with idiopathic normal pressure hydrocephalus (INPH) for shunt surgery. The test characterizes cerebrospinal fluid dynamics and estimates parameters of the cerebrospinal fluid system, the pressure-volume index (PVI) and the outflow conductance (Cout). The Oscillating Pressure Infusion (OPI) method was developed to improve the test and reduce the investigation time. The aim of this study was to evaluate the new OPI method by comparing it with an established reference method.

METHODS

Forty-seven patients (age 71.2 ± 8.9 years) with communicating hydrocephalus underwent a preoperative lumbar infusion investigation with two consecutive infusion protocols, reference (42 min) and new (20 min), that is, 94 infusion tests in total. The OPI method estimated Cout and PVI simultaneously. A real-time analysis of reliability was applied to investigate the possibility of infusion time reduction.

RESULTS

The difference in Cout between the methods was 1.2 ± 1.8 μl/s/kPa (ΔRout = -0.8 ± 3.5 mmHg/ml/min), P < 0.05, n = 47. With the reliability analysis, the preset 20 min of active infusion could have been even further reduced for 19 patients to between 10 and 19 min. PVI was estimated to 16.1 ± 6.9 ml, n = 47.

CONCLUSIONS

The novel Oscillating Pressure Infusion method produced real-time estimates of Cout including estimates of reliability that was in good agreement with the reference method and allows for a reduced and individualized investigation time.

Influence of comorbidities in idiopathic normal pressure hydrocephalus - research and clinical care. A report of the ISHCSF task force on comorbidities in INPH

Idiopathic normal pressure hydrocephalus (INPH) is a syndrome of ventriculomegaly, gait impairment, cognitive decline and incontinence that occurs in an elderly population prone to many types of comorbidities. Identification of the comorbidities is thus an important part of the clinical management of INPH patients. In 2011, a task force was appointed by the International Society for Hydrocephalus and Cerebrospinal Fluid Disorders (ISHCSF) with the objective to compile an evidence-based expert analysis of what we know and what we need to know regarding comorbidities in INPH. This article is the final report of the task force. The expert panel conducted a comprehensive review of the literature. After weighing the evidence, the various proposals were discussed and the final document was approved by all the task force members and represents a consensus of expert opinions. Recommendations regarding the following topics are given: I. Musculoskeletal conditions; II. Urinary problems; III. Vascular disease including risk factors, Binswanger disease, and white matter hyperintensities; IV. Mild cognitive impairment and Alzheimer disease including biopsies; V. Other dementias (frontotemporal dementia, Lewy body, Parkinson); VI. Psychiatric and behavioral disorders; VII. Brain imaging; VIII. How to investigate and quantify. The task force concluded that comorbidity can be an important predictor of prognosis and post-operative outcome in INPH. Reported differences in outcomes among various INPH cohorts may be partly explained by variation in the rate and types of comorbidities at different hydrocephalus centers. Identification of comorbidities should thus be a central part of the clinical management of INPH where a detailed history, physical examination, and targeted investigations are the basis for diagnosis and grading. Future INPH research should focus on the contribution of comorbidity to overall morbidity, mortality and long-term outcomes.

Flow-regulated versus differential pressure-regulated shunt valves for adult patients with normal pressure hydrocephalus

BACKGROUND

Since 1965 many ventriculo-peritoneal shunt systems have been inserted worldwide to treat hydrocephalus. The most frequent indication in adults is normal pressure hydrocephalus (NPH), a condition that can be difficult to diagnose precisely. Surgical intervention with flow-regulated and differential pressure-regulated ventriculo-peritoneal shunts remains controversial. Knowledge about the benefits and harms of these interventions is limited.

OBJECTIVES

The objective of this review is to summarize the evidence on benefits and harms of flow-regulated versus differential pressure-regulated shunt valves for adult patients with NPH, based on reported findings of randomised clinical trials.

SEARCH METHODS

The ALOIS (www.medicine.ox.ac.uk/alois), the Cochrane Dementia and Cognitive Improvement Group Specialized Register; MEDLINE (from 1950) (Ovid SP); EMBASE (from 1980) (Ovid SP); CINAHL (from 1980) (EBSCOhost); PsycINFO (from 1806) (Ovid SP); LILACS (from 1982 ) (BIREME); ClinicalTrials.gov; Umin Japan Trial Register; WHO portal;The Cochrane Library's Central Register of Controlled trials (CENTRAL); ISI Web of Knowledge Conference Proceedings; Index to Theses; and Australasian Digital Theses were searched until May 16, 2012.The search terms used were NPH, "normal pressure hydrocephalus," iNPH, idiopathic normal pressure hydrocephalus, sNPH, and "secondary normal pressure hydrocephalus."

SELECTION CRITERIA

We planned to include randomised clinical trials comparing flow-regulated versus differential pressure-regulated shunt valves.

DATA COLLECTION AND ANALYSIS

Two authors with expert knowledge within the field independently reviewed studies for eligibility, assessed risk of bias, and extracted data.

MAIN RESULTS

No randomised clinical trials comparing flow-regulated versus differential pressure-regulated shunt valves were found.

AUTHORS' CONCLUSIONS

There is no evidence from randomised clinical trials indicates that flow-regulated and differential pressure-regulated shunt valves differ with regard to clinical outcome, shunt failure, or intervention risks. Randomised clinical trials are needed that take into account the large number of VP shunts implanted each year in patients with NPH.

Do systolic BP and pulse pressure relate to ventricular enlargement?

BACKGROUND AND PURPOSE

To evaluate the association between systolic, diastolic and pulse pressure, and increase in ventricular size (VS). Observations in laboratory animals suggest intraventricular pulse pressure (systolic-diastolic) may play a role in ventricular enlargement.

METHODS

Initial magnetic resonance (MR) scans and vascular risk factors evaluation were performed in 1812 Atherosclerosis Risk in Communities participants in 1994-1995. In 2004-2006, 1130 participants underwent repeat MR. VS was rated using a validated nine-point scale. Multiple logistic regression analysis assessed association between blood pressure measures and pulse pressure, and the change between the MR scans of VS controlling for age, sex and race.

RESULTS

At baseline 1112 participants (385 black women, 200 black men, 304 white women and 223 white men) had a mean age of 61.7 ± 4.3 years. In adjusted models pulse pressure at baseline was associated with an increase in VS [odds ratio (OR) 1.19, 95% confidence interval (CI) 1.01-1.40], as was systolic pressure (OR 1.28, 95% CI 1.03-1.58).

CONCLUSIONS

Systolic pressure and pulse pressure are associated with future development of increased VS. The findings are consistent with the animal literature that increased pulse pressure predisposes to risk of future increased VS. High pulse pressure might play a role in the pathogenesis of normal pressure hydrocephalus.

One-year outcome in the European multicentre study on iNPH

OBJECTIVES

To assess the 1-year outcome after shunt surgery in patients with idiopathic normal pressure hydrocephalus (iNPH).

METHODS

Patients (n = 142) were prospectively included in the European multicentre study by 13 centres. Diagnoses were based solely on clinical and radiological findings. All received a programmable ventriculoperitoneal shunt. Re-examinations, 12 months after surgery, were performed in 115 patients, and the outcome was assessed by the modified Rankin scale (mRs) and a new iNPH grading scale. Improvement was defined as ≥1 step on the mRs and ≥5 points on the iNPH scale.

RESULTS

The scores on both scales were significantly improved after 1 year of shunt treatment (Ps < 0.001). Sixty-nine per cent of the patients were improved according to the mRs and 84% according to the iNPH scale. The proportion able to live independently (scores 0-2 on the mRs) was increased from 53% before to 82% 12 months after surgery (P < 0.001). Neither classification (typical or questionable) nor comorbidity affected the level of improvement. Patients not completing the study were worse off with regard to their clinical condition at entry than completers. Twenty-eight per cent of the patients experienced complications and were either conservatively (13%) or surgically (15%) treated.

CONCLUSION

The results of this prospective multicentre study on patients with iNPH diagnosed solely on clinical and radiological criteria support shunt surgery in patients presenting with symptoms and signs and MRI findings suggestive of iNPH.

Hydrodynamics of the Certas™ programmable valve for the treatment of hydrocephalus

Background

The new Certas™ shunt for the treatment of hydrocephalus has seven standard pressure settings that according to the manufacturer range from 36 to 238 mmH₂O, and an additional “Virtual Off” setting with an opening pressure >400 mmH₂O. Information on actual pressure response and reliability of shunt performance is important in clinical application, especially the “Virtual Off” setting as a non-surgical replacement for shunt ligation. The objective of this study was to evaluate the in-vitro hydrodynamic performance of the Certas™ shunt.

Methods

Six new Certas™ shunts with proximal and distal catheters were tested with an automated, computerized test system that raised the pressure from zero to a maximum pressure and back to zero at each valve setting. Opening pressure and flow resistance were determined.

Results

For settings 1–7 the measured opening pressure range was 26 to 247 mmH₂O, and the mean change in opening pressure for a one-step adjustment was between 33 and 38 mmH₂O. For setting 8 (“Virtual Off”) the measured mean opening pressure was 494 ± 34 mmH₂O (range 451 to 556 mmH₂O). The mean outflow resistance was 7.0 mmHg/ml/min (outflow conductance 17.9 μl/s/kPa).

Conclusions

The six shunts had similar characteristics and closely matched the manufacturer’s specifications for opening pressure at settings 1–7. The opening pressure for the “Virtual Off” setting was nearly 500 mmH₂O, which is 100 mmH₂O higher than the manufacturer’s specification of “>400” and should be functionally off for most patients with communicating hydrocephalus. Clinical studies are needed to evaluate if the CSF dynamic profile persists after implantation in patients.