National and regional incidence of surgery for adult hydrocephalus in Sweden

Structural neuroimaging markers of normal pressure hydrocephalus versus Alzheimer's dementia and Parkinson's disease, and hydrocephalus versus atrophy in chronic TBI-a narrative review

Introduction

Normal Pressure Hydrocephalus (NPH) is a prominent type of reversible dementia that may be treated with shunt surgery, and it is crucial to differentiate it from irreversible degeneration caused by its symptomatic mimics like Alzheimer's Dementia (AD) and Parkinson's Disease (PD). Similarly, it is important to distinguish between (normal pressure) hydrocephalus and irreversible atrophy/degeneration which are among the chronic effects of Traumatic Brain Injury (cTBI), as the former may be reversed through shunt placement. The purpose of this review is to elucidate the structural imaging markers which may be foundational to the development of accurate, noninvasive, and accessible solutions to this problem.

Methods

By searching the PubMed database for keywords related to NPH, AD, PD, and cTBI, we reviewed studies that examined the (1) distinct neuroanatomical markers of degeneration in NPH versus AD and PD, and atrophy versus hydrocephalus in cTBI and (2) computational methods for their (semi-) automatic assessment on Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) scans.

Results

Structural markers of NPH and those that can distinguish it from AD have been well studied, but only a few studies have explored its structural distinction between PD. The structural implications of cTBI over time have been studied. But neuroanatomical markers that can predict shunt response in patients with either symptomatic idiopathic NPH or post-traumatic hydrocephalus have not been reliably established. MRI-based markers dominate this field of investigation as compared to CT, which is also reflected in the disproportionate number of MRI-based computational methods for their automatic assessment.

Conclusion

Along with an up-to-date literature review on the structural neurodegeneration due to NPH versus AD/PD, and hydrocephalus versus atrophy in cTBI, this article sheds light on the potential of structural imaging markers as (differential) diagnostic aids for the timely recognition of patients with reversible (normal pressure) hydrocephalus, and opportunities to develop computational tools for their objective assessment.

Prevalence of Possible Idiopathic Normal Pressure Hydrocephalus in Sweden: A Population-Based MRI Study in 791 70-Year-Old Participants

BACKGROUND AND OBJECTIVES

Very divergent prevalence rates for idiopathic normal pressure hydrocephalus (iNPH) are reported, probably due to differences in study sample selection and diagnostic criteria. This MRI-based study aimed to determine the prevalence of iNPH and iNPH-specific radiologic changes and their association with clinical symptoms in a large, 70-year-old population-based cohort (Gothenburg H70).

METHODS

In this cross-sectional study, disturbances in gait and balance, cognition, and urinary continence were assessed using clinical examination and self-report. MRI was evaluated for iNPH-specific imaging markers. iNPH was diagnosed according to International Guidelines (I.G.). Based on radiologic findings, participants were allocated to 1 of 4 groups: (A) Evans index (EI) ≤0.3 (reference), (B) EI >0.3 without other iNPH-typical radiologic findings, (C) radiologically probable iNPH according to I.G., and (D) radiologically holistically probable (h-probable) iNPH fulfilling radiologic criteria according to I.G. plus highly iNPH-specific changes according to an experienced neuroradiologist.

RESULTS

The Gothenburg H70 Studies include 791 individuals (377 men, 414 women) born in 1944 who underwent brain MRI. The prevalence of iNPH was 1.5% (2.1% for men, 0.96% for women) according to I.G. Ninety participants (11%) had EI >0.3 without other iNPH-typical radiologic findings, 29 (3.7%) fulfilled the I.G. radiologic probable iNPH criteria alone, and 11 (1.4%) were classified as radiologically h-probable iNPH. Forty participants (5.1%) had I.G. radiologic features of iNPH (70% men vs 30% women, p = 0.005). Gait disturbances were more common in participants with EI >0.3 without other radiologic iNPH features (B) (33%) compared with the reference group (A) (19%) (p = 0.006). All clinical symptoms were more common in participants with I.G. radiologic features of iNPH (C + D) than they were in the reference group (A) (p < 0.03).

DISCUSSION

The iNPH prevalence of 1.5% among 70-year-olds, which is considerably higher than earlier reported in this age group, suggests that iNPH may be more common than previously assumed. This is supported by the 5.1% total prevalence of imaging signs of iNPH. Ventriculomegaly without other iNPH-typical radiologic findings may be an early sign of developing iNPH in some patients.

Invasive Preoperative Investigations in Idiopathic Normal Pressure Hydrocephalus: A Comprehensive Review

Idiopathic normal pressure hydrocephalus (iNPH) is a neurological disorder characterized by the triad of gait disturbance, cognitive impairment, and urinary incontinence. The condition is diagnosed mainly in older adults and is associated with ventricular enlargement without an increase in cerebrospinal fluid pressure. The clinical assessment involves a detailed medical history, physical examination, and cognitive testing. Neuroimaging is an essential part of the diagnostic workup for iNPH. However, to determine the suitability of patients for shunt surgery, a range of invasive preoperative investigations are employed. This narrative review aims to provide a comprehensive analysis of the current literature on invasive preoperative investigations in iNPH, focusing primarily on the lumbar infusion test, cerebrospinal fluid drainage tests, and continuous intracranial pressure monitoring. The strengths and limitations of each method, as well as their potential impact on treatment outcomes, are discussed.

Health-Related Quality of Life and Role of Surgical Treatment in Idiopathic Normal Pressure Hydrocephalus: A Systematic Review

OBJECTIVE

Although shunting has been shown to ameliorate symptoms in idiopathic normal pressure hydrocephalus (iNPH), its impact on health-related quality of life (HRQoL) has yet to be fully elucidated. Patient and caregiver subjective life satisfaction and HRQoL represent crucial indicators for assessing the well-being of individuals facing chronic illnesses, including iNPH. This study aimed to systematically analyze the existing data about HRQoL in iNPH-treated patients to evaluate the role of surgical treatment in such a scenario.

METHODS

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the literature in the PubMed/Medline, Web of Science, and Scopus databases was searched. Fourteen studies met our inclusion criteria. The Joanna Briggs Institute critical appraisal tool was used to assess the risk of bias.

RESULTS

Overall, HRQoL improved significantly within 1 year after shunt placement although patients with iNPH reported worse HRQoL values compared with healthy-matched individuals. Up to 5 years after shunting, a sustained heterogeneity exists on published data showing improved scores across all domains for at least 21 months after shunting. Further, although surgical treatment can improve HRQoL, long-term follow-up showed that it remained lower than that of healthy controls. These data suggest a significant decrease of HRQoL in patients with iNPH over time after shunting, probably due to aging, comorbidities, and disease progression.

CONCLUSIONS

Despite that iNPH has been recognized as a potentially reversible neurological disorder, the available data about the impact of shunting on the HRQoL are unsatisfactory. To improve the well-informed clinical decision-making, it is essential to reach additional high-quality evidence regarding the effect of shunting on HRQoL. New prospective studies, using validated instruments specifically tailored for assessing HRQoL in patients with iNPH, and improved reporting standards are needed. Current evidence suggests that although shunting can provide initial benefits, affected patients may experience long-term impairment in HRQoL.

Idiopathic Normal Pressure Hydrocephalus: The Real Social and Economic Burden of a Possibly Enormous Underdiagnosis Problem

Normal Pressure Hydrocephalus (iNPH) typically affects the elderly and can cause cognitive decline, resulting in its differential diagnosis with other neurodegenerative conditions. Moreover, it is probably underdiagnosed; such under- and misdiagnosis prevents the patient from receiving the right treatment and significantly affects the quality of life and life expectancy. This investigation is an in-depth analysis of the actual incidence of iNPH in the population of the province served by our hospital (circa 580,000 individuals). The first phase of this study was conducted by visualizing a total of 1232 brain CT scans performed in the Emergency Departments of the four hospitals of our network on patients who were admitted for different complaints yet screened as suspicious for iNPH. Subsequently, corresponding Emergency Department medical records were investigated to understand the medical history of each patient in search of elements attributable to an alteration of CSF dynamics. The cohort of positive CT scans, according to the radiological and clinical inclusion criteria, included 192 patients. Among the reasons to require acute medical care, "Fall" was the most common. The cumulative incidence of CT scans suggestive of iNPH among the patients undergoing CT scans was as high as 15.58%, and the period prevalence calculated for the total amount of patients accessing the Emergency Departments was 1.084%. The real incidence of iNPH in the population may be underestimated, and the social burden linked to the assistance of patients suffering from such untreated conditions could be significantly relieved.

[Coincidence of normal pressure hydrocephalus and Alzheimer`s disease: therapeutic implications and open questions]

Normal pressure hydrocephalus (NPH) is prevalent in aging patient populations. Despite its clinical relevance, many patients with NPH may not receive adequate treatment. Because of the frequency of Alzheimer`s disease in these patients, there could be overlapping pathophysiological mechanisms that are as yet incompletely understood. Cerebral comorbidities seem to have negative effects on therapeutic response to ventriculoperitoneal shunting. In order to avoid unnecessary and unsuccessful surgery in highly vulnerable elderly patients, they have to be taken into consideration in the diagnostic process.

Adult-Onset Neuroepidemiology in Finland: Lessons to Learn and Work to Do

Finland is a relatively small genetic isolate with a genetically non-homogenous population. Available Finnish data on neuroepidemiology of adult-onset disorders are limited, and this paper describes the conclusions that can be drawn and their implications. Apparently, Finnish people have a (relatively) high risk of developing Unverricht-Lundborg disease (EPM1), Multiple Sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS), Spinal muscular atrophy, Jokela type (SMAJ) and adult-onset dystonia. On the other hand, some disorders, such as Friedreich's ataxia (FRDA) and Wilson's disease (WD), are almost absent or completely absent in the population. Valid and timely data concerning even many common disorders, such as stroke, migraine, neuropathy, Alzheimer's disease and Parkinson's disease, are unavailable, and there are virtually no data on many less-common neurological disorders, such as neurosarcoidosis or autoimmune encephalitides. There also appear to be marked regional differences in the incidence and prevalence of many diseases, suggesting that non-granular nationwide data may be misleading in many cases. Concentrated efforts to advance neuroepidemiological research in the country would be of clinical, administrative and scientific benefit, but currently, all progress is blocked by administrative and financial obstacles.

The demography of idiopathic normal pressure hydrocephalus: data on 3000 consecutive, surgically treated patients and a systematic review of the literature

OBJECTIVE

The objective of this study was to describe the demographic characteristics of patients with idiopathic normal pressure hydrocephalus (iNPH) through an analysis of 3000 consecutive, surgically treated Swedish patients and a systematic review of the literature.

METHODS

Data on age, sex, comorbidities, diagnostic delay, initial symptoms, and severity of symptoms at diagnosis were extracted from the Swedish Hydrocephalus Quality Registry. In addition, a systematic PRISMA-based review of the literature published from database inception until August 2019 was performed using the PubMed, Cochrane, and Scopus databases on the basis of two concepts: normal pressure hydrocephalus and demography and their association with related terms. Of 1020 unique articles, 16 were eligible for study inclusion and were assessed for quality using the Newcastle-Ottawa Scale. Mean and weighted mean values were calculated.

RESULTS

The mean patient age at the time of surgery was 74.4 years, 79% of patients were in their 70s, and 60% of the patients were men. Almost 50% of the patients had symptoms from four main domains (i.e., balance, gait, cognition, and urinary dysfunction) at disease onset. Patients aged < 60 years (2%) reported more headaches and fewer balance problems than those aged ≥ 60. Women were more impaired in function than men at the time of diagnosis. Dementia (Mini-Mental State Examination score < 25) was found in 47% of the patients. Men had more diabetes, heart disease, hypertension, and stroke than women, and comorbidity correlated with increased impairment. The incidence of surgery for iNPH was 20%-40% of the disease incidence according to survey and operation-based studies.

CONCLUSIONS

Most iNPH patients undergo surgery in their 70s. Those aged < 60 years show slightly different symptomatology and probably present with a specific disease entity, indicating that the lower age limit for iNPH should be 60 years. iNPH patients have severe impairment preceded by a long diagnostic delay. Even though the included study designs differed, the systematic review showed that the disorder has a very low treatment incidence. The importance of diagnosing and treating iNPH is further emphasized by the fact that iNPH may account for a considerable part of all cases of dementia.

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.

A novel model of acquired hydrocephalus for evaluation of neurosurgical treatments

Background

Many animal models have been used to study the pathophysiology of hydrocephalus; most of these have been rodent models whose lissencephalic cerebral cortex may not respond to ventriculomegaly in the same way as gyrencephalic species and whose size is not amenable to evaluation of clinically relevant neurosurgical treatments. Fewer models of hydrocephalus in gyrencephalic species have been used; thus, we have expanded upon a porcine model of hydrocephalus in juvenile pigs and used it to explore surgical treatment methods.

Methods

Acquired hydrocephalus was induced in 33–41-day old pigs by percutaneous intracisternal injections of kaolin (n = 17). Controls consisted of sham saline-injected (n = 6) and intact (n = 4) animals. Magnetic resonance imaging (MRI) was employed to evaluate ventriculomegaly at 11–42 days post-kaolin and to plan the surgical implantation of ventriculoperitoneal shunts at 14–38-days post-kaolin. Behavioral and neurological status were assessed.

Results

Bilateral ventriculomegaly occurred post-induction in all regions of the cerebral ventricles, with prominent CSF flow voids in the third ventricle, foramina of Monro, and cerebral aqueduct. Kaolin deposits formed a solid cast in the basal cisterns but the cisterna magna was patent. In 17 untreated hydrocephalic animals. Mean total ventricular volume was 8898 ± 5917 SD mm³ at 11–43 days of age, which was significantly larger than the baseline values of 2251 ± 194 SD mm³ for 6 sham controls aged 45–55 days, (p < 0.001). Past the post-induction recovery period, untreated pigs were asymptomatic despite exhibiting mild-moderate ventriculomegaly. Three out of 4 shunted animals showed a reduction in ventricular volume after 20–30 days of treatment, however some developed ataxia and lethargy, from putative shunt malfunction.

Conclusions

Kaolin induction of acquired hydrocephalus in juvenile pigs produced an in vivo model that is highly translational, allowing systematic studies of the pathophysiology and clinical treatment of hydrocephalus.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12987-021-00281-0.

Lumbar and ventricular CSF concentrations of extracellular matrix proteins before and after shunt surgery in idiopathic normal pressure hydrocephalus

Background

Idiopathic normal pressure hydrocephalus (iNPH) is a reversible CNS disease characterized by disturbed cerebrospinal fluid (CSF) dynamics. Changes in the extracellular matrix (ECM) composition might be involved in the pathophysiology of iNPH. The aim of this study was to explore possible differences between lumbar and ventricular CSF concentrations of the ECM markers brevican and neurocan, matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase-1 (TIMP-1) and their relation to clinical symptoms in iNPH patients before and after shunt surgery.

Methods

Paired lumbar and ventricular CSF was collected from 31 iNPH patients, before and four months after shunt surgery. CSF was analysed for concentrations of tryptic peptides originating from brevican and neurocan using a mass spectrometry-based panel, and for MMP-1, -2, -9, -10 and TIMP-1 using fluorescent or electrochemiluminescent immunoassays.

Results

Brevican and neurocan peptide levels were not influenced by CSF origin, but MMP-1, -2, -10 and TIMP-1 were increased (p ≤ 0.0005), and MMP-9 decreased (p ≤ 0.0003) in lumbar CSF compared with ventricular CSF. There was a general trend of ECM proteins to increase following shunt surgery. Ventricular TIMP-1 was inversely correlated with overall symptoms (rho = − 0.62, p < 0.0001). CSF concentrations of the majority of brevican and neurocan peptides were increased in iNPH patients with a history of cardiovascular disease (p ≤ 0.001, AUC = 0.84–0.94) compared with those without.

Conclusion

Levels of the CNS-specific proteins brevican and neurocan did not differ between the lumbar and ventricular CSF, whereas the increase of several CNS-unspecific MMPs and TIMP-1 in lumbar CSF suggests contribution from peripheral tissues. The increase of ECM proteins in CSF following shunt surgery could indicate disturbed ECM dynamics in iNPH that are restored by restitution of CSF dynamics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12987-021-00256-1.

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.

Lumboperitoneal shunts for the treatment of idiopathic normal pressure hydrocephalus

The standard of care for idiopathic normal pressure hydrocephalus (iNPH) is placement of a ventriculoperitoneal (VP) shunt. However, VP shunts require intracranial intervention and are associated with notable postoperative complications, with some groups reporting complication rates for VP shunts ranging from 17 to 33%, along with failure rates up to 17.7%. Lumboperitoneal (LP) shunts are an alternative for cerebrospinal fluid diversion that do not require intracranial surgery, thus providing utility in patients where intracranial surgery is not possible or preferred. Here we retrospectively reviewed our 25 patients with LP horizontal-vertical (LP-HV) shunts placement for initial treatment for iNPH from 2014 to 2019. All patients had preoperative gait dysfunction, 16 (64%) had urinary incontinence, and 21 (84%) exhibited cognitive insufficiency. Two weeks post-shunt placement, 23/25 (92%) patients demonstrated improvement in gait, 11/16 (68%) had improvement in incontinence, and 14/21 (66%) had improvement cognitive insufficiency. At six months or greater follow up 13/20 (65%) had improvement in gait, 7/15 (47%) showed improvement in incontinence, and 11/15 (73%) demonstrated improvement in cognitive function. Six patients (24%) required at least one revision of the LP shunt. Shunt malfunctions resulted from CSF leak in one patient, shunt catheter migration in two patients, peritoneal catheter pain in one patient, and clinical symptoms for overdrainage in two patients. Thus, we demonstrate that LP-HV shunt placement is safe and efficacious alternative to VP shunting for iNPH, resulting in notable symptomatic improvement and low risk of overdrainage, and may be considered for patients where cranial approaches should be avoided.

Inpatient diagnoses of idiopathic normal pressure hydrocephalus in the United States: Demographic and socioeconomic disparities

INTRODUCTION

Epidemiology provides an avenue for identifying disease pathogenesis, hence determining national incidence, along with socioeconomic and demographic variables involved in iNPH, can provide direction in elucidating the etiology and addressing healthcare inequalities.

METHODS

To investigate incidence (per 100,000) of iNPH diagnoses applied to the inpatient population, with respect to sex, age, income, residence, and race/ethnicity, we queried the largest American administrative dataset (2008-2016), the National (Nationwide) Inpatient Sample (NIS), which surveys 20% of United States (US) discharges.

RESULTS

Annual national inpatient incidence (with 25th and 75th quartiles) for iNPH diagnoses was 2.86 (2.72, 2.93). Males had an inpatient incidence of 3.27 (3.11, 3.39), higher (p = 0.008) than female at 2.45 (2.41, 2.47). Amongst age groups inpatient incidence varied (p = 0.000004) and was largest amongst the 85+ group at 18.81 (16.40, 19.95). Individuals with middle/high income had an inpatient incidence of 2.96 (2.77, 3.06), higher (p = 0.008) than the 2.37 (2.24, 2.53) of low-income patients. Depending on whether patients lived in urban, suburban, or rural communities, inpatient incidence diverged (p = 0.01) as follows, respectively: 2.65; 2.66; 3.036. Amongst race/ethnicity (p = 0.000003), inpatient incidence for Whites, Blacks, Hispanics, Asian/Pacific Islanders, and Native Americans were as follows, respectively: 3.88 (3.69, 3.93), 1.065 (1.015, 1.14); 0.82 (0.76, 0.85); 0.43 (0.33, 0.52); 0.027 (0.026, 0.12).

CONCLUSION

In the US, inpatient incidence for iNPH diagnoses exhibited disparities between socioeconomic and demographic strata, emphasizing a healthcare inequality. Disproportionately, diagnoses were applied most to patients who were White, male, 65 and older, middle/high income, and living in rural communities.

A systematic review on the epidemiology of normal pressure hydrocephalus

BACKGROUND

The aim of this systematic review is to gather all available studies reporting prevalence and incidence rates of iNPH and to assess their methodological quality and consistency.

METHODS

All available studies published up to June 2019 were retrieved searching the databases PubMed, ISI Web of Science, and the Cochrane Database of Systematic Reviews. All included studies were qualitatively assessed by two independent reviewers using the MORE Checklist for Observational Studies of Incidence and Prevalence.

KEY RESULTS

Bibliographic searches and other sources yielded 659 records. A total of 28 studies were selected and applied the predefined inclusion and exclusion criteria. Fourteen studies were further excluded, and 14 studies (10 on prevalence and 6 on incidence) were included in the qualitative analysis. Results from the prevalence studies reported crude overall rates ranging from 10/100 000 to 22/100 000 for probable iNPH and 29/100 000 for possible iNPH, and age-specific rates ranging from 3.3/100 000 in people aged 50-59 to 5.9% in people aged ≥ 80 years. Results from incidence studies reported overall crude rates ranging from 1.8/100 000 to 7.3/100 000 per year, and age-specific rates ranging from 0.07/100 000/year in people aged < 60 years to 1.2/1000/year in people aged ≥ 70 years.

CONCLUSIONS & INFERENCES

The high methodological and clinical heterogeneity of included studies does not allow drawing adequate conclusions on the epidemiology of iNPH. Further, high-quality, population-based studies should be carried out to allow for a better understanding of the epidemiology of this condition. Moreover, the implementation in current clinical practice of guidelines on the diagnosis and management of iNPH should also be endorsed.

Incidence, diagnostic criteria and outcome following ventriculoperitoneal shunting of idiopathic normal pressure hydrocephalus in a memory clinic population: a prospective observational cross-sectional and cohort study

OBJECTIVE

To evaluate diagnostic criteria for idiopathic normal pressure hydrocephalus (INPH) among patients with memory impairment, and to estimate the incidence of INPH.

DESIGN

Prospective observational cross-section and cohort study of diagnostic accuracy.

SETTING

Memory Disorders Clinic following referral by the medical practitioners.

PARTICIPANTS

408 consecutive patients enrolled 2010-2014.

OUTCOME MEASURES

Reference diagnostic test was the clinical judgement of an experienced specialist based on the presence of cognitive impairment and/or balance and gait disorders in the presence of dilated ventricles. Mini-Mental State Examination (MMSE), Tinetti balance and gait tests were performed before and 12 months after ventriculoperitoneal shunt surgery. The association between reference diagnosis, clinical and brain CT scan measurements was estimated by multivariate Poisson regression. Triage index diagnostic test scores were calculated from the regression coefficients, with diagnostic thresholds selected using receiver operating characteristic analysis.

RESULTS

The presence of balance and/or gait disorders, especially fear of falling, difficulty standing on toes/heals, urinary disturbances, ventriculomegaly with Evans ratio greater than Combined Diagnostic Threshold (0.377-{Maximum width of posterior horns*0.0054}), strongly predict the diagnosis of INPH; while hallucinations and/or delusions and forgetfulness reduce the likelihood of the diagnosis. This triage index test had high sensitivity (95.2%) and specificity (91.7%). 62 of 408 (15%) participants with cognitive impairment had INPH, an incidence of 11.9/100 000/year and 120/100 000/year over 75 years. 96% of participants following shunting, compared with 45% of the non-shunted, improved by over 25% of available measurable improvement in either MMSE or balance/gait scores (51% difference; 95% CI 28% to 74%; p<0.001), and 56% vs 5% improved by over 50% of maximum in both (51% difference; 95% CI 30% to 73%; p<0.001).

CONCLUSION

The triage index test score is a simple tool that may be useful for physicians to identify INPH diagnoses and need for referral for shunt surgery, which may improve cognitive, balance and gait functioning.

The prevalence and clinical associations of disproportionately enlarged subarachnoid space hydrocephalus (DESH), an imaging feature of idiopathic normal pressure hydrocephalus in community and memory clinic based Singaporean cohorts

INTRODUCTION

Disproportionately Enlarged Subarachnoid space Hydrocephalus (DESH) is considered as an important imaging feature of idiopathic normal pressure hydrocephalus (iNPH).

METHOD

Subjects aged 60 and over in a memory clinic and a community-based cohort were assessed for the presence of ventriculomegaly, Sylvian dilatation, and high convexity tightness by neuroimaging, and a clinical triad of iNPH symptoms, i.e. cognitive, gait and urinary symptoms.

RESULTS

In the memory clinic-based study (548 subjects), the prevalence of DESH was 1.1% and increased with age. The clinical triad was significantly more frequent in subjects with DESH (50%) compared to those with normal images (none), Sylvian dilatation (7%), and ventriculomegaly (12%). Gait disturbance was also significantly more frequent in DESH (83%) compared to those with normal images (2%), Sylvian dilatation (14%), and ventriculomegaly (26%). In the community-based cohort (946 subjects), the prevalence of DESH was 1.0% and increased with age. The clinical triad (11%) was significantly more common in subjects with DESH compared to those with normal images (none), Sylvian dilatation (2%), and ventriculomegaly (7%). Gait disturbance was also significantly more common in DESH (33%) compared to those with normal images (1%), Sylvian dilatation (4%), and ventriculomegaly (10%).

CONCLUSION

The reported prevalence of DESH was approximately 1%, and increased with age. DESH and high convexity tightness were specifically associated with the clinical triad of iNPH. Of the triad, gait disturbance was associated to DESH and high convexity tightness.

CSF biomarkers distinguish idiopathic normal pressure hydrocephalus from its mimics

OBJECTIVE

To examine the differential diagnostic significance of cerebrospinal fluid (CSF) biomarkers reflecting Alzheimer's disease-related amyloid β (Aβ) production and aggregation, cortical neuronal damage, tau pathology, damage to long myelinated axons and astrocyte activation, which hypothetically separates patients with idiopathic normal pressure hydrocephalus (iNPH) from patients with other neurodegenerative disorders.

METHODS

The study included lumbar CSF samples from 82 patients with iNPH, 75 with vascular dementia, 70 with Parkinson's disease, 34 with multiple system atrophy, 34 with progressive supranuclear palsy, 15 with corticobasal degeneration, 50 with Alzheimer's disease, 19 with frontotemporal lobar degeneration and 54 healthy individuals (HIs). We analysed soluble amyloid precursor protein alpha (sAPPα) and beta (sAPPβ), Aβ species (Aβ38, Aβ40 and Aβ42), total tau (T-tau), phosphorylated tau, neurofilament light and monocyte chemoattractant protein 1 (MCP-1).

RESULTS

Patients with iNPH had lower concentrations of tau and APP-derived proteins in combination with elevated MCP-1 compared with HI and the non-iNPH disorders. T-tau, Aβ40 and MCP-1 together yielded an area under the curve of 0.86, differentiating iNPH from the other disorders. A prediction algorithm consisting of T-tau, Aβ40 and MCP-1 was designed as a diagnostic tool using CSF biomarkers.

CONCLUSIONS

The combination of the CSF biomarkers T-tau, Aβ40 and MCP-1 separates iNPH from cognitive and movement disorders with good diagnostic sensitivity and specificity. This may have important implications for diagnosis and clinical research on disease mechanisms for iNPH.

Current epidemiology of cerebrospinal fluid shunt surgery in the UK and Ireland (2004-2013)

OBJECTIVES

To determine current epidemiology and clinical characteristics of cerebrospinal fluid (CSF) shunt surgery, including revisions.

METHODS

A retrospective, multicentre, registry-based study was conducted based on 10 years' data from the UK Shunt Registry, including primary and revision shunting procedures reported between 2004 and 2013. Incidence rates of primary shunts, descriptive statistics and shunt revision rates were calculated stratified by age group, geographical region and year of operation.

RESULTS

41 036 procedures in 26 545 patients were submitted during the study period, including 3002 infants, 4389 children and 18 668 adults. Procedures included 20 947 (51.0%) primary shunt insertions in 20 947 patients, and 20 089 (49.0%) revision procedures. Incidence rates of primary shunt insertions for infants, children and adults were 39.5, 2.4 and 3.5 shunts per 100 000 person-years, respectively. These varied by geographical subregion and year of operation. The most common underlying diagnoses were perinatal intraventricular haemorrhage (35.3%) and malformations (33.9%) in infants, tumours (40.5%) and malformations (16.3%) in children, and tumours (24.6%), post-haemorrhagic hydrocephalus (16.2%) and idiopathic normal pressure hydrocephalus (14.2%) in adults. Ninety-day revision rates were 21.9%, 18.6% and 12.8% among infants, children and adults, respectively, while first-year revision rates were 31.0%, 25.2% and 17.4%. The main reasons for revision were underdrainage and infection, but overdrainage and mechanical failure continue to pose problems.

CONCLUSIONS

Our report informs patients, carers, clinicians, providers and commissioners of healthcare, researchers and industry of the current epidemiology of shunting for CSF disorders, including the potential risks of complications and frequency of revision.

Global hydrocephalus epidemiology and incidence: systematic review and meta-analysis

OBJECTIVE

Hydrocephalus is one of the most common brain disorders, yet a reliable assessment of the global burden of disease is lacking. The authors sought a reliable estimate of the prevalence and annual incidence of hydrocephalus worldwide.

METHODS

The authors performed a systematic literature review and meta-analysis to estimate the incidence of congenital hydrocephalus by WHO region and World Bank income level using the MEDLINE/PubMed and Cochrane Database of Systematic Reviews databases. A global estimate of pediatric hydrocephalus was obtained by adding acquired forms of childhood hydrocephalus to the baseline congenital figures using neural tube defect (NTD) registry data and known proportions of posthemorrhagic and postinfectious cases. Adult forms of hydrocephalus were also examined qualitatively.

RESULTS

Seventy-eight articles were included from the systematic review, representative of all WHO regions and each income level. The pooled incidence of congenital hydrocephalus was highest in Africa and Latin America (145 and 316 per 100,000 births, respectively) and lowest in the United States/Canada (68 per 100,000 births) (p for interaction < 0.1). The incidence was higher in low- and middle-income countries (123 per 100,000 births; 95% CI 98-152 births) than in high-income countries (79 per 100,000 births; 95% CI 68-90 births) (p for interaction < 0.01). While likely representing an underestimate, this model predicts that each year, nearly 400,000 new cases of pediatric hydrocephalus will develop worldwide. The greatest burden of disease falls on the African, Latin American, and Southeast Asian regions, accounting for three-quarters of the total volume of new cases. The high crude birth rate, greater proportion of patients with postinfectious etiology, and higher incidence of NTDs all contribute to a case volume in low- and middle-income countries that outweighs that in high-income countries by more than 20-fold. Global estimates of adult and other forms of acquired hydrocephalus are lacking.

CONCLUSIONS

For the first time in a global model, the annual incidence of pediatric hydrocephalus is estimated. Low- and middle-income countries incur the greatest burden of disease, particularly those within the African and Latin American regions. Reliable incidence and burden figures for adult forms of hydrocephalus are absent in the literature and warrant specific investigation. A global effort to address hydrocephalus in regions with the greatest demand is imperative to reduce disease incidence, morbidity, mortality, and disparities of access to treatment.

Age-specific global epidemiology of hydrocephalus: Systematic review, metanalysis and global birth surveillance

Background

Hydrocephalus is a debilitating disorder, affecting all age groups. Evaluation of its global epidemiology is required for healthcare planning and resource allocation.

Objectives

To define age-specific global prevalence and incidence of hydrocephalus.

Methods

Population-based studies reporting prevalence of hydrocephalus were identified (MEDLINE, EMBASE, Cochrane, and Google Scholar (1985–2017)). Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Two authors reviewed abstracts, full text articles and abstracted data. Metanalysis and meta-regressions were used to assess associations between key variables. Heterogeneity and publication bias were assessed. Main outcome of interest was hydrocephalus prevalence among pediatric (≤ 18 years), adults (19–64 years), and elderly (≥ 65) patients. Annual hydrocephalus incidence stratified by country income level and folate fortification requirements were obtained (2003–2014) from the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR).

Results

Of 2,460 abstracts, 52 met review eligibility criteria (aggregate population 171,558,651). Mean hydrocephalus prevalence was 85/100,000 [95% CI 62, 116]. The prevalence was 88/100,000 [95% CI 72, 107] in pediatrics; 11/100,000 [95% CI 5, 25] in adults; and 175/100,000 [95% CI 67, 458] in the elderly. The ICBDSR-based incidence of hydrocephalus diagnosed at birth remained stable over 11 years: 81/100,000 [95% CI 69, 96]. A significantly lower incidence was identified in high-income countries.

Conclusion

This systematic review established age-specific global hydrocephalus prevalence. While high-income countries had a lower hydrocephalus incidence according to the ICBDSR registry, folate fortification status was not associated with incidence. Our findings may inform future healthcare resource allocation and study.

Shunt surgery in idiopathic normal pressure hydrocephalus is cost-effective-a cost utility analysis

Background

The objective was to evaluate the cost-effectiveness of shunt surgery in patients with idiopathic normal pressure hydrocephalus (iNPH).

Methods

Health-related quality of life was evaluated before and 6 months after surgery using the EQ-5D-3 L (EuroQOL group five-dimensions health survey) in 30 patients (median age, 71 years; range, 65–89 years) diagnosed with iNPH. The costs associated with shunt surgery were assessed by a detailed survey with interviews and extraction of register data concerning the cost of hospital care, primary care, residential care, home-care service and informal care. The cost of untreated patients was derived from the cost of dementia disorders in Sweden in 2012, as reported by the National Board of Health and Welfare. The cost effectiveness analysis used a decision-analytic Markov model. We used a societal perspective and a lifelong time horizon to estimate costs and effects. One-way sensitivity analysis and probabilistic sensitivity analysis were carried out to test the robustness of the model.

Results

The shunt surgery model as the standard treatment in iNPH resulted in a gain of 2.2 life years and 1.7 quality-adjusted life years (QALY), along with an incremental cost per patient of €7,500/QALY. The sensitivity analysis showed that the results were not sensitive to changes in uncertain parameters or assumptions.

Conclusions

Shunt surgery in iNPH, an underdiagnosed condition severely impairing elderly patients, is not only an effective medical treatment, it is also cost-effective, adding 2.2 additional life years and 1.7 QALYs at a low cost, a remarkable gain for an individual aged around 70 years.

Incidence, Comorbidities, and Mortality in Idiopathic Normal Pressure Hydrocephalus

OBJECT

To investigate the incidence, comorbidities, mortality, and causes of death in idiopathic normal pressure hydrocephalus (iNPH).

METHODS

A cohort of 536 patients with possible NPH from a defined population with a median follow-up time of 5.1 years, (range 0.04-19.9 years) was included in the study. Patients were evaluated by brain imaging and intraventricular pressure monitoring, with a brain biopsy specimen immunostained against amyloid-β and hyperphosphorylated τ. Hospital records were reviewed for vascular diseases and type 2 diabetes mellitus (T2DM). Death certificates and yearly population of the catchment area were obtained from national registries.

RESULTS

A total of 283 patients had a clinical diagnosis of iNPH, leading to a median annual incidence of 1.58 iNPH patients per 100,000 inhabitants (range, 0.8-4.5). Alzeimer disease-related brain biopsy findings were less frequent in iNPH patients than in non-iNPH patients (P < 0.05). An overrepresentation of hypertension (52% vs. 33%, P < 0.001) and T2DM (23% vs. 13%, P = 0.002) was noted in iNPH patients. Age (hazard ratio [HR] 1.04/year, 95% confidence interval [CI] 1.03-1.06, P < 0.001) and T2DM (HR 1.63, 95% CI 1.23-2.16, P < 0.001) increased the risk of death in the iNPH patients and in the total population. iNPH was associated with decreased risk of death (HR 0.63, 95% CI 0.50-0.78, P < 0.001). The most frequent causes of death were cardiovascular and cerebrovascular disease. Dementia as a cause of death was more common in non-iNPH patients (27% vs. 10%, P < 0.001).

CONCLUSIONS

Hypertension and T2DM are common in iNPH and the latter causes excess mortality in the affected patients.

[Idiopathic normal pressure hydrocephalus: High incidence in people over 80 years of age]

INTRODUCTION

Idiopathic normal pressure hydrocephalus is usually observed in adults over 60 years of age. The highest incidence of cases is between 70 and 80 years-old, and it could be under-diagnosed in over 80 year-olds.

OBJECTIVE

A description is presented on the overall incidence and age group incidence, the delay in the diagnosis, and main outcomes.

PATIENTS AND METHODS

A descriptive study was performed on patients with idiopathic normal pressure hydrocephalus, in the population of Osona County during the years 2010-2015.

RESULTS

The annual incidence rate was 4.43 per 100,000 inhabitants. The incidence increased with age; from 8.09 per 100,000 in the 60 to 69 years age group, to 23.61 per 100,000 in the 70-79 years age group of, and to 37.02 per 100,000 in the 80-89 years age. The delay in the diagnosis was 15.01 ± 10.35 months. All the patients improved after surgery, but only 73.3% of the patients maintained the improvement after one year.

CONCLUSIONS

Idiopathic normal pressure hydrocephalus is an age related disease and probably underdiagnosed in the elderly. An early diagnosis and a clinical suspicion are essential in patients over 80 years old.

Epidemiology of adult-onset hydrocephalus: institutional experience with 2001 patients

OBJECTIVE Adult-onset hydrocephalus is not commonly discussed in the literature, especially regarding its demographic distribution. In contrast to pediatric hydrocephalus, which is related to a primary CSF pathway defect, its development in adults is often secondary to other pathologies. In this study, the authors investigated the epidemiology of adult-onset hydrocephalus as it pertains to different etiologies and in reference to age, sex, and race distributions. METHODS The authors retrospectively reviewed the clinical notes of 2001 patients with adult-onset hydrocephalus who presented to Louisiana State University Health Sciences Center within a 25-year span. Significant differences between the groups were analyzed by a chi-square test; p < 0.05 was considered significant. RESULTS The overall mean (± SEM) incidence of adult hydrocephalus in this population was 77 ± 30 per year, with a significant increase in incidence in the past decade (55 ± 3 [1990-2003] vs 102 ± 6 [2004-2015]; p < 0.0001). Hydrocephalus in a majority of the patients had a vascular etiology (45.5%) or was a result of a tumor (30.2%). The incidence of hydrocephalus in different age groups varied according to various pathologies. The incidence was significantly higher in males with normal-pressure hydrocephalus (p = 0.03) or head injury (p = 0.01) and higher in females with pseudotumor cerebri (p < 0.0001). In addition, the overall incidence of hydrocephalus was significantly higher in Caucasian patients (p = 0.0002) than in those of any other race. CONCLUSIONS Knowledge of the demographic variations in adult-onset hydrocephalus is helpful in achieving better risk stratification and better managing the disease in patients. For general applicability, these results should be validated in a large-scale meta-analysis based on a national population database.

Mortality and risk of dementia in normal-pressure hydrocephalus: A population study

INTRODUCTION

We examined mortality, dementia, and progression of hydrocephalic symptoms among untreated individuals with idiopathic normal-pressure hydrocephalus (iNPH) in a population-based sample.

METHODS

A total of 1235 persons were examined between 1986 and 2012. Shunted individuals were excluded. We examined 53 persons with hydrocephalic ventricular enlargement (probable iNPH: n = 24, asymptomatic or possible iNPH: n = 29). Comparisons were made with individuals without hydrocephalic ventricular enlargement.

RESULTS

The 5-year mortality was 87.5% among those with probable iNPH. The hazard ratio (HR) for death was 3.8 (95% confidence interval [CI]: 2.5-6.0) for probable iNPH. Those with possible iNPH and asymptomatic hydrocephalic ventricular enlargement had increased risk of developing dementia, HR 2.8 (95% CI: 1.5-5.2). Only two individuals with hydrocephalic ventricular enlargement remained asymptomatic.

DISCUSSION

In the present sample, persons with clinical and imaging signs of iNPH had excess mortality and an increased risk of dementia. The data also suggest that radiological signs of iNPH might be more important than previously supposed.

Diagnosis and Treatment of Idiopathic Normal Pressure Hydrocephalus

PURPOSE OF REVIEW

This article provides neurologists with a pragmatic approach to the diagnosis and treatment of idiopathic normal pressure hydrocephalus (iNPH), including an overview of: (1) key symptoms and examination and radiologic findings; (2) use of appropriate tests to determine the patient's likelihood of shunt responsiveness; (3) appropriate referral to tertiary centers with expertise in complex iNPH; and (4) the contribution of neurologists to the care of patients with iNPH following shunt surgery.

RECENT FINDINGS

The prevalence of iNPH is higher than previously estimated; however, only a fraction of persons with the disorder receive shunt surgery. iNPH should be considered as a diagnosis for patients with unexplained symmetric gait disturbance, a frontal-subcortical pattern of cognitive impairment, and urinary urge incontinence, whose MRI scans show enlarged ventricles and whose comorbidities are not sufficient to explain their symptoms. Physiologically based tests, such as the tap test (large-volume lumbar puncture) or temporary spinal catheter insertion for external lumbar drainage with gait testing before and after CSF removal, or CSF infusion testing for measurement of CSF outflow resistance, can reliably identify patients who are likely to respond to shunt surgery. Properly selected patients have an 80% to 90% chance of responding to shunt surgery, and all symptoms can improve following shunt surgery. Longitudinal care involves investigating the differential diagnosis of any symptoms that either fail to respond to shunt surgery or that worsen after initial improvement from shunt surgery.

SUMMARY

Neurologists play an important role in the identification of patients who should be evaluated for possible iNPH. With contemporary diagnostic tests and treatment with programmable shunts, the benefit-to-risk ratio of shunt surgery is highly favorable. For more complex patients, tertiary centers with expertise in complex iNPH are available throughout the world.

Anatomic Eponyms in Neuroradiology: Brain, Cerebral Vasculature, and Calvarium

Medical eponyms are ubiquitous, numerous, and at times controversial. They are often useful for succinctly conveying complex concepts, and familiarity with eponyms is important for proper usage and appropriate communication. In this historical review, we identify 18 anatomic eponyms used to describe structures of the brain, cerebral vasculature, and calvarium. For each structure, we first offer a biographical sketch of the individual for whom the structure is named. This is followed by a description of the anatomic structure and a brief discussion of its clinical relevance.

Nationwide Incidence of Normal Pressure Hydrocephalus (NPH) Assessed by Insurance Claim Data in Germany

BACKGROUND

The purpose of this study is to investigate the epidemiology of the idiopathic normal pressure hydrocephalus (iNPH) in Germany.

METHODS

The database of the nationwide Barmer Health Insurance was queried for specific combinations of corresponding International Classification of Diseases, Ninth Revision (ICD-9) codes and OPS codes (German modification of the ICPM and official classification of surgical procedures) in order to assess the number of patients treated for iNPH and the number surgical procedures associated with the disease in a 10 years period between 2003 and 2012.

RESULTS

Between 2003 and 2012, the incidence of iNPH increased from zero to 1.36/100.000/year.

CONCLUSION

This is the first population-based epidemiologic study on iNPH in Germany covering a ten year period.

Incidence of Idiopathic Normal-Pressure Hydrocephalus in Northern Spain

BACKGROUND

Although the incidence of idiopathic normal-pressure hydrocephalus (iNPH) can be 1.20 cases/1000 inhabitants/year in individuals ≥ 70 years old, in most series, the incidence of shunt-responsive iNPH appears to be <1/100,000 inhabitants/year. We report the results of a prospective 10-year longitudinal study of the incidence of iNPH in a northern Spanish population.

METHODS

In a stable population of 590,000 inhabitants served by a single neurosurgical department, we periodically asked all primary care practitioners, neurologists, and geriatricians to refer for iNPH screening any patient with ventricular dilation who was complaining of motor disturbances, cognitive impairment, or sphincter dysfunction.

RESULTS

From January 2003 to December 2012, 293 patients were referred with suspected normal-pressure hydrocephalus. In 187 patients, iNPH was diagnosed; 89 of these patients were classified as probable iNPH, and 98 were classified as possible iNPH. Cerebrospinal fluid diversion was performed in 152 patients, and 119 showed a good outcome. The incidence of iNPH was significantly greater in male patients and patients >60 years old and increased exponentially with age. After age 60, the standardized age- and sex-adjusted incidence rates for iNPH, shunt surgery for iNPH, and shunt-responsive iNPH were 13.36 cases/100,000 inhabitants/year, 10.85 cases/100,000 inhabitants/year, and 8.55 cases/100,000 inhabitants/year. No differences were detected in the response rate between probable and possible iNPH (80.52% vs. 76.00%; P = 0.497).

CONCLUSIONS

Even with a protocol for patient referral in place, reported iNPH incidence was lower than predicted, reflecting a persistent problem of underdiagnosis in our population.

Epidemiology of Idiopathic Normal Pressure Hydrocephalus: A Systematic Review of the Literature

BACKGROUND

Idiopathic normal pressure hydrocephalus (iNPH) is an important cause of gait disturbance and cognitive impairment in elderly adults. However, the epidemiology of iNPH is relatively unknown, largely as a result of the paucity of specifically designed population studies. This systematic review aims to assess the prevalence and incidence of iNPH.

METHODS

A systematic literature review on the epidemiology of iNPH was conducted using MEDLINE/PubMed searching for articles published up to June 2014.

RESULTS

The inclusion criteria were met by 21 studies. Of the studies, 12 were specifically designed for detecting cases of iNPH; however, only 4 were prospective. In people >65 years old, pooled prevalence obtained from specific population studies was 1.3%, which was almost 50-fold higher than that inferred from door-to-door surveys of dementia or parkinsonism. Prevalence may be higher in assisted-living and extended-care residents, with 11.6% of patients fulfilling the criteria for suspected iNPH and 2.0% of patients showing permanent improvement after cerebrospinal fluid diversion. The only prospective population-based survey that reported iNPH incidence estimated 1.20 cases/1000 inhabitants/year, 15-fold higher than estimates obtained from studies based on hospital catchment areas. The incidence of shunt surgery for iNPH and shunt-responsive iNPH obtained from incident cases of hospital catchment areas appears to be <2 cases/100,000 inhabitants/year and 1 case/100,000 inhabitants/year, respectively. No population-based study reporting the real values for these 2 parameters could be found.

CONCLUSIONS

iNPH appears to be extremely underdiagnosed. Properly designed and adequately powered population-based studies are required to characterize the epidemiology of this disease accurately.

Diagnosis and prognosis in idiopathic normal pressure hydrocephalus

Idiopathic normal pressure hydrocephalus (iNPH) is a communicating hydrocephalus, of unknown pathophysiology, characterized by the classical triad of dementia, urinary incontinence, and ataxia. The most popular treatment option is shunt surgery, although it is not a cure. The diagnosis of the disorder is challenging as it may mimic a lot of other neurological conditions and has no distinct biomarker. It becomes even more challenging as majority of the cases are diagnosed by invasive cerebrospinal fluid (CSF) removal tests. However, a careful history taking, a keen and detailed physical examination, and pertinent imaging studies can lead to an early diagnosis. The gait symptoms respond the most to surgery. The predictors deciding the postsurgical prognosis has been discussed. Improved shunting modalities and novel shunt materials with valve adjustments have improved the precision of the shunting procedures. Still we have lot more to achieve in terms of early diagnosis and definitive management of iNPH.

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.

Assessment of the urodynamic diagnosis in patients with urinary incontinence associated with normal pressure hydrocephalus

AIMS

To assess the urodynamic patterns present in patients with adult normal pressure hydrocephalus (NPH) in our institution.

METHODS

Retrospectively conducted study on patients diagnosed with NPH by the Neurosurgery Department of our institution, without etiological treatment or urogynecological disorders, who underwent an urodynamic study (UDS) performed according to methods proposed by the International Society of Continence (ICS). Clinical information, complementary tests and UDS were collected, and descriptive analysis was performed, with special focus in urodynamic final diagnosis.

RESULTS

Eighty-one UDS performed between 2003 and 2013. Fifty-one Males (63%). Mean age: 74.89 ± 8.58 years old (range 52-88 years). Classical triad of symptoms: gait disturbance, dementia, and urinary incontinence (UI) presented in 48.1%. Urinary urgency in 80.9% and UI in 70%. In two cases (2.5%) UDS was not valuable. Urodynamic features of the 79 remaining studies revealed overactive detrusor (OD) in 56 patients (70.9%), being associated with Stress UI (SUI) in one case and with bladder outlet obstruction (BOO) in 19. SUI in six patients (7.6%) and BOO in five (6.3%). Detrusor underactivity in four cases (5%) and normal study in eight (10.1%). About 47.1% of males presented BOO. Cerebrospinal fluid shunt surgery was performed on 32 patients during follow-up, with subsequent clinical improvement in 90.6% of them.

CONCLUSIONS

OD was the most frequent diagnosis within UDS conducted on adult NPH patients in our institution, with BOO in an elevated percentage of them. Etiological treatment led to symptomatic improvement in most of patients.

Normal pressure hydrocephalus: how often does the diagnosis hold water?

OBJECTIVE

To determine our community's incidence of clinically suspected normal pressure hydrocephalus (NPH), the rate of shunting for NPH, and short- and long-term outcomes of shunting.

METHODS

A retrospective query of the Mayo Clinic medical records linkage system was conducted to identify residents of Olmsted County, Minnesota, undergoing an invasive diagnostic procedure for evaluation of suspected NPH from 1995 through 2003. Among patients with shunts, early- and long-term outcomes were determined via a review of available medical records.

RESULTS

Forty-one patients underwent an invasive diagnostic procedure for evaluation of suspected NPH; 13 ultimately received shunts, representing an incidence of 1.19/100,000/year. The incidence of sustained definite improvements at 3 years after shunting was only 0.36/100,000/year. Definite gait improvement was documented in 75% at 3-6 months after shunt placement, although it dropped to 50% at 1 year and to 33% at 3 years. Only 1 of 8 patients with cognitive impairment and 1 of 6 patients with urinary incontinence had definite improvement in these symptoms at 3 years. No patient with moderate to severe postural instability experienced sustained definite improvement in any symptom. Complications occurred in 33% of patients including one perioperative death. Additional or alternative neurologic diagnoses later surfaced in 5 of 12 patients.

CONCLUSIONS

In this community, NPH is relatively rare with an incidence approximating that of progressive supranuclear palsy in this population. Whereas early gait improvement was common, only one-third of patients enjoyed continued improvement by 3 years; cognition or urinary incontinence was even less responsive long term. Baseline postural instability predicted poor outcome. Clinicians should balance potential benefits of shunting against the known risks.

Rehabilitation of patients with chronic normal-pressure hydrocephalus after aneurysmal subarachnoid hemorrhage benefits from ventriculoperitoneal shunt

This study compares the effect and rehabilitation prognosis of 6-month combined ventriculoperitoneal shunt (VPS) versus rehabilitation training alone in chronic normal-pressure hydrocephalus patients.

METHOD

After suffering from aneurysmal subarachnoid hemorrhage, 39 subjects were diagnosed with chronic normal-pressure hydrocephalus because of clinical deterioration or nonimprovement of gait ataxia, cognitive disturbance, and/or urinary incontinence during rehabilitation. Twenty-four subjects underwent ventriculoperitoneal shunt (VPS) placement, while 15 subjects did not undergo the procedure.

RESULTS

Statistically significant increases in the Barthel Index (BI) were observed between the treatment and control groups 1 month (p < .05) and 6 months (p < .01) after VPS placement. Similar changes also were observed for the Mini-Mental State Examination (MMSE) at the 1-month (p < .01) and 6-month follow-up visits (p < .01). Significant differences in the change in MMSE and BI at admission, before VPS placement, and at 1 month and 6 months after VPS placement in the treatment group were demonstrated (p < .01).

CONCLUSION

Chronic normal-pressure hydrocephalus after aneurysmal subarachnoid hemorrhage is an important issue to which clinicians should pay attention. It negatively influences the functional and behavioral outcome of rehabilitation but can be treated.

Five-year incidence of surgery for idiopathic normal pressure hydrocephalus in Norway

OBJECTIVES

We have previously determined the incidence and prevalence of idiopathic normal pressure hydrocephalus (iNPH) in the county of Vestfold in Norway. This study aimed at determining the incidence of surgeries for iNPH.

MATERIALS AND METHODS

Information about age, sex, operation year and operation type was collected retrospectively for all patients hospitalized from 2002 to 2006 with any diagnosis of iNPH and operated with insertion of a ventriculo-peritoneal or ventriculoatrial shunt system, or with endoscopic third ventriculostomy in any of Norway's five regional neurosurgical centers.

RESULTS

Two hundred fifty-two patients were operated during the 5-year period, making the total incidence 1.09/100,000/year. The yearly incidence ranged from a minimum of 0.84/100,000 in 2006 to a maximum of 1.47/100,000 in 2004. The incidence was highest in the age group 70-79 years. There were little regional differences regarding incidence, sex, and age and operation type.

CONCLUSIONS

The data suggest that too few patients are being offered surgical treatment for iNPH in Norway.

Treatment of hydrocephalus in adults

The following patients with multiple complex diagnoses define the adult hydrocephalus population: (1) transition patients (previously treated for hydrocephalus as children), (2) adults with previously untreated congenital hydrocephalus, (3) adults with acquired hydrocephalus with an identifiable etiology, and (4) patients with suspected or proven idiopathic normal pressure hydrocephalus. Restricting the outpatient care or hydrocephalus clinic definition to a single hydrocephalus patient subpopulation limits our understanding of these patients and effectively abandons the remaining adult patients with hydrocephalus to a less focused and potentially less effective healthcare arrangement. A comprehensive adult hydrocephalus clinic model is described and recommended to advance our understanding of this diverse patient population, which will ultimately lead to the development and provision of a better standard of patient care.

Brain metabolism in adult chronic hydrocephalus

Normal pressure hydrocephalus (NPH) is the most frequent form of chronic hydrocephalus in adults. NPH remains underdiagnosed although between 5% and 10% of all demented patients may suffer from this disorder. As dementia is an increasing demographic problem, treatable forms such as in NPH have become a central issue in neurology. Despite the traditional perception of hydrocephalus being a disorder of disturbed CSF dynamics, in NPH metabolic impairment seems at least as important. So far, the only valid animal model of NPH is chronic adult kaolin hydrocephalus. In this model, opening of alternative CSF outflow pathways leads to normal or near-normal intracranial pressure and CSF outflow resistance. Yet, various metabolic disturbances cause ongoing ventricular enlargement and characteristic symptoms including cognitive decline and gait ataxia. Delayed hippocampal neuronal death, accumulation of beta-amyloid and disturbed cholinergic neurotransmission may contribute to memory dysfunction. Compromised periventricular blood flow, decreased dopamine levels in the substantia nigra and damaged striatal GABAergic interneurons may reflect basal ganglia symptoms. At least in human hydrocephalus cerebrovascular co-morbidity of the white matter plays an important role as well. It seems that in hydrocephalus from a certain 'point of no return' metabolic impairment becomes decoupled from CSF dynamics and, at least partly, self-sustained. This is probably the reason why despite restored CSF circulation by shunting many patients with chronic hydrocephalus still suffer from severe neurological deficits. The present paper offers a comprehensive review of the experimental and clinical data suggesting metabolic disturbances in chronic hydrocephalus.

Biomarkers in chronic adult hydrocephalus

Awareness of the importance of chronic adult hydrocephalus has been raised again with the recent emergence of epidemiological studies. It is estimated that between 5 and 10% of patients suffering from dementia might, in fact, have chronic hydrocephalus. Although, surgical diversion of the cerebrospinal fluid (CSF) represents the only known procedure able to treat the symptoms of this condition, the selection of surgical patients has always been problematic. In the last 40 years, we have become wiser in using appropriate diagnostic tests for the selection of these patients; however, the area of biological markers has so far been overlooked in this condition, in contrast to that for other neurodegenerative disorders and dementias. Biomarkers are biological substances that may be used to indicate either the onset or the presence, and the progression of a clinical condition, being closely linked to its pathophysiology. In such a setting they might assist in the more appropriate selection of patients for shunt surgery. In this article, we have reviewed research carried out in the last 25 years regarding the identification of serum and CSF biomarkers for chronic hydrocephalus, discussed the potential for each one, and finally discussed the limitations for use, as well as future directions and possibilities in this field. It is concluded that tumour-necrosis factor, tau protein, lactate, sulfatide and neurofilament triple protein are the most promising CSF markers for chronic hydrocephalus. At present however, none of these meet the criteria required to justify a change clinical practice. In the future, collaborative multi-centre projects will be needed to obtain more substantial data that overcome the problems that arise from small individual and uncoordinated studies.

Intracranial Pressure during Wakefulness and Sleep in 55 Adult Patients with Chronic Hydrocephalus

OBJECTIVE:

To record the levels of intracranial pressure (ICP) during wakefulness and sleep in hydrocephalic adults and to correlate the ICP levels with symptoms and degree of improvement after surgical treatment.

METHODS:

ICP and patient behavior were registered overnight (17–26 h) in 29 patients with noncommunicating and 26 with communicating hydrocephalus. Mean ICP was calculated during wakefulness (sitting or lying supine) and during sleep. Clinical symptoms and changes after surgery were scored on a continuous scale.

RESULTS:

Mean ICP during sleep was 13.4 mmHg (11.1–15.7 mmHg) in noncommunicating hydrocephalus versus 10.1 mmHg (8.8–11.4 mmHg) in communicating hydrocephalus (P &lt; 0.001). Patients with idiopathic communicating hydrocephalus had higher ICP, 11.4 mmHg (9.9–12.9 mmHg), than patients with secondary communicating hydrocephalus, 8.6 mmHg (6.5–10.6 mmHg). ICP was higher during sleep than when the patients were awake lying supine, 10.9 mmHg (8.7–13.1 mmHg) in noncommunicating versus 6.8 mmHg (5.3–8.3 mmHg) in communicating hydrocephalus (P &lt; 0.0001). The mean ICP in the sitting position was 2.4 mmHg (0.5–4.3 mmHg) in noncommunicating versus 0.5 mmHg (-0.7–1.8 mmHg) in communicating hydrocephalus. All but one patient with communicating hydrocephalus had a normal ICP (≤ 15 mmHg) versus 20 of the 29 patients with noncommunicating hydrocephalus. ICP levels showed no correlation with either symptoms or improvement after surgery.

CONCLUSION:

ICP is higher during sleep than during periods of awake lying supine (P &lt; 0.001) and is not correlated with either symptoms or the rate of improvement after surgery. ICP is normal in most adults with hydrocephalus.