Prevalence of idiopathic normal pressure hydrocephalus: A prospective, population-based study

Splenial angle on axial T1 and fluid-attenuated inversion-recovery MRI images and idiopathic normal pressure hydrocephalus

OBJECTIVES

The splenial angle (SA), measured on axial DTI colour fractional anisotropy MRI, outperformed the callosal angle (CA) in predicting idiopathic normal pressure hydrocephalus (NPH) patients from those with Alzheimer's dementia, Parkinson's disease (PD), and healthy controls (HC). We investigated its reliability and classification performance on more commonly acquired T1 magnetization-prepared rapid gradient-echo (MPRAGE) and fluid-attenuated inversion-recovery (FLAIR) images.

METHODS

Splenial angle was measured on axial MPRAGE and FLAIR images in 57 subjects (19 NPH, PD and HC each) by 2 raters and compared across groups. Receiver operating characteristics (ROC) analysis was used to assess its classification performance, differentiating NPH from non-NPH groups, in comparison to the CA.

RESULTS

Inter-rater reliability for SA was excellent (intraclass correlation coefficients ≥ 0.91). Splenial angle was effective in differentiating NPH from non-NPH patients on MPRAGE and FLAIR images (P < .001). Its ROC curves showed excellent performance classifying NPH from HC (Area under the curve [AUC] 1) and PD (AUC > 0.93) groups and were highly comparable to those for CA (1; 0.947). Angles wider than 60° and narrower than 45° robustly (100%) excluded and predicted NPH from HC, respectively. The narrower 45° cutoff yielded better sensitivity (84.2%-89.5%) in differentiating NPH from PD patients.

CONCLUSIONS

The SA on MPRAGE/FLAIR images showed excellent inter-rater reliability and classification performance predicting NPH from non-NPH groups, rivalling those of the CA.

ADVANCES IN KNOWLEDGE

The SA on MPRAGE and FLAIR images is reproducible and shows excellent diagnostic performance, differentiating NPH from non-NPH groups, with potential to replace the CA in NPH screening given its accessibility on routine axial neuroimaging.

Effect of ventricular volume on cerebrospinal fluid Alzheimer's disease biomarkers in patients with idiopathic normal pressure hydrocephalus

BackgroundIdiopathic normal pressure hydrocephalus (iNPH) is a common disorder in aging populations. Alzheimer's disease (AD) is a significant comorbidity in iNPH patients, and the presence of AD pathology is associated with worse shunting outcomes. Cerebrospinal fluid (CSF) concentrations of AD-associated biomarkers in iNPH patients are universally reduced and the exact mechanism related to this is unknown.ObjectiveOur aim was to study the effects of ventricular volume on CSF AD-associated biomarker levels in iNPH patients, to determine whether a dilution effect occurs and to assess if brain AD pathology contributes to this effect.MethodsA total of 153 iNPH patients had lumbar CSF samples available for analysis, along with brain MRIs of sufficient quality. Automated image analysis software was used to determine the volume of different brain segments. Volumes normalized for age, sex and head size were used for analysis. Brain biopsy data on AD pathology was also available.ResultsNone of the intracerebral ventricular volumes correlated with CSF levels of AD-associated biomarkers, indicating no dilution effect was present in this context. However, in iNPH patients positive for amyloid-β pathology in the biopsy, the volume of the fourth ventricle correlated inversely with all investigated biomarkers.ConclusionsIntracerebral ventricular volumes do not correlate with AD biomarker levels in CSF, arguing against a dilution effect. However, in patients with AD pathology, the volume of the fourth ventricle is inversely correlated with CSF T-Tau and P-Tau181 levels, suggesting a complex relationship between brain AD pathology, CSF flow and CSF volume in iNPH patients.

Fundoscopy as a diagnostic biomarker in idiopathic normal pressure hydrocephalus: a pilot study

Background

Idiopathic normal pressure hydrocephalus (iNPH) has a prevalence of approximately 5%. It is characterised by Hakim's triad of impaired gait, cognitive dysfunction and urinary incontinence. Despite radiological markers and liquor-dynamic tests, iNPH is difficult to diagnose due to many overlapping symptoms. The aim of this study was to evaluate funduscopy as a noninvasive method of screening patients with suspected iNPH.

Methods

Patients with suspected iNPH who underwent a lumbar infusion test (LIT) were included. Funduscopy was performed before the start of the LIT, and intracranial pressure (ICP) was continually measured via lumbar cannulation. Retinal images were analysed using an artificial intelligence algorithm to determine the arteriole-venule (A/V) ratio. The A/V ratio and ICP measurements were compared with the iNPH diagnosis. In addition, the mean difference in shunt response was evaluated.

Results

A significantly lower mean A/V ratio was found in the iNPH group compared with the non-iNPH group (p value: 0.02). Receiver operating characteristic curve analysis with an area under the curve of 0.75 showed a sensitivity of 88% and a specificity of 50% with an A/V cut-off of 0.86. Although not statistically significant, the mean A/V ratio was lower in the group with clinical shunt effect compared with those without (p value: 0.305).

Conclusions

This study found a statistically significant difference in baseline A/V ratios between iNPH and non-iNPH groups. This pilot study suggests the A/V ratio might be able to serve as a screening tool for iNPH. If so, this would be highly beneficial for patients and could have significant medical and socioeconomic implications.

Long-term outcomes of ventriculoperitoneal shunt therapy in idiopathic normal pressure hydrocephalus

BACKGROUND

Limited data are available regarding the long-term functional outcomes and associated factors in patients with idiopathic normal pressure hydrocephalus (iNPH) undergoing ventriculoperitoneal shunt (VPS) placement. This study aimed to retrospectively evaluate the long-term outcomes of iNPH patients treated with VPS.

METHODS

Functional outcomes were assessed preoperatively and at 1-year, 2-year, and 3-year intervals postoperatively using the modified Rankin Scale (mRS), the iNPH grading scale (iNPHGS), and the Mini-Mental State Examination (MMSE).

RESULTS

Significant improvements were observed in mRS and iNPHGS scores at 1, 2, and 3 years post-surgery compared to the baseline level. MMSE scores showed significant improvement at 1-year and 3-year follow-ups. Multivariate regression analysis identified key factors influencing changes in mRS scores: postoperative complications and education level at 1 year, postoperative complications at 2 years, and sex, education level, postoperative complications, and smoking at 3 years. For iNPHGS scores, significant factors included sex, age at surgery, and smoking at 1 and 2 years. Changes in MMSE scores were associated with sex and the duration of preoperative symptoms at 1 year, and postoperative complications, education level, and smoking at 3 years.

CONCLUSION

This study affirmed the efficacy and safety of VPS in managing iNPH. Factors influencing postoperative outcomes predominantly included education level, smoking, duration of preoperative symptoms, and postoperative complications. However, further research is required to validate these findings.

Adult Hydrocephalus and the Glymphatic System

Adult hydrocephalus, especially idiopathic normal pressure hydrocephalus (iNPH), involves cerebrospinal fluid (CSF) dysfunction that is associated with impaired waste clearance in the brain, potentially causing toxic protein buildup. This condition shares features with neurodegenerative diseases like Alzheimer's, where amyloid-β and tau proteins accumulate. Recent discoveries in the glymphatic and meningeal lymphatic systems, key in CSF and metabolic waste clearance, provide insights into these protein imbalances. However, altered CSF flow in iNPH may disrupt glymphatic transport, exacerbating protein deposits. This review proposes reframing iNPH as a cerebral "CSF-proteinopathy" disorder, although its full relationship with glymphatic impairment needs further exploration.

Adult Hydrocephalus: Natural History, Clinical Outcomes, Quality of Life, and Health Economics

Adult hydrocephalus comprise a family of disorders characterized by a cerebrospinal fluid dynamic disturbance and a shared core symptomatology. Idiopathic normal pressure hydrocephalus (iNPH) has gained an increasing scientific attention over the past decades and is the most studied type of adult hydrocephalus. While knowledge of iNPH have accumulated and expanded, literature is still meagre in other, more uncommon adult hydrocephalus. In this focused review, we describe the most important advances in the literature on natural course, outcomes, quality of life and health economics with a focus on iNPH, the type of adult hydrocephalus where substantial research data exist.

Diagnostic and Prognostic Biomarkers of Idiopathic Normal Pressure Hydrocephalus in Cerebrospinal Fluid and Blood

Idiopathic normal pressure hydrocephalus (iNPH) is a treatable condition marked by gait disturbances, cognitive decline, and urinary incontinence. Biomarkers play a crucial role in distinguishing iNPH from Alzheimer's disease (AD) and predicting shunt surgery outcomes. Aβ1-42, Aβ1-40, t-tau, and p-tau181 differentiate iNPH from AD, with iNPH showing a higher Aβ1-42/Aβ1-40 ratio and normal tau levels. Neurofilament light chain and soluble amyloid precursor protein derivatives provide prognostic insights with lower preoperative levels linked to better surgical outcomes. Elevated LRG-1 and MCP-1 in cerebrospinal fluid aid in diagnosis and predict favorable responses to shunt surgery, enhancing clinical decision making and patient care.

Improvement of the vestibular functions as measured by video head Impulse test in patients undergoing ventriculoperitoneal shunt surgery for Idiopathic normal pressure Hydrocephalus: Moving Forward in a yet unexplored territory

INTRODUCTION

Idiopathic Normal pressure hydrocephalus (iNPH) is the most common form of reversible dementia in the elderly. Few were investigated about CSF dynamic disturbances and brainstem functions, though it could be a potentially interesting and yet "unexplored" territory. The objective was to evaluate high-frequency VOR through VHIT before and after ventriculoperitoneal (VPS) shunting.

MATERIALS AND METHODS

We investigated a total of 9 patients suffering a confirmed from iNPH diagnosis. Patients underwent video Head Impulse Test (vHIT) before and 10 days after VPS. The VOR measurement was performed focusing on the horizontal semicircular canals (HSC) and on both sides. The PR and saccadic profiles were investigated through vHIT. For each patient, we recorded age, sex, and comorbidities.

RESULTS

Our preliminary results showed a generally reduced gain in the pre-operative phase (average gain on both sides: 0.66 ± 0.14) and an increase in gain in the post-operative phase, detectable at the first re-evaluation (average gain at the first post-operative --operative: 0.79 ± 0.11) and an increased PR preoperatively (average PR on both sides 44.8 ± 28.25) with a reduction in PR postoperatively (average PR on both sides 27.57 ± 21.88). Such results, despite the small cohort, were significant. Furthermore, an interesting age-related effect was outlined for PR and saccades profile.

CONCLUSIONS

The increase in VOR gain is a constant finding as is the reduction in saccade amplitude. The saccadic organization seems to increase after VPS in most patients. Chemical-physical and hydrodynamic variations of the cerebrospinal fluid may explain the parameters change and the improvement of the vestibular function.

Higher-level gait disorders: a population-based study on prevalence, quality of life, depression and confidence in gait and balance

Background

Higher-level gait disorders (HLGDs) are slow, unsteady neurological GDs in older people. GDs can reduce quality of life (QoL) and cause depression. This has not been investigated in HLGD even though some HLGD causes are treatable, potentially affecting associated problems. We aimed to investigate gait and balance confidence, depressive symptoms and QoL in HLGD.

Methods

In a population (n=3769, 65-84y), 798 reported gait impairment (questionnaire) and were clinically examined together with 249 age- and sex-matched controls. Gait property groups were formed: 'HLGD', 'other neurological GD', 'non-neurological GD' or 'no GD'. Swedish Falls Efficacy Scale (FES(S)), Modified Gait Efficacy Scale (mGES), Euro Quality of Life 5-Dimension 5-Level index, Euro Quality of Life Visual Analogue Scale (EQ VAS) and Geriatric Depression Scale-15 (GDS-15) were compared.

Results

In the general population, 38% had GDs, of which 16% (n=87/561) were HLGDs, giving an HLGD prevalence of 5.8%; 26% (n=145/561) were other neurological GDs; and 59% (n=329/561) non-neurological GDs. HLGD had more depressive symptoms than non-neurological GD and no GD (GDS-15 HLGD, 3.9±3.4; non-neurological GD, 2.5±2.8; no GD, 1.4±2.0; p<0.05), lower EQ VAS (HLGD, 63±17; non-neurological GD, 71±18; no GD, 82±14; p<0.001), lower gait confidence (mGES HLGD, 60±22; non-neurological GD, 74±21; no GD, 90±13; p<0.001) and lower balance confidence (FES(S) HLGD, 93±32; non-neurological GD, 111±25; no GD, 124±13; p<0.001).

Conclusions

HLGDs are common and associated with reduced QoL, reduced confidence in gait and balance, and depressive symptoms, emphasising awareness of mental health among older people with slow unsteady gait.

Impact of Surgical Timing on Ventriculoperitoneal Shunt Failure Rates: A Population-Based Cohort Study

OBJECTIVE

Hydrocephalus is a common neurosurgical condition treated primarily through ventriculoperitoneal (VP) shunt placement. This study aims to investigate the relationship between the timing of VP shunt surgery (on-call vs. regular hours) and shunt failure rates.

METHODS

In this single-center, population-based observational cohort study, all adult patients who underwent VP shunt surgery were included. The main outcome was reoperation due to shunt failure within 12 months of the index surgery, comparing rates between procedures performed during regular hours and on-call periods. Adjustments for confounders were made using multivariable logistic regression.

RESULTS

Out of 810 cases included, 25% underwent surgery during on-call hours. Shunt failure occurred in 10% of cases, most often due to infection. Patients operated on during on-call hours had a significantly higher rate of shunt failure compared to those operated on during regular hours (17% vs. 7.9%, P < 0.001). However, after adjusting for confounders in a multivariable logistic regression, this relationship was no longer statistically significant (OR: 1.60, P = 0.073).

CONCLUSIONS

The rate of shunt failure was significantly greater in surgeries conducted during on-call hours as opposed to regular hours, but this was not statistically significant after adjusting for confounders. Therefore, the timing of VP shunt surgery may not be an independent risk factor for shunt failure. High-risk scenarios still deserve added caution, and further research is needed to identify factors influencing shunt outcomes and develop strategies to minimize failure rates.

Long-term outcomes after shunt surgery in older patients with idiopathic normal pressure hydrocephalus

OBJECTIVE

This study aimed to evaluate the survival and functional outcomes in older patients with idiopathic normal pressure hydrocephalus (iNPH) following shunt surgery.

METHODS

We performed shunt surgery in patients with iNPH and followed up at an outpatient clinic. The survival time was analyzed using Kaplan-Meier survival analysis. The maintenance period of activities of daily living (ADL) was measured using the modified Rankin Scale in part of patients.

RESULTS

Out of 200 patients with iNPH (mean age, 78.1 years old, standard deviation, 5.0), 110 had a lumboperitoneal shunt, 68 had a ventriculoperitoneal shunt, and 22 had a ventriculoatrial shunt. The median follow-up time was 5.0 years for all patients, with 99 (49.5 %) dying during the follow-up period. The median overall survival was 7.7 years (5.9 years in males, 8.8 years in females, P = 0.006). The common causes of death were senility, pneumonia, and cancer. Decreased ADL was observed in 66 out of 88 patients (75.0 %) during a median follow-up of 2.2 years. The maintenance period of ADL was 2.6 years in both sexes. The most common cause of decreased ADL was a progression of frailty, followed by pneumonia and stroke. Patients over 80 had similar survival times and ADL maintenance periods as those under 80.

CONCLUSIONS

The survival time of patients with iNPH after shunt surgery was 7.7 years, and females lived longer than males. Older patients over 80 years old had relatively good survival outcomes. Frailty progressed continuously in patients with iNPH after surgical treatment.

What is idiopathic in normal pressure hydrocephalus?

INTRODUCTION

Normal pressure hydrocephalus (NPH) can be caused by acquired events - e.g. subarachnoid hemorrhage, meningitis, or trauma - or can be "idiopathic" (iNPH) when no clear cause is identifiable. The entity and nosology of iNPH has received renewed attention and has recently gone through scrutiny and academic debate.

EVIDENCE ACQUISITION

Authors searched PubMed using the following keywords: "adult hydrocephalus," "alfa synuclein," "Alzheimer's disease," "beta-amyloid," "cerebrospinal fluid," "cilia," "CSF," "genes," "hydrocephalus," "idiopathic," "Lewy Body Dementia," "phosphorylated tau," "shunt responsiveness".

EVIDENCE SYNTHESIS

During the past decades several studies have reshaped our view of iNPH, examples are the identification of monogenic forms of iNPH caused by genes involved in the structure and function of cilia or the discovery of the glymphatic system. This review will discuss the causes of iNPH and particularly the relationship with neurodegeneration in terms of: 1) coincidental association; 2) iNPH predisposing to neurodegeneration, 3. neurodegeneration predisposing to iNPH, and 4. independent processes (genetic and environmental) predisposing to both. Based on the gathered evidence, a unified model is then presented, characterized by three sequential events: impairment of CSF dynamic, occurrence of reversible signs, occurrence of irreversible signs.

CONCLUSIONS

Almost 70 years after its description, a growing literature on its basic mechanisms is clarifying that iNPH is a syndrome with pathogenetic mechanisms arising from different causes. The paradigm shift has been recognizing that iNPH is not just a CSF disorder but rather a brain disorder expressing with ventriculomegaly. Finally, the better understanding of what causes iNPH support the proposal of changing its name into "Hakim's disease."

The Na+,K+,2Cl- Cotransporter, Not Aquaporin 1, Sustains Cerebrospinal Fluid Secretion While Controlling Brain K+ Homeostasis

Disturbances in the brain fluid balance can lead to life-threatening elevation in intracranial pressure (ICP), which represents a vast clinical challenge. Targeted and efficient pharmaceutical therapy of elevated ICP is not currently available, as the molecular mechanisms governing cerebrospinal fluid (CSF) secretion are largely unresolved. To resolve the quantitative contribution of key choroid plexus transport proteins, this study employs mice with genetic knockout and/or viral choroid plexus-specific knockdown of aquaporin 1 (AQP1) and the Na+, K+, 2Cl- cotransporter 1 (NKCC1) for in vivo determinations of CSF dynamics, ex vivo choroid plexus for transporter-mediated clearance of a CSF K+ load, and patient CSF for [K+] quantification. CSF secretion and ICP management occur independently of choroid plexus AQP1 expression, whereas both parameters are reduced by 40% upon choroid plexus NKCC1 knockdown. Elevation of [K+]CSF increases the choroid plexus Na+/K+-ATPase activity, and favors inwardly-directed net NKCC1 transport, which, together, promote CSF K+ clearance, while maintaining undisturbed CSF secretion rates. CSF from patients with post-hemorrhagic hydrocephalus does not display elevated [K+]CSF, suggesting that NKCC1 maintains net outward transport direction during post-hemorrhagic hydrocephalus formation. Direct or indirect therapeutic modulation of choroid plexus NKCC1 can thus be a potential promising pharmacological approach against brain pathologies associated with elevated ICP.

Prevalence of idiopathic normal pressure hydrocephalus in older adult population in Shanghai, China: A population-based observational study

INTRODUCTION

Idiopathic normal pressure hydrocephalus (iNPH), a condition that primarily affects the elderly, has an unclear prevalence rate in China.

METHODS

A cross-sectional survey involving 1491 seniors aged 60 and above in Shanghai was conducted. Clinical symptoms and brain imaging data were collected for the diagnosis of suboptimal probable iNPH (s-probable iNPH). The crude prevalence was calculated and the estimated prevalence was inferred.

RESULTS

The crude prevalence of s-probable iNPH was 3.09% and 2.62% respectively, using DESH score ≥6 and Radscale score ≥7 as the primary imaging diagnostic criteria. The estimated prevalence of Shanghai was 2.59% among people over 60 years old and it rose to 7.99% among people aged over 90, and it was estimated that 134,152 and 11,708, respectively, had s-probable iNPH among the corresponding age group.

DISCUSSION

The prevalence of s-probable iNPH fluctuates based on the radiological scoring systems and the defined thresholds employed, and it tends to rise with advancing age.

HIGHLIGHTS

**Significant Prevalence**: The study identified a substantial prevalence of iNPH in older adults, with rates increasing significantly with age, particularly among those aged 90-99 years and centenarians. **Diagnostic Approach**: The research utilized novel diagnostic methodologies by integrating the DESH score or Radscale score with stringent clinical symptoms, providing a closer approximation to the true prevalence of iNPH. **Gender Disparity**: A marked gender difference was observed, with the prevalence of iNPH being significantly higher in males compared to females across all age groups. **Clinical Implications**: The findings underscore the importance of considering iNPH in the differential diagnosis of dementia, particularly among older male patients presenting with cognitive impairment and gait disturbances. **Public Health Impact**: The estimated number of s-probable iNPH patients in Shanghai highlights the need for increased awareness and better management strategies for this underdiagnosed condition in the aging population.

Hakim's disease: an update on idiopathic normal pressure hydrocephalus

INTRODUCTION

Idiopathic normal pressure hydrocephalus (iNPH) increases with age but is still underdiagnosed and undertreated. In the last decade, iNPH research has expanded into understanding broader contributions to iNPH, the role of cerebrospinal fluid (CSF), and imaging biomarkers to aid early detection, help diagnosis and differentiation from iNPH mimics, and aid with outcome prediction.

EVIDENCE ACQUISITION

We performed a literature search on the PubMed database. English language articles published between 2015-2024 were included. The strategies focused on iNPH and specific terms related to the topics of this review.

EVIDENCE SYNTHESIS

We first addressed the ambiguity of current classification terminology and reviewed the newly proposed classification system. This review has shown that prevalence is higher than previously reported. We have reviewed imaging and found numerous highly sensitive and specific imaging markers to aid diagnosis and differentiate from common mimics. CSF biomarkers have revealed that amyloid β and tau levels were lower in iNPH patients, which helped with differentiation from iNPH mimics, and that other emerging inflammatory markers need to be studied further. We also found numerous promising genetic markers in familial iNPH involved in cilial dysfunction, neuroinflammation, and neurodegeneration. Literature also reported the frequent presence of spinal stenosis, and studies reported better iNPH outcomes when these were addressed.

CONCLUSIONS

This has shown that there is a need for the development of a structured and standardized classification system, iNPH assessment protocol with standardized testing, and standardized biomarkers to aid diagnosis and treatment, and that this needs an interdisciplinary team approach.

Technological Advances for Gait and Balance in Normal Pressure Hydrocephalus: A Systematic Review

Normal pressure hydrocephalus (NPH) is a recognized cause of reversible cognitive and motor decline, with gait and balance impairments often emerging early. Technologies providing gait and balance measures can aid in early detection, diagnosis, and prognosis of the disease. This systematic review comprehensively discusses previous studies on the instrumental assessment of gait and balance in NPH. A PubMed search following PRISMA guidelines identified studies published between 2000 and 2024 that used laboratory instruments to assess gait and balance in NPH. Studies underwent quality assessment for internal, statistical, and external validity. Methodological details such as motor tasks, instruments, analytical approaches, and main findings were summarized. Overall, this review includes 41 studies on gait and 17 on balance, most of which used observational, cross-sectional designs. These studies employed various tools, such as pressure-sensitive platforms, optoelectronic motion-capture systems, and wearable inertial sensors. Significant differences in kinematic measures of gait and balance have been found in NPH patients compared to healthy controls and individuals with other neurological conditions. Finally, this review explores potential pathophysiological mechanisms underlying the kinematic changes in gait and balance in NPH and emphasizes the absence of longitudinal data, which hinders drawing definitive conclusions for prognostic purposes.

Venous compression causes chronic cerebral ischaemia in normal pressure hydrocephalus patients

BACKGROUND

Cerebral autoregulation is a robust regulatory mechanism that stabilizes cerebral blood flow in response to reduced blood pressure, thereby preventing cerebral ischaemia. Scientists have long believed that cerebral autoregulation also stabilizes cerebral blood flow against increases in intracranial pressure, which is another component that determines cerebral perfusion pressure. However, this idea was inconsistent with the complex pathogenesis of normal pressure hydrocephalus, which includes components of chronic cerebral ischaemia due to mild increases in intracranial pressure.

METHODS

Twenty-one patients who underwent ventriculoperitoneal shunt surgery for normal pressure hydrocephalus were included in this study. To determine the pressure setting of the Codman-Hakim programmable valve, intracranial pressure was measured after shunt surgery by puncturing the Ommaya reservoir, which formed a closed circuit with the needle and the syringe. Then, intracranial pressure was continuously measured with intermittent infusion of cerebrospinal fluid from the same closed circuit. We also continuously measured oximetry data, such as regional cerebral oxygen saturation derived from near-infrared spectroscopy monitoring. These data were digitized, recorded, and used for calculating intracranial compliance and the relationship between cerebrospinal fluid volume loading and intracranial pressure.

RESULTS

This study demonstrates that in patients with normal pressure hydrocephalus, cerebral venous vascular bed compression induces mild cerebral ischaemia when intracranial pressure is slightly higher than physiological venous pressure. Cerebral venous compression impairs cerebral blood flow by quadratically increasing circulatory resistance according to Poiseuille's law. Furthermore, chronic cerebral ischaemia occurred even at low or normal intracranial pressures when deep and subcortical white matter hyperintensities (DSWMHs) were severe.

CONCLUSION

The fact that cerebral blood flow impairment begins at very low intracranial pressures indicates that cerebral autoregulation to compensate for reduced venous blood flow is not functioning adequately in NPH. These processes provide a link between impaired cerebrospinal fluid circulation, cerebral autoregulation, and neurological dysfunction, which has been missing in patients with NPH involving small vessel arteriosclerosis. These findings may provide insight into similar conditions, such as normal-tension glaucoma and chronic kidney disease, in which a mild increase in local compartment pressure leads to chronic ischemia in organs protected by autoregulatory mechanisms.

Automated Detection of Normal Pressure Hydrocephalus Using CT Imaging for Calculating the Ventricle-to-Subarachnoid Volume Ratio

BACKGROUND AND PURPOSE

Normal pressure hydrocephalus (NPH) is a diagnostic challenge because its clinical symptoms and imaging appearance resemble normal aging and other forms of dementia. Identifying NPH is essential so that patients can receive timely treatment to improve gait distortion and quality of life. An automated marker of NPH was developed and evaluated on clinical CT images, and its utility was assessed in a large patient cohort.

MATERIALS AND METHODS

A retrospective review was conducted of CT images from 306 tap test-responsive patients with NPH between January 2015 and January 2022. Control CT images were obtained from patients in the emergency department who were evaluated for headache and had unremarkable CT findings between June 2021 and August 2022. The ventricle-to-subarachnoid volume ratio (VSR) was automatically calculated by the imaging software and used as a predictor of NPH in linear regression modeling with adjustment for age and sex. The correlations of VSR with age, sex, and the receiver operating characteristic were computed.

RESULTS

VSR was significantly greater in patients with NPH than controls (P < .001). Importantly, VSR was not significantly correlated with age (P = .56, R2 = 0.001). VSR identifies NPH with a sensitivity and specificity of 94.1% and 92.5%, respectively, with an area under the receiver operating characteristic curve of 0.99 (95% CI 0.975-0.995).

CONCLUSIONS

Automated assessment of the VSR on head CT images identified probable NPH with 93% accuracy. The assessment of a large cohort of patients with NPH supports the generalizability of clinical screening of CT images. Moreover, the results support the utility of ventricle-to-sulcal concordance often used by radiologists but not currently a part of the accepted guidelines for imaging markers of NPH.

Osteoporosis in older patients with idiopathic normal pressure hydrocephalus

Both osteoporosis and idiopathic normal pressure hydrocephalus may increase the risk of falls and fractures. This study showed that osteoporosis is more common in older patients with iNPH. It is important to raise awareness of osteoporosis in older patients with iNPH to prevent adverse health consequences.

PURPOSE

Idiopathic normal pressure hydrocephalus (iNPH), a potentially reversible condition with timely intervention, may cause cognitive impairment, balance and gait disturbance, and urinary incontinence in advanced age. Osteoporosis is a progressive metabolic bone disease that increases bone fragility in older adults. Both conditions may lead to falls and fractures. Therefore, this study aims to investigate osteoporosis in older adults with iNPH.

METHODS

A total of 64 patients diagnosed with iNPH and 458 participants in the control group were included in the study. Demographic and clinical characteristics, including age, sex, comorbidities, laboratory findings, and comprehensive geriatric assessment parameters, were recorded. Osteoporosis was defined according to the WHO classification. The relationship between osteoporosis and iNPH was assessed with regression analysis.

RESULTS

The mean age was higher in the iNPH group than in the control group (79.91 ± 6.36 vs 75.86 ± 6.51 years, p < 0.001). The frequency of female patients was higher in the control group than in the iNPH group (81% vs 70.3%, p = 0.046). The osteoporosis frequency was higher in the iNPH group than in the controls (51.6% vs 32.1%, p = 0.002). Adjusted for age and gender, iNPH was associated with osteoporosis (odds ratio (OR), 1.750; confidence interval (CI) 95%, 1.002-3.054; p = 0.049).

CONCLUSIONS

This study showed that osteoporosis is more common in older patients with iNPH. Therefore, screening and treatment of osteoporosis in these individuals is crucial to avoid adverse health outcomes such as fractures.

A Case of Lacunar Stroke in a Patient with Possible Normal Pressure Hydrocephalus (NPH)

Background

Normal pressure hydrocephalus (NPH) is a condition seen in the elderly, characterized by gait disturbances, urinary incontinence, and cognitive impairment. However, sudden onset neurological deficits suggest a vascular event rather than NPH.

Methodology

We report a case of a 65-year-old male who presented with sudden onset gait difficulty and speech impairment, initially suspected to be idiopathic NPH. The diagnostic process and management strategies are discussed.

Results

The patient's symptoms, including insidious gait difficulties, speech impairment, and memory loss, led to a suspected diagnosis of NPH. However, the sudden improvement of neurological deficits indicated a vascular cause. Computed Tomography (CT) imaging identified supporting evidence of a lacunar stroke, leading to a revised diagnosis.

Conclusion

This case highlights the importance of considering vascular events in the differential diagnosis of NPH, especially when sudden neurological deficits improve rapidly. Early identification and differentiation between NPH and vascular events are crucial for appropriate management, particularly in low-resource settings.

Herbal prescription Siryeongtang and acupuncture treatment for gait disturbance due to idiopathic normal pressure hydrocephalus: A case report

BACKGROUND

Idiopathic normal-pressure hydrocephalus (iNPH), characterized by unexplained normal-pressure hydrocephalus, primarily presents with symptoms such as gait disturbances, cognitive impairment, and urinary incontinence. Currently, cerebrospinal fluid (CSF) drainage via shunting is the only effective treatment for iNPH.

CASE PRESENTATION

A 56-year-old Asian woman visited our hospital with a worsening gait disturbance and a history of recurrent falls over the past 2 years. She was diagnosed with iNPH using brain computed tomography. Notably, her gait disturbances continued to worsen despite undergoing a ventriculoperitoneal (VP) shunt. The patient was prescribed the herbal medicine Siryeongtang along with acupuncture and electroacupuncture. Subsequently, the changes in gait balance and speed were objectively assessed during the treatment period using the WIN-TRACK evaluation tool. The symmetry index for step length improved after 42 days of treatment, reaching 111 %, 71 %, and 37 % on days 15, 24, and 42, respectively. The symmetry index for step speed also decreased from 77 % on day 15 to 5 % on day 42. In addition, the time required to walk 5 m was reduced to 13, 10, and 9 s on days 15, 24, and 42, respectively.

CONCLUSIONS

Treatment with Korean medicine improved gait balance and speed in a patient with iINPH whose symptoms did not improve following shunt surgery.

Idiopathic normal pressure hydrocephalus: A critical analysis of its underrepresentation across Italian medical-scientific societies in the last 5 years

BACKGROUND

The scientific debate concerning clinical, translational and surgical aspects of iNPH could still be limited in respect to the incidence of this condition. The aim of this paper is to systematically assess the extent of the debate on INPH in the context of the congresses of the relevant medical and scientific societies in our Country.

METHODS

We thoroughly examined the websites and scientific programs of 12 leading scientific societies linked to medical specialities involved in diagnosis and management of INPH, among which the neurological, neurosurgical, neurophysiological, rehabilitation medicine and urologic societies. The amount of time (in hours) was examined in a time span of events which took place between 2019 and 2023.

RESULTS

Notably, across 4 years (2019-2023), a total of 7 out of 12 (58.3%) of the aforementioned leading scientific societies dedicated a total of zero minutes to the topic "iNPH", two further societies hosted talks for a total of less than one hours concerning such condition. The amount of time dedicated to giant intracranial aneurysms and vestibular schwannomas was in respect to the incidence of the conditions, significantly longer than the time spent debating on iNPH.

CONCLUSIONS

The results demonstrates that in our country, despite the high and increasing incidence of INPH, the awareness raised on the topic could still be limited, especially compared to other, significantly rarer intracranial conditions such as giant intracranial aneurysms and vestibular schwannomas.

Association between telomere length and idiopathic normal pressure hydrocephalus: a Mendelian randomization study

Objective

Idiopathic normal pressure hydrocephalus (iNPH) is highly prevalent among elderly individuals, and there is a strong correlation between telomere length and biological aging. However, there is limited evidence to elucidate the relationship between telomere length and iNPH. This study aimed to investigate the associations between telomere length and iNPH using the Mendelian randomization (MR) method.

Methods

The genetic variants of telomere length were obtained from 472,174 UK Biobank individuals. Summary level data of iNPH were acquired from 218,365 individuals of the FinnGen consortium. Five MR estimation methods, including inverse-variance weighting (IVW), MR-Egger regression, weighted median, weighted mode and simple mode, were used for causal inference. Comprehensive sensitivity analyses were conducted to test the robustness of the results. In addition, multivariable MR was further implemented to identify potential mechanisms in the causal pathway from telomere length to iNPH.

Results

Genetically determined longer telomere length was significantly associated with decreased risk of iNPH (OR = 0.44, 95% CI 0.24-0.80; p = 0.008). No evident heterogeneity (Cochran Q = 138.11, p = 0.386) and pleiotropy (MR Egger intercept = 0.01, p = 0.514) were observed in the sensitivity analysis. In addition, multivariable MR indicated that the observed association was attenuated after adjustment for several vascular risk factors, including essential hypertension (IVW OR = 0.55, 95% CI 0.30-1.03; p = 0.061), type 2 diabetes (IVW OR = 0.71, 95% CI 0.09-5.39; p = 0.740) and coronary artery disease (IVW OR = 0.58, 95% CI 0.31-1.07; p = 0.082).

Conclusion

Our MR study revealed a strong negative correlation of telomere length with iNPH. The causal relationship might be driven by several vascular risk factors.

Analyzing the relationship between specific brain structural changes and the diffusion tensor image analysis along the perivascular space index in idiopathic normal pressure hydrocephalus

BACKGROUND

Diffusion Tensor Image Analysis Along the Perivascular Space (DTI-ALPS) evaluates the glymphatic system in patients with idiopathic normal-pressure hydrocephalus (iNPH). However, white matter compression due to ventricular enlargement may affect the ALPS index. This study aimed to investigate the relationship among the ALPS index, white matter changes, and clinical symptoms in patients with iNPH.

METHODS

We calculated the ALPS index in 30 patients with iNPH, aged 70 and above, using DTI data and correlated it with various clinical and imaging indices, including the Evans index, callosal angle, cognitive tests, gait assessment (timed up-and-go [TUG] test), cerebrospinal fluid (CSF) medullary pressure, and various DTI indices (axial diffusivity [AD], radial diffusivity [RD], mean diffusivity [MD], fractional anisotropy [FA]).

RESULTS

Significant negative correlations were observed between the ALPS index and the rate of change in step count in the TUG test after the tap test (r = -0.5014, p = 0.0048), as well as CSF medullary pressure (r = -0.4651, p = 0.0096). Positive correlations were identified between the ALPS index and both AD (r = 0.4984, p = 0.0051) and MD (r = 0.3631, p = 0.0486).

CONCLUSION

A lower ALPS index was associated with gait improvement following the tap test as well as higher CSF medullary pressure. The ALPS index may detect subtle periventricular compression-induced changes in iNPH. Consequently, it could potentially serve as a predictor for tap test effectiveness in patients with iNPH, offering a new perspective on its application in iNPH diagnosis and treatment.

MRI markers of idiopathic normal pressure hydrocephalus in a population study with 791 participants: Exploring reference values and associations

PURPOSE

Epidemiological studies on idiopathic normal pressure hydrocephalus (iNPH) imaging markers and their normal values are scarce. This population-based study aimed to analyze several morphologic and volumetric iNPH-related imaging markers in a large sample, determining their distribution, diagnostic accuracy, suggested cut-offs, and associations with iNPH symptoms.

METHODS

This cross-sectional study included 791 70 year olds, 40 with radiologically probable iNPH (iNPHRadiol) and 751 without iNPH features (reference). MRI measures included Evans index (EI), z-EI, brain per ventricle ratio at anterior (BVRAC) and posterior commissures (BVRPC), sulcal compression, Sylvian fissure enlargement, callosal angle, diameter of temporal horns, 3rd and 4th ventricles, midbrain, and pons. Volumes of ventricles, corpus callosum, and brainstem were computed using automated segmentation. ROC analysis determined imaging markers' cut-offs. Symptoms were evaluated clinically and through self-report.

RESULTS

In the reference group, median values (95% CI) for imaging markers were as follows: EI: 0.27 (0.26-0.27), z-EI: 0.28 (0.26-0.31), BVRAC: 1.69 (1.48-1.90), and BVRPC: 2.66 (2.24-3.27). Most imaging markers differed significantly between iNPHRadiol and the reference. Lateral ventricle volumes correlated better with z-EI and BVR than EI (Rs > 0.81 vs 0.68). Optimal cut-off values for z-EI, and BVRAC and BVRPC for distinguishing iNPHRadiol were 0.32, 1.36, and 1.83, respectively. Clinical symptoms correlated moderately with imaging markers (Rs < 0.49 for iNPHRadiol, p < .01).

CONCLUSIONS

We report population-based reference values and propose cut-offs for iNPH-related imaging markers and volumetric measurements. Z-EI and BVR are likely superior markers for assessing ventricular enlargement in iNPH. Imaging markers of iNPH correlate moderately with iNPH symptoms.

Artificial Intelligence for Prediction of Shunt Response in Idiopathic Normal Pressure Hydrocephalus: A Systematic Review

BACKGROUND

Idiopathic normal pressure hydrocephalus (iNPH) is a reversible cause of dementia, typically treated with shunt surgery, although outcomes vary. Artificial intelligence (AI) advancements could improve predictions of shunt response (SR) by analyzing extensive datasets.

METHODS

We conducted a systematic review to assess AI's effectiveness in predicting SR in iNPH. Studies using AI or machine learning algorithms for SR prediction were identified through searches in MEDLINE, Embase, and Web of Science up to September 2023, adhering to Synthesis Without Meta-Analysis reporting guidelines.

RESULTS

Of 3541 studies identified, 33 were assessed for eligibility, and 8 involving 479 patients were included. Study sample sizes varied from 28 to 132 patients. Common data inputs included imaging/radiomics (62.5%) and demographics (37.5%), with Support Vector Machine being the most frequently used machine learning algorithm (87.5%). Two studies compared multiple algorithms. Only 4 studies reported the Area Under the Curve values, which ranged between 0.80 and 0.94. The results highlighted inconsistency in outcome measures, data heterogeneity, and potential biases in the models used.

CONCLUSIONS

While AI shows promise for improving iNPH management, there is a need for standardized data and extensive validation of AI models to enhance their clinical utility. Future research should aim to develop robust and generalizable AI models for more effective diagnosis and management of iNPH.

Hydrocephalus: An update on latest progress in pathophysiological and therapeutic research

Hydrocephalus is a severe and life-threatening disease associated with the imbalance of CSF dynamics and affects millions globally at any age, including infants. One cause of pathology that is wide-ranging is genetic mutations to post-traumatic injury. The most effective current pharmacological treatments provide only symptomatic relief and do not address the underlying pathology. At the same time, surgical procedures such as VP shunts performed in lower-income countries are often poorly tolerated due to insufficient diagnostic resources and suboptimal outcomes partially attributable to inferior materials. These problems are compounded by an overall lack of funding that keeps high-quality medical devices out of reach for all but the most developed countries and even among those states. There is a massive variance in treatment effectiveness. This review indicates the necessity for innovative and low-cost, accessible treatment strategies to close these gaps, focusing on current advances in novel therapies, including Pharmacological, gene therapy, and nano-based technologies, which are currently at different stages of clinical trial phases. This review provides an overview of pathophysiology, current treatments, and promising new therapeutic strategies for hydrocephalus.

A case of mimicking normal pressure hydrocephalus in a female older patient: co-existence of probable Alzheimer's dementia and colpocephaly

Colpocephaly, a cause of hydrocephalus, is characterized by disproportionately enlarged occipital horns of the lateral ventricles. It is rarely seen in the older adults. Few cases were reported as colpocephaly in elderly individuals in the literature. However, it has not been reported as idiopathic normal pressure hydrocephalus-like clinical presentation in older adults. To the best of our knowledge, the co-existence of colpocephaly and Alzheimer's disease has not been reported previously. In these respects, it is the first case in the literature.

Volumes and velocities: Meta-analysis of PC-MRI studies in normal pressure hydrocephalus

PURPOSE  : Phase contrast magnetic resonance imaging (PC-MRI) represents an opportunity to non-invasively investigate cerebral spinal fluid (CSF) flow in patients with idiopathic normal pressure hydrocephalus (iNPH). Studies in recent years have explored the diagnostic and prognostic value of PC-MRI derived parameters. This review aims to identify all PC-MRI studies of iNPH published since 2010, synthesise a review based on collated results, and analyse specific flow parameters identified in the selected studies.

METHODS

Our protocol was prospectively registered on PROSPERO [CRD42020180826]. We systematically searched four databases: Pubmed, Web of Science, Ovid, and Cochrane library to identify all eligible studies. Quality assessment was performed using a modified Newcastle-Ottawa Scale [19]. Systematic review was conducted according to Prisma guidelines. A random-effects model was used to perform meta-analysis on the available flow parameters.

RESULTS

Eighteen records were identified for inclusion. Five studies were eligible for meta-analysis, representing 107 iNPH patients and 82 controls. CSF flow parameters available for analysis were stroke volume and peak velocity. Both were significantly higher than controls (p = 0.0007 and p = 0.0045 respectively) according to our random-effects analysis, consistent with a model of hyper-dynamic CSF in iNPH. Our systematic review revealed average stroke volumes in iNPH ranging from 43uL to over 200uL. Peak velocity values ranged from 5.9 cm/s to 12.8 cm/s.

CONCLUSION

Significant increases in stroke volume and peak velocity values in iNPH patients suggest a place for PC-MRI as supplementary evidence in the diagnostic work-up of iNPH. Although shunting reduces aqueductal stroke volume and peak velocity, the ability of pre-shunt values to reliably predict treatment response remains complicated. We suggest that it may be more appropriate to consider a range of values that reflect varying probabilities of shunt success. We recommend that future studies should prioritise standardising PC-MRI protocols, and before then PC-MRI findings should be considered supportive rather than determinative.

Diagnostic importance of disproportionately enlarged subarachnoid space hydrocephalus and Callosal Angle measurements in the context of normal pressure hydrocephalus: A useful tool for clinicians

Hydrocephalus is a clinical and neurologic condition characterized by an abnormal accumulation of cerebrospinal fluid (CSF). Currently, idiopathic Normal Pressure Hydrocephalus (iNPH) is recognized as a late-onset neurologic disorder defined by a clinical triad of gait disturbance, urinary incontinence, and dementia. Imaging studies often reveal a disproportionate increase in subarachnoid space and ventricular size relative to brain volume, with normal CSF pressure during lumbar puncture. Recent developments in neuroimaging have led to the establishment of criteria for diagnosing and managing iNPH, incorporating the concept of Disproportionately Enlarged Subarachnoid-space Hydrocephalus (DESH). Distinguishing iNPH from the natural neurological aging process and other forms of dementia, wherein brain atrophy and hydrocephalus ex vacuo can be observed, can present challenges for both neurologists and neuroradiologists. Despite DESH becoming a radiologic criterion for diagnosing iNPH in some guidelines, its recognition remains limited.

Survival After Shunt Therapy in Normal-Pressure Hydrocephalus: A Meta-Analysis of 1614 Patients

BACKGROUND

Ventriculoperitoneal (VP) shunt therapy is a crucial intervention for normal-pressure hydrocephalus (NPH). This meta-analysis delves into survival time and the impact of baseline symptom burden on survival after VP shunt therapy for NPH, employing reconstructed pooled survival curves and a one-stage meta-analysis.

METHODS

IPD regarding overall survival (OS) were acquired from published Kaplan-Meier charts, utilizing the R package IPDfromKM in R (Version 4.3.1, the R Foundation for Statistical Computing). Reconstructed Kaplan-Meier charts were then generated from the pooled IPD data. Both one-stage and two-stage meta-analyses were executed, with hazard ratios (HRs) employed as metrics to evaluate effectiveness.

RESULTS

From the initial screening of 216 records, five articles encompassing 1614 patients met the eligibility criteria for inclusion. In two of the five included studies, overall survival was stratified by gait score (1-4 vs. ≥4) in 1043 patients, continence score (1-3 vs. ≥4) in 1022 patients, and mRS (0-2 vs. ≥3) in 956 patients. Patients with good gait demonstrated a mean survival of 8.24 years, while those with poor gait had a mean survival of 6.19 years (log-rank test: p < 0.001). The HR for gait was 2.25 (95% CI: 1.81-2.81, p < 0.001). Continence score stratification revealed a significant difference in survival time (log-rank test: p < 0.001), with an HR of 1.66 (95% CI: 1.33-2.06, p < 0.001). Similarly, mRS stratification demonstrated a significant survival difference (log-rank test: p < 0.001), with an HR of 2.21 (95% CI: 1. 74-2.80, p < 0.001). The reconstructed survival curves for all NPH patients treated with VP shunt therapy, pooling data from five studies, revealed a median survival time of 8.82 years (95% CI: 8.23-9.40). Survival rates at 1, 3, 5, 7, 9, 11, and 13 years were 95.7%, 83.8%, 70.5%, 59.5%, 48.7%, 35.8%, and 25.4%, respectively. Comparison with a general control population showed an HR of 1.79 (95% CI: 1.62-1.98, p < 0.001).

CONCLUSIONS

This comprehensive meta-analysis underscores the influence of baseline symptom burden on survival after VP shunt therapy in NPH. Therapy in the early stages for those without significant comorbidities may enhance survival.

The CSF lipid profile in patients with probable idiopathic normal pressure hydrocephalus differs from control but does not differ between shunt responders and non-responders

Idiopathic normal pressure hydrocephalus is a common form of hydrocephalus in the elderly, characterized by enlarged ventricles combined with clinical symptoms presenting as gait impairment, urinary incontinence, and dementia. Idiopathic normal pressure hydrocephalus may be difficult to differentiate clinically from other neurodegenerative disorders, and up to 80% of cases may remain unrecognized and thus untreated. Consequently, there is a pressing demand for biomarkers that can confirm the diagnosis of idiopathic normal pressure hydrocephalus. In this exploratory study, CSF was sampled from the lumbar compartment of 21 control individuals and 19 probable idiopathic normal pressure hydrocephalus patients and analyzed by an untargeted mass spectroscopy-based platform to reveal a complete CSF lipid profile in these samples. Two hundred forty-four lipids from 17 lipid classes were detected in CSF. Various lipid classes, and select individual lipids, were reduced in the CSF obtained from patients with probable idiopathic normal pressure hydrocephalus, whereas a range of lipids belonging to the class of triacylglycerols was elevated. We detected no difference in the CSF lipid profile between probable idiopathic normal pressure hydrocephalus patients with and without clinical improvement following CSF shunting. In conclusion, the lipidomic profile of the CSF in patients with probable idiopathic normal pressure hydrocephalus, therefore, may serve as a sought after biomarker of the pathology, which may be employed to complement the clinical diagnosis.

The effectiveness of various CSF diversion surgeries in idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis

Background

Idiopathic normal pressure hydrocephalus (iNPH) is commonly treated using cerebrospinal fluid (CSF) diversion procedures, most commonly ventriculoperitoneal (VP) but also lumboperitoneal (LP), ventriculoatrial (VA) shunting, and endoscopic third-ventriculostomy (ETV). Despite the prevalence of these interventions and recent advancements in iNPH diagnostic processes, there is limited up-to-date evidence regarding surgical outcomes.

Methods

A systematic review and meta-analysis were conducted to analyse the effects of CSF diversion surgeries among iNPH patients. The primary outcome was efficacy of the CSF diversion procedure, defined as symptomatic improvement, and secondary outcomes included surgical complications. Several major databases were searched for original studies from inception up to June 4, 2024, which were evaluated using random-effects meta-analyses, meta-regression, and influence analyses. This study was registered with PROSPERO: CRD42023458526.

Findings

Out of the 1963 studies screened, 54 were included in this review, and 4811 patients were pooled. Overall, more than 74% of patients experienced improvement after surgical treatment (95% CI: 70-78%). VP shunting demonstrated an efficacy of 75% (95% CI 70-79%), VA shunting at 75% (95% CI: 70-80%), and LP shunting at 70% (95% CI: 52-83%). ETV had a success rate of 69% (95% CI: 58-78%). Gait improvement was high at 72% (95% CI: 67-77%), while urinary and cognitive dysfunction each improved in approximately 50% of patients. The efficacy of surgery did not increase between 2005 and 2024 (p = 0.54). Complications occurred in 20.6% of cases, with a surgery revision rate of 15.1%.

Interpretation

This meta-analysis found that the overall efficacy of CSF diversion procedures for iNPH remained unchanged from 2005 to 2024, with 74% of cases showing improvement. No procedure was found to be clearly superior, and only half of the patients saw improvements in urinary and cognitive dysfunction. The stagnant efficacy over time and frequent complications highlight the need for improved patient selection criteria to best identify those most likely to benefit from CSF shunting.

Funding

None for this study.

A wearable gait-analysis device for idiopathic normal-pressure hydrocephalus (INPH) monitoring

Idiopathic Normal Pressure Hydrocephalus (iNPH) is a progressive neurologic disorder (fluid build-up in the brain) that affects 0.2%-5% of the UK population aged over 65. Mobility problems, dementia and urinary incontinence are symptoms of iNPH but often these are not properly evaluated, and patients receive the wrong diagnosis. Here, we describe the development and testing of firmware embedded in a wearable device in conjunction with a user-based software system that records and analyses a patient's gait. The movement patterns, expressed as quantitative data, allow clinicians to improve the non-invasive assessment of iNPH as well as monitor the management of patients undergoing treatment. The wearable sensor system comprises a miniature electronic unit that attaches to one ankle of the patient via a simple Velcro strap which was designed for this application. The unit monitors acceleration along three axes with a sample rate of 60 Hz and transmits the data via a Bluetooth communication link to a tablet or smart phone running the Android and the iOS operating systems. The software package extracts statistics based on stride length, stride height, distance walked and speed. Analysis confirmed that the system achieved an average accuracy of at least 98% for gait tests conducted over distances 9 m. This device has been developed to assist in the management and treatment of older adults diagnosed with iNPH.

Sarcopenia in older patients with idiopathic normal pressure hydrocephalus: an observational study from a single geriatric clinic in Turkey

OBJECTIVE

Idiopathic normal pressure hydrocephalus (iNPH), a classical triad of gait abnormality, cognitive disturbance, and urinary incontinence, increases in prevalence with aging. Sarcopenia is also characterized by low muscle strength and mass, contributing to gait difficulty. Gait abnormality and lower physical activity also lead to the development of sarcopenia. Therefore, this study aims to investigate the relationship between sarcopenia and iNPH.

METHODS

A total of 327 participants were included in this retrospective cross-sectional study. Demographic and clinical characteristics, including age, sex, comorbidity index, number of medications, recurrent falls in the last year, laboratory findings and comprehensive geriatric assessment (CGA) parameters were recorded. Sarcopenia was defined according to the EGWSOP2 criteria. The relationship between sarcopenia and iNPH was assessed with regression analysis.

RESULTS

There were 51 participants with iNPH, 49% female, mean age 78 years (SD 5.7) and 276 control participants, 74% female, mean age 72 years (SD 6.1). The sarcopenia rates in patients with iNPH and controls were 19.6% and 2.5%, respectively (p < 0.01). The odds of probable sarcopenia were 3.89 times, and the slow gait speed was 8.47 times higher in iNPH patients than in controls after adjusting for age, sex, and the other confounders. The Mini-Mental State Examination score (p = 0.042, OR = 0.869 with 95% CI:0.759-0.995) was associated with probable sarcopenia among patients with iNPH.

CONCLUSION

This study demonstrated that sarcopenia was common in older patients with iNPH, which seems to be closely associated with decreased muscle strength and slowed gait speed. Thus, considering the potential untoward effects of both diseases, it is important for physicians to evaluate sarcopenia routinely in the follow-up and treatment of older patients with iNPH.

Association between idiopathic normal pressure hydrocephalus and Alzheimer's disease: a bidirectional Mendelian randomization study

Observational studies have suggested a bidirectional relationship between idiopathic normal pressure hydrocephalus (iNPH) and Alzheimer's disease (AD). However, the causal association between these two neurodegenerative disorders remains unclear. This study aimed to explore the causal relationship between iNPH and AD using a two-sample bidirectional Mendelian randomization (MR) method. Large-scale genome-wide association studies of iNPH (Ncase = 767, Ncontrol = 375,610) and AD (Ncase/proxy = 111,326, Ncontrol = 677,663) in European individuals were used to screen genetic instruments for MR analysis. Inverse variance-weighted (IVW) method was used as the main analysis, other MR methods and a series of sensitivity analyses were performed to ensure the reliability. In the forward MR analysis, genetic predisposition to iNPH had no effects on the risk of AD development. Likewise, in the reverse MR analysis, AD did not demonstrate a significant causal effect on iNPH. Sensitivity analyses bolstered the reliability of the MR results. Our MR study indicated no genetic evidence supporting a suggestive association between AD and iNPH in either direction, and provided evidence on the dichotomy between true iNPH and neurodegenerative NPH.

The contribution of cognitive reserve in explaining the dual-task walking performance in iNPH patients: comparison with other cognitive, functional, and socio-demographic variables

BACKGROUND

Idiopathic normal pressure hydrocephalus (iNPH) is a prevalent neurological disorder, but its diagnosis remains challenging. Dual-task (DT) walking performance is a reliable indicator of iNPH but less is known about the role of cognitive reserve (CR) in predicting DT walking performance.

AIMS

The objective of this study was to evaluate the contribution of CR on DT walking in healthy controls (HC) and in iNPH patients (iNPH-P).

METHODS

68 iNPH-P (77.2 +/- 6.7 years old) and 28 HC (74.5 +/- 5.7 years old) were evaluated on their single-task walking (Vsimple) and on 4 DT walking (walking and counting or counting backwards, naming animals, naming words beginning with the letter P) (Vcount, VcountB, Vanimals and Vletter respectively). The contribution of CR on the different DT walking speeds was compared between HC and iNPH-P. In iNPH-P, the contribution of CR on the walking speeds was compared with regard to other cognitive, functional, and socio-demographic variables.

RESULTS

Simple linear regression demonstrated a moderate influence of CR on single and DT walking speed in iNPH-P (β > 0.3, p < .001) but not in HC where the relation was not significant. In iNPH-P, results showed that CR played a major role in explaining each of the single and DT walking speeds with NPH-scale.

CONCLUSION

As CR could be improved through the life cycle, these results support the idea of developing and supporting physical activity programs that will enrich social, physical, and cognitive resources to protect against age-related functional decline, especially in iNPH-P patients where the age-related deficits are greater.

Risk Variants Associated With Normal Pressure Hydrocephalus: Genome-Wide Association Study in the FinnGen Cohort

BACKGROUND AND OBJECTIVES

Large-scale genome-wide studies of chronic hydrocephalus have been lacking. We conducted a genome-wide association study (GWAS) in normal pressure hydrocephalus (NPH).

METHODS

We used a case-control study design implementing FinnGen data containing 473,691 Finns with genotypes and nationwide health records. Patients with NPH were selected based on ICD-10 G91.2 diagnosis. To select patients with idiopathic NPH (iNPH) for sensitivity analysis, we excluded patients with a potentially known etiology of the condition using an algorithm on their disease history. The controls were the remaining non-hydrocephalic participants. For a replication analysis, the NPH cohort from UK Biobank (UKBB) was used.

RESULTS

We included 1,522 patients with NPH (mean age 72.2 years, 53% women) and 451,091 controls (mean age 60.5 years, 44% women). In the GWAS comparing patients with NPH with the controls, we identified 6 gene regions significantly (p < 5.0e-8) associated with NPH that replicated in a meta-analysis with UKBB (NPH n = 173). The top loci near the following genes were rs7962263, SLCO1A2 (odds ratio [OR] 0.71, 95% CI 0.65-0.78, p = 1.0e-14); rs798495, AMZ1/GNA12 (OR 1.29, 95% CI 1.20-1.39, p = 2.9e-12); rs10828247, MLLT10 (OR 0.77, 95% CI 0.71-0.83, p = 1.5e-11); rs561699566 and rs371919113, CDCA2 (OR 0.76, 95% CI 0.70-0.82, p = 1.5e-11); rs56023709, C16orf95 (OR 1.24, 95% CI 1.16-1.33, p = 3.0e-9); and rs62434144, PLEKHG1 (OR 1.23, 95% CI 1.14-1.32, p = 1.4e-8). In the sensitivity analysis comparing only patients with iNPH (n = 1,055) with the controls (n = 451,091), 4 top loci near the following genes remained significant: rs7962263, SLCO1A2 (OR 0.70, 95% CI 0.63-0.78, p = 2.1e-11); rs10828247, MLLT10 (OR 0.74, 95% CI 0.62-0.82, p = 4.6e-10); rs798511, AMZ1/GNA12 (OR 1.28, 95% CI 1.17-1.39, p = 1.7e-8); and rs56023709, C16orf95 (OR 1.28, 95% CI 1.17-1.39, p = 1.7e-8).

DISCUSSION

We identified 6 loci significantly associated with NPH in the thus far largest GWAS in chronic hydrocephalus. The genes near the top loci have previously been associated with blood-brain barrier and blood-CSF barrier function and with increased lateral brain ventricle volume. The effect sizes and allele frequencies remained similar in NPH and iNPH cohorts, indicating the identified loci are risk determinants for iNPH and likely not explained by associations with other etiologies. However, the exact role of these loci is still unknown, warranting further studies.

Biomarker changes in suspected idiopathic normal-pressure hydrocephalus patients undergoing external lumbar drainage: a pilot study

AIM

To examine whether changes in biomarker concentrations in patients with idiopathic normal-pressure hydrocephalus (iNPH) during 72 h of external lumbar drainage (ELD) can differentiate between responders and non-responders.

METHODS

Twenty patients with clinical and neuroradiological signs of iNPH underwent ELD over a period of 72 h. During this period, changes in cerebrospinal fluid (CSF) concentrations of biomarkers (amyloid-β, total and phosphorylated tau proteins) and intracranial pressure were monitored, and the volume of drained CSF was measured. Changes in the concentrations of selected biomarkers at three time points (0, 36, and 72 h) during ELD were tested for association with changes in clinical condition.

RESULTS

Ten patients showed significant clinical improvement after ELD, quantified as a difference of two or more points on the Mini-Mental State Examination and/or Japanese iNPH grading scale. The concentration of all tested biomarkers increased during the first 36 h. Respondents had higher Aβ 1-42 at all time points, with a significant difference seen after 72 h. They also had a significantly higher Aβ1-42/Aβ1-40 ratio at all time points.

CONCLUSION

A gradual increase in Aβ 1-42 concentration during three-day ELD represents a possible positive prognostic factor for the placement of permanent CSF drainage in patients with iNPH.

Molecular signatures of normal pressure hydrocephalus: a large-scale proteomic analysis of cerebrospinal fluid

Given the persistent challenge of differentiating idiopathic Normal Pressure Hydrocephalus (iNPH) from similar clinical entities, we conducted an in-depth proteomic study of cerebrospinal fluid (CSF) in 28 shunt-responsive iNPH patients, 38 Mild Cognitive Impairment (MCI) due to Alzheimer's disease, and 49 healthy controls. Utilizing the Olink Explore 3072 panel, we identified distinct proteomic profiles in iNPH that highlight significant downregulation of synaptic markers and cell-cell adhesion proteins. Alongside vimentin and inflammatory markers upregulation, these results suggest ependymal layer and transependymal flow dysfunction. Moreover, downregulation of multiple proteins associated with congenital hydrocephalus (e.g., L1CAM, PCDH9, ISLR2, ADAMTSL2, and B4GAT1) points to a possible shared molecular foundation between congenital hydrocephalus and iNPH. Through orthogonal partial least squares discriminant analysis (OPLS-DA), a panel comprising 13 proteins has been identified as potential diagnostic biomarkers of iNPH, pending external validation. These findings offer novel insights into the pathophysiology of iNPH, with implications for improved diagnosis.

Shunting for idiopathic normal pressure hydrocephalus

BACKGROUND

Normal pressure hydrocephalus (NPH) occurs when the brain ventricles expand, causing a triad of gait, cognitive, and urinary impairment. It can occur after a clear brain injury such as trauma, but can also occur without a clear cause (termed idiopathic, or iNPH). Non-randomised studies have shown a benefit from surgically diverting ventricular fluid to an area of lower pressure by cerebrospinal fluid (CSF)-shunting in iNPH, but historically there have been limited randomised controlled trial (RCT) data to confirm this.

OBJECTIVES

To determine the effect of CSF-shunting versus no CSF-shunting in people with iNPH and the frequency of adverse effects of CSF-shunting in iNPH.

SEARCH METHODS

We searched the Cochrane Dementia and Cognitive Improvement Group's register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid SP), Embase (Ovid SP), PsycINFO (Ovid SP), CINAHL (EBSCOhost), Web of Science Core Collection (Clarivate), LILACS (BIREME), ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform on 15 February 2023.

SELECTION CRITERIA

We included only RCTs of people who had symptoms of gait, cognitive, or urinary impairment with communicating hydrocephalus (Evans index of > 0.3) and normal CSF pressure. Control groups included those with no CSF shunts or those with CSF shunts that were in 'inactive' mode.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Where necessary, we contacted study authors requesting data not provided in the papers. We assessed the overall certainty of the evidence using GRADE.

MAIN RESULTS

We included four RCTs, of which three were combined in a meta-analysis. The four RCTs included 140 participants (73 with immediate CSF-shunting and 67 controls who had delayed CSF-shunting) with an average age of 75 years. Risk of bias was low in all parallel-group outcomes evaluated apart from gait speed, cognitive function (general cognition and Symbol Digit Test) (some concerns) and adverse events, which were not blind-assessed. CSF-shunting probably improves gait speed at less than six months post-surgery (standardised mean difference (SMD) 0.62, 95% confidence interval (CI) 0.24 to 0.99; 3 studies, 116 participants; moderate-certainty evidence). CSF-shunting may improve qualitative gait function at less than six months post-surgery by an uncertain amount (1 study, 88 participants; low-certainty evidence). CSF-shunting probably results in a large reduction of disability at less than six months post-surgery (risk ratio 2.08, 95% CI 1.31 to 3.31; 3 studies, 118 participants; moderate-certainty evidence). The evidence is very uncertain about the effect of CSF-shunting on cognitive function at less than six months post-CSF-shunt surgery (SMD 0.35, 95% CI -0.04 to 0.74; 2 studies, 104 participants; very low-certainty evidence). The evidence is also very uncertain about the effect of CSF-shunt surgery on adverse events (1 study, 88 participants; very low-certainty evidence). There were no data regarding the effect of CSF-shunting on quality of life.

AUTHORS' CONCLUSIONS

We found moderate-certainty evidence that CSF-shunting likely improves gait speed and disability in iNPH in the relative short term. The evidence is very uncertain regarding cognition and adverse events. There were no longer-term RCT data for any of our prespecified outcomes. More studies are required to improve the certainty of these findings. In addition, more information is required regarding patient ethnicity and the effect of CSF-shunting on quality of life.

A bibliometric analysis and visualization of normal pressure hydrocephalus

Background

Normal pressure hydrocephalus (NPH) has drawn an increasing amount of attention over the last 20 years. At present, there is a shortage of intuitive analysis on the trends in development, key contributors, and research hotspots topics in the NPH field. This study aims to analyze the evolution of NPH research, evaluate publications both qualitatively and quantitatively, and summarize the current research hotspots.

Methods

A bibliometric analysis was conducted on data retrieved from the Web of Science Core Collection (WoSCC) database between 2003 and 2023. Quantitative assessments were conducted using bibliometric analysis tools such as VOSviewer and CiteSpace software.

Results

A total of 2,248 articles published between 2003 and 2023 were retrieved. During this period, the number of publications steadily increased. The United States was the largest contributor. The University of Gothenburg led among institutions conducting relevant research. Eide P. K. was the most prolific author. The Journal of Neurosurgery is the leading journal on NPH. According to the analysis of the co-occurrence of keywords and co-cited references, the primary research directions identified were pathophysiology, precise diagnosis, and individualized treatment. Recent research hotspots have mainly focused on epidemiology, the glymphatic system, and CSF biomarkers.

Conclusion

The comprehensive bibliometric analysis of NPH offers insights into the main research directions, highlights key countries, contributors, and journals, and identifies significant research hotspots. This information serves as a valuable reference for scholars to further study NPH.

Depressive symptoms, functional impairment, and health-related quality of life in idiopathic normal pressure hydrocephalus: A population-based study

BACKGROUND

Maximising quality of life is a central goal for all healthcare, especially when dealing with dementing disorders. In this study we aimed to compare health-related quality of life (HRQoL), depressive symptoms and functional impairment between individuals with and without idiopathic normal pressure hydrocephalus (iNPH) from the general population.

METHODS

A total of 122 individuals, 30 with iNPH (median age 75 years, 67 females) underwent neurological examinations and computed tomography of the brain with standardised rating of imaging findings and clinical symptoms. The participants completed the Geriatric Depression Scale (GDS-15) and the HRQoL instrument EQ5D-5L. In addition, the modified Rankin Scale (mRS) was used to evaluate functional impairment.

RESULTS

Compared with participants without iNPH, those with iNPH reported a higher score on GDS-15 (median 3 vs 1) and mRS (median 2 vs 1) (p < 0.05). Further, those with iNPH rated lower on EQ5D-5L (index 0.79, VAS 70) than those without iNPH (index 0.86, VAS 80) (p < 0.05). In logistic regression models, low HRQoL was associated with more depressive symptoms, a higher degree of iNPH symptoms, and lower functional status.

CONCLUSIONS

In this population-based sample, those with iNPH had more depressive symptoms, lower functional status, and worse quality of life compared to those without iNPH. The strongest association with low HRQoL was found for depressive symptoms, functional level, and degree of iNPH symptoms. These results underline the value of shunt surgery because of its potential to reduce symptoms and disability in iNPH and therefore improve HRQoL.

Regulation of brain fluid volumes and pressures: basic principles, intracranial hypertension, ventriculomegaly and hydrocephalus

The principles of cerebrospinal fluid (CSF) production, circulation and outflow and regulation of fluid volumes and pressures in the normal brain are summarised. Abnormalities in these aspects in intracranial hypertension, ventriculomegaly and hydrocephalus are discussed. The brain parenchyma has a cellular framework with interstitial fluid (ISF) in the intervening spaces. Framework stress and interstitial fluid pressure (ISFP) combined provide the total stress which, after allowing for gravity, normally equals intracerebral pressure (ICP) with gradients of total stress too small to measure. Fluid pressure may differ from ICP in the parenchyma and collapsed subarachnoid spaces when the parenchyma presses against the meninges. Fluid pressure gradients determine fluid movements. In adults, restricting CSF outflow from subarachnoid spaces produces intracranial hypertension which, when CSF volumes change very little, is called idiopathic intracranial hypertension (iIH). Raised ICP in iIH is accompanied by increased venous sinus pressure, though which is cause and which effect is unclear. In infants with growing skulls, restriction in outflow leads to increased head and CSF volumes. In adults, ventriculomegaly can arise due to cerebral atrophy or, in hydrocephalus, to obstructions to intracranial CSF flow. In non-communicating hydrocephalus, flow through or out of the ventricles is somehow obstructed, whereas in communicating hydrocephalus, the obstruction is somewhere between the cisterna magna and cranial sites of outflow. When normal outflow routes are obstructed, continued CSF production in the ventricles may be partially balanced by outflow through the parenchyma via an oedematous periventricular layer and perivascular spaces. In adults, secondary hydrocephalus with raised ICP results from obvious obstructions to flow. By contrast, with the more subtly obstructed flow seen in normal pressure hydrocephalus (NPH), fluid pressure must be reduced elsewhere, e.g. in some subarachnoid spaces. In idiopathic NPH, where ventriculomegaly is accompanied by gait disturbance, dementia and/or urinary incontinence, the functional deficits can sometimes be reversed by shunting or third ventriculostomy. Parenchymal shrinkage is irreversible in late stage hydrocephalus with cellular framework loss but may not occur in early stages, whether by exclusion of fluid or otherwise. Further studies that are needed to explain the development of hydrocephalus are outlined.

Improvement in gait velocity variability after cerebrospinal fluid elimination and its relationship to clinical symptoms in patients with idiopathic normal pressure hydrocephalus

AIM

This study aimed to investigate the improvement in gait velocity variability after cerebrospinal fluid (CSF) elimination, and the association between gait velocity variability and gait and cognitive impairment in patients with idiopathic normal pressure hydrocephalus.

METHODS

The gait velocity of 44 patients with idiopathic normal pressure hydrocephalus was measured using the Timed Up and Go Test (TUG) for a total of 10 times over 3 days each before and after CSF elimination. The coefficient of variation (CV) in the time required for the sequence of actions in TUG (TUG-CV) was calculated using 10 TUG data, and used for measuring intraindividual gait velocity variability. Gait quality was evaluated with the Gait Status Scale Revised (GSSR), and cognitive function was evaluated with the Mini-Mental State Examination and the Frontal Assessment Battery.

RESULTS

The TUG, TUG-CV, GSSR and Frontal Assessment Battery results improved significantly after CSF elimination. The analyses using pre-CSF elimination results showed that the TUG-CV significantly and positively correlated with the TUG and GSSR results, and negatively with Mini-Mental State Examination results, but not with age and the Frontal Assessment Battery results. The stepwise multiple regression analysis indicates that the TUG, GSSR and Mini-Mental State Examination results were significant predictors of the TUG-CV. The analysis using data of change after CSF elimination showed that ΔTUG and ΔGSSR were significant predictors of ΔTUG-CV.

CONCLUSIONS

Gait velocity variability improved after CSF elimination, and gait velocity variability was associated with gait disturbances and cognitive impairment in patients with idiopathic normal pressure hydrocephalus. Geriatr Gerontol Int 2024; 24: 693-699.

The impact of telomere length on the risk of idiopathic normal pressure hydrocephalus: a bidirectional Mendelian randomization study

Idiopathic normal pressure hydrocephalus (iNPH) affects mainly aged populations. The gradual shortening of telomere length (TL) is one of the hallmarks of aging. Whereas the genetic contribution of TL to the iNPH is incompletely understood. We aimed to investigate the causal relationship between TL and iNPH through the Mendelian randomization (MR) analysis. We respectively obtained 186 qualified single nucleotide polymorphisms (SNPs) of TL and 20 eligible SNPs of iNPH for MR analysis. The result of MR analysis showed that genetically predicted longer TL was significantly associated with a reduced odd of iNPH (odds ratio [OR] = 0.634 95% Confidence interval [CI] 0.447-0.899, p = 0.011). The causal association remained consistent in multivariable MR (OR = 0.530 95% CI 0.327-0.860, p = 0.010). However, there was no evidence that the iNPH was causally associated with the TL (OR = 1.000 95% CI 0.996-1.004, p = 0.955). Our study reveals a potential genetic contribution of TL to the etiology of iNPH, that is a genetically predicted increased TL might be associated with a reduced risk of iNPH.

Assessing CT-based Volumetric Analysis via Transfer Learning with MRI and Manual Labels for Idiopathic Normal Pressure Hydrocephalus

Background

Brain computed tomography (CT) is an accessible and commonly utilized technique for assessing brain structure. In cases of idiopathic normal pressure hydrocephalus (iNPH), the presence of ventriculomegaly is often neuroradiologically evaluated by visual rating and manually measuring each image. Previously, we have developed and tested a deep-learning-model that utilizes transfer learning from magnetic resonance imaging (MRI) for CT-based intracranial tissue segmentation. Accordingly, herein we aimed to enhance the segmentation of ventricular cerebrospinal fluid (VCSF) in brain CT scans and assess the performance of automated brain CT volumetrics in iNPH patient diagnostics.

Methods

The development of the model used a two-stage approach. Initially, a 2D U-Net model was trained to predict VCSF segmentations from CT scans, using paired MR-VCSF labels from healthy controls. This model was subsequently refined by incorporating manually segmented lateral CT-VCSF labels from iNPH patients, building on the features learned from the initial U-Net model. The training dataset included 734 CT datasets from healthy controls paired with T1-weighted MRI scans from the Gothenburg H70 Birth Cohort Studies and 62 CT scans from iNPH patients at Uppsala University Hospital. To validate the model's performance across diverse patient populations, external clinical images including scans of 11 iNPH patients from the Universitatsmedizin Rostock, Germany, and 30 iNPH patients from the University of Alabama at Birmingham, United States were used. Further, we obtained three CT-based volumetric measures (CTVMs) related to iNPH.

Results

Our analyses demonstrated strong volumetric correlations (ϱ=0.91, p<0.001) between automatically and manually derived CT-VCSF measurements in iNPH patients. The CTVMs exhibited high accuracy in differentiating iNPH patients from controls in external clinical datasets with an AUC of 0.97 and in the Uppsala University Hospital datasets with an AUC of 0.99.

Discussion

CTVMs derived through deep learning, show potential for assessing and quantifying morphological features in hydrocephalus. Critically, these measures performed comparably to gold-standard neuroradiology assessments in distinguishing iNPH from healthy controls, even in the presence of intraventricular shunt catheters. Accordingly, such an approach may serve to improve the radiological evaluation of iNPH diagnosis/monitoring (i.e., treatment responses). Since CT is much more widely available than MRI, our results have considerable clinical impact.

Idiopathic normal pressure hydrocephalus: Validation of the DESH score as a prognostic tool for shunt surgery response

OBJECTIVE

Several radiological markers have been linked to clinical improvement after shunt surgery for idiopathic normal pressure hydrocephalus (iNPH). However, iNPH has no pathognomonic feature, and patients are still diagnosed as probable, possible, or unlikely cases based on clinical symptoms, imaging findings, and invasive supplementary tests. The predictive value of the disproportionately enlarged subarachnoid space hydrocephalus (DESH) score is not yet conclusively determined, but it might offer a more accurate diagnostic method. The aim of the present retrospective cohort study was to validate the predictive power of the DESH score for clinical improvement after shunt surgery in iNPH patients.

METHODS

We retrospectively obtained presurgical MRI and/or CT scans from 71 patients with iNPH who underwent ventriculoperitoneal shunt surgery. Radiological images were evaluated for Evans index (EI), corpus callosal angle (CA), tight high convexity (THC), Sylvian fissure dilation, and focal sulci dilation. These markers were aggregated to determine the DESH score. Patient journal entries were used to subjectively determine the extent of improvement in gait function, urinary incontinence, and/or cognition as a measure of shunt surgery response.

RESULTS

Multiple logistic regression analysis, controlling for age and sex (α = 0.05), showed that DESH score was significantly correlated (OR 1.77) with subjective shunt-surgery response at a minimum of 1-month follow-up. Patients with higher DESH scores were more likely to have a favorable response to shunt surgery.

CONCLUSION

Aggregating radiological markers into the DESH score is useful for predicting shunt responders among iNPH patients and can aid the selection of patients for surgery. These findings provide further support for the DESH score as a diagnostic tool for iNPH.

Ventriculoperitoneal Shunt Placement Safety in Idiopathic Normal Pressure Hydrocephalus: Anticoagulated Versus Non-Anticoagulated Patients

BACKGROUND

Many patients with idiopathic normal pressure hydrocephalus (iNPH) have medical comorbidities requiring anticoagulation that could negatively impact outcomes. This study evaluated the safety of ventriculoperitoneal shunt placement in iNPH patients on systemic anticoagulation versus those not on anticoagulation.

METHODS

Patients >60 years of age with iNPH who underwent shunting between 2018 and 2022 were retrospectively reviewed. Baseline demographics, comorbidities (quantified by modified frailty index and Charlson comorbidity index), anticoagulant/antiplatelet agent use (other than aspirin), operative details, and complications were collected. Outcomes of interest were the occurrence of postoperative hemorrhage and overdrainage.

RESULTS

A total of 234 patients were included in the study (mean age 75.22 ± 6.04 years; 66.7% male); 36 were on anticoagulation/antiplatelet therapy (excluding aspirin). This included 6 on Warfarin, 19 on direct Xa inhibitors, 10 on Clopidogrel, and 1 on both Clopidogrel and Warfarin. Notably, 70% of patients (164/234) used aspirin alone or combined with anticoagulation or clopidogrel. Baseline modified frailty index was similar between groups, but those on anticoagulant/antiplatelet therapy had a higher mean Charlson comorbidity index (2.67 ± 1.87 vs. 1.75 ± 1.84; P = 0.001). Patients on anticoagulants were more likely to experience tract hemorrhage (11.1 vs. 2.5%; P = 0.03), with no significant difference in the rates of intraventricular hemorrhage or overdrainage-related subdural fluid collection.

CONCLUSIONS

Anticoagulant and antiplatelet agents are common in the iNPH population, and patients on these agents experienced higher rates of tract hemorrhage following ventriculoperitoneal shunt placement; however, overall hemorrhagic complication rates were similar.

Predicting post-surgical outcomes in idiopathic normal pressure hydrocephalus using clinically important changes from the cerebrospinal fluid tap test

OBJECTIVE

Patients diagnosed with idiopathic Normal Pressure Hydrocephalus (iNPH) typically experience symptom improvements after undergoing a cerebrospinal fluid-tap test (CSF-TT), These improvements are recognized as indicative of potential improvements following surgical intervention. As gait disturbance is the most common iNPH symptom, gait improvements are of predominant interest. The purpose of this study was to examine if clinically important changes in gait and balance from CSF-TT predict meaningful changes following surgery.

METHOD

The study involved analysis of data collected in a prospective observational study for 34 iNPH patients who underwent a CSF-TT and subsequent surgery. Linear regression, logistic regression and classification trees were used for predictive modelling comparing changes from CSF-TT with post-surgical changes in Tinetti, Timed Up and Go (TUG) and Berg Balance Scale (BBS) outcomes.

RESULTS

Predictive models for minimal clinically important differences (MCIDs) from CSF-TT to surgery were significant for Tinetti (odds ratio = 1.42, p = 0.02) and BBS (odds ratio = 1.57, p < 0.01). Four items on Tinetti and two items on BBS were identified with a predictive accuracy of 79% and 76% respectively. BBS has the highest sensitivity (85%) and negative predictive value (77%). TUG had a 100% specificity and 100% positive predictive value. The predictive model using MCIDs for TUG was not significant (odds ratio = 1.13, p = 0.06).

CONCLUSION

Clinically important changes from CSF-TT are useful in predicting post-surgical outcomes in iNPH patients. Tinetti and BBS, both have predictive value using MCID scores as cut off values, of which BBS is a stronger outcome measure for prediction.