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

Increasing incidence of normal pressure hydrocephalus in Germany: an analysis of the Federal Statistical Office Database from 2005 to 2022

Normal pressure hydrocephalus (NPH) is a reversible cause of gait disturbances and dementia in the elderly, posing diagnostic and therapeutic challenges. In Germany, the epidemiology and surgical management of NPH are not well understood. This study aimed to characterise epidemiological trends and evaluate surgical management strategies for NPH in Germany. A retrospective nationwide population-based study of NPH cases in Germany from 2005 to 2022 was conducted using data from the German Federal Statistical Office. Parameters assessed included incidence trends, demographic characteristics, and surgical interventions. A total of 118,526 NPH diagnoses were recorded, with 29,662 surgical interventions. The population-adjusted incidence of NPH increased by 48%, from 5.4 to 8.0 cases per 100,000 individuals (p < 0.001), peaking in 2018. The largest increases were seen in the "80-89" age group, followed by the "70-79" and "90+" age groups. Surgical interventions increased by 8.4% (p < 0.001), with ventriculoperitoneal shunt being the predominant procedure. The study highlights a 48% rise in NPH incidence in Germany from 2005 to 2022, particularly affecting the elderly. There was also an increase in surgical interventions, underscoring the need for prioritising NPH in national healthcare research agendas.

Discrepancies in Subjective Perceptions of Hydrocephalus Management and Self-Reported Outcomes

Background/Objectives: Despite surgical interventions with advances in endoscopic procedures as well as shunt technologies, the quality of life in patients with hydrocephalus can be poor. Clinical experience suggests discrepancies between objective measures of treatment success and subjective patient satisfaction. With this study, we retrospectively investigated patients' knowledge of their treatment as well as their satisfaction with received interventions. Methods: Retrospective analysis of self-reporting forms, routinely handed out in the hydrocephalus clinic of a tertiary neurosurgical center, was performed. Clinical data were gathered between 1 January 2020 and 31 March 2023. Correlation of self-reporting forms and available clinical data was performed. Results: A total of 261 forms from 215 patients were obtained. The mean age at visit was 57.5 ± 18.5 years (range 19-88). The most common pathology was normal pressure hydrocephalus (NPH, 31.6%); 31.2% had an occlusive etiology, 22.3% posthemorrhagic, 9.8% benign intracranial hypertension and 5.1% another pathology. Overall, 53% of patients (n = 114) indicated the correct therapy on the self-reporting forms (χ2 (56) = 100.986, p < 0.001). Symptoms and subjective benefit did not differ in the different types of provided therapy. Conclusions: Merely half of the patients with hydrocephalus are able to correctly indicate the treatment they had received. The type of shunt valve did not affect the rate of self-reported symptoms. The symptoms and subjective benefits did not differ in the different types of provided therapy. Poor patient knowledge could correlate with poor self-reported quality of life. Medical professionals should emphasize and advocate for better patient education.

Alzheimer's disease CSF biomarkers correlate with early pathology and alterations in neuronal and glial gene expression

INTRODUCTION

Normal pressure hydrocephalus (NPH) patients undergoing cortical shunting frequently show early Alzheimer's disease (AD) pathology on cortical biopsy, which is predictive of progression to clinical AD. The objective of this study was to use samples from this cohort to identify cerebrospinal fluid  (CSF) biomarkers for AD-related central nervous system (CNS) pathophysiologic changes using tissue and fluids with early pathology, free of post mortem artifact.

METHODS

We analyzed Simoa, proteomic, and metabolomic CSF data from 81 patients with previously documented pathologic and transcriptomic changes.

RESULTS

AD pathology on biopsy correlates with CSF β-amyloid-42/40, neurofilament light chain (NfL), and phospho-tau-181(p-tau181)/β-amyloid-42, while several gene expression modules correlate with NfL. Proteomic analysis highlights seven core proteins that correlate with pathology and gene expression changes on biopsy, and metabolomic analysis of CSF identifies disease-relevant groups that correlate with biopsy data.

DISCUSSION

As additional biomarkers are added to AD diagnostic panels, our work provides insight into the CNS pathophysiology these markers are tracking.

HIGHLIGHTS

AD CSF biomarkers correlate with CNS pathology and transcriptomic changes. Seven proteins correlate with CNS pathology and gene expression changes. Inflammatory and neuronal gene expression changes correlate with YKL-40 and NPTXR, respectively. CSF metabolomic analysis identifies pathways that correlate with biopsy data. Fatty acid metabolic pathways correlate with β-amyloid pathology.

Structural and functional connectivity in hydrocephalus: a scoping review

Optimizing the treatment of hydrocephalus remains a major challenge in adult and pediatric neurosurgery. Currently, clinical treatment relies heavily on anatomic imaging of ventricular size and clinical presentation. The emergence of functional and structural brain connectivity imaging has provided the basis for a new paradigm in the management of hydrocephalus. Here we review the pertinent advances in this field. Following PRISMA-ScR guidelines for scoping reviews, we searched PubMed for relevant literature from 1994 to April 2023 using hydrocephalus and MRI-related terms. Included articles reported original MRI data on human subjects with hydrocephalus, while excluding non-English or pre-1994 publications that didn't match the study framework. The review identified 44 studies that investigated functional and/or structural connectivity using various MRI techniques across different hydrocephalus populations. While there is significant heterogeneity in imaging technology and connectivity analysis, there is broad consensus in the literature that 1) hydrocephalus is associated with disruption of functional and structural connectivity, 2) this disruption in cerebral connectivity can be further associated with neurologic compromise 3) timely treatment of hydrocephalus restores both cerebral connectivity and neurologic compromise. The robustness and consistency of these findings vary as a function of patient age, hydrocephalus etiology, and the connectivity region of interest studied. Functional and structural brain connectivity imaging shows potential as an imaging biomarker that may facilitate optimization of hydrocephalus treatment. Future research should focus on standardizing regions of interest as well as identifying connectivity analysis most pertinent to clinical outcome.

Clinical improvements in temporospatial gait variables after a spinal tap test in individuals with idiopathic normal pressure hydrocephalus

Idiopathic Normal Pressure Hydrocephalus (iNPH) is a neurological condition that often presents gait disturbance in the early stages of the disease and affects other motor activities. This study investigated changes in temporospatial gait variables after cerebrospinal fluid (CSF) removal using a spinal tap test in individuals with idiopathic normal pressure hydrocephalus (iNPH), and explored if the tap test responders and non-responders could be clinically identified from temporospatial gait variables. Sixty-two individuals with iNPH were recruited from an outpatient clinic, eleven were excluded, leaving a total of 51 who were included in the analysis. Temporospatial gait variables at self-selected speed were recorded at pre- and 24-h post-tap tests which were compared using Paired t-tests, Cohen's d effect size, and percentage change. A previously defined minimal clinical important change (MCIC) for gait speed was used to determine the changes and to classify tap test responders and non-responders. A mixed model ANOVA was used to determine the within-group, between-group, and interaction effects. Comparisons of the data between pre- and post-tap tests showed significant improvements with small to medium effect sizes for left step length, right step time, stride length and time, cadence, and gait speed. Gait speed showed the largest percentage change among temporospatial gait variables. Within-group and interaction effects were found in some variables but no between-group effect was found. Tap test responders showed significant improvements in right step length and time, stride length and time, cadence, and gait speed while non-responders did not. Some individuals with iNPH showed clinically important improvements in temporospatial gait variables after the tap test, particularly in step/stride length and time, cadence, who could be classified by gait speed. However, gait-related balance variables did not change. Therefore, additional treatments should focus on improving such variables.