Idiopathic normal-pressure hydrocephalus: the cost-effectiveness of delivering timely and adequate treatment in Germany

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.

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.

Forget About Memory: Disentangling the Amnestic Syndrome in Idiopathic Normal Pressure Hydrocephalus

Background

Idiopathic normal pressure hydrocephalus (iNPH) can present with both episodic amnestic syndrome and biomarkers of Alzheimer's disease (AD) pathology.

Objective

To examine the associations between amnestic syndrome and cerebrospinal fluid (CSF) AD biomarkers in iNPH and the CSF tap test response in iNPH patients with amnestic syndrome.

Methods

We used the Free and Cued Selective Reminding Test to divide iNPH into amnestic and non-amnestic patients. We compared their clinical, biological, and radiological characteristics and examined the reversibility of gait spatiotemporal parameters and neuropsychological performances after a CSF tap test. Univariate and multiple linear regression models examined the association between memory performance and clinical-biological characteristics.

Results

Sixty-two non-amnestic patients (mean age 77.0±7.0 years, 38.7% female) and thirty-eight amnestic patients (mean age 77.0±5.9 years, 36.8% female) presented similar levels of AD biomarkers and clinical-radiological profiles. Global cognition and education levels were lower in the amnestic iNPH group. We found no association between AD biomarkers and memory performances (total tau: β= -4.50; 95% CI [-11.96;2.96]; p = 0.236; amyloid-β (1-42): β= 8.60, 95% CI [-6.30;23.50]; p = 0.240). At baseline, amnestic iNPH patients performed worse on executive functions, attention, and gait speed but improved similarly to the non-amnestic iNPH patients after the tap test.

Conclusions

In our clinical sample of iNPH patients, we confirm the lack of specificity of the amnestic profile for predicting AD pathology. Clinicians should not preclude amnestic iNPH patients from undergoing an invasive procedure of CSF derivation.

Hospital incidence and costs of congenital hydrocephalus in Spain: a multicenter retrospective study

BACKGROUND

Congenital hydrocephalus continues to represent a therapeutic challenge; however, few studies are available evaluating its hospital incidence and medical costs in Spain. This study aimed to review the profile of patients with this disorder admitted in Spanish hospitals and to estimate medical costs at the hospital level.

METHODS

Records of hospital admissions of patients with congenital hydrocephalus between 2010 and 2019 were obtained from a Spanish hospital discharge database and analyzed in a retrospective multicenter study.

RESULTS

A third of the patients included in the study were perinatal patients, however, the hospitalization rate in this group was higher to that in patients over 1 year of age. Perinatal patients required more ICU admissions and longer hospital stays, with more frequent surgical interventions and mechanical ventilation. The mean medical cost associated to congenital hydrocephalus was €9610 per admission, with significantly higher costs found in perinatal patients.

CONCLUSIONS

This study provides novel data on the hospital costs of congenital hydrocephalus in Spain. The hospital medical costs of this disorder have decreased over the past decade for perinatal patients but not in those aged 1 year and older, which should be considered in upcoming healthcare plans and resource allocation decisions.

The Pathogenesis Based on the Glymphatic System, Diagnosis, and Treatment of Idiopathic Normal Pressure Hydrocephalus

Idiopathic normal pressure hydrocephalus (iNPH) is a rare neurological disorder with no clear prevalence factors and is a significant danger to the elderly. The intracranial glymphatic system is the internal environment that maintains brain survival and metabolism, and thus fluid exchange changes in the glymphatic system under various pathological conditions can provide important insights into the pathogenesis and differential diagnosis of many neurodegenerative diseases such as iNPH. iNPH can be diagnosed using a combination of clinical symptoms, imaging findings and history, and cerebrospinal fluid biomarkers due to the glymphatic system disorder. However, only few researchers have linked the two. Shunt surgery can improve the glymphatic system disorders in iNPH patients, and the surgical approach is determined using a combination of clinical diagnosis and trials. Therefore, we have composed this review to provide a future opportunity for elucidating the pathogenesis of iNPH based on the glymphatic system, and link the glymphatic system to the diagnosis and treatment of iNPH. The review will provide new insights into the medical research of iNPH.