The pathogenesis of idiopathic normal pressure hydrocephalus based on the understanding of AQP1 and AQP4

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.

Mechanisms of hydrocephalus after intraventricular haemorrhage: a review

Intraventricular haemorrhage (IVH) is bleeding within the ventricular system, which in adults is usually mainly secondary to cerebral haemorrhage and subarachnoid haemorrhage. Hydrocephalus is one of the most common complications of intraventricular haemorrhage, which is characterised by an increase in intracranial pressure due to an increased accumulation of cerebrospinal fluid within the ventricular system, and is closely related to the patient's prognosis. Surgical methods such as shunt surgery have been used to treat secondary hydrocephalus in recent years and have been effective in improving the survival and prognosis of patients with hydrocephalus. However, complications such as shunt blockage and intracranial infection are often faced after surgery. Moreover, little is known about the mechanism of hydrocephalus secondary to intraventricular haemorrhage. This review discusses the mechanisms regarding the occurrence of secondary hydrocephalus after intraventricular haemorrhage in adults in terms of blood clot obstruction, altered cerebrospinal fluid dynamics, inflammation, and blood composition.

Correlation between serum levels of cyclooxygenase-2, aquaporin-1, pepsinogen I, gastrin-17 and pathological features of Laryngeal Cancer

Objective

To explore the association between the levels of cyclooxygenase-2 (COX-2), aquaporin-1 (AQP1), pepsinogen I (PGI), and gastrin-17 (G17) and pathological features of laryngeal cancer (LC).

Methods

Clinical data of 120 patients with LC, treated in Shanghai Jiao Tong University School of Medicine from May 2022 to May 2023, as well as 120 healthy individuals who underwent physical examinations during the same period, were retrospectively analyzed. Serum levels of COX-2, AQP1, PGI, and G17 of LC patients and the healthy cohort were compared, and their association with pathological features of LC was investigated.

Results

LC was associated with significantly higher serum levels of COX-2, AQP1, and G17 and lower of PGI compared to the control group (P<0.05). Levels of COX-2, AQP1, and G17 positively correlated with the tumor, node and metastasis (TNM) staging, infiltration depth, and the lymph node metastases, and negatively correlated with the degree of differentiation (P<0.05). There was a significant negative correlation between the level of PGI and TNM staging, infiltration depth, and lymph node metastases. PG1 also positively correlated with the degree of differentiation (P<0.05). Area under curve (AUC) of combined COX-2, AQP1, PG-I, and G17 was significantly higher than that of each index alone (P<0.05).

Conclusions

Levels of COX-2, AQP1, PGI, and G17 showed significant association with specific pathological features of LC. Serum levels of COX-2, AQP1, PGI, and G17 have certain predictive value for LC, and the combined predictive value of these four indicators is higher than that of a single indicator.

Comparative analysis of meningeal transcriptomes in birds: Potential pathways of resilience to repeated impacts

The meninges and associated vasculature (MAV) play a crucial role in maintaining cerebral integrity and homeostasis. Recent advances in transcriptomic analysis have illuminated the significance of the MAV in understanding the complex physiological interactions at the interface between the skull and the brain after exposure to mechanical stress. To investigate how physiological responses may confer resilience against repetitive mechanical stress, we performed the first transcriptomic analysis of avian MAV tissues using the Downy Woodpecker (Dryobates pubescens) and Tufted Titmouse (Baeolophus bicolor) as the comparison species. Our findings reveal divergences in gene expression profiles related to immune response, cellular stress management, and protein translation machinery. The male woodpeckers exhibit a tailored immune modulation strategy that potentially dampens neuroinflammation while preserving protective immunity. Overrepresented genes involved in cellular stress responses suggest enhanced mechanisms for mitigating damage and promoting repair. Additionally, the enrichment of translation-associated pathways hints at increased capacity for protein turnover and cellular remodeling vital for recovery. Our study not only fills a critical gap in avian neurobiology but also lays the groundwork for research in comparative neuroprotection.

Brain and Ventricle Volume Alterations in Idiopathic Normal Pressure Hydrocephalus Determined by Artificial Intelligence-Based MRI Volumetry

The aim of this study was to employ artificial intelligence (AI)-based magnetic resonance imaging (MRI) brain volumetry to potentially distinguish between idiopathic normal pressure hydrocephalus (iNPH), Alzheimer's disease (AD), and age- and sex-matched healthy controls (CG) by evaluating cortical, subcortical, and ventricular volumes. Additionally, correlations between the measured brain and ventricle volumes and two established semi-quantitative radiologic markers for iNPH were examined. An IRB-approved retrospective analysis was conducted on 123 age- and sex-matched subjects (41 iNPH, 41 AD, and 41 controls), with all of the iNPH patients undergoing routine clinical brain MRI prior to ventriculoperitoneal shunt implantation. Automated AI-based determination of different cortical and subcortical brain and ventricular volumes in mL, as well as calculation of population-based normalized percentiles according to an embedded database, was performed; the CE-certified software mdbrain v4.4.1 or above was used with a standardized T1-weighted 3D magnetization-prepared rapid gradient echo (MPRAGE) sequence. Measured brain volumes and percentiles were analyzed for between-group differences and correlated with semi-quantitative measurements of the Evans' index and corpus callosal angle: iNPH patients exhibited ventricular enlargement and changes in gray and white matter compared to AD patients and controls, with the most significant differences observed in total ventricular volume (+67%) and the lateral (+68%), third (+38%), and fourth (+31%) ventricles compared to controls. Global ventriculomegaly and marked white matter reduction with concomitant preservation of gray matter compared to AD and CG were characteristic of iNPH, whereas global and frontoparietally accentuated gray matter reductions were characteristic of AD. Evans' index and corpus callosal angle differed significantly between the three groups and moderately correlated with the lateral ventricular volumes in iNPH patients [Evans' index (r > 0.83, p ≤ 0.001), corpus callosal angle (r < -0.74, p ≤ 0.001)]. AI-based MRI volumetry in iNPH patients revealed global ventricular enlargement and focal brain atrophy, which, in contrast to healthy controls and AD patients, primarily involved the supratentorial white matter and was marked temporomesially and in the midbrain, while largely preserving gray matter. Integrating AI volumetry in conjunction with traditional radiologic measures could enhance iNPH identification and differentiation, potentially improving patient management and therapy response assessment.

Changes in postural stability after cerebrospinal fluid tap test in patients with idiopathic normal pressure hydrocephalus

Introduction

In patients with idiopathic normal pressure hydrocephalus (iNPH), the characteristics of balance disturbance are not as well understood as those related to gait. This study examined changes in postural stability in quiet standing after the cerebrospinal fluid tap test (CSFTT) in these patients. Furthermore, the study explored the relationship between the amount of spontaneous body sway and both gait and executive function.

Materials and methods

All patients diagnosed with iNPH underwent CSFTT. We evaluated their center of pressure (COP) measurements on a force plate during quiet standing, both pre- and post-CSFTT. Following the COP measurements, we calculated COP parameters using time and frequency domain analysis and assessed changes in these parameters after CSFTT. At pre-CSFTT, we assessed the Timed Up and Go (TUG) and the Frontal Assessment Battery (FAB). We investigated the relationship between COP parameters and the TUG and FAB scores at pre-CSFTT.

Results

A total of 72 patients with iNPH were initially enrolled, and 56 patients who responded positively to CSFTT were finally included. Post-CSFTT, significant improvements were observed in COP parameters through time domain analysis. These included the velocity of COP (vCOP), root-mean-square of COP (rmsCOP), turn index, torque, and base of support (BOS), compared to the pre-CSFTT values (p < 0.05). In the frequency domain analysis of COP parameters post-CSFTT, there was a decrease in both the peak and average of power spectral density (PSD) values in both the anteroposterior (AP) and mediolateral (ML) directions below 0.5 Hz (p < 0.05). In addition, the TUG scores showed a positive correlation with vCOP, rmsCOP, turn index, torque, BOS, and both the peak and average PSD values in the AP and ML directions below 0.5 Hz (p < 0.05). The FAB scores demonstrated a negative correlation with vCOP, rmsCOP, turns index, BOS, and both peak and average PSD values in the AP direction below 0.5 Hz (p < 0.05).

Conclusion

In patients with iNPH who responded to CSFTT, there was an improvement in spontaneous body sway during quiet standing after CSFTT. Increased spontaneous sway is associated with impaired gait and frontal lobe function. This may be linked to impaired cortico-cortical and cortico-subcortical circuits in patients with iNPH.

Aquaporin-4 and Parkinson's Disease

The water-selective channel aquaporin-4 (AQP4) is implicated in water homeostasis and the functioning of the glymphatic system, which eliminates various metabolites from the brain tissue, including amyloidogenic proteins. Misfolding of the α-synuclein protein and its post-translational modifications play a crucial role in the development of Parkinson's disease (PD) and other synucleopathies, leading to the formation of cytotoxic oligomers and aggregates that cause neurodegeneration. Human and animal studies have shown an interconnection between AQP4 dysfunction and α-synuclein accumulation; however, the specific role of AQP4 in these mechanisms remains unclear. This review summarizes the current knowledge on the role of AQP4 dysfunction in the progression of α-synuclein pathology, considering the possible effects of AQP4 dysregulation on brain molecular mechanisms that can impact α-synuclein modification, accumulation and aggregation. It also highlights future directions that can help study the role of AQP4 in the functioning of the protective mechanisms of the brain during the development of PD and other neurodegenerative diseases.

The glymphatic system: a new perspective on brain diseases

The glymphatic system is a brain-wide perivascular pathway driven by aquaporin-4 on the endfeet of astrocytes, which can deliver nutrients and active substances to the brain parenchyma through periarterial cerebrospinal fluid (CSF) influx pathway and remove metabolic wastes through perivenous clearance routes. This paper summarizes the composition, overall fluid flow, solute transport, related diseases, affecting factors, and preclinical research methods of the glymphatic system. In doing so, we aim to provide direction and reference for more relevant researchers in the future.