The prevalence of cardiovascular disease in non-communicating hydrocephalus

Vascular risk factors for idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis

Objective

Idiopathic normal-pressure hydrocephalus (iNPH) is a treatable cause of dementia; however, its etiology and pathogenesis remain poorly understood. The objective of this study was to investigate the prevalence and impact of vascular risk factors in patients with iNPH compared to a control cohort to better understand the potential mechanisms and preventive measures.

Methods

We systematically searched PubMed, Web of Science, Embase, and the Cochrane Library (from inception to December 20, 2022) for studies reporting vascular risk factors for the development of iNPH. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using random-effects models.

Results

After screening 1,462 articles, 11 case-control studies comprising 1,048 patients with iNPH and 79,668 cognitively unimpaired controls were included in the meta-analysis. Our data showed that hypertension (N = 991, OR = 2.30, 95% CI 1.64 to 3.23, I2= 64.0%), diabetes mellitus (DM) (N = 985, OR = 3.12, 95% CI 2.29 to 4.27, I2= 44.0%), coronary heart disease (CHD; N = 880, OR = 2.34, 95% CI 1.33 to 4.12, I2= 83.1%), and peripheral vascular disease (N = 172, OR = 2.77, 95% CI 1.50 to 5.13, I2= 0.0%) increased the risk for iNPH, while overweight was a possible factor (N = 225, OR = 2.01, 95% CI 1.34 to 3.04, I2= 0.0%) based on the sensitivity analysis. Smoking and alcohol consumption were not associated with iNPH.

Conclusions

Our study suggested that hypertension, DM, CHD, peripheral vascular disease, and overweight were associated with iNPH. These factors might be involved in the pathophysiological mechanisms promoting iNPH. These findings require further investigation in future studies.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, CRD42022383004.

Hydrodynamic comparison of shunt and endoscopic third ventriculostomy in adult hydrocephalus using in vitro models and fluid-structure interaction simulation

OBJECTIVE

The comparison of the efficiency of shunt placement and endoscopic third ventriculostomy (ETV) in treating of adult hydrocephalus patients with various intensities and different obstruction intensities in the aqueduct of Sylvius (AS).

METHODS

In vitro models with separated ventricles were simulated and implemented for modeling shunt and ETV surgeries in one healthy subject and hydrocephalus patients with various intensities, as well as three different obstruction intensities in AS and under two cerebrospinal fluid (CSF) dynamic conditions. The fluid-structure interaction simulation was also carried out to validate in vitro results.

RESULTS

The efficiency of both methods in reducing the maximum CSF pressure in the subarachnoid space (MCPS) decreased by an increase in the patient's intensities. Contrary to shunting, the efficiency of ETV in reducing MCPS demonstrated a decline (8.3-16.4%) by an increase in obstruction levels in AS. Based on the findings, shunt efficiency in decreasing MCPS in patients with low intensity was more remarkable compared to ETV. However, ETV was more efficient than shunt in the patient with intracranial hypertension. Further, shunt placement and ETV led to a significant reduction in the amplitude of CSF pressure in the SAS (ACPS) in patients with sneezing, coughing, Valsalva maneuver, and exercising effects in contrast to other patients. Moreover, ACPS reduction was not related to the intensity of the disease in both treatment methods. In contrast to shunt, an increase in the obstruction level in AS led to a reduction in ACPS in ETV in both CSF dynamic conditions.

CONCLUSIONS

The noises from irregular disorders increased the discharging of CSF after shunt placement, and activities such as sneezing, coughing, Valsalva maneuvers, and exercising increased the risk of shunt overdrainage by 10.4~47.8%, especially in the patient with intracranial hypertension. Based on the proposed in vitro ETV and shunt models, an increase of head compliance was higher in ETV compared to the shunt. Eventually, an increase in the obstruction level of AS after ETV led to a decline in head compliance in contrast to shunt.

Boundary conditions investigation to improve computer simulation of cerebrospinal fluid dynamics in hydrocephalus patients

Three-D head geometrical models of eight healthy subjects and 11 hydrocephalus patients were built using their CINE phase-contrast MRI data and used for computer simulations under three different inlet/outlet boundary conditions (BCs). The maximum cerebrospinal fluid (CSF) pressure and the ventricular system volume were more effective and accurate than the other parameters in evaluating the patients' conditions. In constant CSF pressure, the computational patient models were 18.5% more sensitive to CSF volume changes in the ventricular system under BC "C". Pulsatile CSF flow rate diagrams were used for inlet and outlet BCs of BC "C". BC "C" was suggested to evaluate the intracranial compliance of the hydrocephalus patients. The results suggested using the computational fluid dynamic (CFD) method and the fully coupled fluid-structure interaction (FSI) method for the CSF dynamic analysis in patients with external and internal hydrocephalus, respectively.

Chiari type 1-a malformation or a syndrome? A critical review

OBJECTIVE

As the understanding of pathophysiology behind Chiari malformation still is limited, the treatment of Chiari malformation type 1 remains rather empirical. This may result in suboptimal treatment strategy and outcome in many cases. In this review, we critically address whether the condition known today as Chiari malformation type I should rather be denoted Chiari syndrome.

METHODS

The current knowledge of Chiari malformation type 1 is summarized from the historical, etymological, genetic, clinical, and in particular pathophysiological perspectives.

RESULTS

There are several lines of evidence that Chiari malformation type 1 represents a condition significantly different from types 2 to 4. Unlike the other types, the type 1 should rather be considered a syndrome, thus supporting the reasons to reappraise the traditional classification of Chiari malformations.

CONCLUSION

We propose that Chiari malformation type 1 should rather be denoted Chiari syndrome, while the notation malformation is maintained for types 2-4.

Comparing the Efficiency of Two Treatment Methods of Hydrocephalus: Shunt Implantation and Endoscopic Third Ventriculostomy

Introduction:

Hydrocephalus is one of the most common diseases in children, and its treatment requires brain operation. However, the pathophysiology of the disease is very complicated and still unknown.

Methods:

Endoscopic Third Ventriculostomy (ETV) and Ventriculoperitoneal Shunt (VPS) implantation are among the common treatments of hydrocephalus. In this study, Cerebrospinal Fluid (CSF) hydrodynamic parameters and efficiency of the treatment methods were compared with numerical simulation and clinical follow-up of the treated patients.

Results:

Studies have shown that in patients under 19 years of age suffering from hydrocephalus related to a Posterior Fossa Brain Tumor (PFBT), the cumulative failure rate was 21% and 29% in ETV and VPS operation, respectively. At first, the ETV survival curve shows a sharp decrease and after two months it gets fixed while VPS curve makes a gradual decrease and reaches to a level lower than ETV curve after 5.7 months. Post-operative complications in ETV and VPS methods are 17% and 31%, respectively. In infants younger than 12 months with hydrocephalus due to congenital Aqueduct Stenosis (AS), and also in the elderly patients suffering from Normal Pressure Hydrocephalus (NPH), ETV is a better treatment option. Computer simulations show that the maximum CSF pressure is the most reliable hydrodynamic index for the evaluation of the treatment efficacy in these patients. After treatment by ETV and shunt methods, CSF pressure decreases about 9 and 5.3 times, respectively and 2.5 years after shunt implantation, this number returns to normal range.

Conclusion:

In infants with hydrocephalus, initial treatment by ETV was more reasonable than implanting the shunt. In adult with hydrocephalus, the initial failure in ETV occurred sooner compared to shunt therapy; however, ETV was more efficient.

FSI simulation of CSF hydrodynamic changes in a large population of non-communicating hydrocephalus patients during treatment process with regard to their clinical symptoms

3D fluid-structure interaction modelling was utilized for simulation of 13 normal subjects, 11 non-communicating hydrocephalus (NCH) patients at pre-treatment phase, and 3 patients at five post-treatment phases. Evaluation of ventricles volume and maximum CSF pressure (before shunting) following results validation indicated that these parameters were the most proper hydrodynamic indices and the NCH type doesn't have any significant effect on changes in two indices. The results confirmed an appropriate correlation between these indices although the correlation decreased slightly after the occurrence of disease. NCH raises the intensity of vortex and pulsatility (2.4 times) of CSF flow while the flow remains laminar. On day 18 after shunting, the CSF pressure decreased 81.0% and all clinical symptoms of patients vanished except for headache. Continuing this investigation during the treatment process showed that maximum CSF pressure is the most sensitive parameter to patients' clinical symptoms. Maximum CSF pressure has decreased proportional to the level of decrease in clinical symptoms and has returned close to the pressure range in normal subjects faster than other parameters and simultaneous with disappearance of patients' clinical symptoms (from day 81 after shunting). However, phase lag between flow rate and pressure gradient functions and the degree of CSF pulsatility haven't returned to normal subjects' conditions even 981 days after shunting and NCH has also caused a permanent volume change (of 20.1%) in ventricles. Therefore, patients have experienced a new healthy state in new hydrodynamic conditions after shunting and healing. Increase in patients' intracranial compliance was predicted with a more accurate non-invasive method than previous experimental methods up to more than 981 days after shunting. The changes in hydrodynamic parameters along with clinical reports of patients can help to gain more insight into the pathophysiology of NCH patients.

The pathophysiology of chronic noncommunicating hydrocephalus: lessons from continuous intracranial pressure monitoring and ventricular infusion testing

OBJECTIVE The pathophysiology of chronic noncommunicating hydrocephalus (ncHC) is poorly understood. This present study explored whether lessons about the pathophysiology of this clinical entity might be retrieved from results of overnight monitoring of pulsatile and static intracranial pressure (ICP) and ventricular infusion testing. METHODS The study cohort included adult patients (> 20 years of age) with chronic ncHC due to aqueductal stenosis in whom symptoms had lasted a minimum of 6 months. A reference cohort consisted of age- and sex-matched patients managed for communicating HC (cHC). Information about symptoms and clinical improvement following surgery was retrieved from a quality register, and results of overnight ICP recordings and ventricular infusion testing were retrieved from the hospital ICP database. RESULTS The cohort with ncHC consisted of 61 patients of whom 6 (10%) were managed conservatively, 34 (56%) by endoscopic third ventriculostomy (ETV), and 21 (34%) using ETV and subsequent shunt surgery. In patients responding to surgery, pulsatile ICP (mean ICP wave amplitude) was significantly increased to a similar magnitude in patients with ncHC and the reference cohort (cHC). Furthermore, intracranial compliance (ICC) was reduced in clinical responders. The results of ventricular infusion testing provided evidence that patients responding to ETV have impaired ventricular CSF absorption, while those requiring shunt placement after ETV present with impaired CSF absorption both in the intraventricular and extraventricular compartments. CONCLUSIONS The study may provide some lessons about the pathophysiology of chronic ncHC. First, increased pulsatile ICP and impaired ICC characterize patients with chronic ncHC who respond clinically to CSF diversion surgery, even though static ICP is not increased. Second, in patients responding clinically to ETV, impaired ventricular CSF absorption may be a key factor. Patients requiring shunt placement for clinical response appear to have both intraventricular and extraventricular CSF absorption failure. A subgroup of patients with ncHC due to aqueductal stenosis has normal ventricular CSF absorption and normal ICC and may not be in need of surgical CSF diversion.

Cardiovascular risk factors in Chiari malformation and idiopathic intracranial hypertension

OBJECTIVES

Both Chiari malformation type 1 (CMI, i.e., the idiopathic caudal ectopy of cerebellar tonsils into foramen magnum) and idiopathic intracranial hypertension (IIH) are characterized by reduced intracranial compliance (ICC) due to disturbed circulation of cerebrospinal fluid (CSF). An increasing body of evidence links cardiovascular disease to CSF circulation disturbances. The aim of this study was to explore whether the prevalence of cardiovascular risk factors in patients with CMI or IIH is higher than in the general population.

MATERIALS AND METHODS

Among the patients with CMI or IIH treated at our department during the period 2003-2014, we identified those with history of arterial hypertension (AH), myocardial infarction (MI), angina pectoris (AP), or diabetes mellitus (DM). For comparison with a control population, we retrieved information about the prevalence of AH, MI, AP, and DM among participants of the North-Trøndelag Health Study 3 (HUNT3).

RESULTS

Data from 48 CMI and 52 IIH cases were available. Compared to data from the 42,461 individuals participating in the HUNT3, we found increased prevalence of DM in male CMI as well as female IIH cases, and of AH in female IIH cases. Body mass index (BMI) was significantly increased in both female and male IIH cases. Prevalence of MI and AP in the CMI and IIH cohorts was extremely low and therefore not further studied.

CONCLUSIONS

This study provided evidence of an increased prevalence of DM in male CMI as well as female IIH cases and of AH in female IIH cases. Although requiring further exploration, these findings point to AH and DM as potential risk factors in the pathophysiology of CMI and IIH.