Ventriculoperitoneal Shunt Outcomes of Normal Pressure Hydrocephalus: A Case Series of 116 Patients

Prediction of Surgical Outcomes in Normal Pressure Hydrocephalus by MR Elastography

BACKGROUND AND PURPOSE

Normal pressure hydrocephalus is a treatable cause of dementia associated with distinct mechanical property signatures in the brain as measured by MR elastography. In this study, we tested the hypothesis that specific anatomic features of normal pressure hydrocephalus are associated with unique mechanical property alterations. Then, we tested the hypothesis that summary measures of these mechanical signatures can be used to predict clinical outcomes.

MATERIALS AND METHODS

MR elastography and structural imaging were performed in 128 patients with suspected normal pressure hydrocephalus and 44 control participants. Patients were categorized into 4 subgroups based on their anatomic features. Surgery outcome was acquired for 68 patients. Voxelwise modeling was performed to detect regions with significantly different mechanical properties between each group. Mechanical signatures were summarized using pattern analysis and were used as features to train classification models and predict shunt outcomes for 2 sets of feature spaces: a limited 2D feature space that included the most common features found in normal pressure hydrocephalus and an expanded 20-dimensional (20D) feature space that included features from all 4 morphologic subgroups.

RESULTS

Both the 2D and 20D classifiers performed significantly better than chance for predicting clinical outcomes with estimated areas under the receiver operating characteristic curve of 0.66 and 0.77, respectively (P < .05, permutation test). The 20D classifier significantly improved the diagnostic OR and positive predictive value compared with the 2D classifier (P < .05, permutation test).

CONCLUSIONS

MR elastography provides further insight into mechanical alterations in the normal pressure hydrocephalus brain and is a promising, noninvasive method for predicting surgical outcomes in patients with normal pressure hydrocephalus.

Neurocognitive change over the course of a multiday external lumbar drain trial in patients with suspected normal pressure hydrocephalus

Objective: To characterize neurocognitive response to cerebrospinal fluid (CSF) diversion during a multiday external lumbar drainage (ELD) trial in patients with suspected normal pressure hydrocephalus (NPH). Methods: Inpatients (N = 70) undergoing an ELD trial as part of NPH evaluation participated. Cognition and balance were assessed using standardized measures before and after a three-day ELD trial. Cognitive change pre- to post-ELD trial was assessed in relation to change in balance, baseline neuroimaging findings, NPH symptoms, demographics, and other disease-relevant clinical parameters. Results: Multiday ELD resulted in significant cognitive improvement (particularly on measures of memory and language). This improvement was independent of demographics, test-retest interval, number of medical and psychiatric comorbidities, NPH symptom duration, estimated premorbid intelligence, baseline level of cognitive impairment, cerebrovascular disease burden, degree of ventriculomegaly, or other NPH-related morphological brain alterations. Balance scores evidenced a greater magnitude of improvement than cognitive scores and were weakly, but positively correlated with cognitive change scores. Conclusions: Findings suggest that cognitive improvement associated with a multiday ELD trial can be sufficiently captured with bedside neurocognitive testing. These findings support the utility of neuropsychological consultation, along with balance assessment, in informing clinical decision-making regarding responsiveness to temporary CSF diversion for patients undergoing elective NPH evaluation. Implications for the understanding of neuroanatomical and cognitive underpinnings of NPH are discussed.

Comparison of cerebrospinal fluid space between probable normal pressure hydrocephalus and Alzheimer's disease

Introduction

Idiopathic normal pressure hydrocephalus (INPH) is a potentially reversible syndrome characterized by complex symptoms, difficulty in diagnosis and a lack of detailed clinical description, and it is difficult to distinguish from Alzheimer's disease (AD). The objective of this study was to design a method for measuring the actual amount of hydrocephalus in patients with INPH and to evaluate INPH.

Methods

All subjects underwent a 3D T1-weighted MRI. Statistical parametric mapping 12 was used for preprocessing images, statistical analysis, and voxel-based morphometric gray matter (GM) volume, white matter (WM) volume, and cerebrospinal fluid (CSF) volume analysis. The demographic and clinical characteristics of the groups were compared using a t-test for continuous variables and a chi-square test for categorical variables. Pearson's correlation analysis and Bonferroni's statistic-corrected one-way ANOVA were used to determine the relationship among demographic variables. Receiver operating characteristic (ROC) curves were used to assess the accuracy of the callosal angle (CA), WM ratio, and CSF ratio in distinguishing probable INPH from AD.

Results

The study included 42 patients with INPH, 32 patients with AD, and 24 healthy control subjects (HCs). There were no differences among the three groups in basic characteristics except for Mini-Mental State Examination (MMSE). There was a correlation between the intracranial CSF ratio and CA. The WM ratio and CSF ratio in patients with INPH and AD were statistically different. Furthermore, the combination of CA, WM ratio, and CSF ratio had a greater differential diagnostic value between INPH and AD patients than CA alone.

Conclusion

INPH can be accurately assessed by measuring intracranial CSF ratio, and the addition of WM ratio and CSF ratio significantly improved the differential diagnostic value of probable INPH from AD compared to CA alone.

Idiopathic normal pressure hydrocephalus: postoperative patient perspective and quality of life

BACKGROUND

Idiopathic normal pressure hydrocephalus (iNPH) is a potentially reversible disease. Surgical results have been well described in the literature, but only a few studies investigated the subjective outcome. This study aimed to investigate the patient's expectations about surgery, the perceived improvement after treatment, and its impact on the quality of life (QoL).

METHODS

A new dedicated survey was created to investigate subjectively different aspects of the treatment pathway of iNPH (diagnosis, symptoms, expectations from surgery, surgical operation, surgical results, and postoperative QoL), together with the SF-12 and EQ-5D as validated, standardized tools.

RESULTS

Forty-five patients were included. Forty-three percent of cases received the diagnosis after at least 1 year, with symptoms worsening in 73%, and frustration in 93%. Reaching a diagnosis was important for 100% of patients, with high expectations from surgery; 86% of them hoped to return to a normal life. Seventy-two percent of patients reported a significant postoperative improvement (walking 68%, mood 57%). Memory and incontinence did not improve in 64% of cases. Subjectively, QoL improved in 72% of cases. The SF-12 score is comparable to controls >75 years, but lower than the 65-75 years group. The EQ-5D index was 0.66 (lower than those of the 65-75 years group = 0.823, and >75 years group = 0.724). Pain and discomfort, instead, were lower compared to the healthy population (43% vs 56%). The idea of having an implanted device and of long-term follow-up is not worrying for 80% of patients; approximately two-thirds of them reported a regained control of their lives.

CONCLUSIONS

The importance of early diagnosis and patients' perspective, alongside clinical evaluation, is highlighted. The self-reported evaluations on symptoms and QoL, along with the balance between postoperative worries and benefits, should be discussed preoperatively with patients and relatives, and included postoperatively to comprehensively assess the surgical outcome.

Outcomes of Ventriculoperitoneal Shunt in Patients With Idiopathic Normal-Pressure Hydrocephalus 2 Years After Surgery

Objective: To evaluate the outcomes and prognostic factors of ventriculoperitoneal shunts (VP-shunts) in patients with idiopathic normal-pressure hydrocephalus (iNPH) at 6 months and 2 years after surgery.

Method: We retrospectively analyzed 68 patients admitted to our institute and diagnosed with probable iNPH from January 2017 to March 2021. All patients underwent VP-shunt surgery with a programmable valve, and their outcomes were assessed via the Krauss index and modified Rankin scale (mRS) at 6 months and 2 years post-surgery. Univariate and multivariate regression analysis was performed to identify the prognostic factors.

Results: The mean age of the patients was 71.1 ± 8.4 (mean ± standard deviation) years. On the Krauss improvement index, 6-month follow-up results were available for 68 patients. Of these patients, 91.2% experienced attenuation of their preoperative symptoms, with a mean Krauss index of 0.58 ± 0.27, and 48 patients (70.6%) had a Krauss index ≥0.5. Two-year follow-up results were available for 33 patients; 90.9% of them had sustained improvement, with a Krauss index of 0.54 ± 0.31, and 21 patients (66.3%) had a Krauss index ≥0.5. Thirty-three patients (58%) were living independently after 2 years (mRS 0–2). The outcomes were worse for patients with multiple comorbidities. Neither an increased patient age nor a prolonged history of illness was statistically significant prognostic factors for adverse outcomes of VP-shunt surgery.

Conclusion: Surgical treatment was well-tolerated by patients with iNPH who received VP-shunts. Most patients experienced attenuation of their preoperative symptoms. Multiple concurrent comorbidities should be considered as adverse prognostic factors before shunt insertion in patients with iNPH.

Clinical predictors of shunt response in the diagnosis and treatment of idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis

Background

Positive shunt response (SR) remains the gold standard for diagnosing idiopathic normal pressure hydrocephalus (iNPH). However, multiple pathologies mimic iNPH symptoms, making it difficult to select patients who will respond to shunt surgery. Although presenting features, extended lumbar drainage (ELD), infusion test (IT), intracranial pressure monitoring (ICPM), and tap test (TT) have been used to predict SR, uncertainty remains over which diagnostic test to choose.

Objective

To conduct a systematic review and meta-analysis to identify clinical predictors of shunt responsiveness, evaluate their diagnostic effectiveness, and recommend the most effective diagnostic tests.

Methods

Embase, MEDLINE, Scopus, PubMed, Google Scholar, and JSTOR were searched for original studies investigating clinical predictors of SR in iNPH patients. Included studies were assessed using the QUADAS-2 tool, and eligible studies were evaluated using univariate and bivariate meta-analyses.

Results

Thirty-five studies were included. Nine studies discussed the diagnostic use of presenting clinical features, 8 studies ELD, 8 studies IT, 11 studies ICPM, and 6 studies TT. A meta-analysis of 21 eligible studies was conducted for TT, ELD, IT, and ICPM. ICPM yielded the highest diagnostic effectiveness, with diagnostic odds ratio (DOR) = 50.9 and area under curve (AUC) = 0.836. ELD yielded DOR = 27.70 and AUC = 0.753, IT had DOR = 5.70 and AUC = 0.729, and TT scored DOR = 3.86 and AUC = 0.711.

Conclusion

Intraparenchymal ICPM is statistically the most effective diagnostic test, followed by ELD, IT, and lastly TT. Due to the higher accessibility of TT and IT, they are recommended to be used first line, using a timed-up-and-go improvement ≥ 5.6 s or a Rout cut-off range between 13 and 16 mmHg, respectively. Patients who test negative should ideally be followed up with ICPM, using mean ICP wave amplitude \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge$$\end{document}≥ 4 mmHg, or 1- to 4-day ELD with an MMSE cut-off improvement \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge$$\end{document}≥ 3. Future research must use standardized methodologies for each diagnostic test and uniform criteria for SR to allow better comparison.

Prognostic Utility of Disproportionately Enlarged Subarachnoid Space Hydrocephalus in Idiopathic Normal Pressure Hydrocephalus Treated with Ventriculoperitoneal Shunt Surgery: A Systematic Review and Meta-analysis

BACKGROUND

Disproportionately enlarged subarachnoid space hydrocephalus is a specific radiologic marker for idiopathic normal pressure hydrocephalus. However, controversy exists regarding the prognostic utility of disproportionately enlarged subarachnoid space hydrocephalus.

PURPOSE

Our aim was to evaluate the prevalence of disproportionately enlarged subarachnoid space hydrocephalus in idiopathic normal pressure hydrocephalus and its predictive utility regarding prognosis in patients treated with ventriculoperitoneal shunt surgery.

DATA SOURCES

We used MEDLINE and EMBASE databases.

STUDY SELECTION

We searched for studies that reported the prevalence or the diagnostic performance of disproportionately enlarged subarachnoid space hydrocephalus in predicting treatment response.

DATA ANALYSIS

The pooled prevalence of disproportionately enlarged subarachnoid space hydrocephalus was obtained. Pooled sensitivity, specificity, and area under the curve of disproportionately enlarged subarachnoid space hydrocephalus to predict treatment response were obtained. Subgroup and sensitivity analyses were performed to explain heterogeneity among the studies.

DATA SYNTHESIS

Ten articles with 812 patients were included. The pooled prevalence of disproportionately enlarged subarachnoid space hydrocephalus in idiopathic normal pressure hydrocephalus was 44% (95% CI, 34%-54%). The pooled prevalence of disproportionately enlarged subarachnoid space hydrocephalus was higher in the studies using the second edition of the Japanese Guidelines for Management of Idiopathic Normal Pressure Hydrocephalus compared with the studies using the international guidelines without statistical significance (52% versus 43%, P = .38). The pooled sensitivity and specificity of disproportionately enlarged subarachnoid space hydrocephalus for prediction of treatment response were 59% (95% CI, 38%-77%) and 66% (95% CI, 57%-74%), respectively, with an area under the curve of 0.67 (95% CI, 0.63-0.71).

LIMITATIONS

The lack of an established method for assessing disproportionately enlarged subarachnoid space hydrocephalus using brain MR imaging served as an important cause of the heterogeneity.

CONCLUSIONS

Our meta-analysis demonstrated a relatively low prevalence of disproportionately enlarged subarachnoid space hydrocephalus in idiopathic normal pressure hydrocephalus and a poor diagnostic performance for treatment response.

Glymphatic System Impairment in Alzheimer's Disease and Idiopathic Normal Pressure Hydrocephalus

Approximately 10% of dementia patients have idiopathic normal pressure hydrocephalus (iNPH), an expansion of the cerebrospinal fluid (CSF)-filled brain ventricles. iNPH and Alzheimer's disease (AD) both exhibit sleep disturbances, build-up of brain metabolic wastes and amyloid-β (Aβ) plaques, perivascular reactive astrogliosis, and mislocalization of astrocyte aquaporin-4 (AQP4). The glia-lymphatic (glymphatic) system facilitates brain fluid clearance and waste removal during sleep via glia-supported perivascular channels. Human studies have implicated impaired glymphatic function in both AD and iNPH. Continued investigation into the role of glymphatic system biology in AD and iNPH models could lead to new strategies to improve brain health by restoring homeostatic brain metabolism and CSF dynamics.

Schizophrenia-related microdeletion causes defective ciliary motility and brain ventricle enlargement via microRNA-dependent mechanisms in mice

Progressive ventricular enlargement, a key feature of several neurologic and psychiatric diseases, is mediated by unknown mechanisms. Here, using murine models of 22q11-deletion syndrome (22q11DS), which is associated with schizophrenia in humans, we found progressive enlargement of lateral and third ventricles and deceleration of ciliary beating on ependymal cells lining the ventricular walls. The cilia-beating deficit observed in brain slices and in vivo is caused by elevated levels of dopamine receptors (Drd1), which are expressed in motile cilia. Haploinsufficiency of the microRNA-processing gene Dgcr8 results in Drd1 elevation, which is brought about by a reduction in Drd1-targeting microRNAs miR-382-3p and miR-674-3p. Replenishing either microRNA in 22q11DS mice normalizes ciliary beating and ventricular size. Knocking down the microRNAs or deleting their seed sites on Drd1 mimicked the cilia-beating and ventricular deficits. These results suggest that the Dgcr8-miR-382-3p/miR-674-3p-Drd1 mechanism contributes to deceleration of ciliary motility and age-dependent ventricular enlargement in 22q11DS.