Atypical Presentation of Longstanding Overt Ventriculomegaly in Adults: A Case Report.

Hydrocephalus involves the enlargement of the ventricular system due to increased cerebrospinal fluid. This condition often presents with ventriculomegaly, associated with cognitive decline, gait disturbances, visual changes, and other neurological symptoms. In adults, hydrocephalus may result from longstanding overt ventriculomegaly in adults (LOVA), characterized by macrocephaly, subnormal IQ, urinary incontinence, and gait issues. In a recent case report, a 52-year-old Hispanic female displayed similar predisposing factors and radiological findings for a LOVA diagnosis. Despite the absence of focal neurological deficits or typical complaints, she experienced a breakthrough seizure episode after years without incident.

Ventriculoperitoneal shunt patients and glaucoma: a cohort analysis of the NPH registry.

BACKGROUND: Idiopathic Normal Pressure Hydrocephalus (iNPH) is a chronic condition affecting the elderly. It is characterized by a triad of symptoms and radiological findings. Glaucoma is the leading cause of irreversible blindness worldwide. Earlier studies have proposed that the rate of glaucoma is higher in iNPH patients, and of a possible link between ventriculoperitoneal shunt (VP) treatment and the development of glaucoma. OBJECTIVES: This study aimed to determine the prevalence of glaucoma among iNPH patients and assess the impact of VPs on glaucoma prevalence. METHODS: A cohort study was conducted at Kuopio University Hospital (KUH), including 262 patients with a ventriculoperitoneal shunt. Clinical data were obtained from the Kuopio NPH Registry and medical records. Patients were grouped by iNPH status: iNPH (+) - probable/possible iNPH (n = 192), and iNPH (-) - other causes of hydrocephalus (congenital, secondary, obstructive) (n = 70). We conducted statistical analysis using the Independent Samples T-test, Fisher's exact test, and Pearson Chi-Square. We compared demographics, glaucoma prevalence, brain biopsies positive for Amyloid-ß (Aß) and hyperphosphorylated tau (HPτ) as well as comorbidities for hypertension and diabetes medication. Age stratification assessed glaucoma prevalence in the full cohort. RESULTS: Both iNPH (+) and iNPH (-) groups had comparable demographic and comorbidity profiles. The prevalence of glaucoma in the iNPH (+) group was 11.5% (n = 22) and 11.4% (n = 8) in the iNPH (-) group without a statistically significant difference (p = 1.000). Brain biopsies positive for Amyloid-ß (Aß) and hyperphosphorylated tau (HPτ) were similar. CONCLUSIONS: Neither shunted iNPH patients nor those with a comorbid condition other than iNPH showed a markedly higher prevalence of glaucoma. Instead, both groups exhibited age-related increases in glaucoma prevalence, similar to the trends observed in population-based studies. Our data does not suggest a correlation between VP shunts and an elevated rate of glaucoma.

CSF formation rate-a potential glymphatic flow parameter in hydrocephalus?

BACKGROUND: Studies indicate that brain clearance via the glymphatic system is impaired in idiopathic normal pressure hydrocephalus (INPH). This has been suggested to result from reduced cerebrospinal fluid (CSF) turnover, which could be caused by a reduced CSF formation rate. The aim of this study was to determine the formation rate of CSF in a cohort of patients investigated for INPH and compare this to a historical control cohort. METHODS: CSF formation rate was estimated in 135 (75 ± 6 years old, 64/71 men/women) patients undergoing investigation for INPH. A semiautomatic CSF infusion investigation (via lumbar puncture) was performed. CSF formation rate was assessed by downregulating and steadily maintaining CSF pressure at a zero level. During the last 10 min, the required outflow to maintain zero pressure, i.e., CSF formation rate, was continuously measured. The values were compared to those of a historical reference cohort from a study by Ekstedt in 1978. RESULTS: Mean CSF formation rate was 0.45 ± 0.15 ml/min (N = 135), equivalent to 27 ± 9 ml/hour. There was no difference in the mean (p = 0.362) or variance (p = 0.498) of CSF formation rate between the subjects that were diagnosed as INPH (N = 86) and those who were not (N = 43). The CSF formation rate in INPH was statistically higher than in the reference cohort (0.46 ± 0.15 vs. 0.40 ± 0.08 ml/min, p = 0.005), but the small difference was probably not physiologically relevant. There was no correlation between CSF formation rate and baseline CSF pressure (r = 0.136, p = 0.115, N = 135) or age (-0.02, p = 0.803, N = 135). CONCLUSIONS: The average CSF formation rate in INPH was not decreased compared to the healthy reference cohort, which does not support reduced CSF turnover. This emphasizes the need to further investigate the source and routes of the flow in the glymphatic system and the cause of the suggested impaired glymphatic clearance in INPH.

The Importance of Primary Care Cognitive Evaluation in Detecting an Atypical Presentation of Normal Pressure Hydrocephalus.

Normal pressure hydrocephalus (NPH) is a syndrome that characteristically presents with progressive gait impairment, cognitive deficits, and urinary urgency or incontinence. We present a case of a 54-year-old male with a past medical history of alcohol use and no primary care provider with new-onset auditory hallucinations. The patient was found to have a marked enlargement of the supratentorial and infratentorial ventricles on both computed tomography (CT) and magnetic resonance imaging (MRI) and an opening pressure of 21 on the lumbar puncture, concerning for NPH. Clinically, there were signs of cognitive impairment due to memory and cognitive function loss, but the patient lacked gait disturbances or incontinence. Although not common, NPH may present with auditory hallucinations or delusions, as seen with our patient. In this case report, we emphasize the importance of annual cognitive assessments in order to evaluate atypical psychiatric manifestations of neurological disorders. Because clinical symptoms are more likely to be reversible when recognized early in the clinical course and the progression of these symptoms can be prevented with the placement of a ventriculoperitoneal (VP) shunt, it is of utmost importance to accurately recognize and diagnose NPH as early as possible. We also discuss the less commonly known markers of NPH on MRI.

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.

A Rare Presentation of Functional Movement Disorder Mimicking Normal Pressure Hydrocephalus.

Herein, we describe a 55-year-old female patient with a functional movement disorder (FMD) who presented with normal pressure hydrocephalus (NPH)-like clinic. The neuroimaging data and positive response to the tap test initially suggested NPH. However, a detailed investigation of the clinic features yielded a final diagnosis of FMD. Via the presentation of this patient, we expand the phenomenology of FMD. To our knowledge, this is the first presentation of a patient with FMD mimicking NPH. Therefore, we think this rare illustration is interesting and may provide valuable perspectives for clinical practice.

Exploring causal correlations of inflammatory biomarkers in idiopathic normal-pressure hydrocephalus: insights from bidirectional Mendelian randomization analysis.

Background and objective: Neuroinflammatory processes have been identified as playing a crucial role in the pathophysiology of various neurodegenerative diseases, including idiopathic normal-pressure hydrocephalus (iNPH). iNPH, defined as a common disease of cognitive impairment in older adults, poses major challenges for therapeutic interventions owing to the stringent methodological requirements of relevant studies, clinical heterogeneity, unclear etiology, and uncertain diagnostic criteria. This study aims to assess the relationship between circulating inflammatory biomarkers and iNPH risk using bidirectional two-sample Mendelian randomization (MR) combined with meta-analysis. Methods: In our bidirectional MR study, genetic data from a genome-wide association study (GWAS) involving 1,456 iNPH cases and 409,726 controls of European ancestry were employed. Single-nucleotide polymorphisms (SNPs) associated with exposures served as instrumental variables for estimating the causal relationships between iNPH and 132 types of circulating inflammatory biomarkers from corresponding GWAS data. Causal associations were primarily examined using the inverse variance-weighted method, supplemented by MR-Egger, weighted median, simple mode, and weighted mode analyses. In the results, heterogeneity was assessed using the Cochran Q test. Horizontal pleiotropy was evaluated through the MR-Egger intercept test and the MR pleiotropy residual sum and outliers test. Sensitivity analysis was conducted through leave-one-out analysis. Reverse MR analyses were performed to mitigate bias from reverse causality. Meta-analyses of identical inflammatory biomarkers from both data sources strengthened the findings. Results: Results indicated a genetically predicted association between Interleukin-16 (IL-16) [OR: 1.228, 95% CI: 1.049-1.439, p = 0.011], TNF-related apoptosis ligand (TRAIL) [OR: 1.111, 95% CI: 1.019-1.210, p = 0.017] and Urokinase-type plasminogen activator (uPA) [OR: 1.303, 95% CI: 1.025-1.658, p = 0.031] and the risk of iNPH. Additionally, changes in human Glial cell line-derived neurotrophic factor (hGDNF) [OR: 1.044, 95% CI: 1.006-1.084, p = 0.023], Matrix metalloproteinase-1 (MMP-1) [OR: 1.058, 95% CI: 1.020, 1.098, p = 0.003] and Interleukin-12p70 (IL-12p70) [OR: 0.897, 95% CI: 0.946-0.997, p = 0.037] levels were identified as possible consequences of iNPH. Conclusion: Our MR study of inflammatory biomarkers and iNPH, indicated that IL-16, TRAIL, and uPA contribute to iNPH pathogenesis. Furthermore, iNPH may influence the expression of hGDNF, MMP-1, and IL-12p70. Therefore, targeting specific inflammatory biomarkers could be promising strategy for future iNPH treatment and prevention.

Predicting Gait Speed Improvement in Idiopathic Normal Pressure Hydrocephalus Patients: The Role of Evans Index and Ventricular Volume.

Objective This study aims to investigate the association between specific imaging parameters, namely, the Evans index (EI) and ventricular volume (VV), and the variation in gait speed observed in patients with idiopathic normal pressure hydrocephalus (iNPH) before and after cerebrospinal fluid (CSF) removal/lumbar drain (LD). Furthermore, it seeks to identify which imaging parameters are the most reliable predictors for significant improvements in gait speed post procedure. Methods In this retrospective analysis, the study measured the gait speed of 35 patients diagnosed with idiopathic normal pressure hydrocephalus (iNPH) before and after they underwent CSF removal. Before lumbar drain (LD), brain images were segmented to calculate the Evans index and ventricular volume. The study explored the relationship between these imaging parameters (the Evans index and ventricular volume) and the improvement in gait speed following CSF removal. Patients were divided into two categories based on the degree of improvement in gait speed, and we compared the imaging parameters between these groups. Receiver operating characteristic (ROC) curve analysis was employed to determine the optimal imaging parameter thresholds predictive of gait speed enhancement. Finally, the study assessed the predictive accuracy of these thresholds for identifying patients likely to experience improved gait speed post-LD. Results Following CSF removal/lumbar drain, the participants significantly improved in gait speed, as indicated by a paired sample t-test (p-value = 0.0017). A moderate positive correlation was observed between the imaging parameters (EI and VV) and the improvement in gait speed post-LD. Significant differences were detected between the two patient groups regarding EI, VV, and a composite score (statistical test value = 3.1, 2.8, and 2.9, respectively; p-value < 0.01). Receiver operating characteristic (ROC) curve analysis identified the optimal thresholds for the EI and VV to be 0.39 and 110.78 cm³, respectively. The classification based on these thresholds yielded significant associations between patients displaying favorable imaging parameters and those demonstrating improved gait speed post-LD, with chi-square (χ²) values of 8.5 and 7.1, respectively, and p-values < 0.01. Furthermore, these imaging parameter thresholds had a 74% accuracy rate in predicting patients who would improve post-LD. Conclusion The study demonstrates that ventricle volume and the Evans index can significantly predict gait speed improvement after lumbar drain (LD) in patients with iNPH.

Diffusion spectrum imaging in patients with idiopathic normal pressure hydrocephalus: correlation with ventricular enlargement.

BACKGROUND: To investigate the association between white matter changes and ventricular expansion in idiopathic normal pressure hydrocephalus (iNPH) based on diffusion spectrum imaging (DSI). METHODS: We included 32 patients with iNPH who underwent DSI using a 3T MRI scanner. The lateral ventricles were manually segmented, and ventricular volumes were measured. Two methods were utilised in the study: manual region-of-interest (ROI) delineation and tract diffusion profile analysis. General fractional anisotropy (GFA) and fractional anisotropy (FA) were extracted in different white matter regions, including the bilateral internal capsule (anterior and posterior limbs) and corpus callosum (body, genu, and splenium) with manual ROI delineation. The 18 main tracts in the brain of each patient were extracted; the diffusion metrics of 100 equidistant nodes on each fibre were calculated, and Spearman's correlation coefficient was used to determine the correlation between diffusion measures and ventricular volume of iNPH patients. RESULTS: The GFA and FA of all ROI showed no significant correlation with lateral ventricular volume. However, in the tract diffusion profile analysis, lateral ventricular volume was positively correlated with part of the cingulum bundle, left corticospinal tract, and bilateral thalamic radiation posterior, whereas it was negatively correlated with the bilateral cingulum parahippocampal (all p < 0.05). CONCLUSIONS: The effect of ventricular enlargement in iNPH on some white matter fibre tracts around the ventricles was limited and polarizing, and most white matter fibre tract integrity changes were not associated with ventricular enlargement; this reflects that multiple pathological mechanisms may have been combined to cause white matter alterations in iNPH.

Regulation of brain fluid volumes and pressures: basic principles, intracranial hypertension, ventriculomegaly and hydrocephalus.

The principles of cerebrospinal fluid (CSF) production, circulation and outflow and regulation of fluid volumes and pressures in the normal brain are summarised. Abnormalities in these aspects in intracranial hypertension, ventriculomegaly and hydrocephalus are discussed. The brain parenchyma has a cellular framework with interstitial fluid (ISF) in the intervening spaces. Framework stress and interstitial fluid pressure (ISFP) combined provide the total stress which, after allowing for gravity, normally equals intracerebral pressure (ICP) with gradients of total stress too small to measure. Fluid pressure may differ from ICP in the parenchyma and collapsed subarachnoid spaces when the parenchyma presses against the meninges. Fluid pressure gradients determine fluid movements. In adults, restricting CSF outflow from subarachnoid spaces produces intracranial hypertension which, when CSF volumes change very little, is called idiopathic intracranial hypertension (iIH). Raised ICP in iIH is accompanied by increased venous sinus pressure, though which is cause and which effect is unclear. In infants with growing skulls, restriction in outflow leads to increased head and CSF volumes. In adults, ventriculomegaly can arise due to cerebral atrophy or, in hydrocephalus, to obstructions to intracranial CSF flow. In non-communicating hydrocephalus, flow through or out of the ventricles is somehow obstructed, whereas in communicating hydrocephalus, the obstruction is somewhere between the cisterna magna and cranial sites of outflow. When normal outflow routes are obstructed, continued CSF production in the ventricles may be partially balanced by outflow through the parenchyma via an oedematous periventricular layer and perivascular spaces. In adults, secondary hydrocephalus with raised ICP results from obvious obstructions to flow. By contrast, with the more subtly obstructed flow seen in normal pressure hydrocephalus (NPH), fluid pressure must be reduced elsewhere, e.g. in some subarachnoid spaces. In idiopathic NPH, where ventriculomegaly is accompanied by gait disturbance, dementia and/or urinary incontinence, the functional deficits can sometimes be reversed by shunting or third ventriculostomy. Parenchymal shrinkage is irreversible in late stage hydrocephalus with cellular framework loss but may not occur in early stages, whether by exclusion of fluid or otherwise. Further studies that are needed to explain the development of hydrocephalus are outlined.

Enhancing the quality of evidence, comparability, and reproducibility in ventriculoatrial shunt research for normal pressure hydrocephalus: A systematic review and VAS-NPH reporting guideline.

BACKGROUND: Ventriculoatrial shunt (VAS) is an important treatment option for normal pressure hydrocephalus (NPH). However, clinical studies reporting the use of VAS for NPH lack sufficient standardization for meta-analytic comparisons that could provide robust evidence regarding its use. This study aims to assess the quality of reporting in these studies and develop a reporting guideline checklist to standardize terminology, concepts, and reporting while reinforcing the essential elements to ensure comparability and reproducibility. METHODS: This is a systematic literature review that followed the PRISMA guidelines with the search in Medline, Embase, and Web of Science databases, with no timeframe restriction. The level of evidence of the studies was assessed using the GRADE system, and the rigor used in the publication of the results was assessed concerning adherence to the guidelines indicated by the EQUATOR Network Group. Furthermore, the studies were scrutinized focusing on eight domains: (1) Characteristics of the included studies and baseline characteristics of the patients; (2) Reporting methodology; (3) Pivotal concepts definition; (4) Adverse events assessment; (5) Data writing and reporting; (6) Detailed outcomes reporting; (7) Specific clinical outcomes assessment and reporting; and (8) Complications reporting. RESULTS: A total of 14 studies with 734 patients and 753 shunts were included in this review, and the assessment exposes notable deficiencies in reporting, specifically in baseline patient details, methodology, and outcome assessments. Only two studies followed reporting guidelines, prompting concerns about comprehensive reporting of adverse events and intraoperative complications. Varied reporting completeness existed for shunt-related issues. The absence of standardized definitions for key concepts and insufficient intervention details were observed. A VAS-NPH reporting guideline, encompassing 36 items across eight domains, was developed to address these shortcomings. CONCLUSION: This systematic review reveals significant deficiencies in methodological rigor and reporting quality. The proposed VAS-NPH Reporting Guideline covers all essential aspects and is a potential solution to rectify these shortcomings and increase transparency, comparability, and reproducibility. This initiative aims to advance the level of evidence and enhance knowledge regarding the use of VAS in NPH.

Clinical application of single-shot fast spin-echo sequence for cerebrospinal fluid flow MR imaging.

In normal-pressure hydrocephalus, disturbances in cerebrospinal fluid (CSF) circulation occur; therefore, understanding CSF dynamics is crucial. The two-dimensional phase-contrast (2D-PC) method, a common approach for visualizing CSF flow on MRI, often presents challenges owing to prominent vein signals and excessively high contrast, hindering the interpretation of morphological information. Therefore, we devised a new imaging method that utilizes T2-weighted high-signal intensification of the CSF and saturation pulses, without requiring specialized imaging sequences. This sequence utilized a T2-weighted single-shot fast spin-echo combined with multi-phase imaging synchronized with a pulse wave. Optimal imaging conditions (repetition time, presence/absence of fast recovery, and echo time) were determined using self-made contrast and single-plate phantoms to evaluate signal-to-noise ratio, contrast ratio, and spatial resolution. In certain clinical cases of hydrocephalus, confirming CSF flow using 2D-PC was challenging. However, our method enabled the visualization of CSF flow, proving to be useful in understanding the pathophysiology of hydrocephalus.

Long-Standing Overt Ventriculomegaly in Adults (LOVA): Can You Blame Alcohol?

Long-standing overt ventriculomegaly in adults (LOVA) is a kind of chronic hydrocephalus that has been reported to have started in infancy and is characterized by severe ventriculomegaly and macrocephaly. It often manifests clinically in later adulthood. We describe the case of a 34-year-old male patient who had a history of chronic alcoholism and who had been complaining of headaches, disturbed gait, and frequent falls for three months when he arrived in a stupor at the emergency room. Massive ventriculomegaly with Evans' index of 0.40 was found during a head magnetic resonance imaging (MRI). The MRI results were more severe than the clinical manifestations. He was diagnosed with LOVA and treated with conservative hyperosmolar drugs, neuroprotective agents, and intravenous (IV) thiamine. The patient was discharged and consented to follow-up after a hospital stay of seven days.

Is endoscopic third ventriculostomy a viable treatment option for normal pressure hydrocephalus? A systematic review.

Background: Endoscopic third ventriculostomy (ETV) is considered an alternative treatment for hydrocephalus and has become a standard of care for obstructive hydrocephalus. Recent studies have also explored its role in normal pressure hydrocephalus (NPH). We conducted a systematic review aiming to assess the outcomes of this minimally invasive endoscopic technique as a viable treatment option for NPH. Methods: A systematic literature search was performed using PubMed and Scopus databases, using iterations of search terms "Endoscopic third ventriculostomy," "Idiopathic normal pressure hydrocephalus," and "Normal pressure hydrocephalus." To be eligible for inclusion in the review, articles had to report the usage of ETV as a primary treatment modality for NPH, report its outcomes, and be published in the English language. Results: Out of the 13 studies selected for qualitative synthesis, nine supported the use of ETV for NPH as an effective treatment option with improvement in the preoperative symptoms. Two studies favored shunt over ETV, stating that quality of life is better with VP shunt insertion. One study reported that ETV has higher perioperative mortality rates that outweigh its benefits. One study reported it to be an ineffective surgical option. Conclusion: The current review of evidence does not support the use of ETV for the treatment of NPH, except perhaps in a small subset of patients. These patients have a shorter duration of symptoms and a better preoperative neurological status. The lumbar infusion test and ventricular infusion test are modalities useful for selecting these candidates.

Exploring the Association Between Visual Field Testing and CERAD Neuropsychological Battery in Idiopathic Normal Pressure Hydrocephalus Patients.

Background: Association between visual field test indices and The Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Battery (CERAD-NB) is unknown. Idiopathic normal pressure hydrocephalus (iNPH) patients provide a unique set of patient data for analysis. Objective: To assess the reliability of visual field testing using the CERAD-NB in patients with iNPH and to investigate the association between visual field test results and cognitive function. Methods: 62 probable iNPH patients were subjected to comprehensive ophthalmological examination, ophthalmological optical coherence tomography imaging studies, visual field testing, and CERAD-NB. Based on visual field indices, the patients were divided into two groups: unreliable (n = 19) and reliable (n = 43). Independent T-test analysis was performed to examine the relationship between visual field test results and cognitive function. Pearson Chi-square test was used for non-continuous variables. Results: The unreliable group performed worse in CERAD-NB subtests compared to the reliable group. Statistically significant differences were observed in nine out of ten subtests, with only Clock Drawing showing no statistical significance. Pairwise comparison of the groups showed no statistical significance between amyloid-ß (Aß) biopsy, hyperphosphorylated tau biopsy, apolipoprotein E allele or the ophthalmological status of the patient. But there was a statistically significant difference in cerebrospinal fluid Aß42 and age between the groups. Conclusions: Patients with unreliable visual field tests performed worse on CERAD-NB subtests. CERAD-NB subtests do not provide a specific cut-off value to refrain patients from visual field testing. Should patients with unreliable visual field tests be screened for cognitive impairment?

The impact of telomere length on the risk of idiopathic normal pressure hydrocephalus: a bidirectional Mendelian randomization study.

Idiopathic normal pressure hydrocephalus (iNPH) affects mainly aged populations. The gradual shortening of telomere length (TL) is one of the hallmarks of aging. Whereas the genetic contribution of TL to the iNPH is incompletely understood. We aimed to investigate the causal relationship between TL and iNPH through the Mendelian randomization (MR) analysis. We respectively obtained 186 qualified single nucleotide polymorphisms (SNPs) of TL and 20 eligible SNPs of iNPH for MR analysis. The result of MR analysis showed that genetically predicted longer TL was significantly associated with a reduced odd of iNPH (odds ratio [OR] = 0.634 95% Confidence interval [CI] 0.447-0.899, p = 0.011). The causal association remained consistent in multivariable MR (OR = 0.530 95% CI 0.327-0.860, p = 0.010). However, there was no evidence that the iNPH was causally associated with the TL (OR = 1.000 95% CI 0.996-1.004, p = 0.955). Our study reveals a potential genetic contribution of TL to the etiology of iNPH, that is a genetically predicted increased TL might be associated with a reduced risk of iNPH.

Embracing uncertainty in cerebrospinal fluid dynamics: A Bayesian approach to analysing infusion studies.

Introduction: Cerebrospinal fluid (CSF) infusion test analysis allows recognizing and appropriately evaluating CSF dynamics in the context of normal pressure hydrocephalus (NPH), which is crucial for effective diagnosis and treatment. However, existing methodology possesses drawbacks that may compromise the precision and interpretation of CSF dynamics parameters. Research question: This study aims to circumvent these constraints by introducing an innovative analysis method grounded in Bayesian inference. Material and methods: A single-centre retrospective cohort study was conducted on 858 patients who underwent a computerized CSF infusion test between 2004 and 2020. We developed a Bayesian framework-based method for parameter estimation and compared the results to the current, gradient descent-based approach. We evaluated the accuracy and reliability of both methods by analysing erroneous prediction rates and curve fitting errors. Results: The Bayesian method surpasses the gradient descent approach, reflected in reduced inaccurate prediction rates and an improved goodness of model fit. On whole cohort level both techniques produced comparable results. However, the Bayesian method holds an added advantage by providing uncertainty intervals for each parameter. Sensitivity analysis revealed significance of the CSF production rate parameter and its interplay with other variables. The resistance to CSF outflow demonstrated excellent robustness. Discussion and conclusion: The proposed Bayesian approach offers a promising solution for improving robustness of CSF dynamics assessment in NPH, based on CSF infusion tests. Additional provision of the uncertainty measure for each diagnostic metric may perhaps help to explain occasional poor diagnostic performance of the test, offering a robust framework for improved understanding and management of NPH.

Neurologic Quality of Life Outcomes in Patients with Normal Pressure Hydrocephalus After Ventriculoperitoneal Shunt Placement: A Prospective Assessment of Cognition, Mobility, and Social Participation.

BACKGROUND: Idiopathic normal pressure hydrocephalus (iNPH) typically presents with gait disturbances, cognitive decline, and urinary incontinence. Symptomatic improvement generally occurs following shunt placement, but limited evidence exists on the quality of life (QOL) metrics in iNPH. Therefore, we conducted a prospective study of the effect of shunt placement on QOL in iNPH patients, using Quality of Life in Neurologic Disorders (Neuro-QOL) metrics. METHODS: Eligible patients underwent shunt placement after evidence of symptomatic improvement following temporary CSF diversion via inpatient lumbar drain trial. Patients were administered short- and long-form Neuro-QOL assessments prior to shunt placement and at six-month and one-year postoperative timepoints to evaluate lower extremity mobility, cognitive function, and social roles and activities participation. Changes in QOL measures were analyzed using a repeated measures linear mixed effects model. RESULTS: There were forty-eight patients with a mean age of 75.4 ± 6.3 years. Average short-form mobility scores improved by 3.9 points (14.6%) at six-month follow-up and by 6.2 points (23.2%) at one-year follow-up compared to preoperative baseline (p = 0.027 and p = 0.0002, respectively). Short-form cognition scores increased by 5.2 points (22.4%) at six months and 10.9 points (47.0%) at one year postoperatively (p = 0.007 and p < 0.0001, respectively). On long-form assessment, social roles and activity participation scores improved by 29.3 points (23.4%) at six months and 31.6 points (25.2%) at one year after surgery compared to baseline (p = 0.028 and p = 0.02, respectively). CONCLUSION: Our findings demonstrate that shunt placement leads to improved QOL in iNPH patients across multiple domains. Significant improvements in mobility, cognition, and social roles and activity participation are realized within the first six months and are sustained on one-year follow-up.

Brain perfusion SPECT in dementia: what radiologists should know.

The findings of brain perfusion single-photon emission computed tomography (SPECT), which detects abnormalities often before changes manifest in morphological imaging, mainly reflect neurodegeneration and contribute to dementia evaluation. A major shift is about to occur in dementia practice to the approach of diagnosing based on biomarkers and treating with disease-modifying drugs. Accordingly, brain perfusion SPECT will be required to serve as a biomarker of neurodegeneration. Hypoperfusion in Alzheimer's disease (AD) is typically seen in the posterior cingulate cortex and precuneus early in the disease, followed by the temporoparietal cortices. On the other hand, atypical presentations of AD such as the posterior variant, logopenic variant, frontal variant, and corticobasal syndrome exhibit hypoperfusion in areas related to symptoms. Additionally, hypoperfusion especially in the precuneus and parietal association cortex can serve as a predictor of progression from mild cognitive impairment to AD. In dementia with Lewy bodies (DLB), the differentiating feature is the presence of hypoperfusion in the occipital lobes in addition to that observed in AD. Hypoperfusion of the occipital lobe is not a remarkable finding, as it is assumed to reflect functional loss due to impairment of the cholinergic and dopaminergic systems rather than degeneration per se. Moreover, the cingulate island sign reflects the degree of AD pathology comorbid in DLB. Frontotemporal dementia is characterized by regional hypoperfusion according to the three clinical types, and the background pathology is diverse. Idiopathic normal pressure hydrocephalus shows apparent hypoperfusion around the Sylvian fissure and corpus callosum and apparent hyperperfusion in high-convexity areas. The cortex or striatum with diffusion restriction on magnetic resonance imaging in prion diseases reflects spongiform degeneration and brain perfusion SPECT reveals hypoperfusion in the same areas. Brain perfusion SPECT findings in dementia should be carefully interpreted considering background pathology.