Normal Pressure Hydrocephalus Research Articles

Osteoporosis in older patients with idiopathic normal pressure hydrocephalus

Osteoporosis in older patients with idiopathic normal pressure hydrocephalus

Normal pressure hydrocephalus in adult mice causes gait impairment, cognitive deficits, and urinary frequency with incontinence.

Normal pressure hydrocephalus (NPH) is marked by enlarged cerebral ventricles with normal intracranial pressure, plus three stereotypical symptoms: gait impairment, cognitive dysfunction, and urinary frequency with urge-incontinence. The neural circuit dysfunction responsible for each of these symptoms remains unknown, and an adult mouse model would expand opportunities to explore these mechanisms in preclinical experiments. Here, we describe the first mouse model of chronic, communicating hydrocephalus with normal intracranial pressure. Hydrocephalic male and female mice had unsteady gait and reduced maximum velocity. Despite performing well on a variety of behavioral tests, they exhibited subtle learning impairments. Hydrocephalic mice also developed urinary frequency, and many became incontinent. This mouse model, with symptoms resembling human NPH, can be combined with molecular-genetic tools in any mouse strain to explore the neural circuit mechanisms of these symptoms. Preclinical work using this hydrocephalus model will lead to the development of new treatments for NPH symptoms.Significance Statement Like human patients with normal pressure hydrocephalus (NPH), mice with communicating hydrocephalus develop enlarged cerebral ventricles with normal intracranial pressure plus three stereotypical symptoms: gait impairment, cognitive dysfunction, and urinary frequency with incontinence. This mouse model, with symptoms resembling human NPH, can be combined with molecular-genetic tools in any mouse strain to explore neural circuit mechanisms of NPH symptoms.

Abstract 4114994: Nursing Management Practice Variations related to Externalized Ventricular and Lumbar Drains

Introduction/Background: Nursing management of neurologic patients may include placement of externalized ventricular drains (EVDs) or lumbar drains (LDs) to monitor/drain cerebrospinal fluid (CSF), but knowledge and practice related to EVD management varies widely, despite a high potential for life-threatening complications. Limited data exists relative to the relationship between intracranial pressure (ICP) and CSF drainage. These gaps may undermine patient safety. Research Question: What are the nursing practices and perspectives regarding management of EVDs and LDs? Methods/Approach: A 16-question multiple-choice/text entry survey was distributed electronically to nurses and advanced practice nurses who were members of the American Association of Neuroscience Nurses. Data analysis included chi-square test for multiple choice responses, and qualitative data was analyzed using a six-step thematic analysis and an inductive approach. Results/Data: Of 219 participants, 42.8% reported roles as Neuroscience ICU nurses, and 39.2% managed an EVD at least 75% of the time. Neuro ICU nurses were most likely to have a patient with an EVD ( p =.002). Approximately 63% of respondents reported consulting with colleagues about EVDs nearly every time they cared for a patient with an EVD. Nurses reported a very high care burden, including re-leveling the transducer 4 or more times per shift (n=76), and re-zeroing every 8 hours (n=72) to assure accurate calibration. Of these 82.2% reported that they re-zeroed the EVD more often to obtain an accurate reading. Approximately 25% reported accidental over-drainage, some with negative outcomes. Many (79.3%) reported caring for patients with LDs, 47.4% to diagnose normal pressure hydrocephalus. The nursing care workload was described as 30-120 minutes each shift. Conclusion: A wide heterogeneity of nursing practices was revealed in EVD and LD management. No standardized nursing care practices have been adopted by nurses for the management of CSF. The complications of these practice variations have been shown to result in untoward patient outcomes. Increased patient morbidity and mortality are linked to catheter infection and over/under drainage of CSF and may be directly related nursing practice. This reveals critical need for improved, standardized care nursing practices in the management of EVDs and LDs, and an empiric understanding of the relationship between intracranial pressure and the volume and rate of CSF drainage.

Survival After Shunt Therapy in Normal-Pressure Hydrocephalus: A Meta-Analysis of 1614 Patients

Background: Ventriculoperitoneal (VP) shunt therapy is a crucial intervention for normal-pressure hydrocephalus (NPH). This meta-analysis delves into survival time and the impact of baseline symptom burden on survival after VP shunt therapy for NPH, employing reconstructed pooled survival curves and a one-stage meta-analysis. Methods: IPD regarding overall survival (OS) were acquired from published Kaplan–Meier charts, utilizing the R package IPDfromKM in R (Version 4.3.1, the R Foundation for Statistical Computing). Reconstructed Kaplan–Meier charts were then generated from the pooled IPD data. Both one-stage and two-stage meta-analyses were executed, with hazard ratios (HRs) employed as metrics to evaluate effectiveness. Results: From the initial screening of 216 records, five articles encompassing 1614 patients met the eligibility criteria for inclusion. In two of the five included studies, overall survival was stratified by gait score (1–4 vs. ≥4) in 1043 patients, continence score (1–3 vs. ≥4) in 1022 patients, and mRS (0–2 vs. ≥3) in 956 patients. Patients with good gait demonstrated a mean survival of 8.24 years, while those with poor gait had a mean survival of 6.19 years (log-rank test: p < 0.001). The HR for gait was 2.25 (95% CI: 1.81–2.81, p < 0.001). Continence score stratification revealed a significant difference in survival time (log-rank test: p < 0.001), with an HR of 1.66 (95% CI: 1.33–2.06, p < 0.001). Similarly, mRS stratification demonstrated a significant survival difference (log-rank test: p < 0.001), with an HR of 2.21 (95% CI: 1. 74–2.80, p < 0.001). The reconstructed survival curves for all NPH patients treated with VP shunt therapy, pooling data from five studies, revealed a median survival time of 8.82 years (95% CI: 8.23–9.40). Survival rates at 1, 3, 5, 7, 9, 11, and 13 years were 95.7%, 83.8%, 70.5%, 59.5%, 48.7%, 35.8%, and 25.4%, respectively. Comparison with a general control population showed an HR of 1.79 (95% CI: 1.62–1.98, p < 0.001). Conclusions: This comprehensive meta-analysis underscores the influence of baseline symptom burden on survival after VP shunt therapy in NPH. Therapy in the early stages for those without significant comorbidities may enhance survival.

Comprehensive Morphometric Analysis to Identify Key Neuroimaging Biomarkers for the Diagnosis of Adult Hydrocephalus Using Artificial Intelligence.

Hydrocephalus involves abnormal cerebrospinal fluid accumulation in brain ventricles. Early and accurate diagnosis is crucial for timely intervention and preventing progressive neurological deterioration. The aim of this study was to identify key neuroimaging biomarkers for the diagnosis of hydrocephalus using artificial intelligence to develop practical and accurate diagnostic tools for neurosurgeons. Fifteen 1-dimensional (1-D) neuroimaging parameters and ventricular volume of adult patients with non-normal pressure hydrocephalus and healthy subjects were measured using manual image processing, and 10 morphometric indices were also calculated. The data set was analyzed using 8 machine, ensemble, and deep learning classifiers to predict hydrocephalus. SHapley Additive exPlanations (SHAP) feature importance analysis identified key neuroimaging diagnostic biomarkers. Gradient Boosting achieved the highest performance, with an accuracy of 0.94 and an area under the curve of 0.97. SHAP analysis identified ventricular volume as the most important parameter. Given the challenges of measuring volume for clinicians, we identified key 1-D morphometric biomarkers that are easily measurable yet provide similar classifier performance. The results showed that the frontal-temporal horn ratio, modified Evan index, modified cella media index, sagittal maximum lateral ventricle height, and coronal posterior callosal angle are key 1-D diagnostic biomarkers. Notably, higher modified Evan index, modified cella media index, and sagittal maximum lateral ventricle height, and lower frontal-temporal horn ratio and coronal posterior callosal angle values were associated with hydrocephalus prediction. The results also elucidated the relationships between these key 1-D morphometric parameters and ventricular volume, providing potential diagnostic insights. This study highlights the importance of a multifaceted diagnostic approach incorporating 5 easily measurable 1-D neuroimaging biomarkers for neurosurgeons to differentiate non-normal pressure hydrocephalus from healthy subjects. Incorporating our artificial intelligence model, interpreted through SHAP analysis, into routine clinical workflows may transform the diagnostic landscape for hydrocephalus by standardizing diagnosis and overcoming the limitations of visual evaluations, particularly in early stages and challenging cases.

The "Hedgehog-Halo Sign" Is Associated with Gait Symptom Severity and Tap Response in Normal Pressure Hydrocephalus.

Reduced cerebrospinal fluid (CSF) clearance may play a vital role in the pathogenesis of normal pressure hydrocephalus (NPH), but the radiologic marker is yet to be elucidated. This open-label study presents two novel neuroimaging biomarkers based on enlarged perivascular spaces (ePVS) of the sub-insular territory: the Hedgehog and Hedgehog-Halo (H-H) sign, designed to predict gait symptom severity and tap response in NPH. We retrospectively reviewed 203 patients with possible NPH with baseline magnetic resonance imaging and gait analyses before and after lumbar puncture (LP). The Hedgehog/H-H sign was scored using T2-weighted images. The clinical severity at baseline and post-tap gait improvement was compared in patients with and without Hedgehog/H-H sign. The association between Hedgehog/H-H sign and post-tap gait outcomes was assessed using multivariate regression. The diagnostic performance of Hedgehog/H-H sign was compared with conventional radiological markers. Patients with H-H showed higher global disability and more severe gait impairment than those without any signs. Following LP, patients with Hedgehog/H-H sign significantly improved in various gait parameters, unlike those with neither sign. Additionally, sub-insular ePVS was significantly associated with post-tap gait improvement after adjusting covariates. Finally, the Hedgehog/H-H sign showed a higher performance than conventional markers in predicting post-tap gait response. The Hedgehog/H-H sign is a useful neuroimaging biomarker related to the severity and tap response in NPH. This biomarker can be readily applied in clinical practice before undergoing LP, independent of conventional radiological signs. Further research is warranted to determine applicability in predicting post-shunt gait response.

The CSF lipid profile in patients with probable idiopathic normal pressure hydrocephalus differs from control but does not differ between shunt responders and non-responders.

Idiopathic normal pressure hydrocephalus is a common form of hydrocephalus in the elderly, characterized by enlarged ventricles combined with clinical symptoms presenting as gait impairment, urinary incontinence, and dementia. Idiopathic normal pressure hydrocephalus may be difficult to differentiate clinically from other neurodegenerative disorders, and up to 80% of cases may remain unrecognized and thus untreated. Consequently, there is a pressing demand for biomarkers that can confirm the diagnosis of idiopathic normal pressure hydrocephalus. In this exploratory study, CSF was sampled from the lumbar compartment of 21 control individuals and 19 probable idiopathic normal pressure hydrocephalus patients and analyzed by an untargeted mass spectroscopy-based platform to reveal a complete CSF lipid profile in these samples. Two hundred forty-four lipids from 17 lipid classes were detected in CSF. Various lipid classes, and select individual lipids, were reduced in the CSF obtained from patients with probable idiopathic normal pressure hydrocephalus, whereas a range of lipids belonging to the class of triacylglycerols was elevated. We detected no difference in the CSF lipid profile between probable idiopathic normal pressure hydrocephalus patients with and without clinical improvement following CSF shunting. In conclusion, the lipidomic profile of the CSF in patients with probable idiopathic normal pressure hydrocephalus, therefore, may serve as a sought after biomarker of the pathology, which may be employed to complement the clinical diagnosis.

The effectiveness of various CSF diversion surgeries in idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis

Idiopathic normal pressure hydrocephalus (iNPH) is commonly treated using cerebrospinal fluid (CSF) diversion procedures, most commonly ventriculoperitoneal (VP) but also lumboperitoneal (LP), ventriculoatrial (VA) shunting, and endoscopic third-ventriculostomy (ETV). Despite the prevalence of these interventions and recent advancements in iNPH diagnostic processes, there is limited up-to-date evidence regarding surgical outcomes. A systematic review and meta-analysis were conducted to analyse the effects of CSF diversion surgeries among iNPH patients. The primary outcome was efficacy of the CSF diversion procedure, defined as symptomatic improvement, and secondary outcomes included surgical complications. Several major databases were searched for original studies from inception up to June 4, 2024, which were evaluated using random-effects meta-analyses, meta-regression, and influence analyses. This study was registered with PROSPERO: CRD42023458526. Out of the 1963 studies screened, 54 were included in this review, and 4811 patients were pooled. Overall, more than 74% of patients experienced improvement after surgical treatment (95% CI: 70-78%). VP shunting demonstrated an efficacy of 75% (95% CI 70-79%), VA shunting at 75% (95% CI: 70-80%), and LP shunting at 70% (95% CI: 52-83%). ETV had a success rate of 69% (95% CI: 58-78%). Gait improvement was high at 72% (95% CI: 67-77%), while urinary and cognitive dysfunction each improved in approximately 50% of patients. The efficacy of surgery did not increase between 2005 and 2024 (p=0.54). Complications occurred in 20.6% of cases, with a surgery revision rate of 15.1%. This meta-analysis found that the overall efficacy of CSF diversion procedures for iNPH remained unchanged from 2005 to 2024, with 74% of cases showing improvement. No procedure was found to be clearly superior, and only half of the patients saw improvements in urinary and cognitive dysfunction. The stagnant efficacy over time and frequent complications highlight the need for improved patient selection criteria to best identify those most likely to benefit from CSF shunting. None for this study.

Unveiling the enigmatic connection: Belly dancer's dyskinesia as an unusual manifestation of normal pressure hydrocephalus: A case report.

Normal pressure hydrocephalus is rarely associated with Belly dancer's dyskinesia and seizure. Belly dancer's dyskinesia (BDD) is characterized by bilateral, sluggish, involuntary, repetitive, and rhythmic motions of the anterior abdominal wall. We present a rare case of a 78-year-old man diagnosed with normal pressure hydrocephalus associated with BDD and seizure who presented with left-sided weakness of the body and abnormal body movements.

Pathophysiology of Normal Pressure Hydrocephalus

The current perspective for the pathophysiology of normal pressure hydrocephalus is focusing on stiffness of the central nervous tissue, especially on a type of cerebrovascular disorder. Rigid intracranial vessels and tissues derived by either vascular risk factors or aging may lead into impaired dynamics of the cerebrospinal fluid such as increased pulsatility and decreased absorption of the cerebrospinal fluid. Enlarged ventricle may result in a decrease of blood perfusion in brain parenchyma, and in turn global hypoxia and neuro-inflammation along with a breakdown of the blood-brain-barrier. Deterioration of the glymphatic pathway, the crucial disposal pathway of the waste product of the brain, also might contribute to the irreversible injury of the nervous tissue by deposition of abnormal toxic proteins including amyloid beta. Of note, the pathophysiology of the normal pressure hydrocephalus is moving to a type of cerebrovascular disorder instead of the etiology of idiopathic.

Predicting the long-term course: Shunt surgery results in idiopathic normal pressure hydrocephalus-a comprehensive study.

Idiopathic normal pressure hydrocephalus is a neurological disorder primarily affecting the elderly. Shunt surgery is the gold standard treatment, yet long-term outcome remains poorly investigated, especially concerning neuropsychological performance, motor skills and quality of life. This study aimed to evaluate the long-term effects of shunting in iNPH patients up to three years post-surgery. A cohort of 30 patients with iNPH who underwent shunt placement between January 2020 and February 2021 was followed up for three years. A standardized test battery assessed neuropsychological performance, quality of life, and motor skills. The patients were tested before and one, two and three years after surgery. Motor skills, particularly lower body function, significantly improved post-surgery and remained improved even after three years. Upper body motor skills exhibited mixed results, with improvement in manual dexterity but not in finger tapping tests. Neuropsychological assessments revealed sustained improvement in certain aspects up to three years post-surgery, while a various degree of deterioration was observed in others. Quality of life, as measured by the Rankin Scale as well as Stein and Langfitt Grading, showed initial improvement post-surgery but declined over time. iNPH patients demonstrate sustained improvements in motor skills, neuropsychological function and quality of life after shunt surgery. In long-term, motor skill and certain neuropsychological aspects remained improved, quality of life and some other neurocognitive aspects declined progressively over the follow up period.These findings underscore the importance of long-term follow-up and highlight the need for further research to better understand iNPH.

Adult-onset neuronal ceroid lipofuscinosis misdiagnosed as autoimmune encephalitis and normal-pressure hydrocephalus: A 10-year case report and case-based review.

Neuronal ceroid lipofuscinoses (NCLs) are rare, fatal, inherited neurodegenerative disorders characterized by myoclonic epilepsy, cognitive decline, brain atrophy, and retinopathy. The pathogenesis and clinical manifestations of NCL are not well understood and frequently result in misdiagnosis and overtreatment. The aim of this case report and review is to improve our understanding of the clinical features and management of NCL. A 36-year-old woman initially presented with refractory epilepsy. Initially diagnosed with autoimmune encephalitis, the patient was later diagnosed with normal-pressure hydrocephalus. A definitive diagnosis of adult-onset neuronal ceroid lipofuscinosis (ANCL) was established after 10 years of observation, utilizing biopsy and genetic testing. High-dose intravenous immunoglobulin and methylprednisolone were administered, along with the insertion of a ventriculoperitoneal shunt. Despite various treatments, the patient's condition did not improve. ANCL typically presents with the clinical triad of refractory seizures, progressive cognitive decline, and movement disorders. Neuroimaging often reveals progressive brain atrophy on magnetic resonance imaging, while electroencephalograms frequently show epileptiform discharges. The prognosis is generally poor. Improved understanding of ANCL from both clinical and radiological perspectives, coupled with early consideration of differential diagnoses, could minimize unnecessary interventions and optimize patient care.

Good Correlation between CT-Measured Z-Evans’ Index and CT Volumetric of Ventricular System in Patients with iNPH Treated by Cerebrospinal Fluid Shunting

Background: Patients with idiopathic normal pressure hydrocephalus (iNPH) demonstrated an increase in the volume of lateral ventricles oriented along the Z-axial axis, as opposed to the X-axial axis. Objective: To determine which computed tomography (CT)-measured X-Evans’ index and Z-Evans’ index, exhibit a stronger correlation with CT-derived ventricular volume both before and after shunting procedures. Additionally, a comparative examination between those with iNPH characterized by disproportionate enlargement of subarachnoid space hydrocephalus (DESH) and those without DESH features. Materials and Methods: The present study enrolled forty-three iNPH patients who underwent shunting between April 2013 and April 2016. The initial screening involved a thorough review of pre-shunting CT images, leading to the categorization of patients into two distinct groups, those with DESH and without DESH features. Results: Both the X-Evans’ index and Z-Evans’ index exhibited a noteworthy correlation with ventricular volume, substantiated by correlation coefficients (r) of 0.777 (p<0.001) and 0.876 (p<0.001), respectively. Notably, the correlation between the change in CT ventricular volume and the change in Z-Evans’ index was more conspicuous in the overall patient cohort (r=0.730, p<0.001) than X-Evans’ index change (r=0.599, p<0.001). This tendency was particularly discernible within the DESH group, where the correlation with Z-Evans’ index (r=0.826, p<0.001). Conclusion: The Z-Evans’ index emerged as a more effective representation of ventricular volume compared to the X-Evans’ index in the entirety of the iNPH patient cohort. In contrast, during the subsequent CT follow-up, the change in X-Evans’ index exhibited superior efficacy in capturing the corresponding alterations in ventricular volume.

A lumped parameter modelling study of cerebral autoregulation in normal pressure hydrocephalus suggests the brain chooses to be ischemic

Normal pressure hydrocephalus (NPH) is associated with a reduction in cerebral blood flow and an ischemic metabolic state. Ischemia should exhaust the available autoregulation in an attempt to correct the metabolic imbalance. There is evidence of some retained autoregulation reserve in NPH. The aim of this study is to model the cerebral autoregulation in NPH to discover a solution to this apparent paradox. A lumped parameter model was developed utilizing the known limits of autoregulation in man. The model was tested by predicting the cerebral blood volume changes which would be brought about by changes in resistance. NPH and the post shunt state were then modeled using the known constraints provided from the literature. The model successfully predicted the cerebral blood volume changes brought about by altering the cerebral perfusion pressure to the limit of autoregulation. The model suggests that NPH is associated with a balanced increase in resistance within the arterial and venous outflow segments. The arterial resistance decreased after modelling shunt insertion. The model suggests that the cerebral blood flow is actively limited in NPH by arteriolar constriction. This may occur to minimize the rise in ICP by reducing the apparent CSF formation rate.

Experience from a Fast-Track Multidisciplinary Clinic Integrating Movement Disorders Neurologists in Normal Pressure Hydrocephalus Evaluation.

In this prospective observational cohort study, we provide preliminary findings from a same-day multidisciplinary fast-tracked normal pressure hydrocephalus (NPH) clinic; incorporating the expertise of movement disorders neurologists, emphasizing the clinical characteristics, consensus classification, and management of patients referred for suspected NPH. We evaluated 111 patients (male/female: 67/44) from April 2022 to May 2023. Based on the multidisciplinary team consensus, 52 (46.8%) were classified as "probable" idiopathic NPH (iNPH), 14 (12.6%) as "possible" NPH, 42 (37.8%) as "unlikely" NPH, and three (2.7%) as secondary NPH. While parkinsonian syndromes were recognized in 19.2% of "probable" iNPH patients (vs. 7.1% in "possible" and 26.2% in "unlikely" NPH), no significant group differences were noted in the scores of the UPDRS-III scale. Degenerative spine pathologies were prevalent across all NPH categories, affecting at least 50% of patients. In the "probable" iNPH group, 78.8% received programmable ventriculoperitoneal shunts, with clinical improvement identified in 87.8% at 12-month follow-up. Our findings underscore the high prevalence of overlapping and competing movement and spinal disorders in patients with suspected NPH. Further, our novel approach, incorporating movement disorder neurologists in NPH multidisciplinary evaluation, improved diagnostic precision and streamlined personalized plans, including further neurological workups, necessary spinal interventions, and medical management or rehabilitation.

Modeling CSF circulation and the glymphatic system during infusion using subject specific intracranial pressures and brain geometries

BackgroundInfusion testing is an established method for assessing CSF resistance in patients with idiopathic normal pressure hydrocephalus (iNPH). To what extent the increased resistance is related to the glymphatic system is an open question. Here we introduce a computational model that includes the glymphatic system and enables us to determine the importance of (1) brain geometry, (2) intracranial pressure, and (3) physiological parameters on the outcome of and response to an infusion test.MethodsWe implemented a seven-compartment multiple network porous medium model with subject specific geometries from MR images using the finite element library FEniCS. The model consists of the arterial, capillary and venous blood vessels, their corresponding perivascular spaces, and the extracellular space (ECS). Both subject specific brain geometries and subject specific infusion tests were used in the modeling of both healthy adults and iNPH patients. Furthermore, we performed a systematic study of the effect of variations in model parameters.ResultsBoth the iNPH group and the control group reached a similar steady state solution when subject specific geometries under identical boundary conditions was used in simulation. The difference in terms of average fluid pressure and velocity between the iNPH and control groups, was found to be less than 6% during all stages of infusion in all compartments. With subject specific boundary conditions, the largest computed difference was a 75% greater fluid speed in the arterial perivascular space (PVS) in the iNPH group compared to the control group. Changes to material parameters changed fluid speeds by several orders of magnitude in some scenarios. A considerable amount of the CSF pass through the glymphatic pathway in our models during infusion, i.e., 28% and 38% in the healthy and iNPH patients, respectively.ConclusionsUsing computational models, we have found the relative importance of subject specific geometries to be less important than individual differences in resistance as measured with infusion tests and model parameters such as permeability, in determining the computed pressure and flow during infusion. Model parameters are uncertain, but certain variations have large impact on the simulation results. The computations resulted in a considerable amount of the infused volume passing through the brain either through the perivascular spaces or the extracellular space.

A Wearable Gait-Analysis Device for Idiopathic Normal-Pressure Hydrocephalus (INPH) Monitoring.

Idiopathic Normal Pressure Hydrocephalus (iNPH) is a progressive neurologic disorder (fluid build-up in the brain) that affects 0.2-5% of the UK population aged over 65. Mobility problems, dementia and urinary incontinence are symptoms of iNPH but often these are not properly evaluated, and patients receive the wrong diagnosis. Here, we describe the development and testing of a wearable device that records and analyses a patient's gait. The movement patterns, expressed as quantitative data, allow clinicians to improve the non-invasive diagnosis of iNPH as well as monitor the management of patients undergoing treatment. The wearable sensor system comprises a miniature electronic unit that attaches to one ankle of the patient via a simple Velcro strap. The unit monitors acceleration along three axes with a sample rate of 60 Hz and transmits the data via a Bluetooth communication link to a tablet or smart phone running the Android and the iOS operating systems. The software package extracts statistics based on stride length, stride height, distance walked and speed. Analysis confirmed that the system achieved an average accuracy of at least 98% for gait tests conducted over distances 9 m. Using this device will improve the diagnostic process and management of iNPH and the treatment and management of this condition.

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

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

Glymphatic System Assessment Using DTI-ALPS in Age-Dependent Neurodegenerative Diseases

Introduction. Dysfunction of the glymphatic system glymphatic system of the brain is considered a pathogenetic factor in some age-dependent neurodegenerative diseases, including Alzheimer's disease (AD), dementia with Lewy bodies (DLB), Parkinson's disease (PD), and normal pressure hydrocephalus (NPH). The innovative method for calculating DTI-ALPS (Diffusion Tensor Image Analysis ALong the Perivascular Space) allows non-invasive assessment of the glymphatic system status using magnetic resonance imaging (MRI). The aim of the study is to compare DTI-ALPS in patients with AD, DLB, PD, and NPH and to evaluate its potential use as a biomarker of the glymphatic system status in these diseases. Materials and methods. The study included 116 subjects: 32 patients with AD, 15 patients with DLB, 31 patients with PD, 11 patients with NPH, and 27 healthy volunteers. Cognitive testing was performed for patients in the main groups using the Montreal Cognitive Assessment (MoCA) score. All subjects underwent diffusion tensor imaging (DTI) of the brain. DTI-ALPS was then calculated. Results. DTI-ALPS index significantly differed across groups (p 0.001). Patients with AD, DLB, and NPH had a significantly lower DTI-ALPS index on both sides compared to the PD group and healthy volunteers (p 0.01). Analysis of the entire sample showed a direct correlation between MoCA score and DTI-ALPS index (p 0.05). Conclusion. This is the first comparison of DTI-ALPS across such a broad range of age-dependent neurodegenerative diseases. Since our DTI-ALPS results were comparable to previously reported data, we believe that this parameter can be used as an indirect marker of the glymphatic system status.

Psychotic behavior in normal pressure hydrocephalus

Normal pressure hydrocephalus (NPH) usually presents with progressive gait impairment, urinary incontinence, and cognitive deficits. Many studies have shown that NPH can mimic other disorders like Parkinson disease with tremors and rigidity. In this report, we present our experience with three patients who had psychotic behavior and were treated with psychiatric medications but were subsequently investigated and found to have NPH. After lumboperitoneal shunting, all the three became normal and were even able to stop the psychiatric medications completely. The message is that NPH can mimic a psychiatric disorder and awareness about this well treatable condition is important especially among the psychiatrists and geriatricians.