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Background: Diffusion Tensor Image Analysis Along the Perivascular Space (DTI-ALPS) evaluates the glymphatic system in patients with idiopathic normal-pressure hydrocephalus (iNPH). However, white matter compression due to ventricular enlargement may affect the ALPS index. This study aimed to investigate the relationship among the ALPS index, white matter changes, and clinical symptoms in patients with iNPH. Methods: We calculated the ALPS index in 30 patients with iNPH, aged 70 and above, using DTI data and correlated it with various clinical and imaging indices, including the Evans index, callosal angle, cognitive tests, gait assessment (timed up-and-go [TUG] test), cerebrospinal fluid (CSF) medullary pressure, and various DTI indices (axial diffusivity [AD], radial diffusivity [RD], mean diffusivity [MD], fractional anisotropy [FA]). Results: Significant negative correlations were observed between the ALPS index and the rate of change in step count in the TUG test after the tap test (r = −0.5014, p = 0.0048), as well as CSF medullary pressure (r = −0.4651, p = 0.0096). Positive correlations were identified between the ALPS index and both AD (r = 0.4984, p = 0.0051) and MD (r = 0.3631, p = 0.0486). Conclusion: A lower ALPS index was associated with gait improvement following the tap test as well as higher CSF medullary pressure. The ALPS index may detect subtle periventricular compression-induced changes in iNPH. Consequently, it could potentially serve as a predictor for tap test effectiveness in patients with iNPH, offering a new perspective on its application in iNPH diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Idiopathic normal pressure hydrocephalus, secondary chronic hydrocephalus, and other cerebrospinal fluid (CSF) disorders are often challenging to diagnose. Since shunt surgery is usually the only therapeutic option and carries significant morbidity, optimal patient selection is crucial. The tap test is the most commonly used prognostic test to confirm the diagnosis but lacks sensitivity. The lumbar infusion study (LIS) appears to be a better option, offering additional information on brain dynamics without increasing morbidity. However, this technique remains underused. In this narrative review, supported by the extensive experience of several European expert centers, we detail the physiological basis, indications, and CSF dynamics parameters that can be measured. We also discuss technical modalities and variations, including one versus 2 needles, patient positioning, and the site of CSF measurement, as well as in vivo shunt testing. Finally, we discuss the limitations and morbidity associated with the LIS. This review aims to assist teams wishing to incorporate LIS into their screening tools for chronic hydrocephalus and other CSF disorders. [ABSTRACT FROM AUTHOR]

Background: Gait analysis objectively quantifies gait impairment in idiopathic normal pressure hydrocephalus (iNPH), may improve diagnosis and evaluation for surgical candidacy. Objectives: This meta‐analysis aims to understand which objective gait parameters improve after tap‐test (TT) and CSF shunt surgery (CSS), also comparing responders (R) with non‐responders (NR) and to assess if gait restores within the range of healthy controls after procedures. Methods: Studies enrolling iNPH with at least one instrumented gait measure were selected. Three time points of gait assessment were defined: PRE, POST‐TT, and POST‐CSS. Gait velocity, cadence, step length, stride length, and double limb support time were evaluated. Patients were categorized based on responsiveness to CSF diversion procedures. Results: Seventeen studies including 527 patients were selected. iNPH improved significantly in almost all gait parameters POST‐TT, and to a greater extent POST‐CSS. Gait parameters consistently discriminated iNPH from healthy controls. Despite the aforementioned improvements, iNPH's gait did not completely normalize after CSF diversion procedures. Meta‐regression analysis also revealed that TT's effect on gait velocity plateaus after 24–48 hr and returns to baseline in 90–100 hr. Conclusions: Gait analysis is a reliable quantitative instrument to assess gait impairment in iNPH, demarking a net differentiation from healthy controls, according to the notion that the iNPH CSF dynamic alteration also leads to an irreversible damage. Specific gait parameters improve among TT‐R, providing an opportunity to select patients that will respond to CSS. Future studies validating a standardized reporting method including criteria of responsiveness, specific gait parameters, and timeframe of assessment are needed. [ABSTRACT FROM AUTHOR]

Idiopathic normal pressure hydrocephalus (iNPH) refers to a complex brain disorder characterized by ventricular enlargement and the classic Hakim's triad of gait and balance difficulties, urinary incontinence, and cognitive impairment. It predominantly affects older patients in the absence of an identified cause. As the elderly population continues to increase, iNPH becomes a growing concern in the complex spectrum of neuro-geriatric care, with significant socio-economic implications. However, unlike other well-structured management approaches for neurodegenerative disorders, the management of iNPH remains largely uncodified, leading to suboptimal care in many cases. In this article, we highlighted the challenges of current practice and identify key points for an optimal structuration of care for iNPH. Adopting a global approach to iNPH could facilitate a progressive shift in mindset, moving away from solely aiming to cure an isolated neurological disease with uncertain outcomes to providing comprehensive care that focuses on improving the daily life of frail patients with complex neurodegenerative burdens, using tailored goals. [ABSTRACT FROM AUTHOR]

Objectives: To examine the relationship between cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) and tap test response to elucidate the effects of comorbidity of AD in idiopathic normal-pressure hydrocephalus (iNPH). Design: Case–control study. Setting: Osaka University Hospital. Participants: Patients with possible iNPH underwent a CSF tap test. Measurements: Concentrations of amyloid beta (Aβ) 1–40, 1–42, and total tau in CSF were measured. The response of tap test was judged using Timed Up and Go test (TUG), 10-m reciprocation walking test (10MWT), Mini-Mental State Examination (MMSE), and iNPH grading scale. The ratio of Aβ1–42 to Aβ1–40 (Aβ42/40 ratio) and total tau concentration was compared between tap test-negative (iNPH-nTT) and -positive (iNPH-pTT) patients. Results: We identified 27 patients as iNPH-nTT and 81 as iNPH-pTT. Aβ42/40 ratio was significantly lower (mean [SD] = 0.063 [0.026] vs. 0.083 [0.036], p = 0.008), and total tau in CSF was significantly higher (mean [SD] = 385.6 [237.2] vs. 293.6 [165.0], p = 0.028) in iNPH-nTT than in iNPH-pTT. Stepwise logistic regression analysis revealed that low Aβ42/40 ratio was significantly associated with the negativity of the tap test. The response of cognition was significantly related to Aβ42/40 ratio. The association between Aβ42/40 ratio and tap test response, especially in cognition, remained after adjusting for disease duration and severity at baseline. Conclusions: A low CSF Aβ42/40 ratio is associated with a poorer cognitive response, but not gait and urinary response, to a tap test in iNPH. Even if CSF biomarkers suggest AD comorbidity, treatment with iNPH may be effective for gait and urinary dysfunction. [ABSTRACT FROM AUTHOR]

Abstract Background Idiopathic normal pressure hydrocephalus (iNPH) is a progressive and partially reversible form of dementia, characterized by impaired interactions between multiple brain regions. Because of the presence of comorbidities and a lack of accurate diagnostic and prognostic biomarkers, only a minority of patients receives disease-specific treatment. Recently, resting-state functional-magnetic resonance imaging (rs-fMRI) has demonstrated functional connectivity alterations in inter-hemispheric, frontal, occipital, default-mode (DMN) and motor network (MN) circuits. Herein, we report our experience in a cohort of iNPH patients that underwent cerebrospinal fluid (CSF) dynamics evaluation and rs-fMRI. The study aimed to identify functional circuits related to iNPH and explore the relationship between DMN and MN recordings and clinical modifications before and after infusion and tap test, trying to understand iNPH pathophysiology and to predict the best responders to ventriculoperitoneal shunt (VPS) implant. Methods We prospectively collected data regarding clinical assessment, neuroradiological findings, lumbar infusion and tap test of thirty-two iNPH patients who underwent VPS implant. Rs-fMRI was performed using MELODIC-ICA both before and after the tap test. Rs-fMRI data of thirty healthy subjects were also recorded. Results At the baseline, reduced z-DMN and z-MN scores were recorded in the iNPH cohort compared with controls. Higher z-scores were recorded in more impaired patients. Both z-scores significantly improved after the tap test except in subjects with a low resistance to outflow value and without a significant clinical improvement after the test. A statistically significant difference in mean MN connectivity scores for tap test responders and non-responders was demonstrated both before (p = 0.0236) and after the test (p = 0.00137). A statistically significant main effect of the tap test on DMN connectivity after CSF subtraction was recorded (p = 0.038). Conclusions Our results suggest the presence of a partially reversible plasticity functional mechanism in DMN and MN. Low values compensate for the initial stages of the disease, while higher values of z-DMN were recorded in older patients with a longer duration of symptoms, suggesting an exhausted plasticity compensation. The standardization of this technique could play a role as a non-invasive biomarker in iNPH disease, suggesting the right time for surgery. Trial Registration Prot. IRB 090/2021.

Introduction: The aim of this study was to compare clinical and functional performances of idiopathic normal pressure hydrocephalus (INPH) patients with and without parkinsonismat the initial evaluation, 72 h after the cerebrospinal fluid tap test (CSF TT), and 6 months after ventriculoperitoneal shunt (VPS) surgery. Materials andmethods: This is an observational prospective study on patients with INPH who underwent VPS. Patients were classified into INPH with parkinsonism (INPH-P+) and without parkinsonism (INPH-P-). We used the time up and go (TUG) test, Tinetti Performance-Oriented Mobility Assessment (POMA) test, INPH grading scale (INHPGS), and modified Rankin scale (mRS) at baseline, 72 h after CSF TT, and 6 months after VPS surgery. Results: A total of 64 patients with probable INPH were included, 12 patients with INPH-P+ and 52 controls with INPH-P-. Patients with INPH showed significant improvement in all clinical and neurological parameters after VPS including TUG, Tinetti POMA, INPHGS, and mRS (p < 0.001) with the exception of mRS where there was no significant change 72 h after CSF TT compared to baseline for patients with INPH (p = 0.182). Patients with INPH-P+ performed significantly worse than patients with INPH-P-on Tinetti POMA and mRS at baseline, at 72 h post-CSF TT, and at 6 months post-VPS with INPHGS being worst at 72 h post-CSF TT. There was no difference between patients with INPH-P+ and patients with INPH-P-for TUG at baseline (p = 0.270), at 72 h post-CSF TT (p = 0.487), and at 6 months post-VPS (p = 0.182). Patients with INPH-P+ did not show any change in any of the parameters at 72 h post-CSF TT compared to baseline; however, there was a trend toward improvement on TUG (p = 0.058), Tinetti gait (p = 0.062), and Tinetti total (p = 0.067). INPH-P+ significantly improved in all parameters 6 months post-VPS compared to baseline except for mRS (p = 0.124). Patients with INPH-P-significantly improved in all parameters at 72 h post-CSF TT and at 6 months post-VPS compared to baseline, respectively, except on mRS 72 h after CSF TT (p = 0.299). Conclusion: Patients with INPH and parkinsonism overall do worse than patients without parkinsonism. An unsatisfying response to the CSF tap test in INPH patients with parkinsonism should not be used as an exclusion criterion from VPS surgery since patients with and without parkinsonism showed significant improvement post-VPS. [ABSTRACT FROM AUTHOR]

Differentiating idiopathic normal pressure hydrocephalus (iNPH) from other neurodegenerative diseases is challenging. Only a portion of the patients clinically suspected of iNPH would respond to surgical intervention. A cerebrospinal fluid (CSF) tap test is usually used to predict surgery outcomes and hence aid clinical decision-making, but the workup varies. We introduce the CSF tap test conducted at our center and examine its power by analyzing data from a series of iNPH cases that underwent shunt placement. We analyze common features in the past medical history of our patients and investigate whether they are related to the etiology of iNPH. Data from 20 patients who were positive in the tap tests preoperatively and received ventriculoperitoneal shunting (VPS) were retrospectively analyzed. Preoperative and postoperative performance data were analyzed. History of any underlying medical conditions was taken into consideration. Patients with negative tap test results of the same period were also followed up. We performed VPS placement in 20 NPH patients from October 2019 to February 2022. Of these, 90% exhibited improvement in at least 1 of the clinical triad, proving the predictive power of the Peking Union Medical College Hospital test workflow. The underlying conditions like hypertension, diabetes and insufficiency in cerebral blood supply were also found to be associated with the onset of NPH. Our evaluation system is a valid tool for NPH assessment and can guide clinical decision-making. Comorbidities should be taken into consideration as they contribute to the pathogenesis and progression of NPH. Better identification of potential iNPH patients will lower the burden exerted on the family and the aging society. [ABSTRACT FROM AUTHOR]

Abstract Background Idiopathic normal pressure hydrocephalus (iNPH) is a neurological condition with gait apraxia signs from its early manifestation. Ventriculoperitoneal shunt (VPS) is a surgical procedure available for treatment. The Cerebrospinal fluid Tap Test (CSF-TT) is a quick test used as selection criterion for VPS treatment. Its predictive capacity for VPS outcomes is still sub judice. This study is aimed to test the hypothesis that wearable motion sensors provide valid measures to manage iNPH patients with gait apraxia. Methods Forty-two participants of the Bologna PRO-Hydro observational cohort study were included in the analyses. The participants performed the Timed Up and Go (TUG) and the 18 m walking test (18mW) with inertial sensors at baseline, three days after the CSF-TT, and six months after VPS. 21 instrumental variables described gait and postural transitions from TUG and 18mW recordings. Furthermore, participants were clinically assessed with scales (clinical variables). We tested the hypothesis by analysing the concurrent validity of instrumental and clinical variables, their individual- and group-level responsiveness to VPS, and their predictive validity for VPS outcomes after CSF-TT. Results The instrumental variables showed moderate to high correlation with the clinical variables. After VPS, most clinical and instrumental variables showed statistically significant improvements that reflect a reduction of apraxic features of gait. Most instrumental variables, but only one clinical variable (i.e., Tinetti POMA), had predictive value for VPS outcomes (significant adjusted R2 in the range 0.12–0.70). Conclusions These results confirm that wearable inertial sensors may represent a valid tool to complement clinical evaluation for iNPH assessment and prognosis.

IntroductionThe aim of this study was to compare clinical and functional performances of idiopathic normal pressure hydrocephalus (INPH) patients with and without parkinsonism at the initial evaluation, 72 h after the cerebrospinal fluid tap test (CSF TT), and 6 months after ventriculoperitoneal shunt (VPS) surgery.Materials and methodsThis is an observational prospective study on patients with INPH who underwent VPS. Patients were classified into INPH with parkinsonism (INPH-P+) and without parkinsonism (INPH-P−). We used the time up and go (TUG) test, Tinetti Performance-Oriented Mobility Assessment (POMA) test, INPH grading scale (INHPGS), and modified Rankin scale (mRS) at baseline, 72 h after CSF TT, and 6 months after VPS surgery.ResultsA total of 64 patients with probable INPH were included, 12 patients with INPH-P+ and 52 controls with INPH-P−. Patients with INPH showed significant improvement in all clinical and neurological parameters after VPS including TUG, Tinetti POMA, INPHGS, and mRS (p < 0.001) with the exception of mRS where there was no significant change 72 h after CSF TT compared to baseline for patients with INPH (p = 0.182). Patients with INPH-P+ performed significantly worse than patients with INPH-P− on Tinetti POMA and mRS at baseline, at 72 h post-CSF TT, and at 6 months post-VPS with INPHGS being worst at 72 h post-CSF TT. There was no difference between patients with INPH-P+ and patients with INPH-P− for TUG at baseline (p = 0.270), at 72 h post-CSF TT (p = 0.487), and at 6 months post-VPS (p = 0.182). Patients with INPH-P+ did not show any change in any of the parameters at 72 h post-CSF TT compared to baseline; however, there was a trend toward improvement on TUG (p = 0.058), Tinetti gait (p = 0.062), and Tinetti total (p = 0.067). INPH-P+ significantly improved in all parameters 6 months post-VPS compared to baseline except for mRS (p = 0.124). Patients with INPH-P− significantly improved in all parameters at 72 h post-CSF TT and at 6 months post-VPS compared to baseline, respectively, except on mRS 72 h after CSF TT (p = 0.299).ConclusionPatients with INPH and parkinsonism overall do worse than patients without parkinsonism. An unsatisfying response to the CSF tap test in INPH patients with parkinsonism should not be used as an exclusion criterion from VPS surgery since patients with and without parkinsonism showed significant improvement post-VPS.

Background: Idiopathic normal pressure hydrocephalus (iNPH) is a progressive and partially reversible form of dementia, characterized by impaired interactions between multiple brain regions. Because of the presence of comorbidities and a lack of accurate diagnostic and prognostic biomarkers, only a minority of patients receives disease-specific treatment. Recently, resting-state functional-magnetic resonance imaging (rs-fMRI) has demonstrated functional connectivity alterations in inter-hemispheric, frontal, occipital, default-mode (DMN) and motor network (MN) circuits. Herein, we report our experience in a cohort of iNPH patients that underwent cerebrospinal fluid (CSF) dynamics evaluation and rs-fMRI. The study aimed to identify functional circuits related to iNPH and explore the relationship between DMN and MN recordings and clinical modifications before and after infusion and tap test, trying to understand iNPH pathophysiology and to predict the best responders to ventriculoperitoneal shunt (VPS) implant. Methods: We prospectively collected data regarding clinical assessment, neuroradiological findings, lumbar infusion and tap test of thirty-two iNPH patients who underwent VPS implant. Rs-fMRI was performed using MELODIC-ICA both before and after the tap test. Rs-fMRI data of thirty healthy subjects were also recorded. Results: At the baseline, reduced z-DMN and z-MN scores were recorded in the iNPH cohort compared with controls. Higher z-scores were recorded in more impaired patients. Both z-scores significantly improved after the tap test except in subjects with a low resistance to outflow value and without a significant clinical improvement after the test. A statistically significant difference in mean MN connectivity scores for tap test responders and non-responders was demonstrated both before (p = 0.0236) and after the test (p = 0.00137). A statistically significant main effect of the tap test on DMN connectivity after CSF subtraction was recorded (p = 0.038). Conclusions: Our results suggest the presence of a partially reversible plasticity functional mechanism in DMN and MN. Low values compensate for the initial stages of the disease, while higher values of z-DMN were recorded in older patients with a longer duration of symptoms, suggesting an exhausted plasticity compensation. The standardization of this technique could play a role as a non-invasive biomarker in iNPH disease, suggesting the right time for surgery. Trial Registration Prot. IRB 090/2021. [ABSTRACT FROM AUTHOR]

Normal-pressure hydrocephalus (NPH) is a common condition associated with a cognitive deterioration and possibly involving up to 9%–14% of all nursing home residents older than 65 years old. The purpose of the present paper is to introduce an inclusive study protocol aimed at increasing the diagnostic precision and follow-up accuracy. A total of 28 patients were operated on for NPH in our institution in the period ranging between January 2015 and December 2019. All the patients underwent magnetic resonance imaging of the brain with standard sequences, calculation of the Evans index and corpus callosum angle, and evaluations by means of Montreal Cognitive Assessment (MOCA), Mini-Mental State Examination, and Frontal Assessment Battery (FAB) neuropsychological tests preoperatively and at 1 and 6 months. A preoperative lumbar test infusion (LIT) with fine measurement of the intrathecal pressures at the beginning and at the end of the procedures was performed. MOCA and FAB proved an overall improvement of the neurocognitive conditions at 1 month postoperatively. The mean pressure at the beginning of the LIT, was negatively associated with the neuropsychological outcome variables (Mini-Mental State Examination, FAB, and MOCA) in the 3 different evaluations, with FAB and MOCA at 6 months. We found a strong positive correlation between the Evans index as measured on the first magnetic resonance imaging scan both with the diastolic and systolic pressure at the beginning of the test. Neuropsychological assessment, combined with LIT with intrathecal pressure managements aids the diagnostic process in patients affected by NPH. It allows standardizing in a rigorous fashion the follow-up evaluation of patients undergoing surgery for a ventriculoperitoneal shunt. [ABSTRACT FROM AUTHOR]

Introduction: Although the Lumbar Tap Test (LTT) typically involves removing 30-50 ml of cerebrospinal fluid (CSF), the optimal amount for a valid test is unclear. This study investigates the relationship between the volume of CSF removed and the extent of gait improvement in idiopathic normal pressure hydrocephalus (iNPH)., Methods: Seventy-six iNPH patients with gait improvement after LTT were divided into two groups: high CSF volume (> 40 ml) and low CSF volume (< 40 ml). Spearman's r correlations and non-parametric t-tests were used to analyze the relationship between CSF volume removed and gait improvement., Results: Gait improvement after LTT showed a moderate positive correlation (r = 0.372, p < 0.001) with CSF volume. Those in the high-volume group had significantly greater improvement (p < 0.01). Improvement was also correlated with baseline gait parameters: pre-LTT gait speed (r = -4.14, p = 0.006), steps to complete a walking test (r = 0.440, p < 0.001), and a 360° turn (r = 0.563, p < 0.001)., Conclusions: Larger CSF removal during LTT positively affects gait improvement in iNPH patients. Gait improvement is also greater in those with more severe initial gait impairments independently from the CSF volume extracted., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Abstract Background Idiopathic normal pressure hydrocephalus (INPH) is characterized by gait disturbance, urinary incontinence and cognitive decline. Symptoms are potentially reversible and treatment is based on cerebrospinal fluid shunting. The tap test (TT) is used to identify patients that will benefit from surgery. This procedure consists of the withdrawal of 20 to 50 mL of cerebrospinal fluid (CSF) through a lumbar puncture (LP) after which the symptoms of the triad are tested. Improvement in the quality and speed of gait are already recognized but cognitive improvement depends on several factors such as tests used, the time elapsed after LP for re-testing, and the number of punctures. Serial punctures may trigger similar conditions as external lumbar drainage (ELD) to the organism. Objective This study aimed to identify how serial punctures affect cognition to increase the sensitivity of the test and consequently the accuracy of surgical indication. Methods Sixty-one patients with INPH underwent baseline memory and executive tests repeatedly following the 2-Step Tap Test protocol (2-STT – two procedures of 30 mL lumbar CSF drainage separated by a 24-h interval). The baseline scores of INPH patients were compared with those of 55 healthy controls, and with intragroup post-puncture scores of the 2-STT. Results The group with INPH had lower performance than the control group in all cognitive tests (RAVLT, Stroop, CFT, FAR-COWA, FAB, MMSE, orientation, mental control), except for the forward digit span test (p = 0.707). After conducting LP procedures, the Stroop test (words, colors and errors), RAVLT (stage A1, A6 and B1), and CFT (immediate and delayed R) scores were equal to those of the control group (p > 0.05). The INPH group presented significant improvement after the first puncture in MMSE (p = 0.031) and in the Stroop Test (points) (p

Background: Idiopathic normal pressure hydrocephalus (iNPH) is a neurological condition with gait apraxia signs from its early manifestation. Ventriculoperitoneal shunt (VPS) is a surgical procedure available for treatment. The Cerebrospinal fluid Tap Test (CSF-TT) is a quick test used as selection criterion for VPS treatment. Its predictive capacity for VPS outcomes is still sub judice. This study is aimed to test the hypothesis that wearable motion sensors provide valid measures to manage iNPH patients with gait apraxia. Methods: Forty-two participants of the Bologna PRO-Hydro observational cohort study were included in the analyses. The participants performed the Timed Up and Go (TUG) and the 18 m walking test (18mW) with inertial sensors at baseline, three days after the CSF-TT, and six months after VPS. 21 instrumental variables described gait and postural transitions from TUG and 18mW recordings. Furthermore, participants were clinically assessed with scales (clinical variables). We tested the hypothesis by analysing the concurrent validity of instrumental and clinical variables, their individual- and group-level responsiveness to VPS, and their predictive validity for VPS outcomes after CSF-TT. Results: The instrumental variables showed moderate to high correlation with the clinical variables. After VPS, most clinical and instrumental variables showed statistically significant improvements that reflect a reduction of apraxic features of gait. Most instrumental variables, but only one clinical variable (i.e., Tinetti POMA), had predictive value for VPS outcomes (significant adjusted R2 in the range 0.12–0.70). Conclusions: These results confirm that wearable inertial sensors may represent a valid tool to complement clinical evaluation for iNPH assessment and prognosis. [ABSTRACT FROM AUTHOR]

The aim of the present study was the implementation of the composite imaging "Radscale" in patients with idiopathic normal pressure hydrocephalus (iNPH) and the evaluation of its score, as well as absolute stroke volume and peak flow velocity of cerebrospinal fluid (CSF) in aqueduct as indicators of a positive response following a tap test. Forty-five patients with iNPH were included. Clinical evaluation involved the 10 m timed walk test before and every 24 h for 3 consecutive days after evacuative lumbar puncture (LP). Neuropsychological evaluation comprised a mini mental state examination (MMSE), frontal assessment battery (FAB), 5-word test (5WT) and CLOX drawing test 1 and 2, which were carried out before and 48 h after LP. The tap test's response was defined as a ≥20% improvement in gait and/or a ≥10% improvement in neuropsychological tests. All scores of neuropsychological and clinical variables, except for immediate 5WT and CLOX-1, differed significantly before and 48 h after LP. Improvement in time and steps of a 10 m timed walk test differed significantly between female and male patients. Out of 45 total patients, 19 were tap test responders and 26 non-responders. The total score of Radscale and CSF flow parameters did not differ between responders and non-responders. However, "Callosal angle" sub-score differed significantly between these two groups. A greater "callosal angle" sub-score, meaning more acute callosal angle, was associated with a positive tap test response, rendering it a useful measurement in the stratification of iNPH patients that will potentially respond to CSF shunting. [ABSTRACT FROM AUTHOR]

The present study was designed to systemically evaluate changes in the diffusion tensor imaging (DTI)-derived parameters of iNPH (idiopathic normal pressure hydrocephalus) patients with different responses to the tap test (TT), and to correlate cognitive impairment with white matter (WM) degeneration. This study included 22 iNPH patients and 14 healthy controls with structural magnetic resonance imaging (MRI) and DTI scanning. DTI was used to explore the differences in fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) for all participants. DTI parameters were evaluated using an ROI (region of interest)-based and tract-based spatial statistics (TBSS) approach. Neuropsychological assessments and the idiopathic normal pressure hydrocephalus grading scoring scale (iNPHGS) were performed. Compared to the TT non-responders, the TT responders group had significantly lower FA values in the corpus callosum, cingulum cingulate gyrus, superior longitudinal fasciculus, and lower AD values in the right cingulum cingulate gyrus and the left posterior thalamic radiation. Besides, the MD values were significantly increased in the corpus callosum, left anterior corona radiata, and the RD values in the corpus callosum and cingulum cingulate gyrus. In addition, the cognitive improvement was negatively correlated with FA of the corpus callosum, cingulum cingulate gyrus, and MD values of the genu of corpus callosum. While, the cognitive improvement was positively related to the AD of the cingulum cingulate gyrus, superior longitudinal, and RD values of the corpus callosum, cingulum cingulate gyrus and uncinate fasciculus. The ROI specific WM lesions in iNPH patients are the underlying basis for cognitive impairment. [ABSTRACT FROM AUTHOR]

The present study was designed to systemically evaluate changes in the diffusion tensor imaging (DTI)-derived parameters of iNPH (idiopathic normal pressure hydrocephalus) patients with different responses to the tap test (TT), and to correlate cognitive impairment with white matter (WM) degeneration. This study included 22 iNPH patients and 14 healthy controls with structural magnetic resonance imaging (MRI) and DTI scanning. DTI was used to explore the differences in fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) for all participants. DTI parameters were evaluated using an ROI (region of interest)-based and tract-based spatial statistics (TBSS) approach. Neuropsychological assessments and the idiopathic normal pressure hydrocephalus grading scoring scale (iNPHGS) were performed. Compared to the TT non-responders, the TT responders group had significantly lower FA values in the corpus callosum, cingulum cingulate gyrus, superior longitudinal fasciculus, and lower AD values in the right cingulum cingulate gyrus and the left posterior thalamic radiation. Besides, the MD values were significantly increased in the corpus callosum, left anterior corona radiata, and the RD values in the corpus callosum and cingulum cingulate gyrus. In addition, the cognitive improvement was negatively correlated with FA of the corpus callosum, cingulum cingulate gyrus, and MD values of the genu of corpus callosum. While, the cognitive improvement was positively related to the AD of the cingulum cingulate gyrus, superior longitudinal, and RD values of the corpus callosum, cingulum cingulate gyrus and uncinate fasciculus. The ROI specific WM lesions in iNPH patients are the underlying basis for cognitive impairment.

Ahmet Turan Isik,1 Derya Kaya,1 Esra Ates Bulut,1 Ozge Dokuzlar,1 Pinar Soysal2 1Unit for Aging Brain and Dementia, Department of Geriatric Medicine, School of Medicine, Dokuz Eylul University, Izmir, Turkey; 2Department of Geriatric Medicine, Bezmialem Vakif University, Faculty of Medicine, Istanbul, TurkeyCorrespondence: Ahmet Turan IsikUnit for Brain Aging and Dementia, Department of Geriatric Medicine, School of Medicine, Dokuz Eylul University, Balcova, Izmir 35340, TurkeyTel +90 232 412 43 41Fax +90 232 412 43 49Email atisik@yahoo.comPurpose: Elderly patients with iNPH (idiopathic normal pressure hydrocephalus) might be potentially high-risk surgical patients. Our purpose was to investigate the outcome of serial removal of cerebrospinal fluid (CSF) in the patients with iNPH who refused to have the ventriculoperitoneal or lumboperitoneal shunt surgery or had contraindications to them.Patients and methods: There were 42 patients, with a median age of 78 years. Recurrent CSF removal was performed when the patients had deteriorated gait which was defined as >10% pre-removal change on the average of two walking trials during timed up and go (TUG). All the patients underwent mini-mental status examination (MMSE), frontal assessment battery (FAB), Stroop test, Tinetti Performance Oriented Mobility Assessment (POMA), TUG and nine-hole peg test (NHPT) with the dominant hand, before and after CSF removal.Results: Thirty-five patients had two CSF removal procedures with a mean interim period of 7.4 months ranging from 1.5 to 35 months. Thirteen patients had three CSF removal procedures. The mean TUG scores were decreased after the first, second and third procedures (p

Abstract Background The Kuopio University Hospital (KUH) idiopathic normal pressure hydrocephalus (iNPH) cerebrospinal fluid (CSF) shunting protocol is described together with the initial outcomes of 175 patients with probable iNPH treated according to this protocol from a defined population. Our secondary aim was to display the variety of differential diagnoses referred to the KUH iNPH outpatient clinic from 2010 until 2017. Methods Patients were divided into four groups according to the prognostic tests: tap test (positive or negative) and infusion test (positive or negative). The short-term outcome was compared between groups. The 3-month outcome following shunt surgery was assessed by measuring gait speed improvement, using a 12-point iNPH grading scale (iNPHGS) and the 15D instrument. Results From 341 patients suspected of iNPH, 88 patients were excluded from further research mostly due to deviation from the protocol’s gait assessment guidelines. Hence 253 patients with suspected iNPH were included in the study, 177/253 (70%) of whom were treated with a CSF shunt. A favorable clinical outcome following surgery was observed in 79–93% of patients depending on the prognostic group. A moderate association (Cramer’s V = 0.32) was found between the gait speed improvement rate and the prognostic group (X2, p = 0.003). Patients with a positive tap test had the highest gait speed improvement rate (75%). In addition, an improvement in walking speed was observed in 4/11 patients who had both a negative tap test and a negative infusion test. Other outcome measures did not differ between the prognostic groups. Conditions other than iNPH were found in 25% of the patients referred to iNPH outpatient clinic, with the most prevalent being Alzheimer’s disease. Conclusions Our results emphasize the importance of a systematic diagnostic and prognostic workup especially in cases with an atypical presentation of iNPH. Additional diagnostic testing may be required, but should not delay adequate care. Active surgical treatment is recommended in patients with a high clinical probability of iNPH. Other neurological conditions contributed to most of the non iNPH diagnoses.

Background: The value of cerebrospinal fluid (CSF) biomarkers for assessing idiopathic normal pressure hydrocephalus (iNPH) must be determined. This prospective study aimed to reveal the correlation between CSF biomarkers and clinical symptoms of iNPH and the predictive value of these biomarkers for tap test responsiveness.Methods: Thirty-nine patients with suspected iNPH were recruited, contributed qualified CSF, and underwent a tap test and unified pre- and post-test evaluations of the neurological function.Results: The analysis of biomarkers from the patients’ CSF showed decreased levels of tau and its phosphorylated form, especially in the tap test (+) group. The responsiveness of the tap test was also related to the number of combined symptoms (p < 0.01), and a correlation was found between the end pressure or pressure difference in CSF and tap test responsiveness (p < 0.05). The results of the binary logistic regression analysis showed that P (tap test responsiveness) = 1/1 + e∧ − (−5.505 + 55.314 * ratio of p/T-tau − 1.586 * numbers of combined symptoms). The combined indicators (−5.505 + 0.553 * percentage of p/T-tau − 1.586 * numbers of combined symptoms) resulted in the highest sensitivity and specificity of 94.12% and 72.73%, respectively.Conclusions: CSF biomarkers may be assessed to judge tap test responsiveness, which is beneficial for the feasibility of a clinical application.

Surgical treatment of idiopathic normal pressure hydrocephalus (iNPH) by ventriculoperitoneal (VP) or lumboperitoneal (LP) shunting can achieve long-term recovery of activities of daily living; however, in a subset of patients, maintenance of independence lasted for <6 months. This study examined positive preoperative predictive factors of short-term outcome for shunted iNPH patients. Over a 9-year period, consecutive patients from multiple centers diagnosed with probable iNPH underwent either VP or LP shunt surgery. Preoperative variables of age, symptom duration, iNPH severity, tap test response, and magnetic resonance imaging findings of disproportionately enlarged subarachnoid space hydrocephalus (DESH) or incomplete DESH were retrospectively evaluated in relation to 1-year postoperative outcome. Outcome for 154 shunt patients (12 VP, 142 LP) as measured by postoperative disability modified Rankin Scale (mRS) and iNPH−gait disturbance (GD) was the same regardless of age. Symptom duration was inversely correlated with both iNPH severity (P < 0.0001) and postoperative improvement at 1 year (P = 0.0015). Severity also correlated inversely with postoperative improvement at 1 year (P < 0.0001). Age was not significantly correlated with the degree of postoperative improvement (mRS: P = 0.487; iNPH grading scale [GD]: P = 0.725). Outcome at 1 year (mRS, gait domain, and activities of daily living significantly improved in patients with a good response to the tap test (P < 0.0001) Preoperative DESH correlated with improvement in mRS and GD (P < 0.0001). Mild preoperative iNPH severity, shorter preoperative symptom duration, good tap test response, and complete DESH were associated with good short-term postoperative outcome at 1 year. These positive factors may be useful for prediction of short-term surgical outcome in iNPH patients. [ABSTRACT FROM AUTHOR]

Background: The value of cerebrospinal fluid (CSF) biomarkers for assessing idiopathic normal pressure hydrocephalus (iNPH) must be determined. This prospective study aimed to reveal the correlation between CSF biomarkers and clinical symptoms of iNPH and the predictive value of these biomarkers for tap test responsiveness. Methods: Thirty-nine patients with suspected iNPH were recruited, contributed qualified CSF, and underwent a tap test and unified pre- and post-test evaluations of the neurological function. Results: The analysis of biomarkers from the patients' CSF showed decreased levels of tau and its phosphorylated form, especially in the tap test (+) group. The responsiveness of the tap test was also related to the number of combined symptoms (p < 0.01), and a correlation was found between the end pressure or pressure difference in CSF and tap test responsiveness (p < 0.05). The results of the binary logistic regression analysis showed that P (tap test responsiveness) = 1/1 + e∧ − (−5.505 + 55.314 * ratio of p/ T -tau − 1.586 * numbers of combined symptoms). The combined indicators (−5.505 + 0.553 * percentage of p/ T -tau − 1.586 * numbers of combined symptoms) resulted in the highest sensitivity and specificity of 94.12% and 72.73%, respectively. Conclusions: CSF biomarkers may be assessed to judge tap test responsiveness, which is beneficial for the feasibility of a clinical application. [ABSTRACT FROM AUTHOR]

Background: Idiopathic normal pressure hydrocephalus (INPH) is characterized by gait disturbance, urinary incontinence and cognitive decline. Symptoms are potentially reversible and treatment is based on cerebrospinal fluid shunting. The tap test (TT) is used to identify patients that will benefit from surgery. This procedure consists of the withdrawal of 20 to 50 mL of cerebrospinal fluid (CSF) through a lumbar puncture (LP) after which the symptoms of the triad are tested. Improvement in the quality and speed of gait are already recognized but cognitive improvement depends on several factors such as tests used, the time elapsed after LP for re-testing, and the number of punctures. Serial punctures may trigger similar conditions as external lumbar drainage (ELD) to the organism. Objective: This study aimed to identify how serial punctures affect cognition to increase the sensitivity of the test and consequently the accuracy of surgical indication. Methods: Sixty-one patients with INPH underwent baseline memory and executive tests repeatedly following the 2-Step Tap Test protocol (2-STT – two procedures of 30 mL lumbar CSF drainage separated by a 24-h interval). The baseline scores of INPH patients were compared with those of 55 healthy controls, and with intragroup post-puncture scores of the 2-STT. Results: The group with INPH had lower performance than the control group in all cognitive tests (RAVLT, Stroop, CFT, FAR-COWA, FAB, MMSE, orientation, mental control), except for the forward digit span test (p = 0.707). After conducting LP procedures, the Stroop test (words, colors and errors), RAVLT (stage A1, A6 and B1), and CFT (immediate and delayed R) scores were equal to those of the control group (p > 0.05). The INPH group presented significant improvement after the first puncture in MMSE (p = 0.031) and in the Stroop Test (points) (p < 0.001). After the second puncture, subjects improved in orientation, MMSE, RAVLT (B1), Stroop (points, words, errors) and CFT (IR). Conclusion: Progressive cognitive improvement occurred over the 2-STT and changes were more significant after the second LP in all cognitive domains except for RAVLT (A7). Encephalic alert system 'arousal' seems to participate in early improvements observed during 2-STT. The second LP increased the sensitivity of the drainage test to detect changes in cognitive variables, and consequently improved the quality of the method. [ABSTRACT FROM AUTHOR]

The wind energy sources promote the generation of electricity, being environmentally safe, clean and its use has been growing in Brazil, especially in the northeastern states with the implementation of new wind farms. Wind turbines, however, are subject to weather, risk of animal shocks, materials carried by the wind, and the vibrations of the system itself. The blade is the most important component of a wind turbine and is the one with the greatest risk of failure. They are usually made of a composite fiber-reinforced polymer matrix and balsa wood as structural reinforcement. As the material composing this blade has heterogeneous and anisotropic characteristics, conventional inspection techniques are not considered effective. The non-destructive Tap Test technique can be a safe option in composite materials because it does not suffer from these limitations. The objective of this work is to inspect composite plates of polymeric resin used in wind turbines with discontinuities using the non-destructive Tap Test technique, where regions with and without defect were analyzed. The collected signals from an accelerometer and a microphone were processed, to allow the extraction of features and the recognition of discontinuities with the aid of a neural network. [ABSTRACT FROM AUTHOR]

Background: Tap test improves symptoms of idiopathic normal pressure hydrocephalus (iNPH); hence, it is widely used as a diagnostic procedure. However, it has a low sensitivity and there is no consensus on the parameters that should be used nor the volume to be extracted. We propose draining cerebrospinal fluid (CSF) during tap test until a closing pressure of 0 cm H2O is reached as a standard practice. We use this method with all our patients at our clinic. Methods: This is a descriptive cross-sectional study where all patients with presumptive diagnosis of iNPH from January 2014 to December 2019 were included in the study. We used a univariate descriptive analysis and stratified analysis to compare the opening pressure and the volume of CSF extracted during the lumbar puncture, between patients in whom a diagnosis of iNPH was confirmed and those in which it was discarded. Results: A total of 92 patients were included in the study. The mean age at the time of presentation was 79.4 years and 63 patients were male. The diagnosis of iNPH was confirmed in 73.9% patients. The mean opening pressure was 14.4 cm H2O mean volume of CSF extracted was 43.4 mL. Conclusion: CSF extraction guided by a closing pressure of 0 cm H2O instead of tap test with a fixed volume of CSF alone may be an effective method of optimizing iNPH symptomatic improvement and diagnosis. [ABSTRACT FROM AUTHOR]

Background: Extensive research into cerebrospinal fluid (CSF) biomarkers was performed in patients with idiopathic normal pressure hydrocephalus (iNPH). Most prior research into CSF biomarkers has been one-point observation.Objective: To investigate dynamic changes in CSF biomarkers during routine tap test in iNPH patients.Methods: We analyzed CSF concentrations of tau, amyloid-β (Aβ) 42 and 40, and leucine rich α-2-glycoprotein (LRG) in 88 consecutive potential iNPH patients who received a tap test. We collected two-point lumbar CSF separately at the first 1 ml (First Drip (FD)) and at the last 1 ml (Last Drip (LD)) during the tap test and 9 patients who went on to receive ventriculo-peritoneal shunt surgery each provided 1 ml of ventricular CSF (VCSF).Results: Tau concentrations were significantly elevated in LD and VCSF compared to FD (LD/FD = 1.22, p = 0.003, VCSF/FD = 2.76, p = 0.02). Conversely, Aβ42 (LD/FD = 0.80, p < 0.001, VCSF/FD = 0.38, p = 0.03) and LRG (LD/FD = 0.74, p < 0.001, VCSF/FD = 0.09, p = 0.002) concentrations were significantly reduced in LD and VCSF compared to FD. Gait responses to the tap test and changes in cognitive function in response to shunt were closely associated with LD concentrations of tau (p = 0.02) and LRG (p = 0.04), respectively.Conclusions: Dynamic changes were different among the measured CSF biomarkers, suggesting that LD of CSF as sampled during the tap test reflects an aspect of VCSF contributing to the pathophysiology of iNPH and could be used to predict shunt effectiveness. [ABSTRACT FROM AUTHOR]

Idiopathic normal pressure hydrocephalus is a widespread neurodegenerative disease of the elderly. If not treated surgically early, it results in a severe decrease in quality of life and disability. According to current clinical Russian and foreign guidelines the candidates for CSF shunting procedures are selected based on the results of invasive tests, though treatment outcomes are not always optimal. At the same time, in the last decade there have been published a number of studies on promising noninvasive diagnosis and prognosis of the surgical treatment of idiopathic normal pressure hydrocephalus based on neuroimaging findings. The aim of the present systematic review is to demonstrate the most promising imaging predictors of satisfactory outcomes of CSF shunting procedures in patients with idiopathic normal pressure hydrocephalus based on published literature data., Competing Interests: Conflict of interest. The authors declare no conflict of interest.

Idiopathic normotensive hydrocephalus (iNH) is a widespread disease in elderly patients. The effectiveness of iNG treatment and the subsequent quality of patients' lives directly depends on timely and early diagnosis. The criteria for diagnosing iNG that are used in neuroimaging can also be found in patients without clinical manifestations of this disease, and the widely used tap-test is an invasive technique with a rather low sensitivity. The need for early diagnosis and initiation of treatment before the development of irreversible damage to brain structures determines the relevance of the search for an accessible, minimally invasive, accurate and safe diagnostic method. The article presents a clinical observation of the use of phase-contrast MRI of cerebrospinal fluid (CSF) in a female patient with a positive response to the tap test with a quantitative analysis of changes in CSF flow parameters and ALVI and Evans indices depending on the time after CSF evacuation. Phase-contrast MRI of CSF with a quantitative assessment of CSF flow parameters in combination with an assessment of the ALVI index has the potential to increase the accuracy of diagnosing iNH and is of scientific interest for further research.

Objective: To synthesize the evidence regarding the diagnostic value of simple ancillary tests post cerebrospinal fluid drainage in normal pressure hydrocephalus. Data sources: MEDLINE, CINAHL, PsycINFO, Scopus, Web of Science, and Cochrane library databases; last searched on 12 September 2017. Review methods: This review was performed applying the steps of the PRISMA statement. The QUADAS 2 tool was used to assess the risk of bias. Prospective and retrospective trials were systematically reviewed, and data on diagnostic accuracy were extracted. Meta-analysis (where possible) was performed. Hierarchical summary receiver operating characteristic package was used to calculate pooled estimates of included diagnostic studies. Results: Seventeen trials (with 812 subjects in total) were identified for inclusion in the meta-analyses for the 18-meter walk test, video-recorded gait performance, cognitive test, and Timed Up and Go Test. The summary estimates of sensitivity and specificity for the 18-meter walk test was 0.83 (95% CI 0.57 to 0.99) and 0.67 (95% CI 0.33 to 0.95), video-recorded gait performance was 0.85 (95% CI 0.47 to 0.99) and 0.68 (95% CI 0.33 to 0.96), cognitive test was 0.82 (95% CI 0.41–0.99) and 0.75 (95% CI 0.39–0.99), and Timed Up and Go Test was 0.89 (95% CI 0.79–0.95) and 0.63 (95% CI 0.24–0.90), respectively. Conclusion: This review highlights the diagnostic value of the 18-meter walk test, video-recorded gait performance, cognitive test, and Timed Up and Go Test in predicting shunt outcomes among adults with normal pressure hydrocephalus. [ABSTRACT FROM AUTHOR]

The present prospective study examined the utility of the intraoperative tap test/technique for distal tibiofibular syndesmosis in the diagnosis of deltoid ligament rupture and compared the outcomes of transsyndesmotic fixation to deltoid ligament repair with suture anchor. This diagnostic technique was performed in 59 ankle fractures with suspected deltoid ligament injury. The width of the medial clear space of 59 cases was evaluated to assess the sensitivity and specificity. Those with deltoid ligament rupture were randomly assigned to 2 groups and treated with deltoid ligament repair with a suture anchor or with syndesmosis screw fixation. All the patients were assessed with the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, short-form 36-item questionnaire (SF-36), and visual analog scale (VAS). The tap test was positive in 53 cases. However, surgical exploration demonstrated that 51 cases (86.4%) had a combined deltoid ligament injury and fracture. The sensitivity and specificity of the tap test was 100.0% and 75.0%, respectively. Finally, 26 cases (96.3%) in the syndesmosis screw group and 22 (91.7%) in the deltoid repair group were followed up. No statistically significant differences were found in the AOFAS ankle-hindfoot scale score, SF-36 score, or VAS score between the 2 groups. The malreduction rate in the syndesmosis screw group was 34.6% and that in the deltoid repair group was 9.09%. The tap test is an intraoperative diagnostic method to use to evaluate for deltoid ligament injury. Deltoid ligament repair with a suture anchor had good functional and radiologic outcomes comparable to those with syndesmotic screw fixation but has a lower malreduction rate. We did not encounter the issue of internal fixation failure or implant removal. [ABSTRACT FROM AUTHOR]

Objectives The cerebrospinal fluid tap test for idiopathic normal pressure hydrocephalus ( iNPH) is one of the good predictors of the shunt treatment, although this test has a low sensitivity. We aimed to identify key parameters that could be used to improve this sensitivity. Materials & methods During 2010-2011, we recruited and then followed 93 patients with possible iNPH for 12 months after shunt. Among them, 82 patients were finally enrolled in this study. The modified Rankin Scale, iNPH grading scale, and several quantitative measurements were evaluated at entry, after the tap test, before and after shunt. Area under the receiver-operating characteristic curves ( AUCs), sensitivities, and specificities of the tap test for predicting shunt effectiveness were calculated for each measurement. They were additionally assessed after stratification by disease duration since the initial presentation of iNPH symptoms. Results The gait disturbance on the iNPH grading scale had the highest accurate scale at the tap test for predicting effectiveness 12 months after shunt: AUC 0.74, sensitivity 56.5%, specificity 91.7%. This AUC increased to 0.76, 0.91 and 0.94 in the subgroup of disease duration <24, <12, and <6 months, respectively. The sensitivity and specificity of the gait disturbance on the iNPH grading scale in the subgroup of <12 months' duration were 92.3% and 90.0%. Conclusions The shorter period of clinical symptoms, for example, <12 months, made the tap test sufficiently accurate examination for predicting improvement 12 months after shunt surgery. The findings imply that the tap test should be applied to patients being considered for shunt surgery as soon as possible. [ABSTRACT FROM AUTHOR]

Objective: Temporary drainage of CSF with lumbar puncture or lumbar drainage has a high predictive value for identifying patients with suspected idiopathic normal pressure hydrocephalus (iNPH) who may benefit from ventriculoperitoneal shunt insertion. However, it is unclear what differentiates responders from nonresponders. The authors hypothesized that nonresponders to temporary CSF drainage would have patterns of reduced regional gray matter volume (GMV) as compared with those of responders. The objective of the current investigation was to compare regional GMV between temporary CSF drainage responders and nonresponders. Machine learning using extracted GMV was then used to predict outcomes., Methods: This retrospective cohort study included 132 patients with iNPH who underwent temporary CSF drainage and structural MRI. Demographic and clinical variables were examined between groups. Voxel-based morphometry was used to calculate GMV across the brain. Group differences in regional GMV were assessed and correlated with change in results on the Montreal Cognitive Assessment (MoCA) and gait velocity. A support vector machine (SVM) model that used extracted GMV values and was validated with leave-one-out cross-validation was used to predict clinical outcome., Results: There were 87 responders and 45 nonresponders. There were no group differences in terms of age, sex, baseline MoCA score, Evans index, presence of disproportionately enlarged subarachnoid space hydrocephalus, baseline total CSF volume, or baseline white matter T2-weighted hyperintensity volume (p > 0.05). Nonresponders demonstrated decreased GMV in the right supplementary motor area (SMA) and right posterior parietal cortex as compared with responders (p < 0.001, p < 0.05 with false discovery rate cluster correction). GMV in the posterior parietal cortex was associated with change in MoCA (r2 = 0.075, p < 0.05) and gait velocity (r2 = 0.076, p < 0.05). Response status was classified by the SVM with 75.8% accuracy., Conclusions: Decreased GMV in the SMA and posterior parietal cortex may help identify patients with iNPH who are unlikely to benefit from temporary CSF drainage. These patients may have limited capacity for recovery due to atrophy in these regions that are known to be important for motor and cognitive integration. This study represents an important step toward improving patient selection and predicting clinical outcomes in the treatment of iNPH.

Background: To improve the diagnostic performance of the cerebrospinal fluid (CSF) tap test (TT), early and delayed assessments of gait were performed after the removal of 30 ml of CSF in patients with probable idiopathic normal pressure hydrocephalus. Assessments of gait included the 3-m timed up and go test (TUG), and the 10-m walk in time (10Ti) and in step (10St) tests. Methods: Quantitative data for the TUG, the 10Ti, and the 10St were obtained before CSF removal and on days 1 and 4 after removal of 30 ml CSF. CSF shunt surgery was performed in 61 patients within one month after the TT. The gait outcome was assessed 3 months after surgery. The area under the curve (AUC), sensitivity, specificity, and cutoff values were computed for the TUG, the 10Ti, and the 10St on day 1 and day 4 using receiver operating characteristic (ROC) curve analysis. Results: The positive response rate in three measures on day 4 was equal to or higher than the values on day 1. Times were reduced significantly in the TUG and the 10mTi tests between baseline and both days 1 and 4 after TT. No significant differences were noted in the number of steps for the 10St test. The percent change in TUG on day 1 had the highest AUC value among all other variables (0.808). Although this was not statistically different from other variables in the TUG and the 10Ti, it had a good balance of high sensitivity (78.3%) and high specificity (80.0%), with a cutoff value of 11.3%. The change in the measured value in the day 1 TUG had the second highest AUC value at 0.770. The variables on day 4 tended to have high specificities of around 90%, although their sensitivities were low. Conclusions: The percent change of TUG on day 1 showed the highest diagnostic accuracy. Delayed assessments on day 4 were not superior to those on day 1. Thus, the TUG on day 1 is useful as a simple quantitative measure for predicting shunt effectiveness. [ABSTRACT FROM AUTHOR]