Profiling iNPH features through cluster analysis: an aid for clinical suspicion and diagnosis.

PURPOSE: Idiopathic Normal Pressure Hydrocephalus (iNPH) is a neurological syndrome defined by gait disturbance, cognitive impairment and urinary incontinence. However, its clinical presentation can vary widely due to overlapping syndromes and common comorbidities in older adults. This study aims to provide practical guidance to aid in the clinical suspicion and support the diagnostic and therapeutic processes for these patients. METHODS: Six quantitative variables regarding clinical, functional, and demographic aspects were considered for a large sample of patients with diagnosed iNPH. Principal component analysis (PCA) was adopted to define the main dimensions explaining the variability of the phenomenon. Then, two clusters of iNPH patients were described. RESULTS: 178 patients were included in the analysis. The PCA produced two dimensions covering 61.8% of the total variability. The first one relied mainly on both clinical (mRS, iNPHGs) and functional (TUG, Tinetti) variables, while the second one was represented mainly on the demographic pattern (age and education). Cluster analysis depicted two main groups of patients. Cluster n.1 is composed of individuals who are older, more disabled, with poor functional performances, and highly symptomatic. Cluster n.2 patients are slightly younger, more educated, fitter, and with more nuanced clinical aspects. CONCLUSIONS: Profiling iNPH patients using quantitative variables and cluster analysis can help identify distinct characteristics of these patients, aiding in the guidance of both medical and surgical interventions.

Assessment of CSF Dynamics Using Infusion Study: Tips and Tricks.

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.

In vivo assessment of the ocular biomechanical properties in patients with idiopathic normal pressure hydrocephalus.

PURPOSE: Idiopathic normal pressure hydrocephalus (iNPH) is associated with an increased prevalence of open-angle glaucoma, attributed to variations of the pressure gradient between intraocular and intracranial compartments at the level of the lamina cribrosa (LC). As ocular biomechanics influence the behavior of the LC, and a lower corneal hysteresis (CH) has been associated to a higher risk of glaucomatous optic nerve damage, in this study we compared ocular biomechanics of iNPH patients with healthy subjects. METHODS:  Twenty-four eyes of 24 non-shunted iNPH patients were prospectively recruited. Ocular biomechanical properties were investigated using the ocular response analyzer (Reichert Instruments) for the calculation of the CH, corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated intraocular pressure (IOPcc). Results were compared with those of 25 eyes of 25 healthy subjects. RESULTS:  In iNPH eyes, the median CH value and interquartile range (IQR) were 9.7 mmHg (7.8-10) and 10.6 mmHg (9.3-11.3) in healthy controls (p = 0.015). No significant differences were found in IOPcc [18.1 mmHg (14.72-19.92) vs. 16.4 mmHg (13.05-19.6)], IOPg [15.4 mmHg (12.82-19.7) vs. 15.3 mmHg (12.55-17.35)], and CRF [9.65 mmHg (8.07-11.65) vs. 10.3 mmHg (9.3-11.5)] between iNPH patients and controls. CONCLUSIONS:  In iNPH patients, the CH was significantly lower compared to healthy subjects. This result suggests that ocular biomechanical properties may potentially contribute to the risk of development of glaucomatous optic nerve damage in iNPH patients.

Treatment of cerebral ventriculitis with a new self-irrigating catheter system: narrative review and case series.

Cerebral ventriculitis is a life-threatening condition that requires prompt and effective pharmacological intervention. The continuous irrigation of the cerebral ventricles with fluid and its drainage is a system to remove toxic substances and infectious residues in the ventricles; this system is called IRRAflow®. We used this kind of ventricular irrigation/drainage system to treat two patients with post-surgical cerebral ventriculitis and a patient with bacterial meningitis complicated with ventriculitis. In this case series, we discuss the management of these three cases of cerebral ventriculitis: we monitored cytochemical parameters and cultures of the cerebrospinal fluid of patients during their ICU stay and we observed a marked improvement after irrigation and drainage with IRRAflow® system. Irrigation/drainage catheter stay, mode settings, and antibiotic therapies were different among these three patients, and neurological outcomes were variable, according to their underlying pathologies. IRRAflow® system can be applied also in other types of brain injury, such as intraventricular hemorrhage, intracranial abscess, subdural hematomas, and intracerebral hemorrhage, with the aim to remove the hematic residues and enhance the functional recovery of the patients. IRRAflow® seems a promising and useful tool to treat infectious and hemorrhagic diseases in neuro-intensive care unit.

Choroidal morphology and microvascular structure in eyes of patients with idiopathic normal pressure hydrocephalus before and after ventriculo-peritoneal shunt surgery.

The present study aims to investigate the choroidal morphology and microvascular structure in eyes of patients with idiopathic normal pressure hydrocephalus (iNPH) compared with the eyes of healthy age-matched individuals, and to assess the choroidal structure in eyes of iNPH patients before and after shunt surgery using Optical Coherence Tomography (OCT). The primary objective was to assess the choroidal morphology in eyes of iNPH patients before and after ventriculo-peritoneal (VP) surgery compared to age and sex-matched healthy individuals. The secondary objective was to compare the choroidal morphology of iNPH patients before and after a mean of 56 days from shunt surgery. Eighteen consecutive patients diagnosed with iNPH and 18 healthy controls were prospectively recruited between November 2021 and October 2022. Spectral-domain optical coherence tomography (SD-OCT) with enhanced depth imaging (EDI) was conducted before and within 4 months after shunt surgery. Images were binarized using the ImageJ software, and the choroidal vascular index (CVI) was calculated. Sub-foveal choroidal thickness (SFCT), total choroidal area (TCA), luminal choroidal area (LCA), and stromal choroidal area (SCA) were significantly increased in iNPH patients before surgery compared to the control group (p < 0.05). SFCT, TCA, and SCA were significantly increased in iNPH patients after surgery compared to the control group (p < 0.05). There were no differences in the CVI between iNPH patients and controls. No statistical differences in the choroidal structure were observed before and after VP shunt surgery (p > 0.05). In conclusion, the choroid was thicker in iNPH patients before and after VP shunt compared to age-matched healthy individuals. However, there were no difference in the choroidal microstructure in the eyes of iNPH patients before and after a mean of 3 months from VP shunt surgery.

Managing Idiopathic Normal Pressure Hydrocephalus: Need for a Change of Mindset.

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.

Isolated entrapment of the lateral ventricle after neuroendoscopic resection of colloid cysts: single - center experience and management.

BACKGROUND: A minimally invasive option of colloid cyst surgical treatment is endoscopic resection, well validated in various reports and clinical practice. A rare complication of the surgical treatment, previously reported only once in literature, is the entrapment of the lateral ventricle. In this study we aim to outline our experience in the management of this occurrence, hypothesizing possible etiopathogenetic causes. METHODS: Among patients who underwent neuroendoscopic resection for a colloid cysts at our Institution between 2013 and 2022, cases who developed a postoperative lateral ventricle entrapment were retrospectively reviewed and included. Clinical history, imaging and treatment were reported. RESULTS: Among 34 patients treated for a colloid cysts, two (5.9 %) patients developed an ipsilateral ventricular entrapment with dilation from two to five months after the resection. Both patients were substantially asymptomatic and neurologically intact, and therefore treated conservatively. One case underwent complete spontaneous radiological resolution one month later, and the other one has remained neurological asymptomatic at follow-up. CONCLUSIONS: Isolated asymptomatic ventricular entrapment with significant dilation after endoscopic colloid cyst resection is a rare occurrence which can be plausibly caused by scar tissue at the level of the foramen of Monro. Because they can have an indolent course with spontaneous resolution, conservative treatment is a viable option, with strict radiological and clinical follow - up. Given the rarity of the occurrence, further studies with larger cohorts are warranted to confirm the etiopathogenetic hypothesis and validate the clinical management.

A New Clinical Protocol for a Timely Diagnosis and Treatment of Hydrocephalus in Patients with Severe Acquired Brain Injury.

BACKGROUND: Secondary hydrocephalus is a well-known complication of severe acquired brain injuries (sABIs) often diagnosed during inpatient rehabilitation. Currently, there is no gold standard for its detection. Therefore, we designed a novel clinical diagnostic protocol that integrates clinical, functional, biochemical and neuroradiological assessments to improve the accuracy of its diagnosis in patients with sABIs. METHODS: This prospective cohort study will be conducted in a tertiary referral rehabilitation center in Italy. A historical cohort of patients will be compared with a prospective cohort undergoing the new clinical diagnostic protocol. EXPECTED RESULTS: The expected results include an increase in the proportion of diagnosed cases, a reduced incidence of clinical complications, an increase in the rehabilitative outcomes at discharge, a significant reduction in the length of hospital stay, and useful information about the diagnostic and prognostic value of the neuroradiological characteristics. CONCLUSION: We expect that this clinical diagnostic protocol will result in a more appropriate assessment and timely treatment of secondary hydrocephalus in patients with sABIs, with the ultimate goal of improving their prognosis. In addition, it could be adopted by other rehabilitation centers to improve hydrocephalus diagnosis and treatment, thereby reducing the length of hospital stay and accelerating recovery with benefits for both patients and hospitals.

Gait Apraxia and Hakim's Disease: A Historical Review.

In 1965, Prof. Salomón Hakim described, for the first time, a condition characterized by normal pressure hydrocephalus and gait alterations. During the following decades, definitions such as "Frontal Gait", "Bruns' Ataxia" and "Gait Apraxia" have been frequently used in pertinent literature in the attempt to best define this peculiar motor disturbance. More recently, gait analysis has further shed light on the typical spatiotemporal gait alterations that characterize this neurological condition, but a clear and shared definition of this motor condition is still lacking. In this historical review, we described the origins of the terms "Gait Apraxia", "Frontal Gait" and "Bruns' Ataxia", starting with the first works of Carl Maria Finkelburg, Fritsch and Hitzig and Steinthal during the second half of the 19th century and ending with Hakim's studies and his formal definition of idiopathic normal pressure hydrocephalus (iNPH). In the second part of the review, we analyze how and why these definitions of gait have been associated with Hakim's disease in the literature from 1965 to the present day. The definition of "Gait and Postural Transition Apraxia" is then proposed, but fundamental questions about the nature and mechanisms underlying this condition remain unanswered.

Magnetic Resonance-Based Assessment of Optic Nerve Sheath Diameter: A Prospective Observational Cohort Study on Inter- and Intra-Rater Agreement.

BACKGROUND: The measurement of optic nerve sheath diameter (ONSD) as a non-invasive method of estimating intracranial pressure has been widely reported in the literature. However, few studies have evaluated the accuracy of magnetic resonance imaging (MRI) in assessing ONSD measurements, although it is considered a very reliable method, it is not easily repeatable, expensive and is not readily available bedside. Herein, an assessment of the intra- and inter-rater reliability of ONSD assessment using MRI was conducted. METHODS: A consecutive, prospective cohort of patients with suspected idiopathic normal-pressure hydrocephalus was analyzed. ONSD MRI measurements of the transverse and sagittal diameters at a distance of 3 mm behind the papilla were evaluated twice each by two expert neuroradiologists. The correlations between MRI examiners were calculated using the concordance correlation coefficient (CCC). RESULTS: Fifty patients were included in the study. ONSD MRI average measurements were substantially higher than clinically expected (>5 mm). Considering intra-rater concordance, only one of the two neuroradiologists achieved an excellent score at CCC. Only a moderate inter-observer CCC for MRI assessment was found at all diameters. CONCLUSIONS: The use of a widespread MRI sequence (3D T1) to measure ONSD is not an accurate method since it may overestimate measurements and is dependent upon an operator.

INPH and parkinsonism: A positive shunt response with a negative tap test.

Introduction: The 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 methods: 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.

CSF dynamics in long-standing overt ventriculomegaly in adults.

OBJECTIVE: Long-standing overt ventriculomegaly in adults (LOVA) is a form of chronic hydrocephalus and its pathophysiology and treatment remain debated. An analysis of CSF dynamics in this condition has rarely been reported. The aim of this study was to analyze hydrodynamic characteristics of patients with suspected LOVA to discuss its pathophysiological mechanisms and the importance of CSF dynamics analysis for diagnosis and treatment of these patients. METHODS: This retrospective cohort study, conducted between May 2018 and October 2022, included adult patients aged > 18 years investigated in a department of neurosurgery through a lumbar infusion study for suspicion of LOVA (n = 23). These patients were then compared with a control cohort explored for suspicion of idiopathic normal pressure hydrocephalus (iNPH; n = 30). Clinical symptoms, radiological findings, and hydrodynamic parameters were analyzed. The authors specifically compared two hydrodynamic parameters: resistance to CSF outflow, or Rout, which relies on CSF resorption, and pressure-volume index (PVI), which reflect overall craniospinal compliance. The lumbar infusion study was considered pathological (confirming the diagnosis of chronic hydrocephalus) when at least one of these two parameters was altered. RESULTS: Rout was significantly less frequently increased (cutoff ≥ 12 mm Hg/ml/min) in patients with LOVA (52%) than in those with iNPH (97%; p < 0.001). In contrast, PVI was impaired (cutoff ≤ 25 ml) in both cohorts, i.e., in 61% of patients with LOVA and in 83% of patients with iNPH. Overall, the rate of pathological lumbar infusion study in LOVA (87%) was not statistically different than in iNPH (100%). However, PVI was the only impaired parameter most frequently found in those with LOVA (35%) compared with those with iNPH (3%; p = 0.002). CONCLUSIONS: This study suggests that there is a differential CSF dynamics pattern when comparing patients with LOVA versus those with iNPH. A higher proportion of patients with LOVA showed isolated compliance impairment. These findings highlight the utility of CSF dynamics analysis for the evaluation of patients with suspected chronic obstructive hydrocephalus such as LOVA. Future research with larger case series may help define diagnosis and treatment algorithms of chronic obstructive hydrocephalus based on CSF dynamics analysis, in addition to clinical and radiological criteria.

The CLOSED protocol to assess optic nerve sheath diameter using color-Doppler: a comparison study in a cohort of idiopathic normal pressure hydrocephalus patients.

BACKGROUND: Sonographic assessment of the optic nerve sheath diameter represents a promising non-invasive technique for estimation of the intracranial pressure. A wide inter-observer variability, along with a lack of a standardized protocol for the optic nerve sheath diameter measurements, could lead to over- or under-estimation. The present study was aimed at evaluating feasibility of color-Doppler for better delineating optic nerve sheath borders, comparing it to B-mode imaging, using the magnetic resonance measurements as a comparison. METHODS: Optic nerve sheath diameters were evaluated using magnetic resonance by an expert radiologist in a cohort of patients with suspected idiopathic normal pressure hydrocephalus. Magnetic resonance findings were evaluated twice. In the first half of this cohort, optic nerve sheath diameters were measured using B-mode only, in the second half applying color-Doppler. Measurements obtained using these two techniques were compared to magnetic resonance imaging measurements. The Bland-Altman analysis and concordance correlation coefficient were computed to quantify the strength of agreement between the two magnetic resonance assessments. Box plots and average (± SD) were used to compare assessments by sonographic and magnetic resonance methods. RESULTS: Fifty patients were included. MRI assessment showed a moderate concordance correlation coefficient. Optic nerve sheath diameters measured applying color-Doppler were lower (p < 0.001) and less scattered compared to B-mode assessment, which approached more to magnetic resonance measurements. CONCLUSIONS: In this cohort of patients, magnetic resonance showed high intra-rater variability in optic nerve sheath diameter assessments. Optic nerve sheath diameter assessments using color-Doppler yielded lower and less scattered diameters compared to B-mode only.

In vivo assessment of Lewy body and beta-amyloid copathologies in idiopathic normal pressure hydrocephalus: prevalence and associations with clinical features and surgery outcome.

BACKGROUND: Idiopathic normal pressure hydrocephalus (iNPH) is a clinico-radiological syndrome of elderly individuals likely sustained by different neurodegenerative changes as copathologies. Since iNPH is a potentially reversible condition, assessing neurodegenerative pathologies in vitam through CSF biomarkers and their influence on clinical features and surgical outcome represents crucial steps. METHODS: We measured α-synuclein seeding activity related to Lewy body (LB) pathology by the real-time quaking-induced conversion assay (RT-QuIC) and Alzheimer disease core biomarkers (proteins total-tau, phospho-tau, and amyloid-beta) by immunoassays in the cerebrospinal fluid (CSF) of 293 iNPH patients from two independent cohorts. To compare the prevalence of LB copathology between iNPH participants and a control group representative of the general population, we searched for α-synuclein seeding activity in 89 age-matched individuals who died of Creutzfeldt-Jakob disease (CJD). Finally, in one of the iNPH cohorts, we also measured the CSF levels of neurofilament light chain protein (NfL) and evaluated the association between all CSF biomarkers, baseline clinical features, and surgery outcome at 6 months. RESULTS: Sixty (20.5%) iNPH patients showed α-synuclein seeding activity with no significant difference between cohorts. In contrast, the prevalence observed in CJD was only 6.7% (p = 0.002). Overall, 24.0% of iNPH participants showed an amyloid-positive (A+) status, indicating a brain co-pathology related to Aß deposition. At baseline, in the Italian cohort, α-synuclein RT-QuIC positivity was associated with higher scores on axial and upper limb rigidity (p = 0.003 and p = 0.011, respectively) and lower MMSEc scores (p = 0.003). A+ patients showed lower scores on the MMSEc (p = 0.037) than A- patients. Higher NfL levels were also associated with lower scores on the MMSEc (rho = -0.213; p = 0.021). There were no significant associations between CSF biomarkers and surgical outcome at 6 months (i.e. responders defined by decrease of 1 point on the mRankin scale). CONCLUSIONS: Prevalent LB- and AD-related neurodegenerative pathologies affect a significant proportion of iNPH patients and contribute to cognitive decline (both) and motor impairment (only LB pathology) but do not significantly influence the surgical outcome at 6 months. Their effect on the clinical benefit after surgery over a more extended period remains to be determined.

Ventriculoatrial Shunt Under Locoregional Anesthesia: A Technical Note.

BACKGROUND: Ventriculoatrial shunt is routinely performed under general anesthesia and is used to treat various kinds of hydrocephalus. Idiopathic normal pressure hydrocephalus patients are generally elderly and can have high comorbidities; in such patients, avoiding general anesthesia and limiting opioid administration could be beneficial. We started to perform ventriculoatrial shunt under locoregional anesthesia, in order to make this procedure more truly "minimally invasive". METHODS: Demographic data, American Society of Anesthesiologists (ASA) score and vital signs, Ramsay sedation scale, and procedural duration were collected. All procedures were performed combining sedation with cervical plexus and scalp block. After internal jugular vein cannulation, a catheter was inserted and connected with a programmable valve and then with the ventricular catheter. Outcome was assessed by the Idiopathic Normal Pressure Hydrocephalus Grading Scale and complications were recorded at 3-month follow-up. RESULTS: Ten consecutive patients were enrolled; the mean age was 74 years, 8 were male, ASA score median value was 3. Opioids were administered only in 4 patients, in 6 patients the value of Ramsay scale was 5. The average duration of surgery was 59.5 minutes. No procedure was converted to general anesthesia. CONCLUSIONS: Our preliminary experience with ventriculoatrial shunt under locoregional anesthesia demonstrates that this technique is feasible, is not associated with an increase in operating times or complications, can avoid general anesthesia, and helps to limit opioid administration in the elderly. It can therefore represent a valid option in order to improve treatment quality in these complex patients.

Gait apraxia evaluation in normal pressure hydrocephalus using inertial sensors. Clinical correlates, ventriculoperitoneal shunt outcomes, and tap-test predictive capacity.

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.

Open-aqueduct LOVA, LIAS, iNPH: a comparative clinical-radiological study exploring the "grey zone" between different forms of chronic adulthood hydrocephalus.

PURPOSE: The definition of chronic adult hydrocephalus encompasses different pathological entities with overlapping characteristics, including long-standing overt ventriculomegaly in adults (LOVA), late-onset idiopathic aqueductal stenosis (LIAS) and idiopathic normal pressure hydrocephalus (iNPH). The aim of our study was to identify preoperative clinical and radiological features peculiar of these diseases providing some pathophysiology inferences on these forms of hydrocephalus. METHODS: Clinical and radiological preoperative records, type of surgical treatment and clinical outcome of patients with chronic adult hydrocephalus who were surgically treated between 2013 and 2019 were retrospectively reviewed. Univariate and multivariate analyses were performed to evaluate the contribution of each variable to the differential diagnosis. RESULTS: In total, 105 patients were included: 18 with LOVA, 23 with LIAS and 64 with iNPH. On multivariate analysis, an enlarged cisterna magna and a more severe ventriculomegaly were associated with the diagnosis of LOVA, while an older age and DESH with iNPH. LIAS patients tend to have an higher prevalence of raised ICP symptoms. Based on that, a clinical and radiological scoring system was developed to distinguish between iNPH and no iNPH cases. A precise cut-off value with a sensitivity of 95.1% and a specificity of 90.6% was identified. CONCLUSIONS: LOVA, LIAS and iNPH are different forms of chronic adulthood hydrocephalus and present different and peculiar clinical and radiological features, with an impact on the treatment and outcome prediction. The implementation of a clinical-radiological score for differential diagnosis may help the differentiation. Further studies are warranted.

Idiopathic Aqueductal Stenosis: Late Neurocognitive Outcome in ETV Operated Adult Patients.

Objective: The aim of the present study is to evaluate a neurocognitive outcome in patients affected by late-onset idiopathic aqueductal stenosis (LIAS) who underwent endoscopic third ventriculostomy (ETV). Materials and Methods: A prospective study was conducted between January 2015 and December 2017 in a series of 10 consecutive adult patients referred to the Neurosurgery Department of IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy. All the adult patients admitted with absence of CSF flow through the aqueduct in phase-contrast (PC)-MRI sequences or a turbulence void signal in T2-weighted images in midsagittal thin-slice MR sequences underwent a specific neuroradiological, neurological, and neurocognitive assessment pre- and postoperatively. Results: All patients affected by gait and sphincter disturbances improved after ETV. Attentive and executive functions as well as visuo-spatial memory and verbal executive functions improved in several patients. Similarly, the affective and behavioral scales improved in almost 50% of the patients. No major complications have been recorded, and no patients required a second surgery for shunt placement. Conclusion: Endoscopic third ventriculostomy represents a safe and effective surgical procedure for the treatment of LIAS. In addition to neurological improvement, we demonstrated also postoperative neurocognitive improvement mainly in attentive and executive functions, visuo-spatial memory, verbal executive functions, and behavioral and affective domains.