Disproportionately Enlarged Subarachnoid Space Hydrocephalus Research Articles

Deep learning assessment of disproportionately enlarged subarachnoid-space hydrocephalus in Hakim’s disease or idiopathic normal pressure hydrocephalus

Abstract Background Disproportionately enlarged subarachnoid-space hydrocephalus (DESH) is a key feature of Hakim’s disease (synonymous with idiopathic normal pressure hydrocephalus; iNPH). However, it previously had been only subjectively evaluated. Purpose This study aims to evaluate the usefulness of MRI indices, derived from deep learning segmentation of cerebrospinal fluid (CSF) spaces, for DESH detection and to establish their optimal thresholds. Materials and Methods This study retrospectively enrolled a total of 1009 participants, including 77 patients diagnosed with Hakim’s disease, 380 healthy volunteers, 163 with mild cognitive impairment, 256 with Alzheimer’s disease, and 217 with other types of neurodegenerative diseases. DESH, ventriculomegaly, tightened sulci in the high convexities, and Sylvian fissure dilatation were evaluated on three-dimensional T1-weighted MRI by radiologists. The total ventricles, high-convexity part of the subarachnoid space, and Sylvian fissure and basal cistern were automatically segmented using the CSF Space Analysis application (FUJIFILM Corporation). Moreover, DESH, Venthi, and Sylhi indices were calculated based on these 3 regions. The area under the receiver-operating characteristic curves of these indices and region volumes (volume ratios) for DESH detection were calculated. Results Of the 1009 participants, 101 (10%) presented with DESH. The DESH, Venthi, and Sylhi indices performed well with 95.0%-96.0% sensitivity and 91.5%-96.8% specificity at optimal thresholds. All patients with Hakim’s disease were diagnosed with DESH, despite variations in severity. In patients with Hakim’s disease, with or without Alzheimer’s disease, the DESH index and total ventricular volume were significantly higher compared to patients with Alzheimer’s disease, although the total intracranial cerebrospinal fluid volume was significantly lower. Conclusion DESH, Venthi, and Sylhi indices, and the volumes and volume ratios of the ventricle and high-convexity part of the subarachnoid space computed using deep learning were useful for the DESH detection that may help to improve the diagnosis of Hakim’s disease (ie, iNPH).

Evaluation of imaging indicators in differentiating idiopathic normal pressure hydrocephalus from Alzheimer's disease

BackgroundThere are currently many imaging indicators for idiopathic normal pressure hydrocephalus (iNPH). However, their diagnostic performance has not been well compared, especially in differentiating iNPH from Alzheimer's disease (AD). This study aimed to evaluate the diagnostic performance of these imaging indicators in differentiating iNPH from AD. MethodsWe retrospectively collected patients with iNPH from the West China Hospital between June 2016 and December 2023. Age-sex-matched patients with AD and healthy controls (HCs) are included as controls (ChiCTR2300070078, March 2023). Twelve imaging indicators were evaluated on MRI, including disproportionately enlarged subarachnoid space hydrocephalus (DESH), Evans' index (EI), callosal angle, z-EI, temporal horn, dilated Sylvian fissure, focal sulcal dilation, tight high convexity, deep white matter hyperintensities, periventricular hyperintensities, DESH scale, and Simplified Radscale. We analyzed the receiver operating characteristic curves and calculated the sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy. ResultsA total of 46 patients with iNPH (mean age: 73.1 ± 6.5; 35 males), 46 patients with AD (mean age: 73.0 ± 6.6; 35 males), and 46 HCs (mean age: 73.0 ± 5.9; 35 males) were included. The largest area under the receiver operating characteristic curve (AUC) was found in EI (0.93; 95 % CI: 0.89–0.98) and z-EI (0.93; 95 % CI: 0.87–0.98). DESH scale ≥ 6 had the highest specificity (93 %, 43/46). ConclusionEI and z-EI had the best diagnostic performance in differentiating iNPH from AD. The DESH scale could assist in diagnosing iNPH due to its high specificity.

Idiopathic normal pressure hydrocephalus: Validation of the DESH score as a prognostic tool for shunt surgery response

ObjectiveSeveral radiological markers have been linked to clinical improvement after shunt surgery for idiopathic normal pressure hydrocephalus (iNPH). However, iNPH has no pathognomonic feature, and patients are still diagnosed as probable, possible, or unlikely cases based on clinical symptoms, imaging findings, and invasive supplementary tests. The predictive value of the disproportionately enlarged subarachnoid space hydrocephalus (DESH) score is not yet conclusively determined, but it might offer a more accurate diagnostic method. The aim of the present retrospective cohort study was to validate the predictive power of the DESH score for clinical improvement after shunt surgery in iNPH patients. MethodsWe retrospectively obtained presurgical MRI and/or CT scans from 71 patients with iNPH who underwent ventriculoperitoneal shunt surgery. Radiological images were evaluated for Evans index (EI), corpus callosal angle (CA), tight high convexity (THC), Sylvian fissure dilation, and focal sulci dilation. These markers were aggregated to determine the DESH score. Patient journal entries were used to subjectively determine the extent of improvement in gait function, urinary incontinence, and/or cognition as a measure of shunt surgery response. ResultsMultiple logistic regression analysis, controlling for age and sex (α = 0.05), showed that DESH score was significantly correlated (OR 1.77) with subjective shunt-surgery response at a minimum of 1-month follow-up. Patients with higher DESH scores were more likely to have a favorable response to shunt surgery. ConclusionAggregating radiological markers into the DESH score is useful for predicting shunt responders among iNPH patients and can aid the selection of patients for surgery. These findings provide further support for the DESH score as a diagnostic tool for iNPH.

Identifying the Preoperative Radiological Risk Features in Patients with Leptomeningeal Carcinomatosis Undergoing Cerebrospinal Fluid Drainage

Patients with leptomeningeal carcinomatosis (LMC) experience a poor prognosis and rapid progression, and cerebrospinal fluid drainage (CSFD) is used to manage intracranial hypertension and hydrocephalus in LMC patients. This study aims to describe a novel discovery of preoperative radiological features in patients who underwent CSFD for LMC. A retrospective review was conducted during the past 5 years of LMC patients with intracranial hypertension and hydrocephalus who underwent CSFD. We evaluated the patients' preoperative radiological features, clinical characteristics, and survival times. A total of 36 patients were included. Of the 36 patients, 34 underwent ventriculoperitoneal shunting, and 2 patients underwent only external ventricular drainage due to rapid progression. The median preoperative Karnofsky performance scale score was 40.0 (interquartile range [IQR], 20.0-40.0). The median survival time after surgery was 5 months (IQR, 0.00-10.43 months). Of the 36 patients, 24 (66.7%) had supratentorial cerebral edema before surgery, including 14 patients (38.9%) with features of disproportionately enlarged subarachnoid space hydrocephalus (DESH). Four patients (11.1%) exhibited cerebellar swelling and had a median survival time of 0.27 month (IQR, 0.00-0.56 month). Nine patients (25%) have enhancement lesions on the cerebellum. The survival curve analysis shows that patients with features of cerebellar enhancement have shorter survival times than other patients. Patients with DESH features have longer survival times compared with those with global cerebral edema. Patients with radiological features of cerebellar enhancement have shorter postoperative survival than other patients; however, those with supratentorial cerebral edema, especially features of DESH, could benefit from CSFD. Patients with cerebellar swelling should avoid undergoing CSFD.

Automatic assessment of disproportionately enlarged subarachnoid-space hydrocephalus from 3D MRI using two deep learning models.

Disproportionately enlarged subarachnoid-space hydrocephalus (DESH) is a key feature for Hakim disease (idiopathic normal pressure hydrocephalus: iNPH), but subjectively evaluated. To develop automatic quantitative assessment of DESH with automatic segmentation using combined deep learning models. This study included 180 participants (42 Hakim patients, 138 healthy volunteers; 78 males, 102 females). Overall, 159 three-dimensional (3D) T1-weighted and 180 T2-weighted MRIs were included. As a semantic segmentation, 3D MRIs were automatically segmented in the total ventricles, total subarachnoid space (SAS), high-convexity SAS, and Sylvian fissure and basal cistern on the 3D U-Net model. As an image classification, DESH, ventricular dilatation (VD), tightened sulci in the high convexities (THC), and Sylvian fissure dilatation (SFD) were automatically assessed on the multimodal convolutional neural network (CNN) model. For both deep learning models, 110 T1- and 130 T2-weighted MRIs were used for training, 30 T1- and 30 T2-weighted MRIs for internal validation, and the remaining 19 T1- and 20 T2-weighted MRIs for external validation. Dice score was calculated as (overlapping area) × 2/total area. Automatic region extraction from 3D T1- and T2-weighted MRI was accurate for the total ventricles (mean Dice scores: 0.85 and 0.83), Sylvian fissure and basal cistern (0.70 and 0.69), and high-convexity SAS (0.68 and 0.60), respectively. Automatic determination of DESH, VD, THC, and SFD from the segmented regions on the multimodal CNN model was sufficiently reliable; all of the mean softmax probability scores were exceeded by 0.95. All of the areas under the receiver-operating characteristic curves of the DESH, Venthi, and Sylhi indexes calculated by the segmented regions for detecting DESH were exceeded by 0.97. Using 3D U-Net and a multimodal CNN, DESH was automatically detected with automatically segmented regions from 3D MRIs. Our developed diagnostic support tool can improve the precision of Hakim disease (iNPH) diagnosis.

Preoperative Predictors of Outcomes of Cerebrospinal Fluid Shunt Surgery in Patients with Idiopathic Normal Pressure Hydrocephalus

The disproportionately enlarged subarachnoid space hydrocephalus (DESH) findings on cranial images are useful to predict cerebrospinal fluid (CSF) shunt responsiveness to some extent in patients with idiopathic normal-pressure hydrocephalus (iNPH). However, recent studies show that patients with iNPH often have concomitant Alzheimer's or Lewy body disease regardless of DESH findings, which may be associated with poor outcomes of CSF shunt surgery. Moreover, long-term outcomes after CSF shunt surgery in patients with iNPH, which is one of the most important issues to be addressed for effective treatment of iNPH, remain unknown.

Patients with normal pressure hydrocephalus have fewer enlarged perivascular spaces in the centrum semiovale compared to cognitively unimpaired individuals

IntroductionEnlarged perivascular spaces (ePVS) may be an indicator of glymphatic dysfunction. Limited studies have evaluated the role of ePVS in idiopathic normal pressure hydrocephalus (iNPH). We aimed to characterize the distribution and number of ePVS in iNPH compared to controls. MethodsThirty-eight patients with iNPH and a pre-shunt MRI were identified through clinical practice. Age- and sex-matched controls who had negative MRIs screening for intracranial metastases were identified through a medical record linkage system. The number of ePVS were counted in the basal nuclei (BN) and centrum semiovale (CS) using the Wardlaw method blinded to clinical diagnosis. Imaging features of disproportionately enlarged subarachnoid space hydrocephalus (DESH), callosal angle, Fazekas white matter hyperintensity (WMH) grade, and the presence of microbleeds and lacunes were also evaluated. ResultsBoth iNPH patients and controls had a mean age of 74 ± 7 years and were 34% female with equal distributions of hypertension, dyslipidemia, diabetes, stroke, and history of smoking. There were fewer ePVS in the CS of patients with iNPH compared to controls (12.66 vs. 20.39, p < 0.001) but the same in the BN (8.95 vs. 11.11, p = 0.08). This remained significant in models accounting for vascular risk factors (p = 0.002) and MRI features of DESH and WMH grade (p = 0.03). ConclusionsFewer centrum semiovale ePVS may be a biomarker for iNPH. This pattern may be caused by mechanical obstruction due to upward displacement of the brain leading to reduced glymphatic clearance.

Relationship between disproportionately enlarged subarachnoid-space hydrocephalus and white matter tract integrity in normal pressure hydrocephalus

Normal pressure hydrocephalus (NPH) patients had altered white matter tract integrities on diffusion tensor imaging (DTI). Previous studies suggested disproportionately enlarged subarachnoid space hydrocephalus (DESH) as a prognostic sign of NPH. We examined DTI indices in NPH subgroups by DESH severity and clinical symptoms. This retrospective case–control study included 33 NPH patients and 33 age-, sex-, and education-matched controls. The NPH grading scales (0–12) were used to rate neurological symptoms. Patients with NPH were categorized into two subgroups, high-DESH and low-DESH groups, by the average value of the DESH scale. DTI indices, including fractional anisotropy, were compared across 14 regions of interest (ROIs). The high-DESH group had increased axial diffusivity in the lateral side of corona radiata (1.43 ± 0.25 vs. 1.72 ± 0.25, p = 0.04), and showed decreased fractional anisotropy and increased mean, and radial diffusivity in the anterior and lateral sides of corona radiata and the periventricular white matter surrounding the anterior horn of lateral ventricle. In patients with a high NPH grading scale, fractional anisotropy in the white matter surrounding the anterior horn of the lateral ventricle was significantly reduced (0.36 ± 0.08 vs. 0.26 ± 0.06, p = 0.03). These data show that DESH may be a biomarker for DTI-detected microstructural alterations and clinical symptom severity.

FC42: Evaluation of patients with cognitive impairment due to suspected idiopathic normal-pressure hydrocephalus at medical centers for dementia: a nationwide hospital-based survey in Japan

Objective:Treatment of idiopathic normal-pressure hydrocephalus (iNPH) requires collaboration between dementia specialists and neurosurgeons. The role of dementia specialists is to differentiate patients with iNPH from patients with other dementia diseases and to determine if other dementia diseases are comorbid with iNPH. We conducted a nationwide hospital-based questionnaire survey on iNPH in medical centers for dementia (MCDs).Methods:We developed a questionnaire to assess how physicians in MCDs evaluate and treat patients with cognitive impairment due to suspected iNPH and the difficulties these physicians experience in the evaluation and treatment of patients. The questionnaire was sent to all 456 MCDs in Japan.Results:Questionnaires from 279 MCDs were returned to us (response rate: 61.2%). Patients underwent cognitive tests, evaluation of the triad symptoms of iNPH, and morphological neuroimaging examinations in 96.8, 77.8, and 98.2% of the MCDs, respectively. Patients with suspected iNPH were referred to other hospitals (e.g., hospitals with neurosurgery departments) from 78.9% of MCDs, and cerebrospinal fluid (CSF) tap test was performed in 44 MCDs (15.8%). iNPH guidelines (iNPHGLs) and disproportionately enlarged subarachnoid space hydrocephalus (DESH), a specific morphological finding, were used and known in 39.4% and 38% of MCDs, respectively. Logistic regression analysis with “Refer the patient to other hospitals (e.g., hospitals with neurosurgery departments) when iNPH is suspected.” as the response variable and (a) using the iNPHGLs, (b) knowledge of DESH, (c) confidence regarding DESH, (d) difficulty with performing brain magnetic resonance imaging, (e) knowledge of the methods of CSF tap test, (f) absence of physician who can perform lumbar puncture, and (g) experience of being told by neurosurgeons that referred patients are not indicated for shunt surgery as explanatory variables revealed that the last two factors were significant predictors of patient referral from MCDs to other hospitals.Conclusion:Sufficient differential or comorbid diagnosis using CSF tap test was performed in a few MCDs. Medical care for patients with iNPH in MCDs may be improved by having dementia specialists perform CSF tap tests and share the eligibility criteria for shunt surgery with neurosurgeons.

P186: Longitudinal changes in the cerebrospinal-fluid volumes in patients with Alzheimer’s disease.

Objective:Although the previous studies indicated that impaired cerebrospinal fluid (CSF) dynamics might contribute to the pathophysiology of Alzheimer’s disease (AD), the longitudinal changes of CSF volumes in AD has been still unclear. In this study, using the methodology of quantitative assessment of CSF volumes in idiopathic normal pressure hydrocephalus (iNPH), we assessed longitudinal changes in CSF volumes in AD patients.Methods:The subjects were the patients with mild cognitive impairment and dementia due to AD who visited Osaka University Hospital from November 2009 to October 2018. We excluded the patients with gait disturbances and MRI findings such as Disproportionately enlarged subarachnoid-space hydrocephalus (DESH), which was the suggestive finding of iNPH. For each subject, MRI was performed in the first visit and 1 year later. We quantitatively measured CSF volumes in DESH-related regions, such as ventricle systems (VS), Sylvian fissures (SF), and sulci at high convexity and the midline (SHM)., using an automatic brain volumetric software program (AVSIS) (Ishii et al. 2006, 2013). The ratio of each regional volume to the intracranial volume was calculated and we compared these parameters between two visits.Results:We enrolled 98 patients with AD (mean (SD) age = 76.0 (5.7)). Wilcoxon signed rank test revealed that, while the ratios of CSF volumes in VS and SF significantly increased during the one-year observation (VS: 4.01 (1.05) % vs 4.14 (1.09) %, p&lt;0.001 ;SF: 1.40 (0.21) % vs 1.42 (0.22) %, p=0.007), those in SHM significantly decreased (4.30 (0.70) % vs 4.23 (0.69) %, p&lt;0.001). The change ratio of relative volumes in VS was correlated with those in SF and SHM (r=0.451, p&lt;0.001; r=-0.350, p&lt;0.001).Conclusion:In patients with AD, the CSF volumes in VS and SF increased while CSF volumes in SHM decreased. This trend of the longitudinal change was similar to the change in the patients with iNPH. The finding of this study indicates that, in the patients with AD, CSF dynamics may be impaired like the patients with iNPH.

Idiopathic Intracranial Hypertension with Disproportionately Enlarged Subarachnoid Space Hydrocephalus on Imaging: A Case Report.

The pathophysiology of idiopathic intracranial hypertension (IIH) and idiopathic normal-pressure hydrocephalus (iNPH) differs in terms of cerebrospinal fluid (CSF) pressure and imaging-related characteristics. A 51-year-old man presented with optic nerve papillary edema, visual disturbance, bilateral abducens nerve palsy, and a wide-based gait. Imaging showed characteristic findings of IIH and disproportionately enlarged subarachnoid space hydrocephalus (DESH)-characteristic of iNPH. A CSF examination revealed marked CSF hypertension. IIH with iNPH-like imaging features (DESH) was diagnosed, and ventriculoperitoneal shunt surgery was performed. Postoperatively, the visual acuity and visual field improved. This report also describes the distinct and overlapping pathophysiological mechanisms of IIH and iNPH.

Higher prevalence of idiopathic normal pressure hydrocephalus-like MRI features in progressive supranuclear palsy: An imaging reminder of atypical parkinsonism.

The classic triad of idiopathic normal pressure hydrocephalus (NPH) encompass gait disturbance, cognitive impairment, and urinary incontinence. These symptoms overlap with parkinsonism but with distinct treatment. Lacking applicable differentiation also hampers the prediction to therapeutic response. Here, we try to clarify this issue among different Parkinsonian syndromes and propose some innovative thinking while approaching a patient with parkinsonism and hydrocephalus concomitantly. Twenty-four patients with clinical probable multiple system atrophy (MSA), 34 with probable progressive supranuclear palsy (PSP), and 58 with sex- and age-matched Parkinson's disease (PD) were enrolled. Evans' index (EI), callosal angle (CA), antero-posterior (AP) diameterof the midbrain, length of the midbrain tegmentum diameter (MBTegm ), and disproportionately enlarged subarachnoid space hydrocephalus (DESH) were evaluated using the conventional MRI. Logistic regression was applied to identify the independent variables in hydrocephalus. Patients with PSP had higher mean EI than those with MSA and PD. Around 38.2% of patients with PSP had accompanied hydrocephalus (EI>0.3). Parkinsonism subtypes (PD, MSA, or PSP), AP diameterof the midbrain, and MBTegm were significantly different among patients with and without hydrocephalus. After regression analysis, parkinsonism subtype stood out to be the most key risk factor of hydrocephalus. The comparison between patients with PSP with and without hydrocephalus did not disclose specific clinical characteristics or risk factors. This study demonstrates that the presence of NPH-like MRI features is much higher in PSP patients, and this tendency is decided upon the determination of parkinsonism subtype. Sharing pathophysiological characteristics in these two diseases is implied. More diagnostic tools are needed to better differentiate the two diseases and decide the treatment. To closely observe hydrocephalic parkinsonism patients and well inform the possible limited shunting benefits if PSP core features appear, will be more pivotal and practical at present clinical practice.

IMAGING OF NORMAL PRESSURE HYDROCEPHALUS

Normal pressure hydrocephalus (NPH) is hydrocephalus without an increase in intracranial pressure. The term Idiopathic Normal Pressure Hydrocephalus (INPH) has been used to describe individuals presenting with ventriculomegaly of unexplained etiology, accompanied by the classic triad of symptoms (gait disturbance, urinary incontinence, and dementia). CT-scan is more practical, cheaper, widely available, and can assess the anatomical condition of the brain and ventricles, but MRI is the best modality and superior to CT. It can assess the anatomic conditions better, changes in white matter, and the presence of flow-void sign. Radiological signs of INPH are the presence of ventriculomegaly with Evan's index &gt; 0.3, z-EI &gt; 0.42, the presence of DESH (Disproportionately Enlarged Subarachnoid Space Hydrocephalus), cingulate sign, callosal angle &lt;90°

Impact of age on the cerebrospinal fluid spaces: high-convexity and medial subarachnoid spaces decrease with age

BackgroundImpaired cerebrospinal fluid (CSF) dynamics may contribute to the pathophysiology of neurodegenerative diseases, and play a crucial role in brain health in older people; nonetheless, such age-related changes have not been well elucidated. Disproportionately enlarged subarachnoid-space hydrocephalus (DESH) is a neuroimaging phenotype of idiopathic normal-pressure hydrocephalus, originating from impaired CSF dynamics, and closely associated with aging. This study aimed to investigate the pathophysiology of DESH and determine age-related changes in CSF dynamics.MethodsUsing magnetic resonance imaging, we investigated the pathophysiology of DESH by quantitatively evaluating the volumes of DESH-related regions (ventricles [VS], Sylvian fissure [SF], and subarachnoid spaces at high convexity and midline [SHM]) and brain parenchyma in community-dwelling individuals aged ≥ 65 years. DESH-related regions were assessed using a visual rating scale, and volumes measured using voxel-based morphometry. Brain parenchyma volumes were measured using FreeSurfer software.ResultsData from 1,356 individuals were analyzed, and 25 (1.8%) individuals had DESH. Regarding the relationships between the volume of each CSF space and age, VS and SF volumes increased with age, whereas SHM volume did not increase. VS and SF volumes increased as the whole brain volume decreased, whereas SHM volume did not increase even if the whole brain volume decreased; that is, SHM did not expand even if brain atrophy progressed. Moreover, lower Mini-Mental State Examination scores were significantly associated with lower SHM volume and higher VS volume. These associations remained significant even when individuals with DESH were excluded.ConclusionsThis study showed that the volume of high-convexity and medial subarachnoid spaces did not expand and tended to decrease with age; the human brain continuously progresses toward a “DESH-like” morphology with aging in community-dwelling older persons (i.e., DESH might be an “accelerated aging stage” rather than an “age-related disorder”). Our results indicated that brain atrophy may be associated with the development of “DESH-like” morphology. In addition, this morphological change, as well as brain atrophy, is an important condition associated with cognitive decline in older adults. Our findings highlight the importance of investigating the aging process of CSF dynamics in the human brain to preserve brain health in older people.

Prevalence and development of idiopathic normal pressure hydrocephalus: A 16-year longitudinal study in Japan.

We previously investigated the preclinical state of idiopathic normal pressure hydrocephalus (iNPH): asymptomatic ventriculomegaly with features of iNPH on magnetic resonance imaging (AVIM) found in community inhabitants. The aim of the study was to determine how iNPH develops longitudinally. A previous longitudinal prospective community-based cohort study was initiated in 2000. The 271 70year-old participants were followed up in 2016 at the age of 86 years. At this time, 104 participants could be reached for clinical examinations and brain magnetic resonance imaging (MRI). iNPH in this study was diagnosed if the participant had more than one symptom in the clinical triad and disproportionately enlarged subarachnoid space hydrocephalus (DESH) on MRI, fulfilling at least an Evans index >0.3 (ventricular enlargement, VE) and a narrowing of the subarachnoid space at the high convexity (tight high convexity, THC). Asymptomatic VE (AVE) plus THC were considered AVIM. Longitudinally throughout 16 years, 11 patients with iNPH were found. The hospital consultation rate was only 9%. Five of the eight patients with AVIM (62.5%) and six of 30 with AVE (20.0%) developed iNPH. Cross-sectionally, eight patients had iNPH (8/104, 7.7% prevalence at the age of 86) in 2016. Disease development was classified into THC-preceding and VE-preceding iNPH. One VE-preceding iNPH case was considered a comorbidity of Alzheimer's dementia. Idiopathic normal pressure hydrocephalus had a high prevalence among octogenarians in the evaluated community. iNPH developed not only via AVIM but also via AVE, the latter was also frequent in the elderly.

Change in Morphological Features of Enlarged Subarachnoid Spaces Following Treatment in Idiopathic Normal Pressure Hydrocephalus.

Focally enlarged sulci (FES) are areas of proposed extraventricular fluid entrapment that may occur within idiopathic normal pressure hydrocephalus (iNPH) with radiographic evidence of disproportionately enlarged subarachnoid-space hydrocephalus (DESH), and should be differentiated from atrophy. To evaluate for change in FES size and pituitary height after shunt placement in iNPH. Retrospective. A total of 125 iNPH patients who underwent shunt surgery and 40 age-matched controls. 1.5 T and 3T. Axial T2w FLAIR, 3D T1w MPRAGE, 2D sagittal T1w. FES were measured in three dimensions and volume was estimated by assuming an ellipsoid shape. Pituitary gland height was measured in the mid third of the gland in iNPH patients and controls. Wilcoxon signed-rank test for comparisons between MRI measurements; Wilcoxon rank sum test for comparison ofcases/controls. Significance level was P < 0.05. Fifty percent of the patients had FES. FES volume significantly decreased between the pre and first postshunt MRI by a median of 303 mm3 or 30.0%. Pituitary gland size significantly increased by 0.48 mm or 14.4%. FES decreased significantly by 190 mm3 or 23.1% and pituitary gland size increased significantly by 0.25 mm or 6% between the first and last postshunt MRI. Decrease in size of FES after shunt placement provides further evidence that these regions are due to disordered cerebrospinal fluid (CSF) dynamics and should not be misinterpreted as atrophy. A relatively smaller pituitary gland in iNPH patients that normalizes after shunt is a less-well recognized feature of altered CSF dynamics. 3 TECHNICAL EFFICACY: Stage 2.

Can preoperative brain imaging features predict shunt response in idiopathic normal pressure hydrocephalus? A PRISMA review.

This systematic literature review aimed to identify brain computed tomography (CT) and magnetic resonance imaging (MRI) features that could be used to discriminate idiopathic normal pressure hydrocephalus (iNPH) shunt responders from non-responders. PubMed, Embase, Web of Science, and Cochrane were searched following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only original research articles reporting preoperative CT and/or MRI features and iNPH shunt response evaluated by changes in gait, dementia, and urinary incontinence were included. Title and abstract screening and full-text article evaluation were done by two authors. Data on patient demographics and inclusion criteria, brain image evaluation, shunting methods, and shunt response evaluation were recorded. The search resulted in 1274 studies after removing duplicates. Twenty-seven studies were chosen for final review. Both structural (i.e., callosal angle, disproportionately enlarged subarachnoid space hydrocephalus (DESH), and temporal horn diameter) and physiological brain imaging (including aqueductal flow measurement and brain perfusion) had been examined. Fourteen out of 27 studies found no difference in any assessed imaging parameters between responders and non-responders, and none of the examined imaging parameters was repeatedly and consistently reported as significantly different between the two groups. No brain imaging parameters were consistently and repeatedly reported as different between iNPH shunt responders and non-responders.

Evaluation of Patients With Cognitive Impairment Due to Suspected Idiopathic Normal-Pressure Hydrocephalus at Medical Centers for Dementia: A Nationwide Hospital-Based Survey in Japan.

ObjectiveTreatment of idiopathic normal-pressure hydrocephalus (iNPH) requires collaboration between dementia specialists and neurosurgeons. The role of dementia specialists is to differentiate patients with iNPH from patients with other dementia diseases and to determine if other dementia diseases are comorbid with iNPH. We conducted a nationwide hospital-based questionnaire survey on iNPH in medical centers for dementia (MCDs).MethodsWe developed a questionnaire to assess how physicians in MCDs evaluate and treat patients with cognitive impairment due to suspected iNPH and the difficulties these physicians experience in the evaluation and treatment of patients. The questionnaire was sent to all 456 MCDs in Japan.ResultsQuestionnaires from 279 MCDs were returned to us (response rate: 61.2%). Patients underwent cognitive tests, evaluation of the triad symptoms of iNPH, and morphological neuroimaging examinations in 96.8, 77.8, and 98.2% of the MCDs, respectively. Patients with suspected iNPH were referred to other hospitals (e.g., hospitals with neurosurgery departments) from 78.9% of MCDs, and cerebrospinal fluid (CSF) tap test was performed in 44 MCDs (15.8%). iNPH guidelines (iNPHGLs) and disproportionately enlarged subarachnoid space hydrocephalus (DESH), a specific morphological finding, were used and known in 39.4% and 38% of MCDs, respectively. Logistic regression analysis with “Refer the patient to other hospitals (e.g., hospitals with neurosurgery departments) when iNPH is suspected.” as the response variable and (a) using the iNPHGLs, (b) knowledge of DESH, (c) confidence regarding DESH, (d) difficulty with performing brain magnetic resonance imaging, (e) knowledge of the methods of CSF tap test, (f) absence of physician who can perform lumbar puncture, and (g) experience of being told by neurosurgeons that referred patients are not indicated for shunt surgery as explanatory variables revealed that the last two factors were significant predictors of patient referral from MCDs to other hospitals.ConclusionSufficient differential or comorbid diagnosis using CSF tap test was performed in a few MCDs. Medical care for patients with iNPH in MCDs may be improved by having dementia specialists perform CSF tap tests and share the eligibility criteria for shunt surgery with neurosurgeons.

Value of MRI-based semi-quantitative structural neuroimaging in predicting the prognosis of patients with idiopathic normal pressure hydrocephalus after shunt surgery

ObjectivesTo explore the value of structural neuroimaging in predicting the prognosis of shunt surgery for idiopathic normal-pressure hydrocephalus (iNPH) using two different standard semi-quantitative imaging scales.MethodsA total of 47 patients with iNPH who underwent shunt surgery at our hospital between 2018 and 2020 were included in this study. The modified Rankin Scale (mRS) and iNPH grading scale (iNPHGS) were used to evaluate and quantify the clinical symptoms before and after shunt surgery. The disproportionately enlarged subarachnoid space hydrocephalus (DESH) and iNPH Radscale scores were used to evaluate the preoperative MR images. The primary endpoint was improvement in the mRS score a year after surgery, and the secondary endpoint was the iNPHGS after 1 year. The preoperative imaging features of the improved and non-improved groups were compared.ResultsThe rates of the primary and secondary outcomes were 59.6% and 61.7%, respectively, 1 year after surgery. There were no significant differences in preoperative DESH score, iNPH Radscale, Evans’ index (EI), or callosal angle (CA) between the improved and non-improved groups. Significant correlations were observed between the severity of gait disorder and EI and the CA.ConclusionsThe value of structural neuroimaging in predicting the prognosis of shunt surgery is limited, and screening for shunt surgery candidates should not rely only on preoperative imaging findings.Key Points• Early shunt surgery can significantly improve the clinical symptoms and prognosis of patients with idiopathic normal-pressure hydrocephalus (iNPH).• Structural imaging findings have limited predictiveness for the prognosis of patients with iNPH after shunt surgery.• Patients should not be selected for shunt surgery based on only structural imaging findings.

Idiopathic normal pressure hydrocephalus-like MRI features in patients with progressive supranuclear palsy: a comparative case-control study

ABSTRACT Background The occurrence of neurodegenerative disease in patients with normal pressure hydrocephalus (NPH) is emphasized in recent reports. Based on this common co-occurrence, some of the hydrocephalic disorders appearing in late adulthood have been hypothesized to result from initially unapparent parenchymal abnormalities of neurodegenerative origin. Among these diseases, progressive supranuclear palsy (PSP) has been specifically remarked on. We aimed to comparatively investigate the neuroimaging clues of iNPH in our PSP subjects. Methods Eighteen patients with a clinical diagnosis of PSP, 44 with Parkinson’s disease (PD), and 44 healthy control (HC) individuals were enrolled. The disproportionately enlarged subarachnoid space hydrocephalus (DESH) score, the Evans’ index (EI), and the callosal angle (CA) were measured on the conventional magnetic resonance imaging (MRI). The comparative analyses were performed using IBM SPSS Statistics 26. Results We found that dilated Sylvian fissures score (p = 0.016) and focal sulcal dilatation score (p = 0.037) were higher in the PSP group in comparison to HC whereas the CA score was higher in PSP subjects in comparison to both PD patients and HC (p = 0.000). Remarkably, the DESH score was also found to be higher in the PSP group in comparison to the age-matched HC group (p = 0.024). Conclusions We found that the NPH-like MRI features were more common in PSP subjects in comparison to PD subjects and age-matched HC. These results may provide critical contributions to the literature regarding the overlap between PSP and NPH.