The Quest for Predicting Sustained Shunt Response in Normal-Pressure Hydrocephalus: An Analysis of the Callosal Angle's Utility

Efficacy and safety of shunt surgery in patients with idiopathic normal-pressure hydrocephalus: can we predict shunt response by preoperative magnetic resonance imaging (MRI)?

AIM

The aim of this study was to identify preoperative magnetic resonance imaging (MRI) findings that can predict the shunt responsiveness in idiopathic normal-pressure hydrocephalus (iNPH) patients and to investigate postoperative outcome and complications.

MATERIALS AND METHODS

A total of 192 patients with iNPH who underwent shunt at our hospital between 2000 and 2021 were included to investigate complications. Of these, after exclusion, 127 (1-month postoperative follow-up) and 77 (1-year postoperative follow-up) patients were evaluated. The preoperative MRI features (the presence of tightness of the high-convexity subarachnoid space, Sylvian fissure enlargement, Evans' index, and callosal angle) of the shunt-response and nonresponse groups were compared, and a systematic review was conducted to evaluate whether preoperative MRI findings could predict shunt response.

RESULTS

Postoperative complications within one month after surgery were observed in 6.8% (13/192), and the most common complication was hemorrhage. Changes in corpus callosum were observed in 4.2% (8/192). The shunt-response rates were 83.5% (106/127) in the 1-month follow-up group and 70.1% (54/77) in 1-year follow-up group. In the logistic regression analysis, only Evans' index measuring >0.4 had a significant negative relationship with shunt response at 1-month follow-up; however, no significant relationship was observed at 1-year follow-up. According to our systematic review, it is still controversial whether preoperative MRI findings could predict shunt response.

CONCLUSION

Evans' index measure of >0.4 had a significant relationship with the shunt response in the 1-month follow-up group. In systematic reviews, there is ongoing debate about whether preoperative MRI findings can accurately predict responses to shunt surgery. Postoperative corpus callosal change was observed in 4.2% of iNPH patients.

Correlating Evans Index, Callosal Angle, and Lateral Ventricle Volume With Gait Response Outcomes in Idiopathic Normal Pressure Hydrocephalus Diagnosis

OBJECTIVE

Radiological imaging is pivotal in diagnosing idiopathic normal pressure hydrocephalus (iNPH), given the similarity of its symptoms to other neurodegenerative diseases. We aimed to correlate the Evans index (EI), callosal angle (CA), and the volume of the lateral ventricles measured before cerebrospinal fluid removal with the resultant outcomes in gait response.

METHODS

In our retrospective study, we identified 42 patients with a diagnosis of iNPH. These patients underwent gait analysis, imaging, and lumbar puncture. Radiological assessments included measurements of CA EI and lateral ventricular volume. Clinically, we assessed the following 4 gait parameters: cadence, gait speed, stride length, and timed up and go. Change in the 4 gait parameters was calculated, normalized, and compiled into a composite score, following which the group was divided into 'responders' and 'nonresponders' based on z score of 0.5. Our dependent variable was clinical improvement in gait, and our independent variables included lateral ventricular volume, EI, and CA. We performed a Wilcoxon rank-sum test to compare significant responder status using CA, EI, and lateral ventricle volume. A receiver operating characteristic analysis was employed to determine which volume measurement exhibited the strongest correlation with responder status. Determining the significant variables, a chi-square analysis was subsequently conducted.A significance threshold was set at P < 0.05. All our statistical evaluations were conducted in the Spyder environment, which is compatible with Python 3.10.

RESULTS

There was a significant difference for responder status in EI and lateral ventricle volume. Evan index showing a statistic of 2.202 (P value = 0.02) and lateral ventricle volume demonstrating a statistic of 2.086 (P value = 0.03). Subsequent exploration using receiver operating characteristic analysis, with area under the curve of 0.71, identified 105.40 cm3 as the most robustly correlated volume threshold with responder status.

CONCLUSIONS

The lateral ventricular volume demonstrates a stronger correlation with gait improvement compared to the CA or EI. These observations indicate that evaluating the lateral ventricle volume before lumbar puncture could serve as a predictor for gait response after lumbar puncture in individuals with normal pressure hydrocephalus.

Risk estimation for idiopathic normal-pressure hydrocephalus: development and validation of a brain morphometry-based nomogram

OBJECTIVES

To develop and validate a nomogram based on MRI features for predicting iNPH.

METHODS

Patients aged  ≥ 60 years (clinically diagnosed with iNPH, Parkinson's disease, or Alzheimer's disease or healthy controls) who underwent MRI including three-dimensional T1-weighted volumetric MRI were retrospectively identified from two tertiary referral hospitals (one hospital for derivation set and the other for validation set). Clinical and imaging features for iNPH were assessed. Deep learning-based brain segmentation software was used for 3D volumetry. A prediction model was developed using logistic regression and transformed into a nomogram. The performance of the nomogram was assessed with respect to discrimination and calibration abilities. The nomogram was internally and externally validated.

RESULTS

A total of 452 patients (mean age ± SD, 73.2 ± 6.5 years; 200 men) were evaluated as the derivation set. One hundred eleven and 341 patients were categorized into the iNPH and non-iNPH groups, respectively. In multivariable analysis, high-convexity tightness (odds ratio [OR], 35.1; 95% CI: 4.5, 275.5), callosal angle  < 90° (OR, 12.5; 95% CI: 3.1, 50.0), and normalized lateral ventricle volume (OR, 4.2; 95% CI: 2.7, 6.7) were associated with iNPH. The nomogram combining these three variables showed an area under the curve of 0.995 (95% CI: 0.991, 0.999) in the study sample, 0.994 (95% CI: 0.990, 0.998) in the internal validation sample, and 0.969 (95% CI: 0.940, 0.997) in the external validation sample.

CONCLUSION

A brain morphometry-based nomogram including high-convexity tightness, callosal angle  < 90°, and normalized lateral ventricle volume can help accurately estimate the probability of iNPH.

KEY POINTS

• The nomogram with MRI findings (high-convexity tightness, callosal angle, and normalized lateral ventricle volume) helped in predicting the probability of idiopathic normal-pressure hydrocephalus. • The nomogram may facilitate the prediction of idiopathic normal-pressure hydrocephalus and consequently avoid unnecessary invasive procedures such as the cerebrospinal fluid tap test, drainage test, and cerebrospinal fluid shunt surgery.

SV, Borchert R, Russo S, Eide PK. Radiological predictors of shunt response in the diagnosis and treatment of idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis

BACKGROUND

Patients with the dementia subtype idiopathic normal pressure hydrocephalus (iNPH) may improve clinically following cerebrospinal fluid (CSF) diversion (shunt) surgery, though the predictors of shunt response remain debated. Currently, radiological features play an important role in the diagnosis of iNPH, but it is not well established which radiological markers most precisely predict shunt responsive iNPH.

OBJECTIVE

To conduct a systematic review and meta-analysis to identify radiological predictors of shunt responsiveness, evaluate their diagnostic effectiveness, and recommend the most predictive radiological features.

METHODS

Embase, MEDLINE, Scopus, PubMed, Google Scholar, and JSTOR were searched for original studies investigating radiological predictors of shunt response in iNPH patients. Included studies were assessed using the ROBINS-1 tool, and eligible studies were evaluated using a univariate meta-analysis.

RESULTS

Overall, 301 full-text papers were screened, of which 28 studies were included, and 26 different radiological features were identified, 5 of these met the inclusion criteria for the meta-analysis: disproportionately enlarged subarachnoid space (DESH), callosal angle, periventricular white matter changes, cerebral blood flow (CBF), and computerized tomography cisternography. The meta-analysis showed that only callosal angle and periventricular white matter changes significantly differentiated iNPH shunt responders from non-responders, though both markers had a low diagnostic odds ratio (DOR) of 1.88 and 1.01 respectively. None of the other radiological markers differentiated shunt responsive from shunt non-responsive iNPH.

CONCLUSION

Callosal angle and periventricular changes are the only diagnostically effective radiological predictors of shunt responsive iNPH patients. However, due to the DORs approximating 1, they are insufficient as sole predictors and are advised to be used only in combination with other diagnostic tests of shunt response. Future research must evaluate the combined use of multiple radiological predictors, as it may yield beneficial additive effects that may allow for more robust radiological shunt response prediction.

Can Shunt Response in Patients with Idiopathic Normal Pressure Hydrocephalus Be Predicted from Preoperative Brain Imaging? A Retrospective Study of the Diagnostic Use of the Normal Pressure Hydrocephalus Radscale in 119 Patients

BACKGROUND AND PURPOSE

The Normal Pressure Hydrocephalus Radscale is a combined scoring of 7 different structural imaging markers on preoperative brain CT or MR imaging in patients with idiopathic normal pressure hydrocephalus: callosal angle, Evans Index, Sylvian fissure dilation, apical sulcal narrowing, mean temporal horn diameter, periventricular WM lesions, and focal sulcal dilation. The purpose of this retrospective study was to assess the performance of the Normal Pressure Hydrocephalus Radscale in distinguishing idiopathic normal pressure hydrocephalus shunt responders from nonresponders.

MATERIALS AND METHODS

The preoperative MR imaging and CT scans of 119 patients with idiopathic normal pressure hydrocephalus were scored using the Normal Pressure Hydrocephalus Radscale. A summary shunt-response score assessed within 6 months from ventriculoperitoneal shunt surgery, combining the effect on cognition, gait, and urinary incontinence, was used as a reference. The difference between the mean Normal Pressure Hydrocephalus Radscale for responders and nonresponders was tested using the Student t test. The area under the curve was calculated for the Normal Pressure Hydrocephalus Radscale to assess shunt response. To ascertain reproducibility, we assessed the interobserver agreement between the 2 independent observers as intraclass correlation coefficients for the Normal Pressure Hydrocephalus Radscale for 74 MR imaging scans and 19 CT scans.

RESULTS

Ninety-four (79%) of 119 patients were shunt responders. The mean Normal Pressure Hydrocephalus Radscale score for shunt responders was 8.35 (SD, 1.53), and for nonresponders, 7.48 (SD, 1.53) (P = .02). The area under the curve for the Normal Pressure Hydrocephalus Radscale was 0.66 (range, 0.54-0.78). The intraclass correlation coefficient for the Normal Pressure Hydrocephalus Radscale was 0.86 for MR imaging and 0.82 for CT.

CONCLUSIONS

The Normal Pressure Hydrocephalus Radscale showed moderate discrimination for shunt response but cannot, on its own, be used for selecting patients with idiopathic normal pressure hydrocephalus for shunt surgery.

Outcomes of Ventriculoperitoneal Shunt in Patients With Idiopathic Normal-Pressure Hydrocephalus 2 Years After Surgery

Objective: To evaluate the outcomes and prognostic factors of ventriculoperitoneal shunts (VP-shunts) in patients with idiopathic normal-pressure hydrocephalus (iNPH) at 6 months and 2 years after surgery.

Method: We retrospectively analyzed 68 patients admitted to our institute and diagnosed with probable iNPH from January 2017 to March 2021. All patients underwent VP-shunt surgery with a programmable valve, and their outcomes were assessed via the Krauss index and modified Rankin scale (mRS) at 6 months and 2 years post-surgery. Univariate and multivariate regression analysis was performed to identify the prognostic factors.

Results: The mean age of the patients was 71.1 ± 8.4 (mean ± standard deviation) years. On the Krauss improvement index, 6-month follow-up results were available for 68 patients. Of these patients, 91.2% experienced attenuation of their preoperative symptoms, with a mean Krauss index of 0.58 ± 0.27, and 48 patients (70.6%) had a Krauss index ≥0.5. Two-year follow-up results were available for 33 patients; 90.9% of them had sustained improvement, with a Krauss index of 0.54 ± 0.31, and 21 patients (66.3%) had a Krauss index ≥0.5. Thirty-three patients (58%) were living independently after 2 years (mRS 0–2). The outcomes were worse for patients with multiple comorbidities. Neither an increased patient age nor a prolonged history of illness was statistically significant prognostic factors for adverse outcomes of VP-shunt surgery.

Conclusion: Surgical treatment was well-tolerated by patients with iNPH who received VP-shunts. Most patients experienced attenuation of their preoperative symptoms. Multiple concurrent comorbidities should be considered as adverse prognostic factors before shunt insertion in patients with iNPH.

Long term follow-up of shunted idiopathic normal pressure hydrocephalus patients: a single center experience

Idiopathic normal pressure hydrocephalus (iNPH) is a condition characterized by gait disturbance, dementia and/or urinary incontinence and enlarged ventricular system due to disturbance of cerebrospinal fluid (CSF). This study aims to describe the long-term experience with patients with iNPH submitted to ventriculoperitoneal shunt (VPS) with the programmable valve STRATA® (Medtronic). We prospectively selected a cohort of patients with a diagnosis of iNPH from January 2010 to April 2013 in a Brazilian tertiary hospital. All patients underwent clinical evaluation, which consists of the Mini-Mental State Examination and Time Up and Go tests and the application of Japanese Scale for Idiopathic Normal Pressure Hydrocephalus in three stages: prior to the TT, 3 h after the TT and 72 h after the TT. Fifty patients were submitted to VPS and followed. There were 32 men and 18 women. Mean age was 77.1 with standard deviation of 10.9. Follow-up time ranged from 96 to 120 months, with mean of 106 months. After 1 year of follow-up, 42 (83%) patients presented with clinical improvement, decreasing to 62% of patients at mid-term follow-up and 38% of patients at late follow-up. Complications occurred in 18% of subjects, needing reoperation in 16%. Our results show relevant clinical impact of shunting in iNPH patients, decreasing over time. Complications should not be underestimated, reaching up to 18% and demanding reoperation in 16% of cases. Thus, although much has been improved with current shunt technology, it is still important to consider the drawbacks of treatment.

Quantitative imaging features predict spinal tap response in normal pressure hydrocephalus

PURPOSE

Gait improvement following high-volume lumbar puncture (HVLP) and continuous lumbar drain (cLD) is widely used to predict shunt response in patients with suspected normal pressure hydrocephalus (NPH). Here, we investigate differences in MRI volumetric and traditional measures between HVLP/cLD responders and non-responders to identify imaging features that may help predict HVLP/cLD response.

METHODS

Eighty-two patients with suspected NPH were studied retrospectively. Gait testing was performed before and immediately/24 h/72 h after HVLP/cLD. A positive response was defined as improvement in gait post-procedure. Thirty-six responders (26 men; mean age 79.3 ± 6.3) and 46 non-responders (25 men; mean age 77.2 ± 6.1) underwent pre-procedure brain MRI including a 3D T1-weighted sequence. Subcortical regional volumes were segmented using FreeSurfer. After normalizing for total intracranial volume, two-way type III ANCOVA test and chi-square test were used to characterize statistical group differences. Evans' index, callosal angle (CA), and disproportionately enlarged subarachnoid space hydrocephalus were assessed. Multivariable logistic regression models were tested using Akaike information criterion to determine which combination of metrics most accurately predicts HVLP/cLD response.

RESULTS

Responders and non-responders demonstrated no differences in total ventricular and white/gray matter volumes. CA (men only) and third and fourth ventricular volumes were smaller; and hippocampal volume was larger in responders (p < 0.05). Temporal horns volume correlated with degree of improvement in gait velocity in responders (p = 0.0006). The regression model was 76.8% accurate for HVLP/cLD response.

CONCLUSION

CA and third and fourth ventricular volumes and hippocampal volume may serve as potentially useful imaging features that may help predict spinal tap response and hence potentially shunt response.

White Matter Microstructural Damage Associated With Gait Abnormalities in Idiopathic Normal Pressure Hydrocephalus

Background: Idiopathic normal pressure hydrocephalus (iNPH) is a common disease in elderly adults. Patients with iNPH are generally characterized by progressive gait impairment, cognitive deficits, and urinary urgency and/or incontinence. A number of radiographic studies have shown that iNPH patients have enlarged ventricles and altered brain morphology; however, few studies have focused on the relationships between altered brain structure and gait dysfunction due to iNPH. Thus, this study aimed to evaluate the abnormalities of white matter (WM) correlated with gait impairment in iNPH patients and to gain a better understanding of its underlying pathology. Methods: Fifteen iNPH patients (five women, 10 men) were enrolled in this study, and each patient's demographic and gait indices were collected. First, we performed a correlation analysis between the demographic and gait indices. Then, all gait indices were grouped according to the number of WM hyperintensities (WMH) among each WM tract (JHU WM tractography atlas), to perform comparative analysis. Results: Considering sex and illness duration as covariates, correlation analysis showed a significantly negative correlation between step length (r = -0.80, p = 0.001), pace (r = -0.84, p = 2.96e-4), and age. After removing the effects of age, sex, and illness duration, correlation analysis showed negative correlation between step length (r = -0.73, p = 0.007), pace (r = -0.74, p = 0.005), and clinical-grade score and positive correlation between 3-m round trip time (r = 0.66, p = 0.021), rising time (r = 0.76, p = 0.004), and clinical-grade score. Based on WMH of each white matter tract, gait indices showed significant differences (p < 0.05/48, corrected by Bonferroni) between fewer WMH patients and more WMH in the middle cerebellar peduncle, left medial lemniscus, left posterior limb of the internal capsule (IC), and right posterior limb of the IC. Conclusions: Our results indicated that iNPH patients exhibited gait-related WM abnormalities located in motor and sensory pathways around the ventricle, which is beneficial to understand the underlying pathology of iNPH.

Prognostic Utility of Disproportionately Enlarged Subarachnoid Space Hydrocephalus in Idiopathic Normal Pressure Hydrocephalus Treated with Ventriculoperitoneal Shunt Surgery: A Systematic Review and Meta-analysis

BACKGROUND

Disproportionately enlarged subarachnoid space hydrocephalus is a specific radiologic marker for idiopathic normal pressure hydrocephalus. However, controversy exists regarding the prognostic utility of disproportionately enlarged subarachnoid space hydrocephalus.

PURPOSE

Our aim was to evaluate the prevalence of disproportionately enlarged subarachnoid space hydrocephalus in idiopathic normal pressure hydrocephalus and its predictive utility regarding prognosis in patients treated with ventriculoperitoneal shunt surgery.

DATA SOURCES

We used MEDLINE and EMBASE databases.

STUDY SELECTION

We searched for studies that reported the prevalence or the diagnostic performance of disproportionately enlarged subarachnoid space hydrocephalus in predicting treatment response.

DATA ANALYSIS

The pooled prevalence of disproportionately enlarged subarachnoid space hydrocephalus was obtained. Pooled sensitivity, specificity, and area under the curve of disproportionately enlarged subarachnoid space hydrocephalus to predict treatment response were obtained. Subgroup and sensitivity analyses were performed to explain heterogeneity among the studies.

DATA SYNTHESIS

Ten articles with 812 patients were included. The pooled prevalence of disproportionately enlarged subarachnoid space hydrocephalus in idiopathic normal pressure hydrocephalus was 44% (95% CI, 34%-54%). The pooled prevalence of disproportionately enlarged subarachnoid space hydrocephalus was higher in the studies using the second edition of the Japanese Guidelines for Management of Idiopathic Normal Pressure Hydrocephalus compared with the studies using the international guidelines without statistical significance (52% versus 43%, P = .38). The pooled sensitivity and specificity of disproportionately enlarged subarachnoid space hydrocephalus for prediction of treatment response were 59% (95% CI, 38%-77%) and 66% (95% CI, 57%-74%), respectively, with an area under the curve of 0.67 (95% CI, 0.63-0.71).

LIMITATIONS

The lack of an established method for assessing disproportionately enlarged subarachnoid space hydrocephalus using brain MR imaging served as an important cause of the heterogeneity.

CONCLUSIONS

Our meta-analysis demonstrated a relatively low prevalence of disproportionately enlarged subarachnoid space hydrocephalus in idiopathic normal pressure hydrocephalus and a poor diagnostic performance for treatment response.

The Utility of Imaging Parameters in Predicting Long-Term Clinical Improvement After Shunt Surgery in Patients with Idiopathic Normal Pressure Hydrocephalus

OBJECTIVE

It is difficult to predict which patients with idiopathic normal pressure hydrocephalus (iNPH) will improve after shunt surgery. This study investigated the association between preoperative imaging parameters in patients with iNPH and long-term outcome after shunt placement.

METHODS

Patients with iNPH who showed a response to large-volume cerebrospinal fluid drainage and subsequently underwent ventriculoperitoneal shunt surgery were reviewed. Long-term patient-reported outcomes were obtained by telephone interview. Preoperative computed tomography and/or magnetic resonance imaging were retrospectively reviewed to determine associations between imaging parameters and clinical outcome.

RESULTS

The final analysis included 37 patients. The median duration between shunt surgery and telephone interview was 30 months (range, 12-56 months). Gait improvement after shunting was present more often in patients without focally dilated sulci (95% vs. 71%, P = 0.04), but a statistically significant relationship was not established after logistic regression. Patients with cognitive improvement after shunting had a higher preoperative Evans index (mean 0.41 vs. 0.36, P < 0.01), and Evans index was a predictor of cognitive improvement (odds ratio = 1.40, scale of 0.01, P = 0.01).

CONCLUSIONS

Higher Evans index is a predictor of long-term cognitive improvement after shunt placement; however, no cutoff value demonstrates sufficient accuracy for the selection of shunt candidates. None of the evaluated imaging features was predictive of long-term gait or urinary improvement. The utility of imaging to predict a response to shunting is limited, and no imaging feature alone can be used to exclude patients from shunt surgery.

Anterior callosal angle correlates with gait impairment and fall risk in iNPH patients

BACKGROUND

In idiopathic normal pressure hydrocephalus (iNPH), gait and balance impairment is the most frequent symptom, and it is often associated with a higher fall risk. In a prior study, the anterior callosal angle (ACA) was validated as a reliable marker to discriminate iNPH from Alzheimer's disease and healthy controls. However, the potential correlation between the ACA with clinical symptoms and functional outcomes has not been assessed. The objective of this study is to determine the utility of the ACA in predicting gait improvement after ventriculoperitoneal (VP) shunting.

METHODS

Patients with probable iNPH who underwent shunt placement at a single institution were prospectively enrolled from May 2015 to May 2019. Patients were assessed preoperatively and at 6 months postoperatively following a standard clinical and MRI protocol. Callosal angle (CA) and ACA were calculated from 3 T MRI preoperatively and at 6 months postoperatively. CA and ACA were tested for correlation with clinical scores.

RESULTS

Forty-seven patients with probable INPH who completed 6-month postoperative follow-up were enrolled in the study. Baseline ACA was significantly correlated with preoperative fall risk, gait, and balance impairment assessed with Tinetti POMA scale. Additionally, baseline ACA differentiated patients who experienced improvement at Tinetti POMA scale after surgery.

CONCLUSIONS

The baseline ACA is a useful neuroradiological marker to differentiate patients by fall risk and has significant correlation with the improvement in gait and balance impairment following surgery. This study demonstrated that the ACA may be a complementary tool to the CA in predicting shunt responsiveness in iNPH.

Callosal angle in idiopathic normal pressure hydrocephalus: small angular mal-rotations of the coronal plane affect measurement reliability

PURPOSE

The callosal angle (CA) is a useful biomarker in the diagnosis and management of idiopathic normal pressure hydrocephalus (NPH). Used incorrectly, CA measurements are variable, affecting its reliability as a clinical tool. Our objectives are to evaluate (i) reproducibility of established CA measurements between trained raters and (ii) impact of minor angular mal-rotations of the true coronal plane on CA measurements.

METHODS

CAs were measured by two independent raters on three-dimensional isovolumetric T1-weighted brain MRI of NPH patients and healthy controls using the established true coronal plane reformatted orthogonal to the plane containing the anterior-posterior commissural (AC-PC) line at the level of the posterior commissure. CA changes were subsequently evaluated when the coronal plane was mal-rotated by ± 5° and ± 10° in anterior-posterior and clockwise-anticlockwise directions. Inter-rater reliability of CA measurements was assessed using the intraclass correlation coefficient (ICC).

RESULTS

On the true coronal plane, inter-rater ICC was excellent (0.973) for NPH patients and good (0.875) for controls. On mal-rotated coronal plane setups, ICC for CA was worse in controls (0.484-0.886) than NPH (0.879-0.981) groups and in clockwise-anticlockwise (0.484-0.956) than anterior-posterior (0.503-0.981) mal-rotations. CA changes secondary to mal-rotations from the true coronal plane were significant in NPH patients (P < 0.0001 to 0.0378) but not in controls (P > 0.1).

CONCLUSION

This is the first demonstration of how small angular mal-rotations of the coronal plane used for CA measurement affect its value and inter-rater reliability, highlighting the importance of a standardized protocol when measuring the CA in NPH workup.

Prevalence of possible idiopathic normal pressure hydrocephalus in older inpatients with schizophrenia: a replication study

BACKGROUND

We recently reported that older patients with schizophrenia (SZ) show possible idiopathic normal pressure hydrocephalus (iNPH) more frequently than the general population. In this study, we estimated the prevalence of iNPH in a larger number of older SZ patients and explored useful examination values for diagnosis in the SZ population.

METHODS

We enrolled older inpatients with SZ (n = 39, mean age = 68.6 ± 7.7 years) from several psychiatric hospitals in Ehime, Japan and acquired brain imaging data using computed tomography. We evaluated three iNPH symptoms (dementia, gait disturbance, and urinary incontinence). In addition, we combined these data with our previous data to elucidate the relationship between iNPH and characteristics of SZ symptoms.

RESULTS

In total, five (12.8%) patients were diagnosed with possible iNPH. Evans' index for patients with iNPH was significantly higher than for those without iNPH (p = 0.002). The number of disproportionately enlarged subarachnoid space hydrocephalus (DESH) findings was significantly higher in patients with iNPH than in those without iNPH (p <  0.001). Using combined data, Drug-Induced Extra-pyramidal Symptoms Scale (DIEPSS) subscales of gait and bradykinesia showed an increasing trend in the SZ with iNPH group.

CONCLUSIONS

We reconfirmed that older inpatients with SZ experienced possible iNPH more frequently than the general population. We should pay attention to the DIEPSS subscales of gait and bradykinesia and DESH findings in addition to the three main symptoms of iNPH and Evans' index so as to not miss SZ patients with iNPH.

Anterior Callosal Angle: A New Marker of Idiopathic Normal Pressure Hydrocephalus?

OBJECTIVE

Diagnosing idiopathic normal pressure hydrocephalus (iNPH) still remains a clinical challenge. The callosal angle (CA) is a widely used neuroradiologic marker for iNPH. However, the relationship of the CA to clinical features has not been well investigated. We hypothesize that iNPH symptoms might better correlate with a variant of the CA (anterior callosal angle [ACA]). We aim to establish the validity of the ACA measurement for the diagnosis of iNPH and compare it with current radiologic parameters.

METHODS

The multidisciplinary BOLOGNA PRO-HYDRO Study Group performed a retrospective review of consecutive iNPH patients. Magnetic resonance imaging studies for these patients were collected, as well as magnetic resonance imaging studies from Alzheimer disease and healthy control patients. The CA, ACA, and Evans Index were measured by 2 blinded members of the study team based on magnetic resonance images for each of these populations.

RESULTS

The ACA shows high accuracy, sensitivity, and specificity in distinguishing iNPH patients from healthy control and Alzheimer disease patients. The optimal pathologic diagnostic cut-off value for the ACA is 119 degrees. The diagnostic accuracy of the ACA is not significantly different from the CA.

CONCLUSIONS

The ACA could be a valid radiologic parameter in the diagnostic armamentarium for iNPH.

Clinical performance of fixed-pressure Sphera Duo® hydrocephalus shunt

INTRODUCTION

Cerebral hydrodynamics complications in shunted patients are due to the malfunction of the system. The objective of this retrospective, single-center, single-arm cohort study is to confirm the safety and performance of Sphera® Duo when used in adult patients suffering from hydrocephalus, pseudotumor cerebri or arachnoid cysts.

METHODS

Data were generated by reviewing 112 adult patient's charts, who were submitted to a ventriculoperitoneal shunt surgery and followed for one year after surgery.

RESULTS

The results show us that 76% of patients had their neurological symptoms improved and that the reoperation rate was 15% in the first year following surgery.

DISCUSSION

Sphera Duo® shunt system is an applicable shunt option in routine neurosurgical management of hydrocephalus by several causes. It has presented good results while mitigating effects of overdrainage. Overdrainage is especially important in adults with non-hypertensive hydrocephalus and can cause functional shunt failure, which causes subnormal ICP (particularly in the upright position) and is associated with characteristic neurological symptoms, such as postural headache and nausea.

CONCLUSION

Sphera Duo® shunt system is safe when used in adult patients suffering from hydrocephalus, pseudotumor cerebri or arachnoid cyst.

Current Updates on Idiopathic Normal Pressure Hydrocephalus

Idiopathic normal pressure hydrocephalus (iNPH) is one of the neurodegenerative diseases which can be treated surgically with favorable outcome. The gait disturbance, cognitive, and urinary symptoms are known as the clinical triad of iNPH. In this review, we have addressed the comorbidities, differential diagnoses, clinical presentations, and pathology of iNPH. We have also summarized the imaging studies and clinical procedures used for the diagnosis of iNPH. The treatment modality, outcomes, and prognosis were also discussed.