Diagnosis Of Idiopathic Normal Pressure Hydrocephalus Research Articles

Olfactory bulb volume in patients with normal-pressure hydrocephalus: an MRI evaluation

To investigate changes in olfactory bulb (OB) volume in patients with idiopathic normal-pressure hydrocephalus (NPH). This multicentric retrospective study included a test group of 23 patients with NPH (10 male and 13 female patients) and a control group of 27 healthy participants without hydrocephalus. The OB volume in all participants had been measured using cranial magnetic resonance imaging (MRI). In the NPH group, positivity for disproportionately enlarged subarachnoid space hydrocephalus (DESH) was also evaluated. The OB volumes of the NPH group (R 38.29±9.34 mm3 and L37.52±9.59 mm3) were significantly lower than those of the control group (R 45.87±7.33 mm3 and L48.41±7.62 mm3) bilaterally. There were no significant differences between right and left OB volumes in the NPH group. Nine of the 23 patients were DESH positive and 14 were DESH negative. There were no significant differences between OB volumes of the DESH positive and DESH vpatients in the NPH group. In both groups, there was a positive correlation between right and left OB volumes. There were no significant correlations between OB volumes and age or gender. In the NPH group, there were no significant correlations between DESH positivity and OB volumes. OB volume decrease and olfactory problems should be taken into account in idiopathic NPH patients. When expanded ventricles and decreased OB volume are observed at cranial MRI, a diagnosis of idiopathic NPH should be considered.

Reliability and Interobserver Variability of Evans' Index and Disproportionately Enlarged Subarachnoid Space Hydrocephalus as Diagnostic Criteria for Idiopathic Normal Pressure Hydrocephalus.

Background:The image diagnosis of idiopathic normal-pressure hydrocephalus (iNPH) is based on the ventriculomegaly, whose criterion is an Evans' Index (EI) >0.3. Recently, disproportionately enlarged subarachnoid space hydrocephalus (DESH) has been proposed as a morphological characteristic to iNPH. Several studies cast doubt on the reliability of these criteria in the diagnosis of iNPH. Furthermore, interobserver differences of these criteria have not yet been investigated. The objective of this study was to assess the diagnostic reliability and interobserver variability of EI and DESH.Materials and Methods:The preoperative magnetic resonance (MR) images of 84 definite iNPH patients were retrospectively evaluated by a neuroradiologist (NR) and physical therapist (PT). They independently assessed the EI and DESH. The MR images were evaluated preoperatively by a neurosurgeon (NS). The results were showed in mean (standard deviation).Results:The mean age was 78.4 (6.3) years (male:female = 49:35). The mean EI was 0.33 (0.04), 0.32 (0.04), and 0.31 (0.03) for NS, NR, and PT, respectively (P < 0.0001). The rate of accurate diagnosis of iNPH with EI >0.3 was 74%, 66%, and 61% for NS, NR, and PT, respectively, and there was a moderate level of agreement. By contrast, there was a substantial lower level of accuracy in assessment with DESH for all three evaluators as 50%, 44%, and 27% for NS, NR, and PT, respectively, again with a moderate level of agreement. However, the rates of patients fulfilling both EI >0.3 and DESH were remarkably lower than either of the two parameters individually at a mere 37%, 30%, and 16% for NS, NR, and PT, respectively, with a low level of agreement between the rates.Conclusion:This study suggests that DESH cannot be a diagnostic criterion for iNPH. If EI >0.3 and DESH were both necessary to diagnose iNPH, then more than 70% of patients would have been misdiagnosed and would have been deprived of the chance of treatment and its benefits. These results request a paradigm shift in the concepts of iNPH.

The benefit of delayed reassessment post high-volume CSF removal in the diagnosis of shunt-responsive idiopathic normal-pressure hydrocephalus

The principle aim of the study was to demonstrate the value of performing delayed reassessment in the diagnosis of idiopathic normal-pressure hydrocephalus (iNPH) and selection of suitable candidates for ventriculoperitoneal shunting (VPS).Thirty-one consecutive patients underwent the NPH protocol at the Flinders Medical Centre between March 2017 and November 2018. The protocol involved mobility and cognitive testing with reassessment post high-volume cerebrospinal fluid (CSF) removal at 24 h and 48 h. The Assessment of Quality of Life 6D (AQoL-6D) questionnaire and International Consultation on Incontinence Questionnaire – Urinary Incontinence Short Form (ICIQ-UI SF) were completed and repeated again at 6 weeks and 6 months post shunting. Results were analysed to determine the significance of delayed reassessment.Twenty patients (64.5%) underwent insertion of a VPS on the basis of objective improvements and specific criteria. Of these, 6 patients (30%) were shunted based on delayed reassessment at 48 h post CSF removal. Continued improvements were seen for all mobility and cognitive tests from baseline to 48 h post CSF removal. At 6 weeks and 6 months post shunting, there was an overall mean improvement in AQoL-6D and ICIQ-UI SF for the cohort and the improvement was also observed in the subgroup of patients who met shunt criteria at 48 h post CSF removal.In the diagnosis of shunt-responsive idiopathic normal-pressure hydrocephalus, delayed reassessment post CSF removal improves sensitivity and is therefore important.

Incidence, diagnostic criteria and outcome following ventriculoperitoneal shunting of idiopathic normal pressure hydrocephalus in a memory clinic population: a prospective observational cross-sectional and cohort study

ObjectiveTo evaluate diagnostic criteria for idiopathic normal pressure hydrocephalus (INPH) among patients with memory impairment, and to estimate the incidence of INPH.DesignProspective observational cross-section and cohort study of diagnostic accuracy.SettingMemory...

A new quantitative method to assess disproportionately enlarged subarachnoid space (DESH) in patients with possible idiopathic normal pressure hydrocephalus: The SILVER index

ObjectivesPreoperative diagnosis of idiopathic normal-pressure hydrocephalus (iNPH) remains challenging. Recently, the presence of disproportionally enlarged subarachnoid spaces and hydrocephalus (DESH) on diagnostic images has been linked to clinical improvement after ventriculoperitoneal (VP) shunt placement. In this study we describe a new quantitative method to assess DESH on CT scans and to evaluate its prognostic value. Patients and methodsA multiplanar reconstruction software was used to retrospectively evaluate prospectively collected radiological data (CT scans) of 26 controls and 29 consecutive patients that underwent VP shunt placement for possible iNPH. The ratio between the areas of the sylvian fissure and the subarachnoid space at the vertex was calculated (SILVER index). The diagnostic accuracy of the SILVER index and the estimate of the best cut-point were assessed using ROC analysis. ResultsThe mean value of the SILVER index was 11.52±14.27 in the study group and 1.68±0.98 in the control group (p-value<0.0001). The area under the ROC curve for the SILVER index was 0.903 (95% CI 0.813–0.994). A cut-off value for the SILVER index of 3.75 was extrapolated with a sensitivity and specificity of 0.828 and 0.962 respectively. ConclusionsThe SILVER index is a reliable tool to easily quantify DESH on CT scans of patients with suspected iNPH. Its high sensitivity and specificity should encourage further investigations in order to confirm its clinical utility.

Estimated ventricle size using Evans index: reference values from a population-based sample.

Evans index is an estimate of ventricular size used in the diagnosis of idiopathic normal-pressure hydrocephalus (iNPH). Values >0.3 are considered pathological and are required by guidelines for the diagnosis of iNPH. However, there are no previous epidemiological studies on Evans index, and normal values in adults are thus not precisely known. We examined a representative sample to obtain reference values and descriptive data on Evans index. A population-based sample (n = 1235) of men and women aged ≥70 years was examined. The sample comprised people living in private households and residential care, systematically selected from the Swedish population register. Neuropsychiatric examinations, including head computed tomography, were performed between 1986 and 2000. Evans index ranged from 0.11 to 0.46. The mean value in the total sample was 0.28 (SD, 0.04) and 20.6% (n = 255) had values >0.3. Among men aged ≥80 years, the mean value of Evans index was 0.3 (SD, 0.03). Individuals with dementia had a mean value of Evans index of 0.31 (SD, 0.05) and those with radiological signs of iNPH had a mean value of 0.36 (SD, 0.04). A substantial number of subjects had ventricular enlargement according to current criteria. Clinicians and researchers need to be aware of the range of values among older individuals.

MELHORA COGNITIVA DURANTE TAP TEST EM PACIENTES COM HIDROCEFALIA DE PRESSÃO NORMAL

Idiopathic normal pressure hydrocephalus (INPH) is a syndrome characterized by the classic triad of gait disturbance, potentially reversible dementia (progressive mental deterioration) and urinary incontinence. The dementia can involve executive dysfunction, memory failures and bradyphrenia. The criteria for referral for ventriculoperitoneal shunting are still controversial but include the results of a spinal tap, which is performed to simulate the effect of shunting and to analyze the impact of cerebrospinal fluid (CSF) drainage on the patient's gait. Objective: To evaluate the immediate effect of a spinal tap on the executive functions of patients with a diagnosis of probable INPH. Methods: Seventeen participants (seven men and ten women) aged 76.41+6.24 years (mean+SD) with 9.01+4.40 years (mean+SD) of schooling were selected from a group of 130 individuals tested. The neuropsychological tests of executive functions used were the Stroop test, digit span task, verbal fluency (animals and letters) (FAR) and MMSE. Patients were evaluated in three stages: before the first CSF drainage and after the first and second CSF drainages. Results: Statistical analysis showed significant differences between the pre-spinal tap and post-spinal tap results in the forward (p<0.013) and backward (p<0.037) digit span task, the animal fluency (p<0.004) and the first stage of the Stroop test (p<0.033). Significant differences were not observed in the orientation test (WMS), mental control (WMS) or MMSE. Conclusion: Of

A Review of Clinical Outcomes for Gait and Other Variables in the Surgical Treatment of Idiopathic Normal Pressure Hydrocephalus.

Idiopathic normal pressure hydrocephalus (INPH) is a treatable cause of gait disturbance, cognitive impairment, and urinary incontinence. This clinical triad of symptoms occurs in association with ventriculomegaly and normal cerebrospinal fluid (CSF) pressure. Although the treatment outcomes after CSF shunting for INPH have improved significantly since its first description in 1965, shortcomings in our understanding still remain. Not all INPH patients exhibit clinical improvement after shunting, and it is challenging to identify patients who are more likely to benefit from shunting. The Cochrane Library, Medline, Embase, and PubMed databases were searched for English-language publications between 1965 and October 2015. Reference lists of publications were also manually searched for additional publications. The findings of this review indicate that, despite efforts to improve patient selection, the degree of clinical improvement after shunting continues to demonstrate significant variability both within and between studies. These discrepancies in treatment outcomes are the result of controversies in 3 distinct but interrelated domains: the underlying pathophysiology of INPH, the diagnosis of INPH, and the identification of likely shunt-responders. This review focuses on these 3 areas and their relation to surgical treatment outcomes. Despite the limitations of published outcome studies and limitations in our understanding of INPH pathophysiology, shunting is a safe and effective means of achieving meaningful clinical improvement in most patients with INPH.

Unusual idiopathic normal pressure hydrocephalus patient with marked asymmetric and upper body parkinsonism

Asymmetry of parkinsonian symptoms is strong evidence toward the diagnosis of Parkinson's disease (PD). Lower body parkinsonism is characteristic in idiopathic normal pressure hydrocephalus (INPH). We report an unusual INPH patient with marked asymmetric and upper body parkinsonism. An 83-year-old man presented with gait impairment and asymmetric clumsiness of movement. According to the Unified Parkinson's Disease Rating Scale (UPDRS), the motor subscore was 12 in the left limb and 8 in the right. The score was 14 for both the upper and lower body. After the cerebrospinal fluid tap test (CSFTT), he showed marked improvement in the upper body score. A loss of asymmetry of parkinsonian signs, with greater improvement in the left limb, was presented. Fluorinated N-3-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)-nortropane (F-18 FP-CIT) positron emission tomography (PET) imaging was normal. In the differential diagnosis of elderly patients presenting with parkinsonism compatible with PD, we might need to consider a diagnosis of INPH.

Asymmetric and Upper Body Parkinsonism in Patients with Idiopathic Normal-Pressure Hydrocephalus

Background and PurposeOur aims were to analyze the characteristics of parkinsonian features and to characterize changes in parkinsonian motor symptoms before and after the cerebrospinal fluid tap test (CSFTT) in idiopathic normal-pressure hydrocephalus (INPH) patients.MethodsINPH subjects were selected in consecutive order from a prospectively enrolled INPH registry. Fifty-five INPH patients (37 males) having a positive response to the CSFTT constituted the final sample for analysis. The mean age was 73.7±4.7 years. The pre-tap mean Unified Parkinson's Disease Rating Scale motor (UPDRS-III) score was 24.5±10.2.ResultsThere was no significant difference between the upper and lower body UPDRS-III scores (p=0.174). The parkinsonian signs were asymmetrical in 32 of 55 patients (58.2%). At baseline, the Timed Up and Go Test and 10-meter walking test scores were positively correlated with the total motor score, global bradykinesia score, global rigidity score, upper body score, lower body score, and postural instability/gait difficulties score of UPDRS-III. After the CSFTT, the total motor score, global bradykinesia score, upper body score, and lower body score of UPDRS-III significantly improved (p<0.01). There was a significant decrease in the number of patients with asymmetric parkinsonism (p<0.05).ConclusionsIn the differential diagnosis of elderly patients presenting with asymmetric and upper body parkinsonism, we need to consider a diagnosis of INPH. The association between gait function and parkinsonism severity suggests the involvement of similar circuits producing gait and parkinsonian symptoms in INPH.

Automatic Volumetry of the Cerebrospinal Fluid Space in Idiopathic Normal Pressure Hydrocephalus

Objectives: To measure the cerebrospinal fluid (CSF) space volume in idiopathic normal pressure hydrocephalus (INPH), we developed a software that allows us to automatically measure the regional CSF space and compared the volumes of the ventricle systems (VS), Sylvian fissures (SF) and sulci at high convexity and midline (SHM) among INPH patients, Alzheimer's disease (AD) patients and healthy volunteers (HVs). Methods: Fifteen INPH patients, 15 AD patients and 15 HVs were retrospectively selected for this study. 3D-T1 MR images were obtained. We improved upon an automatic gray matter volume system to measure CSF spaces, adopting new regions for the template of INPH-characteristic CSF spaces and measured them. The VS, SF and SHM volumes were calculated relative to the intracranial volume. Results: The relative SHM volume of the INPH group (0.0237 ± 0.0064) was the smallest among the 3 groups (AD: 0.0477 ± 0.0109, HV: 0.0542 ± 0.0045). The VS (0.0499 ± 0.0135) and SF (0.0187 ± 0.0037) volumes of the INPH group were significantly larger than those of the AD (VS: 0.0311 ± 0.0075, SF: 0.0146 ± 0.0026) and HV groups (VS: 0.0167 ± 0.0065, SF: 0.0111 ± 0.017). Conclusion: Automatic volume measurement can be used to delineate the characteristic changes in CSF space in patients with INPH and is useful in the diagnosis of INPH.

Hidrocefalia crónica del adulto: diagnóstico, tratamiento y evolución. Estudio prospectivo

At present, chronic hydrocephalus or normal pressure hydrocephalus (NPH) has a controversial diagnosis in which multiple diagnostic and therapeutic techniques have been used with variable degrees of postoperative success. The aim of our study is to evaluate a number of patients diagnosed with adult chronic idiopathic hydrocephalus who were treated with a CSF shunt at our centre between 2006 and 2009 through clinical scales and radiological controls pre- and postoperatively.We prospectively analysed 40 patients. The diagnosis of idiopathic NPH was established when patients met 3 criteria: (i)clinical; (ii)radiological (Evans >0.3), and (iii)hydrodynamic (Katzman infusion test with Rout >12) or pathological ICP monitoring (B waves in over 20% of a nocturnal registration). We used a low-pressure DVP 5/35 GAV in all cases. Clinical assessments were conducted at 3, 6 and 12 months and radiological assessments at 6 months postoperatively. The clinical improvement of patients was assessed with the NPH, modified RANKIN and modified PFEIFFER rating scales.The study of risk factors (age, gender, smoking, drinking, arterial hypertension, diabetes mellitus, dyslipidemia) did not establish statistically significant relationships. A statistically significant improvement was observed (P<.01) in the NPH and RANKIN tests at 3, 6 and 12 months. Clinical improvement values obtained were: NPH 73%, 74% and 64%, and RANKIN 54%, 72% and 56%, respectively. The PFEIFFER scale only showed a significant improvement at 12 months. These improvements were classified into various levels (high, moderate, mild and no improvement). The initial mean Evans index was 0.385, and 0.3675 postoperatively. There was only one infection of the valvular system (2%) without further complications. Morbidity and mortality related to the procedure were 0%.An appropriate selection of patients through clinical, radiological, hydrodynamic and ICP monitoring criteria enables us to obtain good results and a low complication rate.

Potential placebo effect in assessing idiopathic normal pressure hydrocephalus

Although shunt placement constitutes the primary treatment for idiopathic normal pressure hydrocephalus (INPH), it has been challenging to decide which patients to refer for such an intervention. Procedures involving CSF removal, such as large-volume lumbar puncture (LP) and external lumbar drainage, are commonly used to predict a successful response to surgery, but their positive and negative predictive values have considerable shortcomings. The authors here report the case of a 76-year-old woman with possible INPH whose condition improved equally well after actual and sham large-volume LPs. The authors discuss the implications of this placebo response in the context of the diagnosis and management of INPH. The authors suggest that the clinical response to sham procedures for CSF removal might provide important information for better predicting which patient might respond to shunt surgery.

Proton MR spectroscopy and white matter hyperintensities in idiopathic normal pressure hydrocephalus and other dementias

The differentiation of idiopathic normal-pressure hydrocephalus (INPH) from other types of dementia is a clinical challenge. The aim of this prospective study was to evaluate the role of proton MR spectroscopy (MRS) and white matter hyperintensities (WMH) in the diagnosis of INPH, predicting response to therapy and differentiating INPH from other dementias. The study included 18 patients with INPH (Group 1), 11 patients with other types of dementia (Group 2) and 20 control patients (Group 3). The value of WMH scores and MRS findings in diagnosis, evaluation of response to therapy and in the differentiation of INPH from other dementias was statistically evaluated. The level of statistical significance was set at p<0.05 (Kruskal-Wallis and Mann-Whitney U-test). In both Groups 1 and 2, N-acetylaspartate (NAA)/choline-NAA/creatine ratios were significantly less than in the control group (p<0.05). The WMH and MRS findings of Groups 1 and 2 demonstrated no statistically significant correlation (p>0.05). No correlation was found between the outcome of shunt operations and WMH and MRS findings (p>0.05). In conclusion, neither WMH nor MRS were useful in differentiating INPH from other types of dementia. WMH and MRS showed no additional benefit in identifying INPH patients who will better respond to shunt therapy.

MR cisternography: is it useful in the diagnosis of normal pressure hydrocephalus and the selection of “good shunt responders”?

The aim of this study was to evaluate the efficiency of MR cisternography (MRC) in the diagnosis of idiopathic normal-pressure hydrocephalus (INPH) and in the prediction of the response to shunt treatment. Thirty-six patients with the diagnosis of "probable INPH" were included in the study group and 15 asymptomatic age-matched individuals were included in the control group. Pre-contrast T1-weighted (T1W) imaging was followed by intrathecal administration of 1 ml gadopentetate dimeglumine. Post-contrast T1W images were taken at the 12th, 24th and 48th hours. The presence of contrast material in the lateral ventricles for more than 24 hours was accepted as a positive diagnosis of INPH. Data from both groups were compared statistically. Statistical significance was accepted for P < 0.05. All of the INPH patients had remaining contrast material in their lateral ventricles at the 12th and 24th hours, while only 28 (78%) patients had contrast material remaining at the 48th hour after MRC. Only 3 (20%) of the control cases had remaining contrast material in their lateral ventricles at the 24th hour. No contrast material was present in the control cases at the 48th hour. The contrast material was found to be significantly more prevalent in the INPH patients at the 24th and the 48th hours compared with the control cases (P < 0.001). Shunt placement was performed in 14 INPH patients, and eight improved after shunt placement. All patients (100%) who improved after shunt placement had remaining contrast material in their lateral ventricles at the 24th and at the 48th hours. The sensitivity and specificity of MRC in the prediction of the response to shunt treatment were 100% and 17%, respectively. MRC does not use ionizing radiation and is generally a useful procedure to diagnose NPH and to predict a positive response to shunt treatment; thus, we recommend MRC after routine MRI in patients with the presumed diagnosis of NPH.

A prospective study of cerebral blood flow and cerebrovascular reactivity to acetazolamide in 162 patients with idiopathic normal-pressure hydrocephalus

Cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) to acetazolamide were investigated prospectively in 162 patients with a proposed diagnosis of idiopathic normal-pressure hydrocephalus (NPH). The aim of this study was to assess the usefulness of the measurement of CBF and CVR in determining which patients would be likely to benefit from shunt placement. The mean CBF of the whole brain was measured according to the Patlak plot method by using technetium-99m hexamethylpropyleneamine oxime. The CVR value was obtained from the response to administration of 500 mg acetazolamide and calculated as the percentage change from the baseline mean CBF value. One hundred forty-six patients (90.1%) responded to shunt placement ("responders"), but 16 patients (9.9%) did not ("nonresponders"). No significant difference in preoperative CBF was observed between responders and nonresponders. Preoperative CVR was significantly impaired (p<0.0025) in responders compared with healthy controls, but not in nonresponders. Responders with the incomplete triad had a significant reduction (p<0.001) in preoperative CVR, but not in preoperative CBF, compared with healthy controls. Responders with the complete triad had significantly lower preoperative CBF and CVR than those with the incomplete triad (p<0.01 and p<0.05, respectively). Postoperative CBF and CVR increased significantly (p<0.025 and p<0.001, respectively) in responders. Both CBF and CVR decrease with the development of NPH, suggesting that hemodynamic ischemia may be responsible for manifestation of the symptoms. Impaired CVR and reduced CBF with the development of symptoms can be proposed as diagnostic criteria for idiopathic NPH.

Morphologic Features and Flow Void Phenomenon in Normal Pressure Hydrocephalus and Other Dementias: Are They Really Significant?

The aim of this study was to determine the distinctive features of normal-pressure hydrocephalus (NPH) and other dementias on routine T1-weighted and T2-weighted magnetic resonance (MR) images. Also, the contribution of these parameters to the diagnosis and treatment of NPH was investigated. Routine MR images were used to investigate the morphologic features (dilatation of Sylvian cisterns, narrowness of convexity sulci, thickness of corpus callosum (TCC), and dilatation of perihippocampal fissures) and the flow void phenomenon (FVP) in patients with idiopathic NPH (INPH) and other dementias. Routine MR images of 18 patients with INPH, 11 with dementias other than INPH, and 20 controls were retrospectively examined. Morphologic features and the FVP were graded subjectively. The TCC was measured quantitatively. Morphologic parameters, the FVP, and the shunt response were assessed using Kruskal-Wallis and Mann-Whitney U tests. The mean FVP score was significantly higher in patients with INPH (2.89 +/- 0.75) than in controls and patients with other dementias (1.1 +/- 0.85 and 1.09 +/- 0.83, respectively) (P < .001). There was significant difference in terms of TCC between patients with INPH (3 +/- 0.7 mm), those with other dementias (1.9 +/- 0.7 mm), and controls (5.2 +/- 0.8 mm) (P < .001). Significant differences in terms of other morphologic features were found between patients with INPH and those with other dementias (P < .05). No significant difference was found between morphologic parameters and the FVP and the outcome of cerebrospinal fluid diversion (P > .05). Intense FVP is a signature of but is not pathognomonic for INPH. The morphologic analysis of MR images can be distinctive for the diagnosis of INPH or dementias other than INPH. Detailed evaluation of morphologic features and the FVP in routine MR workup of dementia will be useful for accurate diagnosis.

O.006 Safety of large volume CSF removal for the inner ear function in normal pressure hydrocephalus patients

Preoperative diagnosis of idiopathic normal-pressure hydrocephalus (iNPH) remains challenging. Recently, the presence of disproportionally enlarged subarachnoid spaces and hydrocephalus (DESH) on diagnostic images has been linked to clinical improvement after ventriculoperitoneal (VP) shunt placement. In this study we describe a new quantitative method to assess DESH on CT scans and to evaluate its prognostic value.A multiplanar reconstruction software was used to retrospectively evaluate prospectively collected radiological data (CT scans) of 26 controls and 29 consecutive patients that underwent VP shunt placement for possible iNPH. The ratio between the areas of the sylvian fissure and the subarachnoid space at the vertex was calculated (SILVER index). The diagnostic accuracy of the SILVER index and the estimate of the best cut-point were assessed using ROC analysis.The mean value of the SILVER index was 11.52 ± 14.27 in the study group and 1.68 ± 0.98 in the control group (p-value < 0.0001). The area under the ROC curve for the SILVER index was 0.903 (95% CI 0.813–0.994). A cut-off value for the SILVER index of 3.75 was extrapolated with a sensitivity and specificity of 0.828 and 0.962 respectively.The SILVER index is a reliable tool to easily quantify DESH on CT scans of patients with suspected iNPH. Its high sensitivity and specificity should encourage further investigations in order to confirm its clinical utility.

The Triad of Idiopathic Normal-Pressure Hydrocephalus: A Clinical Practice Case Report

An 89-year-old white male presented with memory impairment, slowness in responsiveness, and frequent falls over a two-year duration. Six months earlier, the patient was believed to have had a “dementia with parkinsonian features,” but showed no response to incrementing doses of both donepezil and carbidopa-levodopa. Urinary urgency was believed to have been due to prostate hypertrophy. A head CT with contrast revealed moderate ventriculomegaly in the setting of mild diffuse cortical atrophy. A diagnosis of idiopathic normal-pressure hydrocephalus (INPH) was made.

Noninvasive MRI assessment of intracranial compliance in idiopathic normal pressure hydrocephalus

To assess the state and dynamics of the intracranial system in idiopathic normal-pressure hydrocephalus (I-NPH), we determined intracranial compliance using magnetic resonance imaging (MRI). The intracranial compliance index (ICCI), which was defined as the ratio of the peak-to-peak intracranial volume change (ICVC(p-p)) to the peak-to-peak cerebrospinal fluid (CSF) pressure gradient (PG(p-p)) during the cardiac cycle, was obtained from the net transcranial blood and CSF flow measured with phase-contrast (PC) cine MRI. ICCI was determined in patients with I-NPH (N = 7), brain atrophy, or asymptomatic ventricular dilation (VD) (N = 6), and in healthy volunteers (control group; N = 11). The changes in ICCI indices were also analyzed after a CSF tap test (N = 2). The ICCI in the I-NPH group was significantly lower than in the control and VD groups, whereas no difference was found between the control and VD groups. The ICVC(p-p) was also lower than in the control and VD groups. However, no significant difference was found in the PG(p-p) between groups. The ICCI increased after the tap test. Intracranial compliance analysis with MRI makes it possible to noninvasively obtain more detailed information of intracranial biomechanics in the I-NPH and to assist in the diagnosis of I-NPH.