Revisiting the diagnostic value of Evans’ index: lessons from an unusual case of normal pressure hydrocephalus with Evans’ index less than 0.3

2019 ◽  
Vol 40 (12) ◽  
pp. 2637-2639
Author(s):  
Jung E. Park ◽  
Hyunjin Ju ◽  
Kayeong Im ◽  
Kyum-Yil Kwon
Keyword(s):  
Normal Pressure Hydrocephalus ◽  
Unusual Case ◽  
Normal Pressure ◽  
Diagnostic Value ◽  
Evans Index

scholarly journals Neuroimaging in normal pressure hydrocephalus

2015 ◽  
Vol 9 (4) ◽  
pp. 350-355 ◽  
Author(s):  
Benito Pereira Damasceno
Keyword(s):  
Normal Pressure Hydrocephalus ◽  
Cerebral Atrophy ◽  
High Sensitivity ◽  
Normal Pressure ◽  
Evans Index ◽  
Flow Void ◽  
High Positive Predictive Value ◽  
Subarachnoid Spaces ◽  
Magnetic Resonance Imaging Mri ◽  
Improved Accuracy

ABSTRACT Normal pressure hydrocephalus (NPH) is a syndrome characterized by the triad of gait disturbance, mental deterioration and urinary incontinence, associated with ventriculomegaly and normal cerebrospinal fluid (CSF) pressure. The clinical presentation (triad) may be atypical or incomplete, or mimicked by other diseases, hence the need for supplementary tests, particularly to predict postsurgical outcome, such as CSF tap-tests and computed tomography (CT) or magnetic resonance imaging (MRI). The CSF tap-test, especially the 3 to 5 days continuous external lumbar drainage of at least 150 ml/day, is the only procedure that simulates the effect of definitive shunt surgery, with high sensitivity (50-100%) and high positive predictive value (80-100%). According to international guidelines, the following are CT or MRI signs decisive for NPH diagnosis and selection of shunt-responsive patients: ventricular enlargement disproportionate to cerebral atrophy (Evans index >0.3), and associated ballooning of frontal horns; periventricular hyperintensities; corpus callosum thinning and elevation, with callosal angle between 40º and 90º; widening of temporal horns not fully explained by hippocampal atrophy; and aqueductal or fourth ventricular flow void; enlarged Sylvian fissures and basal cistern, and narrowing of sulci and subarachnoid spaces over the high convexity and midline surface of the brain. On the other hand, other imaging methods such as radionuclide cisternography, SPECT, PET, and also DTI or resting-state functional MRI, although suitable for NPH diagnosis, do not yet provide improved accuracy for identifying shunt-responsive cases.

scholarly journals Application of Evans Index in Normal Pressure Hydrocephalus Patients: A Mini Review

2022 ◽  
Vol 13 ◽  
Author(s):  
Xi Zhou ◽  
Jun Xia
Keyword(s):  
Normal Pressure Hydrocephalus ◽  
Clinical Symptoms ◽  
Normal Pressure ◽  
Clinical Value ◽  
Incontinence Surgery ◽  
Special Software ◽  
Evans Index ◽  
Ventricle Volume ◽  
Threshold Setting ◽  
Urinary Incontinence Surgery

With an ever-growing aging population, the prevalence of normal pressure hydrocephalus (NPH) is increasing. Clinical symptoms of NPH include cognitive impairment, gait disturbance, and urinary incontinence. Surgery can improve symptoms, which leads to the disease's alternative name: treatable dementia. The Evans index (EI), defined as the ratio of the maximal width of the frontal horns to the maximum inner skull diameter, is the most commonly used index to indirectly assess the condition of the ventricles in NPH patients. EI measurement is simple, fast, and does not require any special software; in clinical practice, an EI >0.3 is the criterion for ventricular enlargement. However, EI's measurement methods, threshold setting, correlation with ventricle volume, and even its clinical value has been questioned. Based on the EI, the z-EI and anteroposterior diameter of the lateral ventricle index were derived and are discussed in this review.

scholarly journals Diagnostic Performance of Glymphatic System Evaluation Using Diffusion Tensor Imaging in Idiopathic Normal Pressure Hydrocephalus and Mimickers

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Hajime Yokota ◽  
Arvind Vijayasarathi ◽  
Milos Cekic ◽  
Yoko Hirata ◽  
Michael Linetsky ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Normal Pressure Hydrocephalus ◽  
Diagnostic Performance ◽  
Roc Analysis ◽  
Diffusion Tensor ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Glymphatic System ◽  
Evans Index ◽  
Diffusion Tensor Imaging Dti

Purpose. To investigate the pathological change of the glymphatic system in idiopathic normal pressure hydrocephalus (iNPH) using diffusion tensor imaging (DTI) analysis. Materials and Methods. 24 right-handed patients were referred to our hydrocephalus clinic for assessment of ventriculomegaly and gait impairment. 12 of 24 were diagnosed as pseudo-iNPH (piNPH) based on assessment by a neurologist. Diffusivity maps in the direction of the x-axis (right-to-left) (Dx), y-axis (anterior-to-posterior) (Dy), and z-axis (inferior-to-superior) (Dz) were computed. The diffusion map was coregistered to International Consortium for Brain Mapping (ICBM) DTI-81 atlas. The analysis along the perivascular space (ALPS) index was defined as mean (Dxpro, Dypro)/mean (Dypro, Dzasc), where Dxpro and Dxasc are Dx values in the projection and association fiber areas, respectively. Evans index and callosal angle were also assessed on each case. Results. ALPS indexes of the control, piNPH, and iNPH cases were 1.18 ± 0.08, 1.08 ± 0.03, and 0.94 ± 0.06, respectively, and there were significant differences among the groups (control vs. piNPH, P = 0.003; control vs. iNPH P < 0.001; piNPH vs. iNPH, P < 0.001). Area under curve (AUC) was 0.92, 1.00, and 1.00 on control vs. piNPH, control vs. iNPH, and piNPH vs. iNPH on ROC analysis. Between piNPH and NPH, ALPS index has higher diagnostic performance than Evans index and callosal angle (AUC = 1.00 vs. 0.84, P = 0.028; AUC = 1.00 vs. 0.74, P = 0.016). Conclusion. Atlas-based ALPS index using the DTI method differentiated among iNPH, piNPH, and controls clearly.

scholarly journals Parkinsonian Symptomatology May Correlate with CT Findings before and after Shunting in Idiopathic Normal Pressure Hydrocephalus

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Mitsuaki Ishii ◽  
Toshio Kawamata ◽  
Ichiro Akiguchi ◽  
Hideo Yagi ◽  
Yuko Watanabe ◽  
...  
Keyword(s):  
Normal Pressure Hydrocephalus ◽  
Postural Stability ◽  
Rating Scale ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Stepwise Multiple Regression ◽  
Ct Findings ◽  
Before And After ◽  
Evans Index ◽  
Disease Rating

We aimed to investigate the characteristics of Parkinsonian features assessed by the unified Parkinson's disease rating scale (UPDRS) and determine their correlations with the computed tomography (CT) findings in patients with idiopathic normal pressure hydrocephalus (iNPH). The total score and the scores for arising from chair, gait, postural stability, and body hypokinesia in the motor examination section of UPDRS were significantly improved after shunt operations. Stepwise multiple regression analysis revealed that postural stability was the determinant of the gait domain score of the iNPH grading scale. The canonical correlation analysis between the CT findings and the shunt-responsive Parkinsonian features indicated that Evans index rather than midbrain diameters had a large influence on the postural stability. Thus, the pathophysiology of postural instability as a cardinal feature of gait disturbance may be associated with impaired frontal projections close to the frontal horns of the lateral ventricles in the iNPH patients.

WP1-10 Prevalence of normal pressure hydrocephalus in falls clinic patients

2019 ◽  
Vol 90 (3) ◽  
pp. e4.2-e4 ◽  
Author(s):  
S Sennik ◽  
C Craven ◽  
L D’Antona ◽  
H Asif ◽  
W Dawes ◽  
...  
Keyword(s):  
General Hospital ◽  
Normal Pressure Hydrocephalus ◽  
Normal Population ◽  
District General Hospital ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
List Type ◽  
Ventricular Enlargement ◽  
Evans Index ◽  
One Year

ObjectivesPatients with idiopathic Normal Pressure Hydrocephalus (iNPH) present with Hakim Adams triad and radiological findings suggestive of iNPH. We compare the presence of clinical and radiological signs of iNPH present in patients presenting to falls clinic at a District General Hospital with the general population.DesignRetrospective analysis of patients referred to falls clinic (January 2017 to December 2017) and interpretation of CT or MRI head imaging with Evans index.SubjectsFalls clinic patients presenting to a District General Hospital outpatient clinic.MethodsRetrospective cohort of patients admitted to a single District General Hospital with falls and recent CT or MRI head. An Evans Index above 0.35 was used as an indicator of hydrocephalic ventricular enlargement.Results371 patients were seen in one year. 216 had previous CT or MRI head. 6.75% of all patients seen in falls clinic (11.6% who have had brain imaging) have hydrocephalic ventricular enlargement. This is compared to 4.5% in a study of patients aged 70 and over in a normal population.1ConclusionsPatients seen in Falls clinic have an increased probability of having radiological signs consistent with idiopathic normal pressure hydrocephalus.ReferenceJaraj D, Marlow T, Jensen C, Skoog I, Wikkelso C. Prevalence of idiopathic normal-pressure hydrocephalus. Neurology2014April 22;82(16):1449–1454.

Sign in / Sign up

Export Citation Format

Share Document