Elsevier

European Journal of Radiology

Volume 116, July 2019, Pages 106-115
European Journal of Radiology

Systematic review and meta-analysis of MRI signs for diagnosis of idiopathic intracranial hypertension

https://doi.org/10.1016/j.ejrad.2019.04.023Get rights and content

Highlights

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    All included studies had a case-control design, which may have resulted in overestimation of diagnostic accuracy.

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    Most MRI signs have overall high specificity but low sensitivity in diagnosing intracranial hypertension.

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    Transverse sinus stenosis appears to be the most useful sign, because it has high specificity and fairly high sensitivity.

Abstract

Objective

To systematically review the potential value of MRI signs in the assessment of intracranial hypertension (IIH).

Methods

MEDLINE and Embase were systematically searched for original studies investigating the accuracy of MRI signs in diagnosing IIH. Methodologic quality of included studies was assessed. Sensitivity and specificity were pooled with a bivariate random-effects model.

Results

Twenty-one studies, comprising a total of 724 patients with IIH, were included. All studies had a case-control design. "Empty" sella (11 studies), posterior displacement of pituitary stalk (2 studies), meningoceles (2 studies), posterior globe flattening (8 studies), optic nerve head protrusion (6 studies), optic nerve enhancement (3 studies), optic nerve sheath distension (12 studies), optic nerve tortuosity (7 studies), slit-like ventricles (4 studies), tight subarachnoid spaces (3 studies), and inferior position of cerebellar tonsils (4 studies) had pooled sensitivity ranging between 6.1% and 68.6%, and pooled specificity ranging between 84.0% and 99.2%. Transverse sinus stenosis (8 studies) had pooled sensitivity of 84.4%; (95% CI: 65.9–93.9%) and pooled specificity of 94.9% (95% CI: 91.7–96.9%).

Conclusion

"Empty" sella, posterior pituitary stalk displacement, meningoceles, posterior globe flattening, optic nerve head protrusion, optic nerve enhancement, optic nerve sheath distension, optic nerve tortuosity, slit-like ventricles, tight subarachnoid spaces, and inferior position of cerebellar tonsils have overall high specificity but low sensitivity. Transverse sinus stenosis appears to be the most useful sign, because it has high specificity and fairly high sensitivity.

Introduction

Idiopathic intracranial hypertension (IIH) is a clinical syndrome characterized by raised intracranial pressure (ICP), without a detectable cause and absence of hydrocephalus [1]. The exact cause is still unclear [2]. Headache and visual impairment are the most common symptoms and blindness occurs in 10% of cases [1]. In young adult women with overweight, incidence is 15–19 cases per 100,000 persons in the USA [3]. Because IIH is associated with obesity [4], its incidence is likely to increase with increasing global obesity [5]. Diagnosis relies on clinical symptoms, absence of hydrocephalus, intracranial mass, structural, or vascular lesion on imaging, raised cerebrospinal fluid (CSF) pressure measured by lumbar puncture, and normal CSF composition.1 However, IIH is frequently overdiagnosed, in as much as 39.5% of patients referred for presumed IIH [6]. The most common diagnostic error is inaccurate funduscopic examination [6], which can be challenging [7]. Moreover, IIH can also occur without papilledema [8]. In these cases, diagnosis may strongly depend on MRI. Reported MRI signs that may be helpful for the diagnosis of IIH include "empty" sella, posterior globe flattening, optic nerve sheath distension with or without optic nerve tortuosity, and transverse sinus stenosis [8]. However, incidental finding of potential nonspecific MRI signs may lead to overdiagnosis of IIH and resultant excessive additional tests, including lumbar punctures [7], and unnecessary treatment. To our knowledge, the potential value of MRI has not been systematically investigated yet. Therefore, the purpose of this study was to systematically review and meta-analyze the potential value of MRI signs in the assessment of IIH.

Section snippets

Data sources

MEDLINE and Embase was searched for publications on the accuracy of MRI in diagnosing IIH. The search terms ((intracranial AND hypertension) OR (pseudotumor AND cerebri)) AND (magnetic resonance OR MR imaging OR MRI OR magnetic resonance tomography OR nuclear magnetic resonance OR NMR) were used. The search was updated until November 24, 2018. Bibliographies of studies which remained after the selection process were screened for potentially suitable references.

Study selection

Original studies investigating the

Literature search

The study selection process is displayed in Fig. 1. Thirty-four studies were potentially eligible for inclusion [[15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44], [45], [46], [47], [48]]. One study was excluded because the full-text version could not be retrieved [42]. After reviewing the full text of the remaining 33 studies, 11 studies were excluded because

Discussion

Brain MRI is routinely performed in patients clinically suspected of having IIH, but also in patients with other causes of headache [49]. It is important to discriminate patients with IIH from those without. Our systematic review showed overall high pooled specificity but low pooled sensitivity of the MRI signs "empty" sella, posterior displacement of pituitary stalk, meningoceles, posterior globe flattening, optic nerve head protrusion, optic nerve enhancement, optic nerve sheath distension,

Conclusions

"Empty" sella, posterior displacement of pituitary stalk, meningoceles, posterior globe flattening, optic nerve head protrusion, optic nerve enhancement, optic nerve sheath distension, optic nerve tortuosity, slit-like ventricles, tight subarachnoid spaces, and inferior position of cerebellar tonsils are MRI signs with overall high specificity but low sensitivity. Transverse sinus stenosis appears to be the most clinically useful MRI sign, because it has high specificity and fairly high

Conflicts of interest

All authors have no conflicts of interest to declare.

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