PSEUDOTUMOR CEREBRI

Idiopathic intracranial hypertension: Imaging and clinical fundamentals

Neuroimaging is a paramount element for the diagnosis of idiopathic intracranial hypertension, a condition characterized by signs and symptoms of raised intracranial pressure without the identification of a mass or hydrocephalus being recognized. The primary purpose of this review is to deliver an overview of the spectrum and the specific role of the various imaging findings associated with the condition while providing imaging examples and educational concepts. Clinical perspectives and insights into the disease, including treatment options, will also be discussed.

Neuro-Ophthalmologic MRI Findings in the Detection of Rhinorrhoea Aetiology

The purpose of this study is to evaluate the importance of neuro-ophthalmological magnetic resonance imaging (MRI) findings in the identification of the aetiology of rhinorrhoea, and the differentiation of spontaneous rhinorrhoea from non-spontaneous rhinorrhoea. MR images of 25 patients with spontaneous and 21 patients with non-spontaneous rhinorrhoea were evaluated for the presence of neuro-ophthalmological findings of intracranial hypertension (IHT). These include optic nerve vertical tortuosity, optic nerve sheath enlargement, flattening of the posterior sclera and optic nerve protrusion, as well as other MRI findings of ICH, such as partial empty sella, dilatation of Meckel's cave and the presence of arachnoid pits. IHT findings were more common in the spontaneous group. Six criteria (optic nerve distention, optic nerve vertical tortuosity, posterior flattening of the sclera, partial empty sella, Meckel's cave dilatation and presence of arachnoid pits) differentiate between patient and control groups. Patients with spontaneous cerebrospinal fluid (CSF) leaks should be evaluated for signs of IHT on MRI, as they are present in the majority of spontaneous CSF leaks and are representative of increased intracranial pressure.

European headache federation guideline on idiopathic intracranial hypertension

Background

Idiopathic Intracranial Hypertension (IIH) is characterized by an elevation of intracranial pressure (ICP no identifiable cause. The aetiology remains largely unknown, however observations made in a number of recent clinical studies are increasing the understanding of the disease and now provide the basis for evidence-based treatment strategies.

Methods

The Embase, CDSR, CENTRAL, DARE and MEDLINE databases were searched up to 1st June 2018. We analyzed randomized controlled trials and systematic reviews that investigate IIH.

Results

Diagnostic uncertainty, headache morbidity and visual loss are among the highest concerns of clinicians and patients in this disease area. Research in this field is infrequent due to the rarity of the disease and the lack of understanding of the underlying pathology.

Conclusions

This European Headache Federation consensus paper provides evidence-based recommendations and practical advice on the investigation and management of IIH.

Electronic supplementary material

The online version of this article (10.1186/s10194-018-0919-2) contains supplementary material, which is available to authorized users.

The Significance and Reliability of Imaging Findings in Pseudotumor Cerebri

The objective of our study was to provide a comparative assessment of previously reported magnetic resonance imaging (MRI) parameters in primary and secondary pseudotumor cerebri (PTC) patients, to examine their diagnostic contribution, and to evaluate their association with symptoms, neuro-ophthalmological findings, laboratory results, and cerebrospinal fluid characteristics. Twenty-eight consecutive patients with PTC were included in the study. Age- and sex-matched 20 individuals with normal neurologic examination served as the control group. Modified Dandy Criteria were used for the diagnosis of PTC. Orbital and cranial MRI and MR venography of all patients and controls were assessed by three radiologists. According to our study, posterior flattening of the globe (64% sensitive, 100% specific), optic nerve sheath distention (46% sensitive, 100% specific), vertical tortuosity of the optic nerve (30% sensitive, 95% specific), and partial empty sella (43% sensitive, 100% specific) emerged as particularly valuable markers for a diagnosis of PTC.

Brain Imaging in Idiopathic Intracranial Hypertension

BACKGROUND

The primary role of brain imaging in idiopathic intracranial hypertension (IIH) is to exclude other pathologies causing intracranial hypertension. However, subtle radiologic findings suggestive of IIH have emerged with modern neuroimaging. This review provides a detailed description of the imaging findings reported in IIH and discusses their possible roles in the pathophysiology and the diagnosis of IIH.

EVIDENCE ACQUISITION

References were identified by searches of PubMed from 1955 to January 2015, with the terms "idiopathic intracranial hypertension," "pseudotumor cerebri," "intracranial hypertension," "benign intracranial hypertension," "magnetic resonance imaging," "magnetic resonance venography," "computed tomography (CT)," "CT venography," "imaging," and "cerebrospinal fluid (CSF) leak." Additional references were identified by hand search of relevant articles. When possible, we extracted the number of patients and control subjects from each study for each radiological finding. When at least 2 studies used the same criteria to define a radiological finding, all patients from these studies were pooled to obtain a mean sensitivity and specificity with 95% confidence interval.

RESULTS

Specific neuroimaging findings may suggest long-standing IIH, including empty sella, flattening of the posterior globes, optic nerve head protrusion, distention of the optic nerve sheaths, tortuosity of the optic nerve, cerebellar tonsillar herniation, meningoceles, CSF leaks, and transverse venous sinus stenosis.

CONCLUSION

Although IIH remains a diagnosis of exclusion, the most recently proposed diagnostic criteria have included neuroimaging findings to suggest IIH when major diagnostic criteria are not fulfilled. However, these findings are not diagnostic of IIH, and their presence is not required for the diagnosis of definite IIH. Their incidental discovery on brain imaging should not prompt invasive procedures, unless other signs of IIH, such as papilledema, are present.

Morphometric and volumetric MRI changes in idiopathic intracranial hypertension

Objective

We aimed at validating established imaging features of idiopathic intracranial hypertension (IIH) by using state-of-the-art MR imaging together with advanced post-processing techniques and correlated imaging findings to clinical scores.

Methods

Twenty-five IIH patients as well as age-, sex- and body mass index (BMI)-matched controls underwent high-resolution T1w and T2w MR imaging in a 1.5 T scanner, followed by assessment of optic nerve sheaths, pituitary gland, ventricles and Meckel's cave. Imaging findings were correlated with cerebrospinal fluid (CSF) opening pressures and clinical symptom scores of visual disturbances (visual field defects or enlarged blind spot), headache, tinnitus (pulsatile and non-pulsatile) and vertigo. CSF as well as ventricle volumes were determined by using an automated MRI volumetry algorithm.

Results

So-called ‘empty sella’ and optic nerve sheath distension were identified as reliable imaging signs in IIH. Posterior globe flattening turned out as a highly specific but not very sensitive sign. No abnormalities of the lateral ventricles were observed. These morphometric results could be confirmed using MR volumetry (VBM). Clinical symptoms did not correlate with an increase in lumbar opening pressure.

Conclusions

Our study results indicate that lateral ventricle size is not affected in IIH. In contrast, abnormalities of the pituitary gland and optic nerve sheath were reliable diagnostic signs for IIH.

Idiopathic Intracranial Hypertension. A Systematic Analysis of Transverse Sinus Stenting

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a disorder characterized by signs and symptoms of increased intracranial pressure without structural cause seen on conventional imaging. Hallmark treatment after failed medical management, has been CSF shunting or optic nerve fenestration with the goal of treatment being preservation of vision. Recently, there have been multiple case reports and case series on dural sinus stenting for this disorder.

OBJECTIVE

We aim to review all published cases and case series of dural sinus stenting for IIH, with analysis of patient presenting symptoms, objective findings (CSF pressures, papilledema, pressure gradients across dural sinuses), follow-up of objective findings, and complications.

METHODS

A Medline search was performed to identify studies meeting pre-specified criteria of a case report or case series of patients treated with dural sinus stent placement for IIH. The manuscripts were reviewed and data was extracted.

RESULTS

A total of 22 studies were identified, of which 19 studies representing 207 patients met criteria and were included in the analysis. Only 3 major complications related to procedure were identified. Headaches resolved or improved in 81% of patients. Papilledema improved the (172/189) 90%. Sinus pressure decreased from an average of 30.3 to 15 mm Hg. Sinus pressure gradient decreased from 18.5 (n=185) to 3.2 mm Hg (n=172). Stenting had an overall symptom improvement rate of 87%.

CONCLUSION

Although all published case reports and case series are nonrandomized, the low complication and high symptom improvement rate make dural sinus stenting for IIH a potential alternative surgical treatment. Standardized patient selection and randomization trials or registry are warranted.

Pseudotumor cerebri: brief review of clinical syndrome and imaging findings

PTC is a clinical entity of uncertain etiology characterized by intracranial hypertension. The syndrome classically manifests with headaches and visual changes in women with obesity. Traditionally, imaging ruled out secondary causes of elevated CSF pressure but now may reveal findings frequently seen in patients with PTC, including the following: flattening of the globe, an empty sella, an enlarged ONS, protrusion and enhancement of the optic nerve head, and increased tortuosity of the optic nerve. Novel imaging methods, including MR venography, have additionally identified sinovenous stenosis as a potential indicator of PTC.

The excessively small ventricle on cranial computed tomography: clinical correlation in 75 patients

Excessively small ventricle (ESV) was demonstrated in 75 (8.3%) of 9,000 patients over 15 years of age examined by cranial computed tomography (CT). The patients had no other CT abnormality except for ESV. Detailed retrospective analysis of clinical records of these 75 patients revealed four major groups of patients: 1) those with seizures (24%); 2) those with headaches (24%); 3) those with acute non-penetrating head trauma (21.5%); and 4) those with benign increased intracranial pressure (8%). The remaining patients (22.5%) had a variety of cerebral derangements.

The excessively small ventricle on computed axial tomography of the brain

Computed axial tomography has made it possible to observe excessively small ventricles in a variety of disorders of the CNS. This finding is presumably due to non-specific and diffuse swelling of brain parenchyma, and is illustrated in cases of trauma, neoplasm, encephalitis, pseudotumor cerebri, metabolic disorder, and probable dilantin effect. It is likely that other causes will be encountered in the future.