Diagnosis of idiopathic intracranial hypertension: A proposal for evidence-based diagnostic criteria

BACKGROUND

Based on expert opinion, abducens nerve palsy and a neuroimaging criterion (≥3 neuroimaging signs suggestive of elevated intracranial pressure) were added to the diagnostic criteria for idiopathic intracranial hypertension. Our objective was to validate this.

METHODS

This prospective study included patients with new-onset idiopathic intracranial hypertension for a standardized work-up: interview, neuro-ophthalmological exam, lumbar puncture, neuroimaging. Neuroimaging was evaluated by a blinded neuroradiologist.

RESULTS

We included 157 patients classified as idiopathic intracranial hypertension (56.7%), probable idiopathic intracranial hypertension (1.9%), idiopathic intracranial hypertension without papilledema (idiopathic intracranial hypertension-without papill edema; 0%), suggested idiopathic intracranial hypertension-without papill edema (4.5%), or non-idiopathic intracranial hypertension (36.9%). Moderate suprasellar herniation was more common in idiopathic intracranial hypertension than non-idiopathic intracranial hypertension (71.4% versus 47.4%, p < 0.01), as was perioptic nerve sheath distension (69.8% versus 29.3%, p < 0.001), flattening of the globe (67.1% versus 11.1%, p < 0.001) and transverse sinus stenosis (60.2% versus 18.9%, p < 0.001). Abducens nerve palsy was of no diagnostic significance. Sensitivity of ≥3 neuroimaging signs was 59.5% and specificity was 93.5%.

CONCLUSION

Moderate suprasellar herniation, distension of the perioptic nerve sheath, flattening of the globe and transverse sinus stenosis were associated with idiopathic intracranial hypertension. We propose that idiopathic intracranial hypertension can be defined by two out of three objective findings (papilledema, opening pressure ≥25 cm cerebrospinal fluid and ≥3 neuroimaging signs).

[Diagnosis and treatment of cerebral venous sinus thrombosis]

Thrombosis of the cerebral sinuses most often affects younger adults. Headache is a common complaint and can be accompanied by vomiting and papilloedema. The diagnosis rests on magnetic resonance imaging and the treatment consists of heparin or low-molecular weight heparin followed by vitamin K antagonists for three months or more. In fulminant cases local thrombolysis is administered, while symptomatic treatment for increased intracranial pressure is given. In retrospective analyses this approach has been associated with a good outcome - even in cases treated by decompressive craniectomy.

Magnetic Resonance Imaging Signs of Idiopathic Intracranial Hypertension

Importance

The magnetic resonance imaging (MRI) criteria currently used to diagnose idiopathic intracranial hypertension (IIH) are based on expert opinion and have limited accuracy. Additional neuroimaging signs have been proposed and used with contradictory results; thus, prospective evidence is needed to improve diagnostic accuracy.

Objective

To provide evidence-based, accurate MRI signs for IIH diagnosis.

Design, Setting, and Participants

This prospective cohort study was conducted from January 2018 to May 2021 with 3 validation cohorts at 2 Danish headache centers and with 3 independent international cohorts. Consecutive patients with suspected IIH were enrolled. Eligibility required the clinical suspicion of IIH, age 18 years or older, and written informed consent. The validation cohorts comprised patients with confirmed IIH from Austria and the US, and patients without IIH from the US. Data analysis was performed from December 2021 to August 2023.

Exposure

Standardized diagnostic workup was performed to classify cases according to current criteria, and blinded evaluation of cerebral radiological diagnostics and papilledema was performed.

Main Outcomes and Measures

The primary outcomes were MRI signs associated with IIH as assessed by univariate analyses. An MRI score estimating papilledema was calculated using machine learning. Internal validation of associations with lumbar puncture opening pressure and outcome and external validation of accuracy were performed in 3 cohorts.

Results

Of 192 eligible patients (185 women [96.4%]; median [IQR] age, 28.0 [23.0-35.0] years), 110 were classified as having IIH, 4 as having probable IIH, and 1 as having suspected IIH without papilledema; 77 did not have IIH and served as controls, with corresponding age, sex, and weight. Papilledema at diagnosis was associated with perioptic subarachnoid space distension (56 patients [68.3%] vs 21 patients [41.2%]), posterior globe flattening (53 patients [66.3%] vs 10 patients [21.3%]), optic nerve disc protrusion (35 patients [30.4%] vs 2 patients [2.3%]), and transverse sinus venous stenosis (75 patients [79.8%] vs 29 patients [46.8%]). The papilledema-estimating MRI score showed optimal balance between sensitivity (49%) and specificity (87%) when 2 of the 3 latter signs were present and was associated with the lumbar puncture opening pressure and ophthalmological outcome. The score showed strong diagnostic accuracy in the external validation cohorts (587 patients; area under the receiver operating characteristic curve, 0.86) and outperformed the current (2013) diagnostic MRI criteria.

Conclusions and Relevance

The findings of this cohort study of patients with IIH and controls suggest that an evidence-based MRI score including posterior globe flattening, optic nerve disc protrusion, and transverse sinus stenosis can estimate the presence of papilledema more accurately than the current diagnostic criteria.

Phenotyping non-idiopathic pseudotumor cerebri syndrome - A prospective cohort study

OBJECTIVE

To identify the most frequent causes of secondary pseudotumor cerebri syndrome and compare phenotype, clinical presentation, and symptoms of secondary pseudotumor cerebri syndrome to the primary form of pseudotumor cerebri syndrome, idiopathic intracranial hypertension.

METHODS

The study was a prospective cohort study including patients with new-onset pseudotumor cerebri syndrome. Diagnostic work up was standardized. Patients were diagnosed with secondary pseudotumor cerebri syndrome or idiopathic intracranial hypertension according to the revised Friedman criteria. Secondary pseudotumor cerebri syndrome patients were categorized into five causes: medication, systemic causes, sleep apnea, cerebrovascular causes, and several competing causes. Phenotype, clinical presentation, symptoms and neuroimaging were compared between groups.

RESULTS

Out of 278 cases, 28 secondary pseudotumor cerebri syndrome and 120 idiopathic intracranial hypertension patients were included. The most frequent causes of secondary pseudotumor cerebri syndrome were medication (n  =  8, 28.6%) and systemic causes (n = 8, 28.6%), followed by sleep apnea (n = 5, 17.9%), cerebrovascular causes (n = 4, 14.3%) and several competing causes (n = 3, 10.7%). Secondary pseudotumor cerebri syndrome and idiopathic intracranial hypertension patients were phenotypically alike and predominately female, premenopausal, and obese. Symptoms and objective findings at disease onset were similar between groups.

CONCLUSION

Secondary pseudotumor cerebri syndrome should be considered in all patients with suspected pseudotumor cerebri syndrome as secondary pseudotumor cerebri syndrome and idiopathic intracranial hypertension patients are phenotypically and clinically alike. A thorough diagnostic workup is needed as treatment of idiopathic intracranial hypertension and secondary pseudotumor cerebri syndrome is markedly different.

The impact of eating disorders on idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension (IIH) occurs more frequently in obese females of childbearing age. A link between eating disorders and poor outcome has been suggested but remains unproven.

METHODS

This prospective field study at two tertiary headache centers included patients with clinically suspected IIH after standardized diagnostic work-up. Eating disorders were evaluated using validated questionnaires (EDQs). Primary outcome was the impact of eating disorders on IIH severity and outcome, secondary outcome was the prevalence and type of eating disorders in IIH compared to controls.

RESULTS

We screened 326 patients; 143 patients replied to the EDQs and were classified as 'IIH' or 'non-IIH' patients. The demographic profile of EDQ-respondents and non-respondents was similar. Presence of an eating disorder did not impact IIH severity (lumbar puncture opening pressure (p = 0.63), perimetric mean deviation (p = 0.18), papilledema (Frisén grad 1-3; p = 0.53)) nor IIH outcome (optic nerve atrophy (p = 0.6), impaired visual fields (p = 0.18)). Moreover, we found no differences in the prevalence and type of eating disorders when comparing IIH with non-IIH patients (p = 0.09).

CONCLUSION

Eating disorders did not affect IIH severity or outcome. We found the same prevalence and distribution pattern of eating disorders in IIH and non-IIH patients advocating against a direct link between IIH and eating disorders.

Good clinical outcome after combined endovascular and neurosurgical treatment of cerebral venous sinus thrombosis

INTRODUCTION

A subgroup of patients suffering from cerebral venous sinus thrombosis (CVST) has a poor prognosis with standard anticoagulant treatment alone. Over a five-year period, we treated nine patients with aggressive endovascular therapy and neurosurgical/neurointensive treatment. In this study, the effect of this treatment is evaluated.

MATERIAL AND METHODS

A retrospective analysis of electronic patient files and data was performed.

RESULTS

All treated patients had partial or complete recanalization of the affected sinus after endovascular treatment. In three patients, a decompressive craniectomy was performed due to elevated intracranial pressure. Eight patients out of nine achieved a good outcome at follow-up (modified Rankin Scale 0-2). One patient died. No patients experienced recurrence of CVST.

CONCLUSION

Aggressive combined endovascular and neurosurgical treatment of patients with severe CVST is associated with a good clinical outcome in the cases in which the patient's clinical condition deteriorates despite standard anticoagulation therapy.

FUNDING

not relevant.

TRIAL REGISTRATION

not relevant.

[Diagnosis and treatment of cerebral venous sinus thrombosis]

Thrombosis of the cerebral sinuses most often affects younger adults. Headache is a common complaint and can be accom­panied by vomiting and papilloedema. The diagnosis rests on magnetic resonance imaging and the treatment consists of heparin or low-molecular weight heparin followed by vitamin K antagonists for three months or more. In fulminant cases local thrombolysis is administered, while symptomatic treatment for increased intracranial pressure is given. In retrospective analyses this approach has been associated with a good outcome – even in cases treated by decompressive craniectomy.