MRI findings as markers of idiopathic intracranial hypertension

Consensus recommendations for the assessment and management of idiopathic intracranial hypertension in children and young people

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a potentially disabling condition. There is a lack of evidence and national guidance on how to diagnose and treat paediatric IIH, leading to variation in clinical practice. We conducted a national Delphi consensus via the Children's Headache Network to propose a best-practice diagnostic and therapeutic pathway.

METHODS

The Delphi process was selected as the most appropriate methodology for examining current opinion among experts in the UK. 104 questions were considered by 66 healthcare professionals, addressing important aspects of IIH care: assessment, diagnosis, treatment, follow-up and surveillance. General paediatricians, paediatric neurologists, ophthalmologists, opticians, neuroradiologists and neurosurgeons with a clinical interest or experience in IIH, were invited to take part.

RESULTS

The Delphi process consisted of three rounds comprising 104 questions (round 1, 67; round 2, 24; round 3 (ophthalmological), 13) and was completed between March 2019 and August 2021. There were 54 and 65 responders in the first and second rounds, respectively. The Delphi was endorsed by the Royal College of Ophthalmologists, which engaged 59 ophthalmologists for round 3.

CONCLUSIONS

This UK-based Delphi consensus process reached agreement for the management of paediatric IIH and has been endorsed by the Children's Headache Network and more broadly, the British Paediatric Neurology Association. It provides a basis for a pragmatic clinical approach. The recommendations will help to improve clinical care while minimising under and over diagnosis.

The diagnostic value of MRI findings in pediatric idiopathic intracranial hypertension: a case-control study

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a rare medical condition in children. Based on the different radiological findings reported in various studies in pediatric IIH, this study was conducted to determine the diagnostic value of MRI findings in diagnosing IIH in children.

METHODS

In this retrospective study, the medical records of all children aged 1 to 18 years who visited Ghaem Hospital in Mashhad, Iran, between 2012 and 2022 and were diagnosed with IIH were gathered. Forty-nine cases of children with IIH and 48 control cases of children with the first unprovoked seizure with no indications of increased intracranial pressure for comparison were selected. Patient demographic information and MRI findings were extracted. The comparison between different MRI findings in the case and control groups was conducted using statistical tests.

RESULTS

In the case group, the mean diameter of the subarachnoid space expansion around the optic nerve was 5.96 ± 1.21, compared to 4.79 ± 0.33 in the control group, with statistically significant difference (P < 0.001). All the patients with flattening of the posterior globe or transverse sinus stenosis were in the case group, and the frequency of these findings in the case group was significantly higher than in the control group (P < 0.001). The majority of patients (95.5%) classified under category 3 and 4 of empty sella were part of the case group, and the statistical test results indicated a significant difference between the two groups (P < 0.001). The optic nerve sheath diameter cut-off of 5.35 mm, when used for expansion of the subarachnoid space around the optic nerve, with a sensitivity of 82% and a specificity of 100% in diagnosing IIH.

CONCLUSION

The most reliable diagnostic indicators for diagnosing IIH in children are perioptic subarachnoid space expansion with high sensitivity, and posterior globe flattening and transverse sinus stenosis with high specificity.

Dimensions of Arachnoid Bulk Ratio: A Superior Optic Nerve Sheath Index for Intracranial Pressure

Background Discrepancies in the literature regarding optimal optic nerve sheath diameter (ONSD) cutoffs for intracranial pressure (ICP) necessitate alternative neuroimaging parameters to improve clinical management. Purpose To evaluate the diagnostic accuracy of the dimensions of the perineural subarachnoid space to the optic nerve sheath ratio, measured using US, in predicting increased ICP. Materials and Methods In a prospective cohort study from April 2022 to December 2023, patients with suspected increased ICP underwent optic nerve US to determine the dimensions of arachnoid bulk (DAB) ratio and ONSD before invasive ICP measurement. Correlation between the parameters and ICP, as well as diagnostic accuracy, was assessed using area under the receiver operating characteristic curve (AUC) analysis. Results A total of 30 participants were included (mean age, 39 years ± 14 [SD]; 24 female). The DAB ratio and ONSD were significantly larger in participants with increased ICP (38% [0.16 of 0.42] and 14% [0.82 of 6.04 mm], respectively; P < .001). The DAB ratio showed a stronger correlation with ICP than ONSD (rs = 0.87 [P < .001] vs rs = 0.61 [P < .001]). The DAB ratio and ONSD optimal cutoffs for increased ICP were 0.5 and 6.5 mm, respectively, and the ratio had higher sensitivity (100% vs 92%) and specificity (94% vs 83%) compared with ONSD. Moreover, the DAB ratio better predicted increased ICP than ONSD, with a higher AUC (0.98 [95% CI: 0.95, 1.00] vs 0.86 [95% CI: 0.71, 0.95], P = .047). Conclusion An imaging ratio was proposed to predict ICP based on the relative anatomy of the cerebrospinal fluid space, demonstrating more accurate diagnosis of increased ICP and a strong correlation with ICP values, suggesting its potential utility as a neuroimaging marker in clinical settings. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Shepherd in this issue.

Rare Complications of CSF Diversion: Paradoxical Neuroimaging Findings in a Double, Chiasmic Case Report

Two patients with CSF shunting systems exhibited symptoms of altered intracranial pressure. Initial neuroimaging led to misinterpretation, but integrating clinical history and follow-up imaging revealed the true diagnosis. In the first case, reduced ventricular size was mistaken for CSF overdrainage, while the actual problem was increased intracranial pressure, as seen in slit ventricle syndrome. In the second case, symptoms attributed to intracranial hypertension were due to CSF overdrainage causing tonsillar displacement and hydrocephalus. Adjusting the spinoperitoneal shunt pressure resolved symptoms and imaging abnormalities. These cases highlight the necessity of correlating clinical presentation with a deep understanding of CSF dynamics in shunt assessments.

The Pseudotumor Cerebri Syndrome

Pseudotumor cerebri syndrome is a syndrome of increased cerebrospinal fluid pressure without ventriculomegaly, mass lesion, or meningeal abnormality. It is either primary (idiopathic intracranial hypertension, IIH) or secondary. A secondary cause is unlikely when adhering to the diagnostic criteria. Permanent visual loss occurs if undetected or untreated, and the associated headaches may be debilitating. Fulminant disease may result in blindness despite aggressive treatment. This study addresses the diagnosis and management of IIH including new insights into the pathobiology of IIH, updates in therapeutics and causes of overdiagnosis.

Is foramen magnum decompression for acquired Chiari I malformation like putting a finger in the dyke? - A simplistic overview of artificial intelligence in assessing critical upstream and downstream etiologies

Background

Missed diagnosis of evolving or coexisting idiopathic (IIH) and spontaneous intracranial hypotension (SIH) is often the reason for persistent or worsening symptoms after foramen magnum decompression for Chiari malformation (CM) I. We explore the role of artificial intelligence (AI)/convolutional neural networks (CNN) in Chiari I malformation in a combinatorial role for the first time in literature, exploring both upstream and downstream magnetic resonance findings as initial screening profilers in CM-1. We have also put together a review of all existing subtypes of CM and discuss the role of upright (gravity-aided) magnetic resonance imaging (MRI) in evaluating equivocal tonsillar descent on a lying-down MRI. We have formulated a workflow algorithm MaChiP 1.0 (Manjila Chiari Protocol 1.0) using upstream and downstream profilers, that cause de novo or worsening Chiari I malformation, which we plan to implement using AI.

Materials and Methods

The PRISMA guidelines were used for "CM and machine learning and CNN" on PubMed database articles, and four articles specific to the topic were encountered. The radiologic criteria for IIH and SIH were applied from neurosurgical literature, and they were applied between primary and secondary (acquired) Chiari I malformations. An upstream etiology such as IIH or SIH and an isolated downstream etiology in the spine were characterized using the existing body of literature. We propose the utility of using four selected criteria for IIH and SIH each, over MRI T2 images of the brain and spine, predominantly sagittal sequences in upstream etiology in the brain and multiplanar MRI in spinal lesions.

Results

Using MaChiP 1.0 (patent/ copyright pending) concepts, we have proposed the upstream and downstream profilers implicated in progressive Chiari I malformation. The upstream profilers included findings of brain sagging, slope of the third ventricular floor, pontomesencephalic angle, mamillopontine distance, lateral ventricular angle, internal cerebral vein-vein of Galen angle, and displacement of iter, clivus length, tonsillar descent, etc., suggestive of SIH. The IIH features noted in upstream pathologies were posterior flattening of globe of the eye, partial empty sella, optic nerve sheath distortion, and optic nerve tortuosity in MRI. The downstream etiologies involved spinal cerebrospinal fluid (CSF) leak from dural tear, meningeal diverticula, CSF-venous fistulae, etc.

Conclusion

AI would help offer predictive analysis along the spectrum of upstream and downstream etiologies, ensuring safety and efficacy in treating secondary (acquired) Chiari I malformation, especially with coexisting IIH and SIH. The MaChiP 1.0 algorithm can help document worsening of a previously diagnosed CM-1 and find the exact etiology of a secondary CM-I. However, the role of posterior fossa morphometry and cine-flow MRI data for intracranial CSF flow dynamics, along with advanced spinal CSF studies using dynamic myelo-CT scanning in the formation of secondary CM-I is still being evaluated.

The Relationship between Lumbar Puncture Opening Pressure and Retinal Nerve Fiber Layer Thickness in the Diagnosis of Idiopathic Intracranial Hypertension: Is a Lumbar Puncture Always Necessary?

OBJECTIVES

Idiopathic intracranial hypertension (IIH), is characterized by elevated intracranial pressure (ICP) without an identified cause. Today, lumbar puncture (LP) is the most common method used for diagnosis by measuring cerebrospinal fluid (CSF) pressure to reflect intracranial pressure. This invasive examination has significant disadvantages, such as complications and negative experiences for patients. Therefore, noninvasive methods for ICP measurement are desired. Optical coherence tomography (OCT) is widely used for the diagnosis and follow-up of IIH patients as it reflects papilledema. The aim of this study is to investigate the relationship between CSF pressure and OCT parameters and the ability of OCT in the diagnostic approach.

METHODS

In our study, patients who were followed up with a diagnosis of IIH with complete neuro-ophthalmological examinations, including visual acuity (VA), visual field, and OCT imaging within 24 hours before lumbar puncture, were retrospectively evaluated. CSF pressure, visual acuity LogMAR, mean deviation of visual fields, retinal nerve fiber layer (RNFL) thickness measured by OCT, and treatment protocols were obtained from our hospital data system.

RESULTS

A total of 42 eyes of 21 patients were enrolled in the study. A statistically significant positive and moderate correlation was found between CSF pressure values and average RNFL thickness ( r =0.507; P =0.001). The same relationship was demonstrated in all 4 quadrants: inferior, superior, nasal, and temporal.

CONCLUSIONS

Increased peripapillary RNFL thickness in optic nerve head OCT may be correlated with increased ICP in IIH patients. A larger number of patients are needed to better understand the correlation between OCT parameters and CSF pressure in patients with IIH.

Idiopathic intracranial hypertension in two twin sisters

Idiopathic intracranial hypertension (IIH) is a condition of unknown aetiology characterised by an increase in the intracranial pressure. Familial cases of IIH are rare and not well-understood. We present two monozygotic twins who developed IIH two years apart. The case involves two monozygotic female twins developing IIH in their 50s. They presented with a history of blurry vision and headaches. The diagnosis included the neurological, radiological and ophthalmological examination, excluding other causes. Both patients received treatment with acetazolamide, successfully resolving the papilloedema and restoring a normal visual field. This case highlights the occurrence of IIH among twins presenting at similar periods, emphasising the potential genetic influence. Clinicians should alert and educate the family regarding the risk factors and potential symptoms of this condition in the unlikely occurrence that other family members are affected.

Understanding Visual Disorders through Correlation of Clinical and Radiologic Findings

Patients presenting with visual disturbances often require a neuroimaging approach. The spectrum of visual disturbances includes three main categories: vision impairment, ocular motility dysfunction, and abnormal pupillary response. Decreased vision is usually due to an eye abnormality. However, it can also be related to other disorders affecting the visual pathway, from the retina to the occipital lobe. Ocular motility dysfunction may follow disorders of the cranial nerves responsible for eye movements (ie, oculomotor, trochlear, and abducens nerves); may be due to any abnormality that directly affects the extraocular muscles, such as tumor or inflammation; or may result from any orbital disease that can alter the anatomy or function of these muscles, leading to diplopia and strabismus. Given that pupillary response depends on the normal function of the sympathetic and parasympathetic pathways, an abnormality affecting these neuronal systems manifests, respectively, as pupillary miosis or mydriasis, with other related symptoms. In some cases, neuroimaging studies must complement the clinical ophthalmologic examination to better assess the anatomic and pathologic conditions that could explain the symptoms. US has a major role in the assessment of diseases of the eye and anterior orbit. CT is usually the first-line imaging modality because of its attainability, especially in trauma settings. MRI offers further information for inflammatory and tumoral cases. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

MRI signs of intracranial hypertension in morbidly obese and normal-weight individuals

PURPOSE

 Idiopathic intracranial hypertension (IIH) is associated with intracranial abnormalities, although not obligatory, which can be detected with cranial MRI. Obesity is an important risk factor for IIH and a pathogenetic link is suspected but the extent to which these MRI signs are already related to obesity has not yet been examined. We investigated whether IIH-MRI signs are present more often in obese individuals with a BMI > 30 kg/m² than in individuals of normal weight.

MATERIALS AND METHODS

 Brain MRI of 32 obese and 53 normal-weight participants from the Food-Chain-Plus cohort were analyzed for three main signs of IIH: (I) stenosis of the transverse sinus, (II) increased width of the optic nerve sheath, and (III) reduction of pituitary height. In addition, a scoring system for the MRI signs was applied. Furthermore, tortuosity of the optic nerve and flattening of the posterior globe were considered as additional MRI signs.

RESULTS

 Obese participants had a significantly higher MRI score (p < 0.001) than those in the normal-weight cohort, with significant differences in quantitative measurements of cerebral venous sinus stenosis (p < 0.001), widening of the optic nerve sheath (p < 0.05), and flattening of the pituitary gland (p < 0.05) also always being observed more frequently and in a more pronounced manner in the obese group. Furthermore, our findings correlated significantly with BMI and proportionately with hip and waist circumference.

CONCLUSION

 Obese individuals show a significantly higher prevalence of cerebral MRI signs related to IIH. This supports the hypothesis that obesity is a risk factor for possible intracranial hypertension and reinforces the suspicion that obesity is involved in the pathomechanism of IIH.

KEY POINTS

  · Obesity is associated with changes such as those seen in IIH.. · BMI, weight, and body measurements correlate with the expression of MRI signs of IIH.. · To prevent IIH symptoms in obesity, the pathomechanism must be further clarified..

CSF hyperdynamics in rats mimicking the obesity and androgen excess characteristic of patients with idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a syndrome exhibiting elevated intracranial pressure (ICP), visual disturbances, and severe headache. IIH primarily affects young obese women, though it can occur in individuals of any age, BMI, and sex. IIH is characterized by systemic metabolic dysregulation with a profile of increased androgen hormones. However, the contribution of obesity/hormonal perturbations to cerebrospinal fluid (CSF) dynamics remains unresolved.

METHODS

We employed obese female Zucker rats and adjuvant testosterone to reveal IIH causal drivers. ICP and CSF dynamics were determined with in vivo experimentation and magnetic resonance imaging, testosterone levels assessed with mass spectrometry, and choroid plexus function revealed with transcriptomics.

RESULTS

Obese rats had undisturbed CSF testosterone levels and no changes in ICP or CSF dynamics. Adjuvant testosterone treatment of obese rats elevated the CSF secretion rate, although with no effect on the ICP, due to elevated CSF drainage capacity of these rats.

CONCLUSIONS

Obesity in itself therefore does not suffice to recapitulate the IIH symptoms in rats, but modulation of CSF dynamics appears with adjuvant testosterone treatment, which mimics the androgen excess observed in female IIH patients. Obesity-induced androgen dysregulation may thus contribute to the disease mechanism of IIH and could potentially serve as a future therapeutic target.

Effect of General Anesthesia on MR Optic Nerve Sheath Diameter in the Pediatric Population

BACKGROUND

Papilledema is thought to be the hallmark sign of increased intracranial pressure (ICP). Distension of the subarachnoid space within the optic nerve sheath is also commonly reported in MR studies as an indirect sign of increased ICP.

HYPOTHESIS

General anesthesia and positive pressure ventilation might result in changes in optic sheath diameter (OSD) observed on clinical brain MRI.

STUDY TYPE

Retrospective.

POPULATION

One hundred forty-five  patients (154 MRI scans, 7.3 years ± 5.1); 97 studies in the anesthesia group (4.4 years ± 3.4) of which 22 had papilledema, and 57 in the non-anesthesia group (12.3 years ± 3.2), of which 28 had papilledema.

FIELD STRENGTH/SEQUENCE

1.5T or 3.0T volumetric T2 images. T2 images were obtained from different vendors.

ASSESSMENT

OSD, optic nerve diameter (OND), and peri-optic cerebrospinal fluid (CSF) were measured manually on T2-weighted MR images for various population subgroups (with and without anesthesia; with or without papilledema). The correlation between these measurements and the clinical diagnosis of papilledema was evaluated via receiver operating characteristic (ROC) analysis.

STATISTICAL TESTS

Chi-square test; Mann-Whitney Test; Spearman's test and ROCs; Interclass correlation coefficient, P = 0.05.

RESULTS

General anesthesia resulted in significantly larger mean OSD in patients with or without papilledema (7.3 ± 1.0 mm vs. 6.1 ± 1.1 mm and 6.7 ± 1.0 mm vs. 5.4 ± 0.9 mm, respectively). In the non-anesthesia group, the average OSD values (6.1 ± 1.1 mm) were significantly higher in papilledema patients compared to non-papilledema patients (5.4 ± 0.9 mm), with larger peri-optic CSF rim (1.6 ± 0.4 mm vs. 1.3 ± 0.3 mm). In the anesthesia group, OND was significantly larger in papilledema patients (3.4 ± 0.4 mm vs. 3.1 ± 0.5 mm), though the average peri-optic CSF rim did not reach a significance in papilledema compared with non-papilledema patients (2.0 ± 0.3 mm vs. 1.8 ± 0.4 mm, P = 0.06). In patients with general anesthesia, peri-optic CSF rim had a limited correlation with increased ICP.

DATA CONCLUSION

In the pediatric population, imaging findings of increased OSD on brain MRI might be related to general anesthesia rather than increased ICP. The interpretation of optic nerve sheath distention should be reported cautiously in conjunction with anesthesia status, especially in the pediatric population.

EVIDENCE LEVEL

4 Technical Efficacy: 5.

Interthalamic Adhesion: Can it be used to Diagnose Idiopathic Intracranial Hypertension?

OBJECTIVE

This retrospective study aimed at determining the dimension of the interthalamic adhesion (ITA) in patients with the idiopathic intracranial hypertension (IIH) for assisting in preoperative radiologic diagnosis.

METHODS

The study universe consisted of magnetic resonance images of 20 patients with IIH (age: 22.70 ± 4.04 years, sex: 14 females and 6 males) and 20 normal subjects (age 22.30± 2.94 years, sex: 14 females and 6 males). To determine the morphology of ITA, its height (vertical diameter) and width (horizontal diameter) were measured on the coronal and axial planes, respectively.

RESULTS

The height and width of ITA in IIH were measured as 2.58 ± 0.71 mm (range: 1.40-4.20 mm) and 2.73 ± 0.77 mm (range: 1.70-4.40 mm), respectively. Its height and width in controls were measured as 4.99 ± 1.04 mm (range: 2.70-6.30 mm) and 4.92 ± 1.11 mm (range: 2.60-6.50 mm), respectively. ITA height and width in IIH was significantly smaller compared with controls (P < 0.001). For an arbitrary cutoff of 3.85 mm, the sensitivity of the height of ITA was 85% with 95% specificity. For an arbitrary cutoff of 4.45 mm, the sensitivity of the width of ITA was 75% with 100% specificity.

CONCLUSIONS

The height and width of ITA are approximately 50% smaller in IIH than controls; therefore alterations in the dimension of ITA may be a valuable radiologic sign for the diagnosis of IIH.

Impact of rater experience and referral question on detecting magnetic resonance imaging features of idiopathic intracranial hypertension

BACKGROUND AND PURPOSE

In idiopathic intracranial hypertension (IIH), magnetic resonance imaging (MRI) features are promising diagnostic markers, but the impact of rater experience and the specific referral question is unknown.

METHODS

From the Vienna Idiopathic Intracranial Hypertension database, patients were included with definitive IIH and routine cranial MRI performed during diagnostic work-up. Frequencies of partial empty sella (ES), optic nerve sheath distension (ONSD), optic nerve tortuosity (ONT), posterior globe flattening (PGF) and transverse sinus stenosis (TSS) were compared in three settings: (i) real-world rating, (ii) junior neuroradiologist without special IIH training and (iii) senior neuroradiologist with experience in IIH imaging (gold standard).

RESULTS

Magnetic resonance imaging scans of 84 IIH patients (88% female, mean age 33.5 years) were evaluated. By gold standard, ONSD was the most frequent (64.3%) followed by TSS (60.0%), ONT (46.4%), ES (44.4%) and PGF (23.8%). Compared to the gold standard, IIH features were described significantly less frequently in routine MRI reports (ONSD 28.6%, ONT 13.1%, PGF 4.8%, TSS 42.9%, p < 0.01 respectively) except for ES (42.9%, p = 0.9). A specific referral question regarding IIH increased detection rates in routine reports, but rates remained significantly lower than by gold standard. In contrast, a rating by a neuroradiologist without special training produced significantly higher frequencies of ONSD (81.0%, p < 0.01) and ONT (60.7%, p < 0.01) but not of ES (47.6%), PGF (29.8%) and TSS (68.1%).

CONCLUSIONS

Idiopathic intracranial hypertension MRI features are underestimated in routine MRI reports and partly overcalled by less experienced neuroradiologists, driven by features less well known or methodologically difficult. Reevaluation of MRI scans by an experienced rater (and to a lesser degree a specific referral question) improves diagnostic accuracy.

A Neuro-Ophthalmologist's Guide to Advances in Intracranial Pressure Measurements

Cerebrospinal fluid disorders have a wide-ranging impact on vision, headache, cognition and a person's quality of life. Due to advances in technology and accessibility, intracranial pressure measurement and monitoring, usually managed by neurosurgeons, are being employed more widely in clinical practice. These developments are of direct importance for Ophthalmologists and Neurologists because the ability to readily measure intracranial pressure can aide management decisions. The aim of this review is to present the emerging evidence for intracranial pressure measurement methods and interpretation that is relevant to Neuro-ophthalmologists.

Secondary headaches - red and green flags and their significance for diagnostics

A small percentage of patients suffer from a secondary headache syndrome. It is imperative that clinicians are able to differentiate primary headache syndromes from secondary headache syndromes, as failure to do so significantly worsens morbidity and mortality. Recent advances in our understanding of pathobiological mechanisms offer useful information on these enigmatic disorders. We now understand that the causes of secondary headache syndromes can vary significantly - these may be infectious, inflammatory, vascular, traumatic or structural in origin. A well-taken history and targeted physical examination coupled with appropriate investigations can enable these syndromes to be recognized consistently and thus allow their timely and appropriate treatment. Along with their epidemiology, some of their key characteristics shall thus be discussed in this review so as to aid the busy clinician at the bedside. Red flags including sudden onset, high pain intensity, pattern of change of a preexisting headache, focal neurological signs or seizure, systemic signs and precipitation by physical activity can guide the clinician to suspect a secondary headache. Importantly a preexisting headache is not an exclusion of a secondary headache - it might even be a predisposition in certain cases.

MRI features of idiopathic intracranial hypertension are not prognostic of visual and headache outcome

BACKGROUND

In idiopathic intracranial hypertension (IIH), certain MRI features are promising diagnostic markers, but whether these have prognostic value is currently unknown.

METHODS

We included patients from the Vienna-Idiopathic-Intracranial-Hypertension (VIIH) database with IIH according to Friedman criteria and cranial MRI performed at diagnosis. Presence of empty sella (ES), perioptic subarachnoid space distension (POSD) with or without optic nerve tortuosity (ONT), posterior globe flattening (PGF) and transverse sinus stenosis (TSS) was assessed and multivariable regression models regarding visual outcome (persistent visual impairment/visual worsening) and headache outcome (headache improvement/freedom of headache) were fitted.

RESULTS

We included 84 IIH patients (88.1% female, mean age 33.5 years, median body mass index 33.7). At baseline, visual impairment was present in 70.2% and headache in 84.5% (54.8% chronic). Persistent visual impairment occurred in 58.3%, visual worsening in 13.1%, headache improvement was achieved in 83.8%, freedom of headache in 26.2%. At least one MRI feature was found in 78.6% and 60.0% had ≥3 features with POSD most frequent (64.3%) followed by TSS (60.0%), ONT (46.4%), ES (44.0%) and PGF (23.8%). In multivariable models, there was no association of any single MRI feature or their number with visual impairment, visual worsening, headache improvement or freedom. Visual impairment at baseline predicted persistent visual impairment (odds ratio 6.3, p<0.001), but not visual worsening. Chronic headache at baseline was significantly associated with lower likelihood of headache freedom (odds ratio 0.48, p=0.013), but not with headache improvement.

CONCLUSIONS

MRI features of IIH are neither prognostic of visual nor headache outcome.

Prognostic role of optic nerve sheath diameter in stroke in emergency department, A case control study

Background

Sonographic measurement of optic nerve sheath diameter (ONSD) can reflect intracranial pressure (ICP) indirectly and determine the neurology intensive care unit (NICU) requirement and mortality in acute ischemic stroke (AIS).

Aim

To demonstrate the effectiveness of ONSD to determine mortality, morbidity, and NICU requirement on patients with the AIS.

Methods

The sonographic ONSD measurements were performed on each patient with AIS, over 18 years old. All patients were categorized according to the Oxfordshire Community Stroke Project (OCSP) classification system. MRI images were examined for increased ICP, and the patients were categorized into two groups as increased ICP (i-ICP) and normal ICP. The ONSD results were evaluated in terms of classifications, outcomes, and prognosis of the patients.

Results

One hundred and five patients were included and 31 (35.2%) were in the i-ICP group. The median ONSDs were 5.26 mm in the i-ICP group and 4.62 mm in the normal ICP group (P < 0.001). The median ONSDs were 5.13 mm in the NICU group and 4.69 mm in the neurology ward (NW) group (P = 0.001). The total anterior circulation infarction (TACI) subgroup had higher ONSDs than the others (TACI: 5.27 mm; PACI: 4.73 mm; POCI: 4.77 mm; and LACI: 4.64 mm, P < 0.001). The NICU requirements were higher in the TACI subgroup. The median ONSD was 5.42 mm in the deceased group (survived: 4.77 mm, P < 0.001).

Conclusion

ONSD may be favorable for predicting the increased ICP and the NICU requirement in OCSP subgroups. Moreover, ONSD can be used to foresee the mortality of AIS.

Modelling idiopathic intracranial hypertension in rats: contributions of high fat diet and testosterone to intracranial pressure and cerebrospinal fluid production

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a condition characterized by increased intracranial pressure (ICP), impaired vision, and headache. Most cases of IIH occur in obese women of childbearing age, though age, BMI, and female sex do not encompass all aspects of IIH pathophysiology. Systemic metabolic dysregulation has been identified in IIH with a profile of androgen excess. However, the mechanistic coupling between obesity/hormonal perturbations and cerebrospinal fluid dynamics remains unresolved.

METHODS

Female Wistar rats were either fed a high fat diet (HFD) for 21 weeks or exposed to adjuvant testosterone treatment for 28 days to recapitulate IIH causal drivers. Cerebrospinal fluid (CSF) and blood testosterone levels were determined with mass spectrometry, ICP and CSF dynamics with in vivo experimentation, and the choroid plexus function revealed with transcriptomics and ex vivo isotope-based flux assays.

RESULTS

HFD-fed rats presented with increased ICP (65%), which was accompanied by increased CSF outflow resistance (50%) without altered CSF secretion rate or choroid plexus gene expression. Chronic adjuvant testosterone treatment of lean rats caused elevated ICP (55%) and CSF secretion rate (85%), in association with increased activity of the choroid plexus Na⁺,K⁺,2Cl^- cotransporter, NKCC1.

CONCLUSIONS

HFD-induced ICP elevation in experimental rats occurred with decreased CSF drainage capacity. Adjuvant testosterone, mimicking the androgen excess observed in female IIH patients, elevated the CSF secretion rate and thus ICP. Obesity-induced androgen dysregulation may thus contribute to the disease mechanism of IIH.

Magnetic Resonance Imaging Findings in Idiopathic Intracranial Hypertension With and Without Pulsatile Tinnitus: An Age-Matched Cohort Study

OBJECTIVE

Many but not all patients with idiopathic intracranial hypertension (IIH) have pulsatile tinnitus (PT). However, little is known about why some patients with IIH develop PT and others do not. The purpose of this study was to determine if any of the classic magnetic resonance imaging (MRI)-detectable markers of IIH differ between patients with and without PT, thereby shedding light on potential pathophysiology.

METHODS

A retrospective age-matched cohort study of patients with documented IIH (diagnosed by neuro-ophthalmologist) was performed. All patients had MRI performed around the time of diagnosis. MRIs were assessed for 16 variables known to be associated with IIH (e.g., pituitary displacement/empty sella, optic nerve tortuosity, transverse sinus stenosis, inferior cerebellar tonsils, arachnoid granulations, slit-like ventricles) by two blinded neuroradiologists. All binary variables were analyzed via χ2 test with Yates correction, or Fisher exact when appropriate. Continuous variables were analyzed via Student t test. Inter-rater reliability for binary variables was assessed by Cohen κ. For continuous variables, intraclass correlation coefficient was calculated.

RESULTS

Forty age-matched patients with IIH met the inclusion criteria (20 with PT, 20 without PT). For all known binary MRI findings associated with IIH, there were no statistically significant differences between groups. Likewise, there were no statistically significant differences for continuous variables.

CONCLUSIONS

The classic MRI findings associated with IIH do not differ between patients with and without PT, suggesting that systemic (rather than localized intrinsic or extrinsic) factors may play a critical role in the pathophysiology.

Transorbital sonography and MRI reliability to assess optic nerve sheath diameter in idiopathic intracranial hypertension

BACKGROUND AND PURPOSE

The purpose of this study was to evaluate the performance of magnetic resonance imaging (MRI) in measuring the optic nerve sheath diameter (ONSD) compared to the established method transorbital sonography (TOS) in patients with idiopathic intracranial hypertension (IIH).

METHODS

Twenty-three patients with IIH were prospectively included applying IIH diagnostic criteria. All patients received a lumbar puncture with assessment of the cerebrospinal fluid (CSF) opening pressure to assure the IIH diagnosis. Measurement of ONSD was performed 3 mm posterior to inner sclera surface in B-TOS by an expert examiner, while three independent neuroradiologists took measurements in axial T-weighted MRI examinations. The sella turcica with the pituitary gland (and potential presence of an empty sella) and the trigeminal cavity were also assessed on sagittal and transversal T1-weighted MRI images by one independent neuroradiologist.

RESULTS

The means of ONSD between ultrasound and MRI measurements were 6.3 mm (standard deviation [SD] = 0.6 mm) and 6.2 mm (SD = 0.8 mm). The interrater reliability between three neuroradiologists showed a high interclass correlation coefficient (ICC) (confidence interval: .573 < ICC < .8; p < .001). In patients with an empty sella, the ONSD evaluated by MRI was 6.6 mm, while measuring 6.1 mm in patients without empty sella. No correlation between CSF opening pressure and ONSD was found.

CONCLUSIONS

MRI can reliably measure ONSD and yields similar results compared to TOS in patients with IIH. Moreover, patients with empty sella showed significantly larger ONSD than patients without empty sella.

Presumptive Idiopathic Intracranial Hypertension Based on Neuroimaging Findings: A Referral Pattern Study

BACKGROUND

Radiologic findings of intracranial hypertension (RAD-IH) are common in idiopathic intracranial hypertension (IIH) patients. Paralleling the increasing rates of obesity, the burden of IIH is growing. Urgent neuro-ophthalmology consultations for possible IIH in patients with incidentally detected RAD-IH are increasing, with many patients receiving unnecessary lumbar punctures (LPs) and treatments. This retrospective observational study aimed to determine the prevalence of neuro-ophthalmology consultations for RAD-IH, rate of funduscopic examination by referring providers, prevalence of papilledema, outcomes after neuro-ophthalmic evaluation, and rates of misdiagnosis.

METHODS

Records of 1,262 consecutive new patients seen in one neuro-ophthalmology clinic from January 2019 to January 2020 were reviewed. We identified patients who were: 1) referred with concern for IIH because of findings of RAD-IH; 2) referred for "papilledema"; 3) referred with a diagnosis of IIH; and 4) referred for spontaneous cranial cerebrospinal fluid (CSF) leaks. In addition to basic demographic profiles for all groups, detailed information was collected for patients referred solely for RAD-IH, including referral patterns, prior history of IIH, previous LPs, prior medical or surgical treatment(s), risk factors for increased intracranial pressure (ICP), presenting symptoms, radiologic features observed on neuroimaging, and final disposition. When available, the neuroimaging was reviewed by an expert neuroradiologist.

RESULTS

Of 1,262 consecutive new patients, 66 (5%) were referred specifically for RAD-IH; most referrals came from neurologists (58%); 8/66 (12%) patients had papilledema; 16/66 (24%) patients had prior LP and 13/66 (20%) were already treated based on MRI findings; and 22/66 (33%) patients had ≤2 RAD-IH. Only 34/66 (52%) of patients referred for RAD-IH had prior funduscopic examinations. We confirmed papilledema in 26/82 (32%) patients referred for "papilledema." Only 29/83 (35%) patients referred with a diagnosis of IIH had active papilledema, and 3/16 (19%) patients with spontaneous CSF leaks had papilledema. In total, 247/1,262 (20%) new patients were referred to our clinic over 1 year with concern for IIH, among whom only 66 (27%) were confirmed to have active IIH with papilledema.

CONCLUSIONS

One in 5 new patient referrals seen in our neuro-ophthalmology clinic were referred because of concern for increased ICP, but only 1/4 had active papilledema. Most patients referred for isolated RAD-IH do not have papilledema, many having undergone unnecessary LPs and treatments. The burden of these "rule-out IIH" consultations is overwhelming and will only continue to increase with the concurrent rise of obesity and IIH, straining the already limited neuro-ophthalmologic resources available in the US.

Noninvasive methods to monitor intracranial pressure

PURPOSE OF REVIEW

Intracranial pressure (ICP) is determined by the production of and outflow facility of cerebrospinal fluid. Since alterations in ICP are implicated in several vision-threatening and life-threatening diseases, measurement of ICP is necessary and common. All current clinical methods to measure ICP are invasive and carry the risk for significant side effects. Therefore, the development of accurate, reliable, objective, and portal noninvasive devices to measure ICP has the potential to change the practice of medicine. This review discusses recent advances and barriers to the clinical implementation of noninvasive devices to determine ICP.

RECENT FINDINGS

Many noninvasive methods to determine ICP have been developed. Although most have significant limitations limiting their clinical utility, several noninvasive methods have shown strong correlations with invasively obtained ICP and have excellent potential to be developed further to accurately quantify ICP and ICP changes.

SUMMARY

Although invasive methods remain the mainstay for ICP determination and monitoring, several noninvasive biomarkers have shown promise to quantitatively assess and monitor ICP. With further refinement and advancement of these techniques, it is highly possible that noninvasive methods will become more commonplace and may complement or even supplant invasively obtained methods to determine ICP in certain situations.

Idiopathic intracranial hypertension in patients with cerebral small vessel disease: A case report

INTRODUCTION

Idiopathic intracranial hypertension (IIH) is a clinical syndrome characterized by increased intracranial pressure (ICP) without any identifiable cause. However, restrictions of cerebrospinal fluid absorption from the cerebral venous system, the glymphatic system overflow, and the cerebrospinal fluid's lymphatic pathways may be involved in the pathophysiology of IIH. Furthermore, an impaired glymphatic system is also implicated in the initiation and progression of cerebral small vessel disease (CSVD). Here, we reported a case of CSVD with concomitant IIH, possibly associated with the brain's glymphatic and lymphatic system dysfunction.

CASE CONCERN

A 39-year-old male presented with worsening headaches over the bilateral parietal areas during the past year and nausea for 2 days. Fundus examination revealed bilateral papilledema and lumbar puncture suggestive of elevated ICP, laboratory results showed hyperhomocysteinemia and mutation of methylenetetrahydrofolate reductase C677T. On magnetic resonance imaging, subcortical small infarct, white matter lesions, lacunes, enlarged perivascular spaces and dilatation of the optic nerve sheaths was detected, and right transverse sinus stenosis and a hypoplastic left sinus were showed on contrast-enhanced magnetic resonance venography.

DIAGNOSIS

The diagnoses of IIH, CSVD, transverse sinus stenosis, and hyperhomocysteinemia were performed.

INTERVISION AND OUTCOMES

The patient received antihypertensive, antiplatelet, anti-atherosclerotic, and homocysteine-lowering therapies. Finally, the patient's symptoms remised, and the increased ICP returned to normal; however, the bilateral TSS persisted after 3 months of follow-up.

CONCLUSIONS

In this case, we speculate that the normal glymphatic outflow pathway may serve as a compensatory mechanism for regulating increased ICP in patients with bilateral venous sinus obstruction, indicating impaired venous outflow pathway, possibly associated with dysfunction of the glymphatic and lymphatic systems in patients with CSVD.

Association between RS3763040 polymorphism of the AQP4 and idiopathic intracranial hypertension in a Spanish Caucasian population

Background

Idiopathic intracranial hypertension (IIH) is a condition of increased intracranial pressure of unknown aetiology. Principal symptoms are headache, visual disturbances, and obesity, together with elevated intracranial pressure. Unspecified MRI, despite normal ventricle size, suggests alterations in the water flux cellular mediated by the brain water channel aquaporin-4 (AQP4). The association among IIH, cerebral spinal fluid malfunction, reabsorption, and functional or regulatory modifications of AQP4 is a hypothesis not confirmed.

Methods

Blood samples were collected from 72 Spanish Caucasian patients with IIH. A genetic association study was performed with bi-allelic SNPs rs1049305 and rs10244884 in AQ1 and rs2075575, rs3763043, and rs3763040 in AQ4. Genetic data were compared with 94 healthy Caucasian control. Statistics studies were assessed by Pearson's χ 2 tests for 2 × 2 (alleles) or 3 × 2 (genotypes) contingency tables. A P value < 0.05 was considered to be statistically significant.

Results

Statistically significant differences were found when comparing the results of the rs3763040 polymorphism of the AQ4 locus of IIH patients with controls, in genotypic frequencies (P = 0.0442) and allele frequencies (P = 0.0171). Furthermore, a statistically significant difference (P = 0.0207) was found in individuals carrying and not carrying the minor allele (GG + GA individuals vs GG homozygotes). No statistically significant differences were found when comparing allele and genotypic frequencies for SNPs rs1049305 and rs10244884 of AQ1 and rs2075575 and rs3763043 of AQ4.

Conclusions

The association of AQP4 and specifically of its polymorphic variant rs3763040 with IIH should be validated in other ethnic groups in order to assess more precisely the role of AQP4 in the etiopathogenesis of IIH.

Efficacy of Dural Sinus Quantitative Measurements in Idiopathic Intracranial Hypertension : A Practical Diagnostic Feature

BACKGROUND AND PURPOSE

This study aimed to investigate the potential contribution of quantitative measurements of dural venous sinuses to the diagnosis of idiopathic intracranial hypertension (IIH) and the relationship between IIH and dural venous sinus dimensions on 3D post-gadolinium T1-weighted magnetic resonance (MR) images.

MATERIAL AND METHODS

A total of 129 individuals (57 IIH patients and 72 controls) who complained of headache and underwent both magnetic resonance venography (MRV) and precontrast/postcontrast 3D T1-weighted MR imaging between 2018 and 2021 were included in this retrospective study. Dural venous sinus and jugular vein diameters were measured in all cases using post-gadolinium 3D T1 TFE images. The presence of transverse sinus (TS) hypoplasia and occipital sinus variation, the number and size of arachnoid granulations in the TS, and the presence of brain parenchymal herniation were also evaluated. Cut-off values that maximized accurate diagnosis of IIH were established on the receiver operating characteristic curve. The sensitivity and specificity of the diagnosis of IIH based on quantitative measurements of the dural sinus were calculated.

RESULTS

The ratios of the maximum to minimum TS diameters and the minimum TS diameters to minimum sigmoid sinus (SS) diameters were significantly higher in IIH patients than in the control group (p < 0.001). The diagnostic sensitivity and specificity values of TS_max/TS_min and TS_{min sum}/SS_{min sum} parameters for the detection of IIH were 84.2%, 84.7% and 83.3%, 84.2%, respectively.

CONCLUSION

Practical measurements from multiplanar T1 sequences can be useful for both quantitative assessment and overcoming misinterpretation due to anatomical variation.

Higher cerebrospinal fluid (CSF) opening pressure in patients with idiopatic intracranial hypertension (IIH) with permanent visual impairment

Objective The aim of this study was to identify potential visual prognostic markers in patients with idiopathic intracranial hypertension (IIH).  Methods Patients with IIH of an outpatient headache clinic in São Paulo, Brazil, were retrospectively evaluated and divided in two groups with and without the presence of permanent visual deficit attributed to IIH. Body mass index (BMI), opening CSF pressure, and the frequency of IIH related MRI abnormalities were compared between these two groups.  Results Twenty-nine patients, with 35,39±9,93 years, being twenty-eight female (96.55%) were included in the study. Reduced visual acuity attributed to IIH was registered in 16 (55.17%). According to BMI 17.4% had overweight and 82.6% were obese. Brain MRI was normal in 6 (20.69%). BMI, obesity, and the presence of MRI abnormalities were not associated with visual impairment. Initial CSF opening pressure was significantly higher in the group of patients with reduced visual acuity (40.4±13.14 x 30.5±3.41, P=0,015).  Conclusion Higher CSF opening pressure at onset was significantly associated with a higher percentage of visual impairment in patients with IIH suggesting this measure as a potential prognostic marker for patients with IIH.  

Cerebrospinal fluid (CSF) and idiopatic intracranial hypertension (IIH): a critical review

Pseudotumor cerebri is a syndrome that results from increased intracranial pressure. The main symptoms are headache, vision disturbances, and pulsatile tinnitus. Definitive diagnosis requires the presence of clinical and/or radiological signs of intracranial hypertension, high opening pressure on lumbar puncture (LP), and normal CSF constitution. Several studies have evaluated new contributions of CSF in the clinical evaluation and the in understanding of the pathophysiology of pseudotumor cerebri. Such studies have included the analysis of inflammatory biomarkers, adipokines, proteomic analysis, and CSF flow studies. In this review, we present the main results obtained so far and critically discuss the present status and the potential role of research involving the CSF in this condition. Based on current knowledge, it is possible to conclude that CSF research with new biomarkers has not yet provided information that can be employed in clinical practice at this moment. However, a better understanding of the constitution and dynamics of CSF circulation in patients with pseudotumor cerebri has brought some information about this condition and can potentially improve our knowledge about this condition in the future.

The Reliability of Venous Sinus Stenosis Using Non Contrast 3D MRV in Prediction of the Diagnosis of Idiopathic Intracranial Hypertension, A Case Control Study

Idiopathic intracranial hypertension, or shorty IIH, refers to a clinical syndrome in which there is elevated CSF pressure and papilledema in the lack of any focal neurological signs. It is largely a diagnosis of exclusion, but imaging workup is undertaken routinely in order to rule out other pathologies. In this study we tried to evaluate the prevalence of venous sinus abnormalities using the simpler and less invasive non contrast enhanced 3D TOF MRV in group of patients with IIH, using the combined stenosis score, and compare this score with a group of controls, to assess the accuracy of MRV alone as an individual test in predicting the diagnosis of IIH.

The study sample included 44 patients and 25 control subjects, following MRV analysis it was found that a combined severity score of cut of value of 4.5 for the combined conduit score (CCS) was associated with 79% sensitivity and 88.6 specificity for the diagnosis of IIH, and a cut off value of 5.5 for the adjusted score method gives a 83% sensitivity and 88.6 % specificity for the diagnosis.

MRV is a valuable in the diagnosis of IIH; non contrast 3D MRV is an efficient test and gives valuable diagnostic information.

Cerebral Venous Outflow Implications in Idiopathic Intracranial Hypertension-From Physiopathology to Treatment

In this review, we provide an update on the pathogenesis, diagnosis, and management of adults with idiopathic intracranial hypertension (IIH) and implications of the cerebral venous system, highlighting the progress made during the past decade with regard to mechanisms of the venous outflow pathway and its connection with the cerebral glymphatic and lymphatic network in genesis of IIH. Early diagnosis and treatment are crucial for favorable visual outcomes and to avoid vision loss, but there is also a risk of overdiagnosis and misdiagnosis in many patients with IIH. We also present details about treatment of intracranial hypertension, which is possible in most cases with a combination of weight loss and drug treatments, but also in selected cases with surgical interventions such as optic nerve sheath fenestration, cerebral spinal fluid (CSF) diversion, or dural venous sinus stenting for some patients with cerebral venous sinus stenosis, after careful analysis of mechanisms of intracranial hypertension, patient clinical profile, and method risks.

[CME: Idiopathic Intracranial Hypertension]

CME: Idiopathic Intracranial Hypertension Abstract. Idiopathic intracranial hypertension is a pressure-induced secondary headache disorder and optic neuropathy. It primarily affects obese women of childbearing age and poses an interdisciplinary challenge both diagnostically and therapeutically. The most common symptom of this disorder are headaches frequently accompanied by photo- and/or phonophobia, whose semiology often resembles that of migraine, followed by transient visual obscurations and pulsatile tinnitus. While protection of visual acuity and visual fields are of first therapeutical priority, adequate headache treatment also plays a key role. In the majority of cases, conservative treatment including weight loss and pharmacological therapy is sufficient. In case of a fulminant disease course or loss of visual function, interventional strategies can be applied additionally. Headache treatment is guided by the predominant semiology.

Advances in the Understanding of the Complex Role of Venous Sinus Stenosis in Idiopathic Intracranial Hypertension

Idiopathic intracranial hypertension (IIH) is a disorder characterized by elevated intracranial pressure (ICP) that predominantly affects young obese women. IIH is a diagnosis of exclusion. That is, if increased ICP is suspected, magnetic resonance imaging and magnetic resonance venography of the brain are recommended to exclude secondary causes. Imaging findings, such as empty sella, orbital findings, meningocele, and encephalocele, are not diagnostic of ICP, nor does their absence exclude ICP either. Therefore, venous manometry is recommended as the gold standard for evaluation, regardless of previous anatomic imaging results. Venous manometry is an invasive examination that is frequently applied to derive physiologic information concerning the nature of the pressure gradient. However, the pathogenesis of IIH has not been fully elucidated. The presence of venous sinus stenosis in a subset of patients has provided some support for the potential mechanisms underlying this condition. Hence, this review provides an up‐to‐date discussion on the potential pathogenic mechanisms of IIH with a special focus on venous sinus stenosis.

[Papilledema as a sign of intracranial hypertension]

Papilledema (choked disk) is a sign of intracranial hypertension (ICH) - condition that presents danger not only for patient's vision, but also for their life. Despite the fact that ICH is usually a neurosurgical pathology, sometimes an ophthalmologist is the first doctor such patients visit, most often in a primary healthcare clinic. At the same time, as practice shows, not all ophthalmologists are well aware about in this pathology; difficulties occur in differential diagnosis of papilledema against similar changes of the optic nerve head seen during ophthalmoscopic examination. This article reviews scientific literature on ICH, including benign ICH, diagnosis and differential diagnosis of papilledema. The authors also share their decades-long experience of working in a neurosurgical facility.

Pediatric Intracranial Hypertension: A Spotlight on Imaging, the Idiopathic Intracranial Hypertension Treatment Trial, and COVID-19 Associated Cases

Primary intracranial hypertension (PIH) is characterized by clinical signs of increased intracranial pressure, papilledema, elevated opening pressure, and absence of mass lesion, hydrocephalus, or meningeal enhancement on neuroimaging. Visual changes are a common presenting feature and if untreated there is risk of irreversible vision loss. There have been recent proposed changes to the criteria for PIH along with studies looking at the differences in imaging characteristics between adult and pediatric PIH. The presence of transverse sinus stenosis alone was highly sensitive and specific for pediatric PIH. The Idiopathic Intracranial Hypertension Treatment Trial was an adult, multicenter study that examined the use of acetazolamide and weight loss on the course of PIH. The study confirmed many previously held beliefs including the most common presenting symptom in PIH is headache. Most patients present with bilateral papilledema with 58.2% of patients having symmetric Frisen scale grading and within one grade in 92.8%. Although diplopia is a common reported symptom, very few have evidence of cranial nerve palsy. Male gender, high-grade papilledema, and decreased visual acuity at presentation are risk factors for treatment failure. Acetazolamide use is associated with mild metabolic acidosis. During acetazolamide treatment, monitoring for hypokalemia or aplastic anemia is not recommended. Monitoring transaminases in the titration phase of treatment should be considered due to a case of transaminitis and pancreatitis with elevated lipase. Newer case reports have also seen associations of secondary intracranial hypertension with concurrent COVID-19 infection and MIS-C.

Transcranial Sonography in the Diagnosis of Pituitary Tumor-A Direct Comparison With MRI

BACKGROUND

Transcranial sonography (TCS) is a convenient tool for detecting certain brain diseases, such as brain tumors. Few studies have reported on the use of TCS in the area of Sella turcica. The accuracy and repeatability of Sella turcica with or without pituitary tumor is not clear.

PURPOSE

This study aimed to investigate the feasibility and accuracy of TCS to measure the size of Sella turcica according to the measurement in MRI and determine its diagnostic performance in individuals with pituitary tumor.

MATERIALS AND METHODS

In this cross-sectional comparative study, healthy volunteers and patients with pituitary tumor were enrolled for examination of TCS and MRI between October 2020 and July 2021. The transverse diameter (D1, cm) of Sella turcica and the volume of the pituitary tumor were measured by TCS and MRI, respectively, and compared by using Student's t-test or Mann-Whitney test, using the receiver operating characteristic (ROC) curve to analyze the diagnostic value of D1 in TCS for pituitary tumor.

RESULTS

A total of 75 healthy volunteers and 51 patients with pituitary tumor were evaluated. In healthy volunteers, the mean D1 was 1.30 ± 0.35 (range, 0.82-3.22) by TCS and 1.32 ± 0.29 (range, 0.94-3.02) by MRI (P = 0.054). In patients with pituitary tumor, the mean D1 was 2.0 ± 0.65 (range, 0.90-3.48) by TCS and 2.42 ± 1.0 (range, 0.80-4.70) by MRI (P = 0.000). The median measurement volume was 4.41 and 6.59 cm³ in TCS and MR, respectively (P = 0.000). The mean D1 was 1.31 ± 0.35 in healthy volunteers and 2.0 ± 0.65 cm in patients with pituitary tumor (P = 0.000). In the ROC curve analysis, the area under the curve was 0.836, and the optimal cutoff value (1.56) exhibited a sensitivity and specificity of 67.31 and 88.0%, respectively.

CONCLUSION

The consistency between the two imaging technologies performed well in D1 measurement, while the volume of the pituitary tumor was smaller as assessed by TCS than by MRI. D1 in TCS had good diagnostic performance in pituitary tumor.