Use of Ocular Coherence Tomography in Children With Idiopathic Intracranial Hypertension-A Single-Center Experience

Diagnostic utility of point-of-care ultrasound and optical coherence tomography for papilloedema in children: a prospective pilot study

BACKGROUND/AIMS

Papilloedema is an important sign of serious neurological disease, but it can be difficult to detect on funduscopy. The purpose of this study was to determine the diagnostic accuracy of point-of-care ultrasound (POCUS) and optical coherence tomography (OCT) for detecting papilloedema in children.

METHODS

This was a prospective observational study at a tertiary care paediatric hospital. Patients were eligible for the study if they underwent a lumbar puncture with opening pressure and had high-quality POCUS and OCT imaging.

RESULTS

A total of 63 eyes from 32 patients were included in the study, 41 (65%) with papilloedema and 22 (35%) without. There were statistically significant differences between the groups in the optic disc elevation (ODE) (p<0.001) and optic nerve sheath diameter (ONSD) (p<0.001) on POCUS, and in the average retinal nerve fibre layer (rNFL) thickness on OCT (p<0.001). Average rNFL thickness had the highest diagnostic accuracy with an area under the curve (AUC) of 0.999 and a 100% sensitivity and 95% specificity for papilloedema (threshold value of ≥108 µm). ODE had an AUC of 0.866 and a 93% sensitivity and 55% specificity (threshold value of ≥0.5 mm). ONSD had an AUC of 0.786 and a 93% sensitivity and 45% specificity (threshold value of ≥5.5 mm).

CONCLUSION

Both OCT and POCUS are potentially useful tools to help diagnose papilloedema in children. Larger studies are needed to further define the role and accuracy of POCUS and OCT in assessing papilloedema in children.

Ultrasound-guided initial diagnosis and follow-up of pediatric idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension in children often presents with non-specific symptoms found in conditions such as hydrocephalus. For definite diagnosis, invasive intracranial pressure measurement is usually required. Ultrasound (US) of the optic nerve sheath diameter provides a non-invasive method to assess intracranial pressure. Transtemporal US allows imaging of the third ventricle and thus assessment for hydrocephalus.

OBJECTIVE

To investigate whether the combination of US optic nerve sheath and third ventricle diameter can be used as a screening tool in pediatric idiopathic intracranial hypertension to indicate elevated intracranial pressure and exclude hydrocephalus as an underlying pathology. Further, to analyze whether both parameters can be used to monitor treatment outcome.

MATERIALS AND METHODS

We prospectively included 36 children with idiopathic intracranial hypertension and 32 controls. Using a 12-Mhz linear transducer and a 1-4-Mhz phased-array transducer, respectively, optic nerve sheath and third ventricle diameters were determined initially and during the course of treatment.

RESULTS

In patients, the mean optic nerve sheath diameter was significantly larger (6.45±0.65 mm, controls: 4.96±0.32 mm) and the mean third ventricle diameter (1.69±0.65 mm, controls: 2.99±1.31 mm) was significantly smaller compared to the control group, P<0.001. Optimal cut-off values were 5.55 mm for the optic nerve sheath and 1.83 mm for the third ventricle diameter.

CONCLUSIONS

The combined use of US optic nerve sheath and third ventricle diameter is an ideal non-invasive screening tool in pediatric idiopathic intracranial hypertension to indicate elevated intracranial pressure while ruling out hydrocephalus. Treatment can effectively be monitored by repeated US, which also reliably indicates relapse.

Optical coherence tomography in papilledema: A probe into the intracranial pressure correlation

PURPOSE

To study the optic nerve head characteristics on optical coherence tomography (OCT) in patients with papilledema and correlate them with intracranial pressure (ICP).

METHODS

A retrospective hospital-based study of 46 eyes of 23 patients with bilateral optic disc edema secondary to increased ICP. The clinical profile and the OCT features in terms of retinal nerve fiber layer thickness (RNFL), ganglion cell inner plexiform layer (GCIPL) thickness, and enhanced depth imaging (EDI) B scan images of the optic nerve head were studied and correlated with the ICP.

RESULTS

Papilledema was secondary to idiopathic intracranial hypertension (IIH) ( n = 20), obstructive hydrocephalus ( n = 2), and communicating hydrocephalus ( n = 1). The mean ICP in 20 IIH patients was 347 mmH 2 O. The ICP and RNFL thickness in all four quadrants were found to be weakly positively correlated: superior RNFL r (38) = 0.17, P = 0.30, and nasal RNFL r (38) = 0.30, P = 0.05, inferior RNFL r (38) = 0.29, P = 0.07, and temporal RNFL, r (38) = -0.001, P = 0.99. The GCIPL layer thickness and the ICP were weakly negatively correlated in all sectors: superior (38) = -0.23, P = 0.16, superonasal, r (38) = -0.07, P = 0.67, inferonasal r (38) = -0.08, P = 0.64, inferior r (38) = -0.21, P = 0.19, inferotemporal r (38) = -0.23, P = 0.17, superotemporal, r (38) -0.21, P = 0.20. Descriptive features on the B scan, such as peripapillary hyperreflective ovoid mass-like structures and microcystic spaces, were observed most commonly with an ICP of 251-350 mmH 2 O, and the hyperreflective dots in the RNFL layer and Bruch's membrane inward denting were observed more commonly with an ICP of 351-450 mmH 2 O.

CONCLUSION

The RNFL thickness in all four quadrants had a weak positive correlation, and the GCIPL layer had a weak negative correlation with the ICP. The EDI descriptive features on OCT may vary with ICP.

Which OCT Measure of the Optic Nerve Head Improves Fastest? Towards Optimizing Early Detection of Resolving Papilledema in Children

Purpose

Optical coherence tomography (OCT) has been used to monitor papilledema. This study aims to determine which OCT-derived measures of the optic nerve head (ONH) detect resolving papilledema in children faster than standard OCT measures.

Methods

Children (≤18 years of age) with papilledema who completed optic nerve SD-OCT pretreatment and had evidence of treatment response on one or more follow-up OCTs within 4 months were included. Standard (mean circumpapillary retinal nerve fiber layer [cpRNFL] thickness), device-derived (per-quadrant cpRNFL) and custom (ONH height, maximum Bruch's membrane displacement [BMD], ONH volume [ONHV], and BMD volume) OCT measures were calculated. Per-eye generalized estimating equations (GEEs) modelled changes in device-derived and custom measures as a function of mean cpRNFL to identify those measures that resolved faster during early (0-2 months) follow-up. Mean cpRNFL coefficients of greater than 1 indicated faster resolving papilledema.

Results

We included 52 eyes of 29 children (mean age, 12.8 years; 72.4% female). In analysis of early follow-up visits (38 eyes from 22 children), nasal cpRNFL and maximum BMD in each quadrant resolved faster than mean cpRNFL (GEE coefficients range, 1.14-3.37). Inferior cpRNFL, superior, nasal, and inferior ONH heights and ONHV resolved slower than mean cpRNFL (GEE coefficients range, 0.67-0.87).

Conclusions

Nasal cpRNFL is a promising device-derived OCT measure for the early detection of resolving papilledema in children compared with mean cpRNFL. Maximum BMD, a custom measure, also shows promise, but its calculation has not yet been incorporated into commercial OCT devices.

Translational Relevance

This study guides the optimal use of OCT in capturing resolving papilledema in children.

Detection of intracranial hypertension in children using optical coherence tomography: a systematic review

OBJECTIVES

To evaluate the diagnostic capability of optical coherence tomography (OCT) in children aged under 18 years old with intracranial hypertension (IH).

DESIGN

Systematic review.

METHODS

We conducted a systematic review using the following platforms to search the keywords 'optical coherence tomography' and 'intracranial hypertension' from inception to 2 April 2020: Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE, PubMed and Web of Science, without language restrictions. Our search returned 2729 records, screened by two independent screeners. Studies were graded according to the Oxford Centre for Evidence-Based Medicine and National Institutes of Health Quality Assessment Tool for observational studies.

RESULTS

Twenty-one studies were included. Conditions included craniosynostosis (n=354 patients), idiopathic IH (IIH; n=102), space-occupying lesion (SOL; n=42) and other pathology (n=29). OCT measures included optic nerve parameters, rim parameters (notably retinal nerve fibre layer thickness) and retinal parameters. Levels of evidence included 2b (n=13 studies), 3b (n=4) and 4 (n=4). Quality of 10 studies was fair and 11 poor. There was inconsistency in OCT parameters and reference measures studied, although OCT did demonstrate good diagnostic capability for IH in craniosynostosis, IIH and SOL.

CONCLUSIONS

This systematic review identified various studies involving OCT to assist diagnosis and management of IH in children with craniosynostosis, IIH, SOL and other pathology, in conjunction with established clinical measures of intracranial pressure. However, no level 1 evidence was identified. Validating prospective studies are, therefore, required to determine optimal OCT parameters in this role and to develop formal clinical guidelines.

PROSPERO REGISTRATION NUMBER

CRD42019154254.

Analysis of the Peripapillary Choroidal Vascular Characteristics in Papilledema Associated with Pseudotumor Cerebri

SIGNIFICANCE

Choroidal vascularity index measured by image binarization method from peripapillary optical coherence tomography sections has been found significantly lower in papilledema patients than healthy controls.

PURPOSE

The purpose of this study was to compare peripapillary choroidal parameters in papilledema patients with control subjects.

METHODS

Peripapillary spectral domain optical coherence tomography scans of 34 patients with papilledema and 34 healthy controls are acquired for the study. Images are binarized with the ImageJ software (National Institutes of Health, Bethesda, MD) to calculate total choroidal area, stromal area, luminal area, and choroidal vascularity index.

RESULTS

Total choroidal area, luminal area, and choroidal vascularity were significantly lower in papilledema patients compared with healthy controls on right (1.343 ± 0.286 vs. 1.694 ± 0.344, P < .001; 0.880 ± 0.209 vs. 1.167 ± 0.255, P < .001; 65.28 ± 2.99% vs. 68.68 ± 2.81%, P < .001, respectively) and left eyes (1.376 ± 0.308 vs. 1.647 ± 0.339, P < .001; 0.899 ± 0.231 vs. 1.134 ± 0.237, P < .001; 64.92 ± 3.44 vs. 68.84 ± 3.23, P < .001, respectively). No difference was found between active and remitted stages of papilledema in terms of choroidal parameters.

CONCLUSIONS

Peripapillary total choroidal area, luminal area, and choroidal vascularity index are significantly reduced in patients with papilledema. These parameters might be beneficial tools for evaluating choroidal vascularity in papilledema quantitatively and differential diagnosis for optic disc edema.

Etiology, pathogenesis and management of idiopathic intracranial hypertension, and role of optic canal size in asymmetric papilledema: A review

Idiopathic intracranial hypertension (IIH) is characterized by raised intracranial pressure of unknown origin that primarily afflicts obese women of childbearing age. There are several treatment options, but currently there are none that are effective for the entire affected population. The lack of a universally effective treatment is related to an incomplete understanding of the etiology of the condition and the lack of a well-defined pathophysiological mechanism for the disease process. Classically, IIH has been thought of as a diagnosis of exclusion once radiographical imaging has ruled out all other causes of elevated intracranial pressure. Today, we know that imaging does capture subtle changes, and might provide keys to finally understand the pathogenesis of IIH so that a definitive treatment can be discovered or developed. Recently, advancements in radiography, optical coherence tomography, and electroretinography have shown promise for the future of IIH evaluation. A topic within IIH imaging that has recently sparked interest is the possibility that the severity of papilledema may have an association with the size of the optic canal. In this article, we also discuss the recent studies on the relationship between asymmetric papilledema and optic canal size.

Optic nerve ultrasonography in monitoring treatment efficacy in pediatric idiopathic intracranial hypertension

PURPOSE

Measurement of optic nerve sheath diameter (ONSD) with ocular ultrasonography (USG) is a noninvasive technique that can be readily used to determine clues of increased intracranial pressure. In this study, we aimed to determine the role of optic nerve sheath diameter measurements in the diagnosis and follow-up of pediatric patients with idiopathic intracranial hypertension (IIH).

METHODS

Eight patients with a diagnosis of IIH with a median age of 11.7 (range 4.5-17) years were examined prospectively. During follow-up, orbital ultrasonography (USG) was performed immediately prior to lumbar puncture (LP) and at 24 h, at 1 week, and between 1 and 18 months after LP. Cranial MRI examinations and automated visual field assessments were performed at baseline and at 3 months, and both measurements were compared with each other.

RESULTS

The mean cerebrospinal fluid opening pressure (37.75 ± 12.64 cm H₂O) and the mean ONSD (5.94 ± 0.46 mm) were correlated. The median follow-up was 16 (range, 12-18 months), and ONSD regressed gradually consistent with clinical and radiologic improvement during follow-up.

CONCLUSIONS

To the best of our knowledge, this is the first prospective pilot study performed on pediatric patients with IIH using orbital USG for ONSD measurements. Despite the small sample size, the present study indicated that orbital USG may be used as a promising noninvasive tool to diagnose increased intracranial pressure and for monitoring treatment efficacy in this special patient population.

Pseudotumor Cerebri Syndrome in Children

PURPOSE OF REVIEW

Pseudotumor cerebri syndrome (PTCS) may affect both children and adults; however, the risk factors and clinical presentation vary greatly between these populations. This review aims to highlight the entity of PTCS in children and the unique considerations in this population; review the epidemiology and demographics; discuss the clinical presentation, revised diagnostic criteria, and approach to evaluation; review management strategies; and discuss the prognosis and long-term outcomes in children with PTCS.

RECENT FINDINGS

Clinical presentation can be variable in children and may be less obvious than in their adult counterparts. Papilledema can also be challenging to diagnose in this population. The upper limits for opening pressure on lumbar puncture differ in children, with a cut-off of 25 cm H20 (or 28 cm H2O in a sedated or obese child). Morbidity related to visual loss, pain and reduced quality of life lends urgency towards accurately identifying, evaluating and managing children with PTCS. There are no randomised controlled studies to allow for evidence-based recommendations for the management of PTCS in children. Further studies are needed to clarify and consolidate management approaches in this population.

Intracranial hypertension: a current review

PURPOSE OF REVIEW

To provide a current review of recent publications with regards to intracranial hypertension.

RECENT FINDINGS

Attempts were made to provide pediatric data; however, the recent completion of the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT) has provided a wealth of data with regards to adult intracranial hypertension.The pediatric incidence of intracranial hypertension ranges between 0.63 and 0.71 per 100 000 children. A majority of pediatric cases responded to acetazolamide, with resolution of headache averaging 3.8 weeks. Most patients require less than 1 year of treatment with male sex, older age at diagnosis, primary intracranial hypertension, and lack of headache being predictors of good response. Fluorescein angiography has the highest accuracy in distinguishing true papilledema from pseudopapilledema. The IIHTT found Frisen grade of papilledema was within 1 grade in 92.8% of patients. Monitoring of potassium levels is not required and aplastic anemia was not seen in patients taking acetazolamide.

SUMMARY

Although the newer pediatric studies report incidence rates in pediatric intracranial hypertension are lower than seen in adults, intracranial hypertension is still a concern in pediatrics. There has been a wealth of information with regards to symptomatology, treatment, and outcomes from the IIHTT that will hopefully assist with management in the pediatric population.

Pediatric Intracranial Hypertension: a Current Literature Review

PURPOSE OF REVIEW

The purpose of this review is to provide an update on pediatric intracranial hypertension.

RECENT FINDINGS

The annual pediatric incidence is estimated at 0.63 per 100,000 in the USA and 0.71 per 100,000 in Britain. The Idiopathic Intracranial Hypertension Treatment Trial found improvement in visual fields, optical coherence tomography, Frisen grade, and quality of life with acetazolamide compared to placebo in adult patients, and these findings have been translated to the pediatric population. Pediatric intracranial hypertension is a disorder that if left untreated can lead to poor quality of life and morbidity. There are no current treatment studies in pediatrics, but adult data suggests acetazolamide remains an acceptable first-line medication.

Bruch's membrane opening on optical coherence tomography in pediatric papilledema and pseudopapilledema

PURPOSE

To determine whether the diameter of Bruch's membrane opening (BMO) can distinguish mild papilledema from pseudopapilledema using optical coherence tomography (OCT).

METHODS

The medical records of pediatric patients with pseudopapilledma due to optic nerve head (ONH) drusen, patients with papilledema, and normal control subjects were retrospectively reviewed. All eyes underwent OCT imaging of the BMO and retinal nerve fiber layer (RNFL). Transverse horizontal diameter of the BMO and papillary height were measured. Mean BMO, papillary height, and RNFL were compared and receiver operating characteristic (ROC) curves were used to calculate the area under the curve (AUC) and determine BMO and RNFL cut-offs for papilledema and pseudopapilledema.

RESULTS

A total of 90 eyes of 90 subjects were included: 58 with pseudopapilledema, 19 with papilledema, and 13 controls. In eyes with papilledema, mean BMO, papillary height, and RNFL decreased as papilledema resolved (1893.8 vs 1582.2 [P = 0.0003], 193.0 vs 108.9 [P < 0.0001], 893.3 vs 695.5 [P = 0.0007], resp.). Eyes with mild papilledema had greater mean BMO and RNFL than those with pseudopapilledema and controls (1893.8 vs 1541.9 vs 1628.8 [P < 0.0001, P = 0.0265] and 193.0 vs 108.7 vs 104.1 [P < 0.0001, P < 0.0001], resp.). Papillary height in mild papilledema was similar to pseudopapilledema but greater than controls (893.3 vs 863.2 vs 593.5 [P = 0.47 and P = 0.0001], resp.). ROC showed good diagnostic discrimination for BMO (AUC = 0.81; 95% CI, 0.70-0.92) and RNFL (AUC = 0.96; 95% CI, 0.93-1.0) in distinguishing mild papilledema from pseudopapilledema.

CONCLUSIONS

The horizontal transverse diameter of BMO is enlarged in eyes with mild papilledema and narrows as papilledema resolves. BMO and RNFL can be used together to help distinguish mild papilledema from pseudopapilledema in children.

Pediatric Pseudotumor Cerebri Syndrome

Idiopathic intracranial hypertension, otherwise known as primary pseudotumor cerebri syndrome (PTCS), most frequently occurs in obese women of childbearing age. However, children may be affected as well. This review will address recent findings regarding demographics, diagnosis, and treatment of pediatric PTCS. Prepubertal children with primary PTCS have an equal sex distribution and less frequent obesity compared with adult patients. However, female gender and obesity are risk factors for primary PTCS in postpubertal children. Compared with adults, children with PTCS more frequently present with ocular motility deficits and more often have associated medical conditions that increase the risk of developing PTCS. Visual field testing may be unreliable, and the optimal modality to monitor visual function is unknown. MRI shows signs of elevated intracranial pressure (ICP) in children with PTCS similar to that of adults. It has now been established that elevated ICP in children ≤18 years old is greater than 25 cm H20 in nonobese, nonsedated children, and greater than 28 cm H2O in the remainder. Optical coherence tomography (OCT) may be used to distinguish pseudopapilledema from papilledema, monitor response to treatment in preverbal children, and identify patients with PTCS at risk for permanent visual loss. However, the precise role of OCT in the management of pediatric PTCS remains to be determined.

Pediatric Pseudotumor Cerebri Syndrome: Diagnosis, Classification, and Underlying Pathophysiology

Pseudotumor cerebri syndrome (PTCS) is defined by the presence of elevated intracranial pressure in the setting of normal brain parenchyma and cerebrospinal fluid. PTCS can occur in the pediatric and adult populations and, if untreated, may lead to permanent visual loss. In this review, discussion will focus on PTCS in the pediatric population and will outline its distinct epidemiology and key elements of diagnosis, evaluation and management. Finally, although the precise mechanisms are unclear, the underlying pathophysiology will be considered.