Ultrasound measurement of optic nerve sheath diameter in a healthy adult Colombian population

The optic nerve sheath in hypertensive disorders of pregnancy and perinatal outcomes: a cohort study

BACKGROUND

Preeclampsia is implicated in 14% of maternal deaths worldwide, mostly due to complications such as intracranial hemorrhage and cerebral edema. Cerebral edema increases intracranial pressure, which can be predicted by ultrasonographic measurement of the optic nerve sheath diameter (ONSD). Greater diameters have been reported in women with preeclampsia and eclampsia; however, data are lacking on the possible association with maternal and neonatal adverse outcomes. This study aimed to determine whether there is an association between hypertensive disorders of pregnancy and the ONSD, and between this measurement and maternal and neonatal adverse outcomes.

METHODS

This was a cohort study involving 183 women in the third trimester of pregnancy or within 24 h following childbirth, distributed as follows: control group (n = 30), gestational hypertension (n = 14), chronic hypertension (n = 12), preeclampsia without severe features (n = 12), preeclampsia with severe features (n = 62), superimposed preeclampsia (n = 23) and eclampsia (n = 30). The participants underwent ocular ultrasonography, and data on maternal and neonatal outcomes were collected from the medical records. To compare the groups, analysis of variance was used for the normally distributed numerical variables and the Kruskal-Wallis test was used for variables with non-normal distribution. Two-tailed p-values ≤ 0.05 were considered statistically significant.

RESULTS

Overall comparison between the seven groups showed no statistically significant difference in the mean ONSD (p = 0.056). Nevertheless, diameters were significantly greater in the eclampsia group compared to the control group (p = 0.003). Greater diameters were associated with maternal admission to the intensive care unit (ICU) (p < 0.01) and maternal near miss (p = 0.01). There was no association between ONSD and admission to the neonatal ICU (p = 0.1), neonatal near miss (p = 0.34) or neonatal death (p = 0.26).

CONCLUSIONS

No association was found between ONSD and the hypertensive disorders of pregnancy in the overall analysis; however, ONSD was greater in women with eclampsia compared to controls. Greater diameters were associated with maternal admission to the ICU and maternal near miss. These findings suggest a potential use for bedside ultrasound as an additional tool for stratifying risk in patients with hypertensive disorders of pregnancy.

Optic nerve sheath measurement to monitor disease activity in giant cell arteritis: a pilot study

INTRODUCTION/OBJECTIVES

Optic nerve sheath (ONS) enhancement using magnetic resonance imaging of the orbits was observed in patients with giant cell arteritis (GCA). We previously showed that ONS diameter (ONSD) by bedside ultrasound is increased in patient with active GCA. This study aims to assess whether ONSD decreases with clinical remission in patients with GCA.

METHODS

A prospective cohort study was conducted from June 2022 to January 2023. Patients who had an optic nerve ultrasound at GCA diagnosis as part of a previous crosssectional study were eligible. Optic nerve ultrasound was performed by the same investigator at diagnosis and month 3. ONSD (includes the optic nerve and its sheath) and optic nerve diameter (OND) were measured. Descriptive statistics for baseline characteristics and paired sample t-test were performed to assess the mean difference in OND and ONSD between diagnosis and month 3.

RESULTS

Nine patients with GCA were included. The median age at disease onset was 79 years (interquartile range (IQR) of 79-82 years), and 7 patients were males. All patients were in clinical remission at month 3 on prednisone (median dose of 15 mg/day, IQR of 10-25 mg). The mean ONSD was lower at month 3 (3.76 mm) compared to baseline (5.98 mm), with a paired mean difference of 2.22 mm (95% CI 1.41-3.03 mm, p < 0.001). As anticipated, OND measurements did not vary between diagnosis and month 3.

CONCLUSION

ONSD on ultrasound improves after 3 months of therapy in patients with GCA. A longer prospective study is required to determine if ONSD is useful to assess disease activity in GCA. Key Points • ONS ultrasound can identify patients with active GCA. • The ONSD on ultrasound is dynamic and improved after 3 months of GCA therapy. • ONS ultrasound may be useful to monitor disease activity in GCA.

Global traumatic brain injury intracranial pressure: from monitoring to surgical decision

Traumatic brain injury (TBI) is a significant global public health issue, heavily impacting human health, especially in low-and middle-income areas. Despite numerous guidelines and consensus statements, TBI fatality rates remain high. The pathogenesis of severe TBI is closely linked to rising intracranial pressure (ICP). Elevated intracranial pressure can lead to cerebral herniation, resulting in respiratory and circulatory collapse, and ultimately, death. Managing intracranial pressure (ICP) is crucial in neuro-intensive care. Timely diagnosis and precise treatment of elevated ICP are essential. ICP monitoring provides real-time insights into a patient's condition, offering invaluable guidance for comprehensive management. ICP monitoring and standardization can effectively reduce secondary nerve damage, lowering morbidity and mortality rates. Accurately assessing and using true ICP values to manage TBI patients still depends on doctors' clinical experience. This review discusses: (a) Epidemiological disparities of traumatic brain injuries across countries with different income levels worldwide; (b) The significance and function of ICP monitoring; (c) Current status and challenges of ICP monitoring; (d) The impact of decompressive craniectomy on reducing intracranial pressure; and (e) Management of TBI in diverse income countries. We suggest a thorough evaluation of ICP monitoring, head CT findings, and GCS scores before deciding on decompressive craniectomy. Personalized treatment should be emphasized to assess the need for surgical decompression in TBI patients, offering crucial insights for clinical decision-making.

Using Optic Nerve Sheath Diameter for Intracranial Pressure (ICP) Monitoring in Traumatic Brain Injury: A Scoping Review

INTRODUCTION

Neuromonitoring represents a cornerstone in the comprehensive management of patients with traumatic brain injury (TBI), allowing for early detection of complications such as increased intracranial pressure (ICP) [1]. This has led to a search for noninvasive modalities that are reliable and deployable at bedside. Among these, ultrasonographic optic nerve sheath diameter (ONSD) measurement is a strong contender, estimating ICP by quantifying the distension of the optic nerve at higher ICP values. Thus, this scoping review seeks to describe the existing evidence for the use of ONSD in estimating ICP in adult TBI patients as compared to gold-standard invasive methods.

MATERIALS AND METHODS

This review was conducted in accordance with the Joanna Briggs Institute methodology for scoping reviews, with a main search of PubMed and EMBASE. The search was limited to studies of adult patients with TBI published in any language between 2012 and 2022. Sixteen studies were included for analysis, with all studies conducted in high-income countries.

RESULTS

All of the studies reviewed measured ONSD using the same probe frequency. In most studies, the marker position for ONSD measurement was initially 3 mm behind the globe, retina, or papilla. A few studies utilized additional parameters such as the ONSD/ETD (eyeball transverse diameter) ratio or ODE (optic disc elevation), which also exhibit high sensitivity and reliability.

CONCLUSION

Overall, ONSD exhibits great test accuracy and has a strong, almost linear correlation with invasive methods. Thus, ONSD should be considered one of the most effective noninvasive techniques for ICP estimation in TBI patients.

Frequency of idiopathic intracranial hypertension with ultrasound in patients with fibromyalgia: Relation with function, central sensitization, and neuropathic pain

OBJECTIVE

The purpose of this study was to evaluate the prevalence of idiopathic intracranial hypertension (IIH) in fibromyalgia (FMS) patients by utilizing ultrasound to measure the optic nerve sheath diameter (ONSD), a marker of elevated intracranial pressure and also to investigate the relationship with function, fatigue, quality of life (QOL), central sensitization (CS) and neuropathic pain.

METHODS

The study encompassed 80 female FMS patients and 75 healthy controls. Ultrasound was employed to measure the average ONSD in both groups. Conditions potentially elevating intracranial pressure were ruled out following neurological assessments. Pain (via visual analog scale, VAS), function (revised Fibromyalgia Impact Questionnaire, r-FIQ), QOL (Short Form-36, SF-36), fatigue (fatigue severity scale, FACIT), CS (Central Sensitization Scale), and neuropathic pain (Douleur Neuropathique-4) were evaluated.

RESULTS

The average ONSD was significantly higher in the patient group than the control group. Patients with ONSD >5.5 mm consistent with IIH were categorized as Group 1 (n = 54, 67.5%), while those with a diameter of 5.5 mm and below-formed Group 2. VAS pain (p = .033) and FIQ-R scores (p = .033) were significantly higher in Group 1 than Group 2. Headache was found more common in Group 1.

CONCLUSION

This study unveils a substantial occurrence (67.5%) of IIH in FMS patients, suggesting shared pathophysiological mechanisms contributing to symptoms like fatigue, headache, and cognitive dysfunction. Additionally, these findings implicate heightened functional impairment, CS, headache, and fatigue in FMS patients with IIH.