Optic nerve sheath diameter correlates with the presence and severity of acute mountain sickness: evidence for increased intracranial pressure

Increased intracranial pressure is suspected in the pathogenesis of acute mountain sickness (AMS), but no studies have correlated it with the presence or severity of AMS. We sought to determine whether increased optic nerve sheath diameter, a surrogate measure of intracranial pressure, is associated with the presence and severity of AMS. We performed a cross-sectional study of travelers ascending through Pheriche, Nepal (4,240 m), from March 3 to May 14, 2006. AMS was assessed using the Lake Louise score. Optic nerve sheath diameter was measured by ultrasound. Ultrasound exams were performed and read by separate blinded observers. Two-hundred eighty seven subjects were enrolled. Ten of these underwent repeat examination. Mean optic nerve sheath diameter was 5.34 mm [95% confidence interval (CI) 5.18–5.51 mm] in the 69 subjects with AMS vs. 4.46 mm (95% CI 4.39–4.54 mm) in the 218 other subjects ( P < 0.0001). There was also a positive association between optic nerve sheath diameter and total Lake Louise score ( P for trend < 0.0001). In a multivariate logistic regression model of factors associated with AMS, optic nerve sheath diameter was strongly associated with AMS (odds ratio 6.3; 95% CI, 3.7–10.8; P < 0.001). In 10 subjects with repeat examinations, change in Lake Louise score had a strong positive correlation with change in optic nerve sheath diameter ( R2 = 0.84, P < 0.001). Optic nerve sheath diameter, a proxy for intracranial pressure, is associated with the presence and severity of AMS.

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Optic nerve sheath diameter, intracranial pressure and acute mountain sickness on Mount Everest: a longitudinal cohort study

British Journal of Sports Medicine ◽

10.1136/bjsm.2007.045286 ◽

2008 ◽

Vol 42 (3) ◽

pp. 183-188 ◽

Cited By ~ 41

Author(s):

A I Sutherland ◽

D S Morris ◽

C G Owen ◽

A J Bron ◽

R C Roach

Keyword(s):

Cohort Study ◽

Optic Nerve ◽

Intracranial Pressure ◽

Acute Mountain Sickness ◽

Optic Nerve Sheath Diameter ◽

Optic Nerve Sheath ◽

Longitudinal Cohort Study ◽

Mount Everest ◽

Nerve Sheath ◽

Mountain Sickness

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Optic nerve sheath diameter changes at high altitude and in acute mountain sickness: meta-regression analyses

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2020-317717 ◽

2020 ◽

pp. bjophthalmol-2020-317717

Author(s):

Tou-Yuan Tsai ◽

George Gozari ◽

Yung-Cheng Su ◽

Yi-Kung Lee ◽

Yu-Kang Tu

Keyword(s):

Optic Nerve ◽

High Altitude ◽

Acute Mountain Sickness ◽

Optic Nerve Sheath Diameter ◽

Optic Nerve Sheath ◽

Cochrane Library ◽

Regression Analyses ◽

Spline Regression ◽

Nerve Sheath ◽

Mountain Sickness

Background/aimsTo assess changes in optic nerve sheath diameter (ONSD) at high altitude and in acute mountain sickness (AMS).MethodsCochrane Library, EMBASE, Google Scholar and PubMed were searched for articles published from their inception to 31st of July 2020. Outcome measures were mean changes of ONSD at high altitude and difference in ONSD change between subjects with and without AMS. Meta-regressions were conducted to investigate the relation of ONSD change to altitude and time spent at that altitude.ResultsEight studies with 248 participants comparing ONSD from sea level to high altitude, and five studies with 454 participants comparing subjects with or without AMS, were included. ONSD increased by 0.14 mm per 1000 m after adjustment for time (95% CI: 0.10 to 0.18; p<0.01). Restricted cubic spline regression revealed an almost linear relation between ONSD change and time within 2 days. ONSD was greater in subjects with AMS (mean difference=0.47; 95% CI: 0.14 to 0.80; p=0.01; I2=89.4%).ConclusionOur analysis shows that ONSD changes correlate with altitude and tend to increase in subjects with AMS. Small study number and high heterogeneity are the limitations of our study. Further large prospective studies are required to verify our findings.

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Ultrasonographic optic nerve sheath diameter to detect increased intracranial pressure in adults: a meta-analysis

Acta Radiologica ◽

10.1177/0284185118776501 ◽

2018 ◽

Vol 60 (2) ◽

pp. 221-229 ◽

Cited By ~ 10

Author(s):

Sung-Eun Kim ◽

Eun Pyo Hong ◽

Heung Cheol Kim ◽

Si Un Lee ◽

Jin Pyeong Jeon

Keyword(s):

Optic Nerve ◽

Intracranial Pressure ◽

Meta Analysis ◽

Optic Nerve Sheath Diameter ◽

Optic Nerve Sheath ◽

Increased Intracranial Pressure ◽

Summary Receiver Operating Characteristic ◽

Nerve Sheath ◽

Study Characteristics ◽

Meta Regression

Background The optimal optic nerve sheath diameter (ONSD) cut-off for identifying increased intracranial pressure (IICP) remains unclear in adult patients. Purpose To validate the diagnostic accuracy of ultrasonographic (US) ONSD > 5.0 mm as a cut-off for detecting IICP by computed tomographic (CT) through a meta-analysis. Material and Methods A systemic literature review was performed of online databases from January 1990 to September 2017. A bivariate random-effects model was used to estimate pooled sensitivity, specificity, and diagnostic odds ratio (DOR) with 95% confidence intervals (CIs). A summary receiver operating characteristic (SROC) graph was used to provide summary points for sensitivity and specificity. Meta-regression tests were performed to estimate the influence of the study characteristics on DOR. Publication bias was assessed using Deeks' funnel plot asymmetry test. Results Six studies with 352 patients were included in the meta-analysis. US ONSD > 5.0 mm revealed pooled sensitivity of 99% (95% CI = 96–100) and specificity of 73% (95% CI = 65–80) for IICP detection. DOR was 178. The area under the SROC curve was 0.981, indicating a good level of accuracy. Meta-regression studies showed no significant associations between DOR and study characteristics such as probe mode (relative DOR [RDOR] = 0.60; P = 0.78), study quality (RDOR = 0.52; P = 0.67), IICP prevalence (RDOR = 0.04; P = 0.17), or pathology at admission (RDOR = 1.30; P = 0.87). Conclusion US ONSD > 5.0 mm can be used to rapidly detect IICP in adults in emergency departments and intensive care units. Further meta-analysis based on individual patient-level databases is needed to confirm these results.

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Optic Nerve Sheath Diameter Ultrasound and the Diagnosis of Increased Intracranial Pressure

Critical Care Nursing Clinics of North America ◽

10.1016/j.cnc.2015.10.005 ◽

2016 ◽

Vol 28 (1) ◽

pp. 95-99 ◽

Cited By ~ 7

Author(s):

Christopher Hylkema

Keyword(s):

Optic Nerve ◽

Intracranial Pressure ◽

Optic Nerve Sheath Diameter ◽

Optic Nerve Sheath ◽

Increased Intracranial Pressure ◽

Nerve Sheath

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Accuracy of Noninvasive Intraocular Pressure or Optic Nerve Sheath Diameter Measurements for Predicting Elevated Intracranial Pressure in Cryptococcal Meningitis

Open Forum Infectious Diseases ◽

10.1093/ofid/ofu093 ◽

2014 ◽

Vol 1 (3) ◽

Cited By ~ 20

Author(s):

Henry W. Nabeta ◽

Nathan C. Bahr ◽

Joshua Rhein ◽

Nicholas Fossland ◽

Agnes N. Kiragga ◽

...

Keyword(s):

Intraocular Pressure ◽

Optic Nerve ◽

Intracranial Pressure ◽

Cryptococcal Meningitis ◽

Optic Nerve Sheath Diameter ◽

Diagnostic Value ◽

Optic Nerve Sheath ◽

Increased Intracranial Pressure ◽

Nerve Sheath ◽

Immunodeficiency Virus

Abstract Background. Cryptococcal meningitis is associated with increased intracranial pressure (ICP). Therapeutic lumbar puncture (LP) is recommended when the initial ICP is >250 mm H2O, yet the availability of manometers in Africa is limited and not always used where available. We assessed whether intraocular pressure could be a noninvasive surrogate predictor to determine when additional therapeutic LPs are necessary. Methods. Ninety-eight human immunodeficiency virus-infected Ugandans with suspected meningitis (81% Cryptococcus) had intraocular pressure measured using a handheld tonometer (n = 78) or optic nerve sheath diameter (ONSD) measured by ultrasound (n = 81). We determined the diagnostic performance of these methods for predicting ICP vs a standard manometer. Results. The median ICP was 225 mm H2O (interquartile range [IQR], 135–405 mm H2O). The median intraocular pressure was 28 mm Hg (IQR, 22–37 mm Hg), and median ultrasound ONSD was 5.4 mm (IQR, 4.95–6.1 mm). ICP moderately correlated with intraocular pressure (ρ = 0.45, P < .001) and with ultrasound ONSD (ρ = 0.44, P < .001). There were not discrete threshold cutoff values for either tonometry or ultrasound ONSD that provided a suitable cutoff diagnostic value to predict elevated ICP (>200 mm H2O). However, risk of elevated ICP >200 mm H2O was increased with an average intraocular pressure >28 mm Hg (relative risk [RR] = 3.03; 95% confidence interval [CI], 1.55–5.92; P < .001) or an average of ONSD >5 mm (RR = 2.39; 95% CI, 1.42–4.03; P = .003). As either intraocular pressure or ONSD increased, probability of elevated ICP increased (ie, positive predictive value increased). Conclusions. Noninvasive intraocular pressure measurements by tonometry or ultrasound correlate with cerebrospinal fluid opening pressure, but both are a suboptimal replacement for actual ICP measurement with a manometer.

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