Transorbital sonography in idiopathic intracranial hypertension: Single‐center study, systematic review and meta‐analysis

Abstract

Background and PurposeTransorbital sonography (TOS) provides a noninvasive tool to detect intracranial pressure by assessing optic nerve sheath diameter (ONSD) and optic disc elevation (ODE). The utility of TOS in the diagnosis of idiopathic intracranial hypertension (IIH) has been increasingly recognized.MethodsA single‐center case‐control study sought to compare TOS‐acquired ONSD and ODE among IIH‐cases versus patients with other neurological diseases (controls). Furthermore, a systematic review and meta‐analysis was conducted to present pooled mean differences and diagnostic measures of ONSD and ODE between IIH‐cases and controls.ResultsIn the single‐center study, consisting of 31 IIH‐cases and 34 sex‐ and age‐matched controls, ONSD values were higher among IIH‐cases than controls (p<.001), while ODE was more prevalent in cases (65% vs. 15%; p<.001). The receiver‐operating characteristic (ROC)‐curve analysis revealed that the optimal cutoff value of ONSD for predicting IIH was 5.15 mm, with an area under the curve (AUC) of 0.914 (95% confidence interval [CI]: 0.861‐0.967) and sensitivity and specificity values of 85% and 90%, respectively. In a meta‐analysis of 14 included studies with 415 IIH‐cases, ONSD and ODE values were higher in IIH‐cases than controls (mean difference in ONSD 1.20 mm; 95% CI: 0.96‐1.44 mm and in ODE 0.3 mm; 95% CI: 0.33‐0.67 mm). With regard to ONSD, pooled sensitivity, specificity, and diagnostic odds ratio were calculated at 85.5% (95% CI: 77.9‐90.8%), 90.7% (95% CI: 84.6‐94.5%), and 57.394 (95% CI: 24.597‐133.924), respectively. The AUC in summary ROC‐curve analysis was 0.878 (95% CI: 0.858‐0.899) with an optimal cutoff point of 5.0 mm.ConclusionsTOS has a high diagnostic utility for the noninvasive diagnosis of IIH and may deserve wider implementation in everyday clinical practice.

Characterization of Ocular Sonography Findings and their Relationship to Clinical Features from a South Indian Cohort of Idiopathic Intracranial Hypertension

“…Our study confirms that ONSD values in IIH patients were significantly higher than in controls, a well-established observation reaffirmed in our research. [ 4 5 6 7 8 9 10 11 12 ] However, the mean ONSD values in our IIH patients were slightly lower than those reported previously. [ 4 5 6 7 8 9 10 11 12 ] It is possible that racial and ethnic differences and larger height and body habitus among Caucasians may account for the differences in ONSD observed between studies.…”

“…[ 4 5 6 7 8 9 10 11 12 ] However, the mean ONSD values in our IIH patients were slightly lower than those reported previously. [ 4 5 6 7 8 9 10 11 12 ] It is possible that racial and ethnic differences and larger height and body habitus among Caucasians may account for the differences in ONSD observed between studies. The cutoffs we determined for IIH diagnosis (0.51 cm in the right eye and 0.5 cm in the left eye) fall within the range of previously reported values (ranging from 0.48 to 0.63 cm).…”

“…Various ONSD cutoff values have been reported in literature, which could be attributed to the ethnic variations and methodologic differences between study populations. [ 12 ] In our study, we derived ONSD cutoffs for the diagnosis of IIH in the South Indian population. This holds significant implications as the standard values and cutoffs specific to IIH in the Indian population have not been previously documented.…”

“…We followed the standard practice of measuring ONSD values 3 mm behind the optic nerve head, similar to previous studies. [ 4 5 6 7 8 9 10 11 12 ]…”

“…[ 4 5 6 7 8 9 10 11 ] ONSD values and cutoffs for diagnosing IIH might also differ with factors such as age, gender, body mass index (BMI), ethnicity, and differences in method of measurement. [ 12 ] ONSD measurements obtained by magnetic resonance imaging (MRI) may yield higher values than those acquired through ultrasound. [ 4 ]…”