Transorbital sonography: A non-invasive bedside screening tool for detection of pseudotumor cerebri syndrome

Abstract

Background Our objective was to assess optic nerve sheath diameter (a marker of elevated intracranial pressure) and optic disc elevation (a marker of papilledema) in pseudotumor cerebri syndrome using transorbital sonography. Methods The study was a prospective case-control study. We included patients with new-onset pseudotumor cerebri syndrome and matched healthy controls. All had fundoscopy, lumbar puncture with opening pressure and transorbital sonography. Sonography was assessed by a blinded observer. Results We evaluated 45 patients and included 23 cases. We recruited 35 controls. Optic nerve sheath diameter was larger in pseudotumor cerebri syndrome compared to controls (6.3 ± 0.9 mm versus 5.0 ± 0.5 mm, p < 0.001) and so was optic disc elevation (0.9 ± 0.4 mm versus 0.4 ± 0.1 mm, p < 0.001). The optimal cut-off point for optic nerve sheath diameter was 6 mm with a sensitivity of 74% for prediction of pseudotumor cerebri syndrome and 68% for prediction of elevated opening pressure. Specificity was 94%. The optimal cut-off point for optic disc elevation was 0.6 mm. Sensitivity was 100% and specificity 83% for prediction of pseudotumor cerebri syndrome. Conclusion Optic disc elevation and optic nerve sheath diameter are increased in new-onset pseudotumor cerebri syndrome. Optic disc elevation achieved high specificity and excellent sensitivity for diagnosis of pseudotumor cerebri syndrome. Transorbital sonography (TOS) is a potential, non-invasive screening tool for pseudotumor cerebri syndrome in headache clinics.

Retinal vessel dynamics analysis as a surrogate marker for raised intracranial pressure in patients with suspected idiopathic intracranial hypertension

“…Patients enrolled at RH served as the experimental group with bilateral fundus videos in all three situations. In addition, optic nerve sheath diameter (ONSD) was measured using transorbital sonography (TOS) before and after CSF drainage, as previously described (21). Papilledema grade was measured from the fundus photos in the IIH-group using Fris en grading (22).…”

Idiopathic intracranial hypertension: expanding our understanding

“…Several recent studies [34,35] have looked at changes in optic nerve sheath diameter and optic disc elevation, as measured by orbital ultrasound Bscans, both showing a significant difference compared to healthy controls. B-scans can have potential variations resulting in a so-called 'blooming' effect, affecting measurement accuracy [36].…”

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

“…After reading the full-text articles, 14 were further excluded. Finally, we identified 14 eligible studies [4][5][6][7][8][29][30][31][32][33][34][35][36] for inclusion in the systematic review and meta-analysis, comprising a total of 415 patients with IIH. The main characteristics of the included studies are presented in Table 3.…”

“…The risk of bias in included studies was assessed by the ROBINS-I tool 17 and is presented in Figure 3. All studies but one 34 presented a moderate or serious risk of bias, mostly due to the inclusion of patients with neurological diseases as controls [4][5][6]33,35 who also had significantly different baseline characteristics compared to the cases. 4,6,29,32,33 Lumbar puncture in controls was not performed in six studies, 6,[30][31][32][33]35 thus normal ICP could not be confirmed by measuring the opening pressure.…”