Study on the feasibility of optic nerve subarachnoid width in qualitative diagnosis of intracranial hypertension

Abstract

Objective To evaluate the feasibility of optic nerve subarachnoid space in non-invasive qualitatively diagnosis of intracranial hypertension. Methods In this retrospective study,patients who received lumbar puncture from October 2009 to June 2015 were enrolled and divided into normal intracranial pressure group (41 cases) and intracranial hypertension group (39 cases). Optic nerve subarachnoid space width (SASW) behind ocular 3 mm (SASW-3),9 mm (SASW-9),and 15 mm (SASW-15) were measured on MRI and compared between groups. Chi-square test, t test and ROC analyses were used. Results SASW-3,SASW-9,and SASW-15 were (1.16±0.21), (0.98±0.21) and (0.92±0.17) mm in normal group and (1.46±0.20), (1.29±0.19) and (1.17±0.20) mm in intracranial hypertension group,respectively. According to independent samples t test,SASW-3,SASW-9,and SASW-15 of intracranial hypertension group was significant larger than those at the same measured site of normal group (P<0.01). According to MedCalc analysis,Receive operating characteristic (ROC) area was 0.849 in SASW-3 and when the cut-off value was fixes as 1.19 mm,the sensibility and specificity were 94.9% and 63.4%,respectively. ROC area was 0.849 in SASW-9 and when the cut-off value was fixes as 1.10 mm,the sensibility and specificity were 84.6% and 78.0%,respectively. ROC area was 0.824 in SASW-15 and when the cut-off value was fixes as 1.06 mm,the sensibility and specificity were 69.2% and 80.5%,respectively. Conclusion SASW-9 can be used to screen and monitor the intracranial hypertension as a non-invasive tool. Key words: Optic nerve; Subarachnoid space; Intracranial pressure; Magnetic resonance imaging