DOI: 10.36347/sjams.2020.v08i11.043

Pages: 2644-2650

Background: Idiopathic Intracranial Hypertension (IIH) has an incidence of about 2.2/100000 in general population. Optic Nerve Sheath Diameter (ONSD) is found to be high in raised intracranial tension. Studies on ONSD and IIH are limited. ONSD measurement is non-invasive compared to spinal manometry. So, measuring the ONSD can be used as a screening tool on outpatient basis in patients suspected to have IIH and also for follow up of patient on treatment. Methods: The aim of this study was to correlate cerebrospinal fluid (CSF) opening pressure with optic nerve sheath diameter measured using ultrasonogram in patients with idiopathic intracranial hypertension and to study changes in optic nerve sheath diameter before Lumbar puncture (LP), one hour after, and 6 months after CSF drainage in patients with idiopathic intracranial hypertension. IIH was diagnosed with modified Dandy’s criteria. A total of 30 cases and 30 controls were included in the study. Trans orbital sonography was done to assess the optic nerve sheath diameter (ONSD) before and after lumbar puncture. CSF opening pressure was measured. ONSD was done in 30 matched controls. Follow up ONSD was done at 6 months. Results: Mean age was 31 years in cases and 30 years in controls. Mean BMI was 35 in cases and 25.5 in controls. Mean ONSD was 6.46±0.67mm in cases, 4.87±0.26mm in control (p<0.001). A positive correlation was found between CSF opening pressure and pre- LP mean ONSD (r=0.584, p<0.001). Post LP mean ONSD was 5.83±0.48mm (p<0.001). Optimum ONSD for detecting IIH was 5.42 mm with sensitivity and specificity of 96.7%. Mean ONSD at 6 months follow up was 5.18±0.58 mm (p<0.001). Conclusions: ONSD measurement can be used as an additional tool to identify patients with IIH. It can also be used to follow up patients on treatment.