Optic nerve sheath ultrasound for the detection and monitoring of raised intracranial pressure in tuberculous meningitis.
Donovan J., Oanh PKN., Dobbs N., Phu NH., Nghia HDT., Summers D., Thuong Thuong NT., Thwaites GE.
<h4>Background</h4>Neurological complications of tuberculous meningitis (TBM) often lead to raised intracranial pressure (ICP) resulting in high morbidity and mortality. Measurement of optic nerve sheath diameter (ONSD) by point-of-care ultrasound may aid in the identification and management of raised ICP in TBM.<h4>Methods</h4>From June 2017 to December 2019, 107 Vietnamese adults with TBM, enrolled in the ACT HIV or LAST ACT trials (NCT03092817; NCT03100786), underwent ONSD ultrasound at one or more of days 0,3,7,14,21 +/-30 after enrolment. Demographic data, TBM severity grade, HIV co-infection status, and clinical endpoints by 3 months were recorded. ONSD values were correlated with disease severity, baseline brain magnetic resonance imaging or computed tomography imaging, cerebrospinal fluid parameters and clinical endpoints.<h4>Results</h4>267 ONSD ultrasound scans were performed in 107 participants over the first 30 days of treatment, with measurements from 0.38-0.74cm. Paired baseline ONSD and brain imaging were performed in 63 participants. Higher baseline ONSD was associated with more severe disease and abnormal brain imaging (abnormal imaging 0.55cm vs 0.50cm normal imaging, p=0.01). Baseline median ONSD was significantly higher in participants who died by 3 months (0.56cm [15/72]) vs. participants who survived by 3 months (0.52cm [57/72]), p=0.02. Median ONSD was higher at all follow up time points in participants who died by 3 months.<h4>Conclusions</h4>Higher ONSD was associated with increased disease severity, brain imaging abnormalities, and increased death by 3 months. ONSD ultrasound has a potential role as a non-invasive and affordable bedside tool for predicting brain pathology and death in TBM.