Sonographic Optic Nerve Sheath Diameter Following Seizure Prophylaxis in Pre‐Eclamptic Parturients With Severe Features

Objectives Neurological manifestations, including raised intracranial pressures, are a hallmark of worsening pre‐eclampsia. Invasive methods for measuring intracranial pressure, though a gold standard, are not always a viable option. Maternal ocular sonography is a promising bedside tool, which serves as a noninvasive, cost‐effective means for measuring optic nerve sheath diameter (ONSD), a surrogate marker of raised intracranial pressures. We studied the ultrasonographically measured ONSD in severely pre‐eclamptic women, and the effect of magnesium sulfate therapy on its values. Methods Thirty severely pre‐eclamptic women at ≥28 weeks gestation were included. We recorded baseline ONSD values, serum magnesium levels, neurological symptoms, vitals, and repeated them at 4 and 12 hours following magnesium sulfate therapy, and then at 24 hours postpartum. An ONSD value >5.8 mm was suggestive of raised intracranial pressure. Primary outcome measure was to evaluate changes in ultrasonographically measured ONSD following seizure prophylaxis with magnesium sulfate. Results Women, 73.3%, had baseline ONSD >5.8 mm, with mean diameter being significantly high (6.02 ± 0.77 mm). There was a statistically nonsignificant decline in mean ONSD values at 4 and 12 hours, as well as at 24 hours postpartum. Patients with neurological symptoms declined significantly (from 70 to 10%; p value