Ultrasonographic optic nerve sheath diameter measurement in overweight parturient with intracranial tumour: Guiding choice of anaesthesia

A 26‐year‐old 36‐week primigravida with body mass index of 28.33 with intracranial space occupying lesion was planned for elective caesarean section. The patient was having frontal headache for past 1 month with left eye ptosis for last 3 weeks. Headache was associated with vomiting. There was no history of seizures. Magnetic resonance imaging (MRI) obtained 3 weeks before showed large lobulated extra‐axial mass (28 mm × 22 mm) in the left parasellar region. Lateral wall of cavernous sinus was inseparable with partial encasement of cavernous internal carotid artery. Lesion was closely abutting optic nerve near optic foramen. There was no midline shift, basal cisterns were not obliterated, ventricles were normal with no obstructions, sulci and gyri were normal, cerebral grey matter and white matter were normal and hence no signs of raised intracranial tension, with possible diagnosis of chondroid [Figure 1]. Neurosurgery along with ophthalmological evaluation was done. There was ophthalmoplegia of the left eye with palsy of cranial nerve 3rd, 4th and 6th with disc pallor; papilloedema was absent. As the pregnancy was term, elective caesarean section was planned to avoid the onset of labour and any associated elevations of blood pressure and intracranial pressure (ICP) after consultation from neurosurgeons and patient also wanted elective caesarean section.