Correlations between optic nerve sheath diameters measured using computed tomography and elevated intracranial pressure levels

Monitoring of optic nerve sheath diameter on computed tomography for noninvasive assessment of intracranial pressure: Case report: Optic nerve sheath and intracranial pressure

Introduction: It is important to measure intracranial pressure because traumatic brain injuries lead to intracranial hypertension and ischaemic brain lesions. The gold standard for measurement of intracranial pressure is invasive methods, but they can lead to complications and are not always available. Measurement of the optic nerve sheath diameter is a useful noninvasive way to estimate intracranial pressure and it can be done via ultrasonography, computed tomography and magnetic resonance imaging. Increased optic nerve sheath diameter on computed tomography can help to diagnose intracranial hypertension and to verify the need for urgent therapy and invasive measurements. Case report: We present 74 years old patient with traumatic brain injury and intracranial bleeding. Optic nerve sheath diameter was 6.81 mm on the left and 6.83 mm on the right side on the initial scan. In the coming days, existing haematomas were enlarged and there were newly formed haematomas, so there were changes in the optic nerve sheath diameter. After the haematoma evacuation, the sheath diameter was 6.56 mm on the left and 6.47 mm on the right side. At the time of the second neurologic deterioration, the sheath diameter was 7.43 mm on the left and 7.25 mm on the right side. On the 25th day, the diameter was 6.72 mm on the left and 6.41 mm on the right side. Conclusion: Measurement of the optic nerve sheath diameter is a significant additional diagnostic method for the assessment of intracranial hypertension and can help to decide on further treatment.