The diagnostics intracranial hypertension using ultrasound of the optic nerve channel in patients with intracranial hemorrhage

Abstract

The purpose.To determine relationshipsbetween the value of intracranial pressure obtained by direct measurement (using ICP sensors), the optic nerve sheath diameter (ONSD), and the optic nerve diameter obtained by ultrasound; to define a threshold for ONSD for diagnosing ICP more than 20 mm Hg.Materials and methods.33 patients with traumatic and non-traumatic intracranial hemorrhages were examined. All patients were continuously monitored by ICP and ultrasound of the optic nerve channel. We evaluated the ONSD and optic nerve diameter (OND) using ultrasound. 16 healthy volunteers were examined to determine the normal values of ONSD and OND.Results.All patients were divided into 2 groups depending on the type of ICP dynamics. Group 1 (n = 26): an initial value of ICP is less than 20 mm Hg, group 2 (n = 7): initially high ICP values. Group 1 was divided into 3 subgroups: 1a (n = 7) – ICP did not increase during the whole monitoring period, 1b1 (n = 10) – ICP transiently increased in the postoperative period and normalized after treating, 1b2 (n = 9) – refractory intracranial hypertension was developed in the postoperative period. Group 2 was divided into two subgroups: 2a (n = 4) – ICP normalized in the postoperative period, 2b (n = 3) – refractory intracranial hypertension was developed in the postoperative period. There was a significant relationship between ICP and ONSD (Spearman n = 318, R = 0.31, p < 0.001; Kruskal– Wallis p < 0.001)in all groups of patients. The diameter of the optic nerve was the same for both groups: healthy volunteers and the experimental group (Spearmann = 334, R = 0.0054, p = 0.96). The optimal value of ONSD for detection the ICP > 20 mm Hg was morethan 5.8 mm.Conclusion.The ultrasound of the optic nerve channel can be an additional screening non-invasive diagnostic method for patients with intracranial hypertension.