Diagnosis of elevated intracranial pressure in children with shunt under special consideration of transglobe sonography of the optic nerve

Objective: Transglobe B-mode sonography of the optic nerve and its sheets is evaluated in respect to its value in detecting increased intracranial pressure. Methods and Patients: For a standardized procedure we used linear probes (7-13 MHz). We measured the total diameter of the optic nerve and evaluated the optic nerve papilla. 60 controls and 102 patients with internal hydrocephalus were studied; of these 50 had no signs and 52 showed signs of elevated intracranial pressure. Results: The total diameter of the nerve with its sheets in the control group varied between 1.8 and 4.1 mm (mean 3.1 mm). In 50 patients without signs of elevated intracranial pressure it measured between 2.6 and 4.1 mm (mean 3.5 mm), and in 52 patients with signs of elevated intracranial pressure between 3.9 and 6.9 min (mean 5.4 mm). The diameter of the optic nerve in patients with elevated intracranial pressure was significantly wider compared to normal data (Wilcoxon's test p < 0.01). 24 patients with a history of elevated intracranial pressure of more than 48 hours' duration showed a papilloedema as an additional finding. The upper limit of the normal diameter of the optic nerve with its sheets is 4.1 mm. Conclusion: A standardized transglobe sonogram of the optic nerve in combination with transcranial and abdominal sonography is a reliable method for the detection of elevated intracranial pressure.