Pediatric Critical Care Medicine:
Abstracts of the 7th World Congress on Pediatric Critical Care
1Pediatric Critical Care, Wolfson Children Hospital, Univ of Florida, Jacksonville, USA
Background and aims: Idiopathic Increased Intracranial Hypertension (IIH), called Pseudotumor cerebri, is a common causes of progressive increased intracranial pressure (ICP) in adolescence. Optic nerve atrophy and blindness may occur if left untreated.
The orbital portion of the optic nerve is surrounded by a sheath comprised of an outer layer (Dura) and an inner sheath (arachnoid) where CSF circulates. Increased ICP augments CSF pressure enlarging the optic nerve sheath diameter (ONSD).
ONSD can be assessed by ultrasonography (US) with a normal size of 4–4.5 mm at adolescence.
Aims: To assess if US could be a noninvasive tool to detect increased ICP in the IIH population.
Methods: Prospective, blind study of patients 12–18 years of age with suspected IIH. ONSD was measured with a 13–6 MHz linear array probe prior to performing a sedated (fentanyl/propofol), recumbent, spinal tap where the opening pressure was recorded. A cut of < 20 cmH2O was considered normal. 3 ONSD measurements were performed in each eye and averaged. IRB approved study with signed informed consent.
Results: 10 patients completed the study, eight had enlarged ONSD and elevated ICP, two had normal ONSD and ICP (p = 0.01).
Conclusions: There is direct correlation between increased ICP and ONSD.
ONSD measurement with a cut off value > 4.5 mmm was associated with an increased ICP in IIH. Further studies are needed to confirm this observation.