MRI Findings in Pediatric Idiopathic Intracranial Hypertension: Evaluating the Oculomotor Nerve Sheath as a Potential New Diagnostic Marker

Purpose Consequently, the significance of neuroimaging in diagnosing pediatric IIH has grown substantially in recent years. This study aims to delineate the magnetic resonance imaging (MRI) findings in children diagnosed with idiopathic intracranial hypertension. Additionally, it introduces the evaluation of the oculomotor nerve cistern (OMC) as a potential novel imaging marker. Methods: Brain magnetic resonance imaging and magnetic resonance venography (MRV) scans from 66 patients aged 0 to 18, all presenting with clinical signs of increased intracranial pressure, were systematically reviewed. The following imaging parameters were evaluated on brain MRI: pituitary gland height and upper contour morphology, cerebrospinal fluid (CSF) distance surrounding the optic nerve, optic nerve tortuosity, posterior scleral flattening, and the oculomotor nerve cistern. Results Among the 66 patients in the study, elevated intracranial pressure and CSF expansion within the optic nerve sheath were the most sensitive imaging findings. When comparing various imaging findings, OMC enlargement demonstrated the second-highest sensitivity (52.2%) for detecting increased intracranial pressure, following optic nerve sheath CSF expansion. Conclusion: The findings from this study suggest that various MRI and MRV features may serve as reliable biomarkers for detecting elevated intracranial pressure. Notably, this study highlights the potential diagnostic utility of a newly identified imaging marker, cerebrospinal fluid expansion in the oculomotor nerve cistern, demonstrating significant sensitivity in distinguishing patients with increased intracranial pressure. Given its diagnostic value, we propose that OMC enlargement may be incorporated into future neuroimaging protocols for evaluating pediatric IIH. Keywords: Neuroimaging, İntracranial Hypertension, Children, Magnetic Resonance Venography