Structural MRI Biomarkers of Intracranial Pressure in IIH: Linking Optic Nerve Sheath, Pituitary Morphology, and Hormonal Changes

PURPOSE: To investigate the relationship between intracranial pressure (ICP), anterior pituitary hormones, and structural brain changes in women with idiopathic intracranial hypertension (IIH). METHODS: Eighteen women with therapy-refractory IIH underwent lumbar puncture, endocrine assessment, and high-resolution brain MRI. Serum levels of pituitary hormones were correlated with ICP and radiological parameters including pituitary volume, flattening, and optic nerve (ON) and optic nerve sheath (ONS) volume. Group comparisons and partial correlations were used to evaluate associations. RESULTS: ICP showed a significant positive association with thyroid-stimulating hormone (TSH) levels (r = 0.628, p = 0.016), and a significant negative association with growth hormone (GH) (r = -0.602, p = 0.023). Regarding structural parameters, only the volume of the right ON showed a strong positive association within the subgroup with elevated ICP (r = 0.90, p = 0.005). Correlations between ONS volumes and ICP in the normal pressure subgroup narrowly missed statistical significance. TSH was the only hormone showing a significant association, with higher TSH levels relating to larger pituitary volume in the normal ICP subgroup (r = 0.88, p = 0.020), but not in the elevated ICP subgroup. CONCLUSION: Our exploratory findings suggest potential interactions between ICP, endocrine markers, and structural MRI measures. However, due to the limited sample size and variability in endocrine parameters, the results should be interpreted cautiously and considered hypothesis generating rather than clinically directive. Larger studies are needed to determine whether endocrine MRI associations hold true and whether they have diagnostic or clinical relevance.