Role of tumor necrosis factor-alpha in the pathophysiology of idiopathic intracranial hypertension

Background: Although the pathogenesis of idiopathic intracranial hypertension (IIH) is still poorly understood, the contribution of inflammatory mechanisms has been proposed in its pathophysiology.

Objective: This study aimed to measure serum tumor necrosis factor-α (TNF-α) levels in patients with IIH and to examine its relationship with clinical and ophthalmological parameters and cerebrospinal fluid (CSF) opening pressure.

Subjects and methods: Thirty-six IIH patients and 30 healthy subjects were enrolled in the study. Patients were subjected to complete neurological, general, and ophthalmological assessments. Serum TNF-α levels were measured for patients and controls using the enzyme-linked immunosorbent assay.

Results: Serum TNF-α levels were significantly higher in IIH patients compared to healthy controls (p value <.001). Serum TNF-α level was significantly negatively correlated with grade of perimetry and CSF opening pressure (r = -.36, p value = .02), (r = -.37, p value = .02) respectively. However, serum TNF-α was not significantly correlated either with age at onset, disease duration, BMI, headache severity, relapse rate, visual acuity, or papilloedema grade. Serum TNF-α was found to be a significant predictor of the severity of the visual field affection in IIH patients, as one-grade increase of the perimetric grading was associated with a decrease in serum TNF-α by 13.96 ng/ml.

Conclusion: Altered serum TNF-α levels may suggest the potential involvement of pro-inflammatory mechanisms in the pathogenesis of IIH. Serum TNF-α level may be an indicator of the severity of the visual field affection in IIH.