Therapeutic effect of a single lumbar puncture in idiopathic intracranial hypertension

Abstract

Background. Idiopathic intracranial hypertension (IIH) is a neurological disorder characterized by increased intracranial pressure. Whilst lumbar puncture (LP) is necessary for the diagnosis of IIH, its therapeutic effect remains unclear. Our aim was to evaluate the therapeutic effect of a single LP in patients with IIH (pwIIH). Methods. In this prospective observational study, we analysed short-term neurological and ophthalmological outcomes in pwIIH before, one (D1) and seven days (D7) after the LP. The primary endpoint was the change in papilledema degree from baseline. Secondary endpoints included visual outcomes, morphological changes in optical coherence tomography (peripapillary retinal nerve fibre layer [pRNFL] thickness and ganglion cell layer [GCL] volume) and transbulbar sonography (arachnoid optic nerve sheath diameter [AONSD]), and headache outcomes (peak and median headache severity and burden related to headache). Results. We included 30 pwIIH (mean age 32.8 years [SD 8.4], 93.3% female, median CSF opening pressure 33.0 cmH₂O [IQR 26.9–35.3], median body mass index (BMI) 34.8 kg/m² [IQR 30.9–40.9]). The median papilledema grading at baseline was 2 (1–3) and was significantly reduced at D7 (2 [1–2], p=0.011). Median pRNFL thickness had decreased significantly at D7 (-9µm [-62.5, -1.3], p=0.035), with pRNFL thickness at baseline being associated with the pRNFL change (F_(1,11)=18.79, p=0.001). Mean AONSD had decreased significantly at both D1 (-0.74mm [0.14], p<0.001) and D7 (-0.65mm [0.17], p=0.01), with AONSD at baseline being associated with the change in AONSD at both time points (D1: b= -0.89, 95% CI -1.37, -0.42, p=0.002; D7: b= -0.85, 95% CI -1.42, -0.28, p=0.007). Peak headache severity was slightly lower at D7 (-1/10 [-3, 0], p=0.026), whereas median headache severity and headache burden remained unchanged. Conclusions. This short-term follow-up study in pwIIH undergoing a single LP suggests a moderate effect on ophthalmological but not headache outcomes. The usefulness of LP as a therapeutic measure in IIH remains controversial and should likely be reserved for patients with limited treatment options, e.g., in pregnancy or intolerability to medication.