Therapeutic effect of a single lumbar puncture in idiopathic intracranial hypertension

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 people 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 outcome was the change in papilledema degree from baseline. Secondary outcomes 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 cerebrospinal fluid [CSF] opening pressure 33.0 cmCSF [IQR 26.9-35.3], median body mass index (BMI) 34.8 kg/m(2) [IQR 30.9-40.9]). The median papilledema grading at baseline was 2 (Friedman DI (1999) Pseudotumor cerebri. Neurosurg Clin N Am 10(4):609-621 viii); (Mollan SP, Aguiar M, Evison F, Frew E, Sinclair AJ (2019) The expanding burden of idiopathic intracranial hypertension. Eye Lond Engl 33(3):478-485); (Ab D, Gt L, Nj V, Sl G, Ml M, Nj N et al. (2007) Profiles of obesity, weight gain, and quality of life in idiopathic intracranial hypertension (pseudotumor cerebri). Am J Ophthalmol [Internet]. Apr [cited 2024 Jun 2];143(4). https://pubmed.ncbi.nlm.nih.gov/17386271/) and was significantly reduced at D7 (2 [1-2], p = 0.011). Median pRNFL thickness had decreased significantly at D7 (-9 mu m [-62.5, -1.3], p = 0.035), with pRNFL thickness at baseline being associated with the pRNFL change (F-(1,F-11) = 18.79, p = 0.001). Mean AONSD had decreased significantly at both D1 (-0.74 mm [0.14], p < 0.001) and D7 (-0.65 mm [0.17], p = 0.01), with AONSD at baseline being associated with the change in AONSD at both time points (D1: beta= -0.89, 95% CI -1.37, -0.42, p = 0.002; D7: beta= -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.