Revisiting the Need for Diagnostic Lumbar Puncture in Idiopathic Intracranial Hypertension

Abstract

W e read with interest the recent article in JNO by Margolis et al (1). Their study, although retrospective in nature, challenges current clinical practice, which dictates that all patients with presumed idiopathic intracranial hypertension (IIH) must undergo lumbar puncture (LP) to check opening pressure and to ensure that cerebrospinal fluid (CSF) contents are normal. We also believe that a blanket approach like this often overestimates the perceived benefits of LP and underestimates the potential risks and limitations associated with this procedure.The COVID-19 pandemic forced us to re-evaluate our approach to all aspects of medical care. As a consequence of the increased risk of nosocomial infection from keeping patients in hospital for LP, we questioned whether LP was always necessary in suspected IIH. We concluded that in young obese women with bilateral mild-to-moderate disc edema, good visual function, classic neuroimaging findings and no atypical features, it was not.Margolis et al (1) comprehensively covered the reasons why in expert hands this approach to what they referred to as patients with "typical" IIH does make sense. We would, however, like to add another argument that we think is important, namely, the issue of patient autonomy. We believe that to present the need for LP as absolute in all cases of suspected IIH does not meet the standards of informed consent. The data provided by Margolis et al (1) add weight to this view, given LP/CSF results did not change diagnosis or management in any of their 156 typical cases. It follows that it should be considered good practice to discuss the relative merits of LP with all patients with suspected IIH. Specifically, in presumed typical cases, we would advocate presenting LP as an option rather than a necessity.