Lumbar Puncture Can Be Safely Deferred for Some With Idiopathic Intracranial Hypertension

Lumbar punctures (LP) required for diagnosis of idiopathic intracranial hypertension (IIH) can be safely deferred when patients have nonsevere papilledema and continue to have visual function, researchers found in a study they presented at the North American Neuro-Ophthalmology Society Annual Meeting.

By obtaining LP, neuro-ophthalmologists can rule out secondary causes, such as meningeal processes, and remove cerebrospinal fluid (CSF) and protect optic nerves. However, obtaining LP can prove challenging in certain circumstances. It can only be done in an emergency department or hospital, there are challenges in conducting LP on patients with obesity, and adverse events, such as intracranial hypotension or back pain, may occur. In addition, while opening pressure can be confirmed in the procedure, it may prove to be inaccurate. Therefore, the researchers sought to determine the urgency of the procedure. 

They conducted a retrospective study of patients who were presumed to have IIH and papilledema, which had been determined through a clinical exam, and did not receive LP.

To participate in the study, the patients had to have had at least 1 follow-up visit and not have any symptoms that indicated meningeal process (infectious, neoplastic, or inflammatory) or secondary causes of raised intracranial pressure (ICP), as viewed on magnetic resonance imaging (MRI) or magnetic resonance venography (MRV).  All patients had a retinal nerve fiber layer (RNFL) of at least 300 µm in both eyes and Humphrey mean deviation (MD) at least -5.00 dB.

The researchers identified 132 eyes of 68 patients (66 women) with a mean age of 31.4 years (SD 10.2 years) and mean body mass index (BMI) of 35.1 kg/m² (SD 6.8 kg/m²). Their logMAR visual acuity was .020 (SD .09), and RNFL thickness of 150.8 µm (SD 48.4 µm). Symptoms of the patients included headache (n=47), pulsatile tinnitus (n=28), transient visual obscurations (n=10) and diplopia (n=2).

At the follow-up, all patients remained systematically well, 31 had lost “at least some weight,” and no additional causes of raised ICP were discovered. Two patients had begun treatment of acetazolamide.

Presumed IIH in most patients with resulting mild vision loss and papilledema can be managed without pharmacologic treatment, the research says.

“Deferring LP in this patient group can result in significant cost and human resource savings especially during the COVID-19 pandemic,” according to the report.

Reference

Vosoughi A, Margolin E, Micieli JA. Can lumbar puncture be safely deferred in patients with mild presumed idiopathic intracranial hypertension? Presented at: North American Neuro-Ophthalmology Society Annual Meeting; February 20-23, 2021; Poster 96.