Evolution of the Criteria to Diagnose Idiopathic Intracranial Hypertension: An Algorithm

Idiopathic intracranial hypertension (IIH) is a condition characterized by elevated intracranial pressure that can cause a variety of symptoms, including transient visual obscurations, pulsatile tinnitus, and progressive visual loss. Lumbar punctures (LPs) have traditionally been considered necessary for diagnostic confirmation. However, with the rapid advances in neuroimaging and strengthened clinical assessment criteria, there have been discussions about whether LP is necessary in all suspected IIH cases. This study aimed to determine whether, in appropriately selected patients, IIH could be reliably diagnosed without LP by integrating detailed clinical evaluation with MRI/MRV findings.

A retrospective chart review was conducted on 100 consecutive patients diagnosed with IIH in our neuro-ophthalmology clinic over 9 years (2016-present). Inclusion criteria required a high clinical suspicion of IIH with no alternative etiology, a complete neuro-ophthalmologic examination before LP, and no prior history of IIH or LP. Ninety-six patients underwent LP, whereas 4 declined. A literature review was additionally performed, which incorporated 3 studies (n = 363) evaluating the use of LP in suspected IIH cases. Clinical course, diagnostic changes, and management alterations after LP were assessed.

Ninety-six patients in our neuro-ophthalmology clinic underwent LP. Of the 96 patients, none had a change in diagnosis or altered management after LP. Four patients in our clinic refused LP. The 4 patients managed without LP experienced no complications or alternative diagnoses. Our thorough literature review showed that in 295 patients who underwent LP, 0/295 patients had an alternative diagnosis or unexpected finding based on LP results. For the remaining 68 patients who did not undergo LP, there were no complications in treatment, and improvement was made without LP. These combined findings from both the literature and our own clinical findings informed the development of a clinical algorithm recommending LP primarily for patients with atypical features or concern for secondary causes, helping improve patient care and comfort while prioritizing safety.

In patients with high clinical suspicion for IIH, as described in this manuscript, with supportive neuroimaging, LP may be safely deferred without compromising diagnostic accuracy or patient care. Using a clinically driven algorithm may reduce unnecessary invasive procedures while maintaining patient safety, although LP remains warranted when atypical features or secondary etiologies are suspected.