Can Lumbar Puncture Be Safely Deferred in Patients With Mild Presumed Idiopathic Intracranial Hypertension?

BACKGROUND

Lumbar puncture (LP) is considered an essential component of the diagnosis of idiopathic intracranial hypertension (IIH) and ruling out IIH mimics, such as meningeal inflammation and neoplastic disease. Such mimics are unlikely in patients who are systemically well and fit the clinical demographic of IIH. It is important to take into account the risks of performing a LP as patients commonly experience mild adverse effects and infrequently more serious ones including psychological distress. LP can also be difficult to obtain in some health care settings, requiring inpatient admission. We examined the clinical course of a subset of presumed patients with IIH with mild vision loss and papilledema to determine whether LP can be safely deferred in this group.

METHODS

This was a retrospective study looking at the clinical characteristics, final visual outcome, and diagnosis of patients with presumed IIH and papilledema determined by clinical examination who did not undergo LP. The inclusion criteria included i) no symptoms suspicious for systemic infectious/neoplastic/inflammatory processes, ii) no secondary causes of raised intracranial pressure seen on magnetic resonance imaging/magnetic resonance venography, iii) optical coherence tomography (OCT)-RNFL thickness ≤300 µm, and iv) automated mean deviation (MD) ≤ -5.00 dB v) at least one follow-up visit.

RESULTS

A total of 132 eyes of 68 patients (66 female and 2 male) were included in the study. The mean ± SD age was 31.4 ± 10.2 years, and body mass index was 35.1 ± 6.8 kg/m 2 . Systemic symptoms included headache (n = 47), pulsatile tinnitus (n = 28), transient visual obscurations (n = 10), and diplopia (n = 2). Presenting logarithm of the minimum angle of resolution visual acuity was 0.020 ± 0.090, automated MD was -2.23 ± 1.38 dB, and OCT RNFL thickness was 150.8 ± 48.4 µm. Patients were followed for a mean number of 63.3 ± 78.3 weeks. No additional cause of intracranial hypertension was discovered, and all patients remained systemically well. Two patients were started on acetazolamide, and 31 patients lost at least some weight. There was a significant improvement in the automated MD (-1.73 ± 1.74 dB; P < 0.001) and OCT RNFL thickness (128.1 ± 38.6 µm; P < 0.001) at final follow-up. Seventy-six eyes of 38 patients were considered to have resolved papilledema at the final follow-up.

CONCLUSIONS

Some patients with presumed IIH may not be able to undergo LP because of patient factors such as refusal, failed attempts, or the environment in which neuro-ophthalmologists practice. This study suggests that it may be acceptable to defer LP for patients with suspected IIH who are under the care of a neuro-ophthalmologist with experience in diagnosing and managing IIH. These patients should be systemically well, in a typical demographic for IIH patients, have mild optic disc edema, and preserved visual function. Patients should be informed about the controversial nature of this decision.