Idiopathic Intracranial Hypertension: Diagnosis and Management

Educational Objectives

The goal of this program is to improve management of idiopathic intracranial hypertension (IIH). After hearing and assimilating this program, the clinician will be better able to:

1. Identify ocular findings traditionally associated with IIH.
2. Optimize treatment of IIH.

Summary

Clinical features: Crum et al (2020) found that 87% of patients presenting with papilledema had idiopathic intracranial hypertension (IIH); patients with typical features of IIH may not require urgent neuroimaging

History: inquire about headaches (variable), transient visual obscurations, a “whooshing” or pulsatile sound in the ear, nausea, vomiting, and diplopia; ask whether the patient takes oral contraceptives, steroids, or tetracyclines; a recent history of weight gain is common

Ocular examination: visual acuity and visual fields are normal; afferent pupillary defect is typically absent; papilledema — severity is graded using the Frisen scale, which is based on obscuration of structures; higher Frisen grade indicates greater likelihood for visual damage; buried optic disc drusen (may be difficult to detect), tilted disc, and small, crowded nerves may mimic IIH and present without papilledema; sixth nerve palsy (causes esodeviation) and funduscopic evidence of peripapillary wrinkles or vessel obscuration are indicative of papilledema; spontaneous venous pulsation suggests against papilledema; en face optical coherence tomography (OCT) helps detect peripapillary wrinkles; fundus autofluorescence detects optic disc drusen better than OCT; retinal nerve fiber layer (RNFL) thickness — though Bassi et al (2014) demonstrate mean RNFL thickness of ≈185 μm for papilledema and ≈122 μm for pseudopapilledema, some overlap was noted; increased nasal RNFL is more diagnostic of papilledema vs pseudopapilledema

Diagnosis: the modified Dandy criteria are used; ocular examination alone is inadequate for diagnosis; in addition to papilledema, other criteria include elevated intracranial pressure (ICP) on lumbar puncture, normal brain imaging, and absence of localizing signs on neurologic examination (except for sixth nerve palsy)

Red flags: include rapid onset of symptoms, worsening of vision or headache, acute vision loss, localizing neurologic signs (eg, homonymous hemianopsia may indicate an intracranial mass), and patients outside the typical demographic profile (most patients are women of childbearing age)

Evaluation in the emergency department: magnetic resonance (MR) imaging rules out a space-occupying lesion; MR venography rules out venous sinus thrombosis; lumbar puncture can rule out infection and alleviate elevated ICP; MR angiography can help in atypical cases; consult neurology and neuroophthalmology

Management

Goals: protect vision and minimize headaches; in case of vision-threatening papilledema, perform emergent lumbar drain and consider cerebrospinal fluid diversion or optic nerve sheath fenestration

Diet and obesity: IIH is associated with obesity; counsel patients with body mass index ≥30 about weight loss; dietary modifications and weight loss can lead to remission; however, studies have demonstrated that the change in ICP does not always correlate with the change in weight; although not all patients with IIH have obesity, adipose tissue may be contributory

Vitamin A: vitamin A intoxication has been shown to elevate ICP in adults; pediatric IIH is associated with vitamin A deficiency; Libien et al (2017) demonstrated no contribution of serum vitamin A levels to IIH

Dietary advice: though low-fat dairy products and lean meats are ideal, salmon and melons are rich sources of vitamin A; avoid foods with high levels of fat, salt, or tyramine (eg, pepperoni, cheese), plus caffeine and alcohol

Weight-loss surgery: Manfield et al (2016) demonstrated 100% resolution of papilledema and 90% reduction in headaches with bariatric surgery, offering more significant improvement than nonsurgical weight-loss methods

Medication management: Wall et al (2014) demonstrated significant improvement in visual fields and papilledema with acetazolamide in combination with dietary intervention, compared with dietary intervention alone; topiramate inhibits carbonic anhydrase and can reduce ICP

Readings

Bassi ST, Mohana KP. Optical coherence tomography in papilledema and pseudopapilledema with and without optic nerve head drusen. Indian J Ophthalmol. 2014;62(12):1146-1151. doi:10.4103/0301-4738.149136; Crum OM, Kilgore KP, Sharma R, et al. Etiology of papilledema in patients in the eye clinic setting. JAMA Netw Open. 2020;3(6):e206625. doi:10.1001/jamanetworkopen.2020.6625; Jacks AS, Miller NR. Spontaneous retinal venous pulsation: aetiology and significance. J Neurol Neurosurg Psychiatry. 2003;74(1):7-9. doi:10.1136/jnnp.74.1.7; Libien J, Kupersmith MJ, Blaner W, et al. Role of vitamin A metabolism in IIH: Results from the idiopathic intracranial hypertension treatment trial. J Neurol Sci. 2017;372:78-84. doi:10.1016/j.jns.2016.11.014; Manfield JH, Yu KK, Efthimiou E, et al. Bariatric surgery or non-surgical weight loss for idiopathic intracranial hypertension? A systematic review and comparison of meta-analyses. Obes Surg. 2017;27(2):513-521. doi:10.1007/s11695-016-2467-7; Wall M, McDermott MP, Kieburtz KD, et al. Effect of acetazolamide on visual function in patients with idiopathic intracranial hypertension and mild visual loss: the idiopathic intracranial hypertension treatment trial. JAMA. 2014;311(16):1641-1651. doi:10.1001/jama.2014.3312.

Disclosures

For this program, members of the faculty and planning committee reported nothing relevant to disclose.

Acknowledgements

Dr. Dunlap was recorded at the 17th Annual Evidence-Based Care Optometry Conference, held on March 3, 2024, in Baltimore, MD, and presented by Johns Hopkins University School of Medicine. For more information about upcoming CME activities from this presenter, please visit https://hopkinscme.cloud-cme.com. Audio Digest thanks the speakers and presenters for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0.50 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0.50 CE contact hours.

Lecture ID:

OP622302

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.