What is the management of Idiopathic Intracranial Hypertension (IIH)?

Management of Idiopathic Intracranial Hypertension

Weight loss of 5-10% of total body weight is the primary disease-modifying treatment for IIH and should be initiated immediately in all overweight patients, combined with acetazolamide for medical management when visual function is threatened. 1, 2

Three Core Treatment Principles

The management of IIH follows three fundamental goals that guide all therapeutic decisions 1:

1. Treat the underlying disease (weight reduction)
2. Protect vision (prevent irreversible visual loss)
3. Minimize headache morbidity

Initial Medical Management

Weight Loss (Primary Treatment)

• All overweight patients (BMI >30 kg/m²) must enter a weight-management program targeting 5-10% weight loss 1, 2, 3
• Combine with a low-salt diet 3
• Bariatric surgery has proven effective for controlling elevated intracranial pressure in appropriate candidates 4

Acetazolamide (First-Line Pharmacotherapy)

• Initiate acetazolamide when there is evidence of mild visual loss or declining visual function 2, 3, 5
• This is the best-supported medical option for pressure control and visual protection 4
• Formal visual field testing must guide treatment intensity 3

Alternative Pharmacotherapy

• Topiramate may be used with weekly dose escalation from 25 mg to 50 mg twice daily 1, 2
• Topiramate has carbonic anhydrase activity and appetite suppression effects 1
• Critical caveat: Women prescribed topiramate must be informed that it reduces oral contraceptive efficacy and carries risks of depression, cognitive slowing, and teratogenic effects 1, 2

Headache Management

• Patients must be informed early about the risks of medication overuse headache 2
• Headache may persist even after intracranial pressure control, requiring ongoing neurological management 2, 4
• The headache phenotype is highly variable and may mimic primary headache disorders 1

Surgical Interventions: Algorithm for Decision-Making

When to Operate

Surgery is indicated when 3, 5, 6:

• Visual loss is severe or rapidly progressive
• Fulminant IIH presents with precipitous visual decline
• Progressive vision loss occurs despite maximal medical therapy
• Patient cannot tolerate or is nonadherent to medical therapy

Temporizing Measures

• A lumbar drain may protect vision while planning urgent surgical treatment 2
• Intravenous steroids plus acetazolamide can be initiated urgently while arranging surgery 5
• Serial lumbar punctures are NOT recommended for IIH management despite providing temporary relief in three-quarters of patients, as CSF is replaced at 25 mL/hour and the procedure causes significant anxiety and potential chronic back pain 1

Surgical Options: Choosing the Right Procedure

CSF Diversion (Preferred for Visual Deterioration)

• Ventriculoperitoneal (VP) shunt should be the preferred CSF diversion procedure due to lower reported revisions per patient 1, 2
• Lumbar peritoneal shunt is an alternative option 1
• Use neuronavigation to place VP shunts 1, 2
• Select adjustable valves with antigravity or antisiphon devices to reduce low-pressure headache risk 1, 2
• Important caveat: UK patients must inform the Driver and Vehicle Licensing Agency following VP shunt placement 1, 2
• Treatment failure rates are substantial: 34% experience worsening vision at 1 year and 45% at 3 years; one-third to one-half fail to improve headache 1, 2

Optic Nerve Sheath Fenestration (ONSF)

• ONSF is preferred in settings of precipitous visual decline, particularly with asymmetric papilledema causing visual loss in one eye 1, 5
• ONSF has fewer complications than CSF diversion with no reported mortalities 1
• Performed more frequently in Europe and USA than UK 1, 2
• Temporary adverse effects include diplopia, anisocoria, and optic nerve head hemorrhages 1
• Rare permanent complications include branch and central retinal artery occlusions 1
• Must be performed by an experienced clinician trained in this technique 1
• Consider as first-line in malignant fulminant cases; if ONSF fails, proceed to CSF diversion 1

Venous Sinus Stenting (Emerging Option)

• The role of neurovascular stenting is not yet established 1, 2
• Many IIH patients have transverse sinus stenosis on venography, though stenosis degree does not uniformly correlate with intracranial pressure or visual loss 1
• Complications include short-lived ipsilateral headache (common), stent-adjacent stenosis requiring retreatment (one-third), and rare vessel perforation causing subdural hematoma, stent migration, or thrombosis 1
• Long-term antithrombotic therapy is required for longer than 6 months following stenting 1, 2
• Has proven safe in selected cases 4

Common Pitfalls to Avoid

• Do not rely on serial lumbar punctures as a management strategy—relief is short-lived and complications are significant 1
• Do not delay surgical intervention in fulminant IIH or progressive visual loss despite medical therapy 2, 5
• Do not assume headache resolution after pressure control—ongoing headache morbidity may require separate neurological management 2, 4
• Do not forget contraceptive counseling when prescribing topiramate 1, 2
• Do not overlook the need for formal visual field testing to guide treatment intensity and monitor response 3