What is the treatment for idiopathic intracranial hypertension?

Treatment of Idiopathic Intracranial Hypertension

Weight loss of 5-15% of total body weight is the only disease-modifying therapy for IIH and must be the primary treatment approach for all patients with BMI >30 kg/m², combined with acetazolamide for those with mild visual loss. 1

Primary Treatment Strategy

Weight Management (First-Line for All Patients)

• All patients with BMI >30 kg/m² require immediate counseling about weight management at the earliest opportunity 1
• Target weight loss is 5-15% of total body weight to achieve disease remission 1
• Refer patients to community weight management programs or hospital-based weight programs 1
• Implement low-salt diet as an adjunct to weight reduction 1
• For sustained weight loss, bariatric surgery should be considered in appropriate candidates 1

Medical Therapy

Acetazolamide:

• Acetazolamide is first-line medication for patients with mild visual loss 1
• Start at 250-500 mg twice daily, gradually titrating upward as needed and tolerated 1
• Maximum dose is 4 g daily, though only 44% of patients tolerate this dose, with most tolerating 1 g/day 1
• The IIHTT trial demonstrated that acetazolamide combined with weight loss improves visual field outcomes, papilledema, intracranial pressure, and quality of life more effectively than weight loss alone 2
• Approximately 48% of patients discontinue acetazolamide at mean doses of 1.5 g due to adverse effects 1
• Common side effects include diarrhea, dysgeusia, fatigue, nausea, paresthesias, tinnitus, vomiting, depression, and rarely renal stones 1

Topiramate (Alternative/Adjunct):

• May be used with weekly dose escalation from 25 mg to 50 mg twice daily 3
• Offers both carbonic anhydrase activity and appetite suppression 4
• Women must be informed that topiramate reduces oral contraceptive efficacy and carries teratogenic risks 3

Headache Management

• Limit caffeine intake, ensure regular meals and adequate hydration, implement exercise program and sleep hygiene 1
• For migraine attacks: triptans combined with NSAIDs or paracetamol and antiemetic, limited to 2 days per week or maximum 10 days per month 1
• Avoid medications that increase weight or exacerbate depression 1
• Address medication overuse headache early, as it is common in IIH patients and prevents optimization of preventative treatments 1

Surgical Interventions

Indications for Surgery

• Urgent surgical intervention is mandatory when there is evidence of declining visual function despite medical therapy 1, 3
• Severe or rapidly progressive visual loss requires immediate surgical treatment 1
• A temporizing lumbar drain may protect vision while planning definitive surgical treatment 1, 3

Surgical Options (in Order of Preference)

1. Ventriculoperitoneal (VP) Shunt:

• VP shunt is the preferred CSF diversion procedure due to lower revision rates per patient compared to lumbar-peritoneal shunts 4, 1, 3
• Neuronavigation should be used for VP shunt placement 4, 3
• Adjustable valves with antigravity or antisiphon devices should be utilized to reduce low-pressure headache risk 4, 3
• Patients in the UK must inform the Driver and Vehicle Licensing Agency following VP shunt placement 4
• Treatment failure rates include worsening vision after initial stabilization in 34% of patients at 1 year and 45% at 3 years 4, 3
• Failure to improve headache occurs in one-third to one-half of surgically treated patients 4, 3

2. Optic Nerve Sheath Fenestration (ONSF):

• ONSF is considered first-line for malignant fulminant cases and asymmetric papilledema causing unilateral visual loss 1, 3
• Has fewer complications than CSF diversion with no reported mortalities in the literature 4, 1
• Should only be performed by experienced clinicians trained in this technique 4, 1
• Temporary adverse effects include double vision, anisocoria, and optic nerve head hemorrhages 4
• Rare permanent sequelae include branch and central retinal artery occlusions 4
• A 2021 systematic review showed ONSF ameliorated papilledema in 90.5%, visual field defects in 65.2%, and headaches in 49.3% of patients, with a 2.2% severe complication rate and 9.4% failure rate 5

3. Venous Sinus Stenting (VSS):

• The role of neurovascular stenting in IIH is not yet fully established, though recent studies show it as a well-tolerated and effective surgical alternative for refractory IIH 1, 6
• A 2021 systematic review demonstrated VSS improved papilledema in 87.1%, visual fields in 72.7%, and headaches in 72.1% of patients, with a 2.3% severe complication rate and 11.3% failure rate 5
• Complications include short-lived ipsilateral headache, stent-adjacent stenosis requiring retreatment in one-third, and rarely vessel perforation, subdural hematoma, stent migration, and thrombosis 4, 1
• Long-term antithrombotic therapy is required for longer than 6 months following neurovascular stenting 4, 3

Monitoring and Follow-up

• Regular ophthalmology assessments to monitor visual function are essential 1
• If visual function deteriorates, perform diagnostic lumbar puncture to reassess intracranial pressure 1
• Monitor for inadequate response, as 34% of patients worsen at 1 year and 45% at 3 years 1

What NOT to Do

• Serial lumbar punctures are NOT recommended for long-term management of IIH 4, 1, 3
• Relief from LP is short-lived (CSF is secreted at 25 mL/hour, rapidly replacing removed volume) 4
• LPs cause significant anxiety and can lead to acute and chronic back pain 4, 3

Special Considerations

• Identify and discontinue medications that might exacerbate IIH: tetracyclines, vitamin A, retinoids, steroids, growth hormone, thyroxine, and lithium 1
• For atypical IIH patients (not female, not of reproductive age, BMI <30 kg/m²), revisit secondary causes 1