What is the approach to managing Idiopathic Intracranial Hypertension (IIH)?

Management of Idiopathic Intracranial Hypertension (IIH)

Weight loss combined with acetazolamide is the first-line approach to managing IIH, with surgical interventions reserved for cases with threatened vision or medical treatment failure. 1

Diagnostic Evaluation

• MRI brain with contrast: Essential to evaluate for signs of IIH (empty sella, flattening of posterior globe) and rule out secondary causes 1
• Complete ophthalmological evaluation: Visual acuity, visual fields, papilledema classification 1
• Lumbar puncture: Measurement of opening pressure (elevated in IIH) 1

Treatment Algorithm

Step 1: Weight Management (First-line)

• Target: 5-15% reduction in body weight for patients with BMI >30 kg/m² 1
• Methods:
  • Self-directed weight loss can achieve clinical remission in many patients (median 11.5% weight loss) 2
  • Multicomponent lifestyle interventions (diet + physical activity + behavior) for BMI <35 kg/m² 3
  • Consider bariatric surgery for BMI ≥35 kg/m² (most robust evidence for sustained weight loss and ICP reduction) 3

Step 2: Pharmacological Management

• First-line: Acetazolamide

  • Starting dose: 250-500mg twice daily
  • Maximum dose: 4g daily as tolerated 1
  • Mechanism: Carbonic anhydrase inhibition reduces CSF production

• Second-line (if acetazolamide not tolerated):

  • Topiramate: Start at 25mg daily with weekly escalation to 50mg twice daily 1

    • Benefits: Weight loss effect, migraine control, carbonic anhydrase inhibition 4
    • Caution: Depression, cognitive slowing, reduced contraceptive efficacy, teratogenic potential 1

  • Zonisamide: Alternative when topiramate has excessive side effects 1

• For severe visual loss requiring rapid intervention:

  • Intravenous dexamethasone (short-term use only) 1

Step 3: Surgical Management (for refractory cases or threatened vision)

• CSF diversion procedures:

  • Ventriculoperitoneal shunt (preferred due to lower revision rates) 1
  • Lumboperitoneal shunt
  • Optic nerve sheath fenestration

• Venous sinus stenting:

  • For patients with venous sinus stenosis who have failed medical therapy and weight loss
  • Requires demonstration of significant pressure gradient across stenosis 1
  • Can rapidly improve symptoms and abolish papilledema 1

Headache Management

• First-line: NSAIDs or paracetamol for short-term relief 1
• For migraine-like attacks: Triptans (limited to 2 days/week or maximum 10 days/month) 1
• Consider: Indomethacin (additional benefit due to ICP-reducing effect) 1
• Avoid: Opioids 1
• For coexisting chronic migraine: Consider weight-neutral migraine preventatives (candesartan or venlafaxine) 1

Monitoring and Follow-up

• Regular ophthalmologic evaluations:
  • Visual acuity, visual fields, papilledema, optical coherence tomography (OCT)
  • Frequency based on severity of papilledema and visual field status 1
• Extended follow-up (>5 years) is essential as late recurrences can occur (10-18% recurrence rate) 1
• Medication discontinuation: Do not discontinue acetazolamide without careful consideration of visual risk 1

Important Caveats

• Visual loss is the main morbidity of IIH but can usually be reversed if recognized early and treated appropriately 1
• Extreme caloric restriction may lead to malnutrition, depression, and disability despite improving IIH symptoms 5
• Balanced approach to weight loss is essential for long-term success and avoiding complications 5
• Novel medical treatments targeting pathways other than carbonic anhydrase inhibition are being developed 6
• Treatment decisions should be based on disease manifestations and aim for IIH remission 6