What is the primary treatment for a patient with Idiopathic Intracranial Hypertension (IIH) and Internuclear Ophthalmoplegia (INO)?

Primary Treatment for Idiopathic Intracranial Hypertension (IIH) with Internuclear Ophthalmoplegia (INO)

The primary treatment for patients with Idiopathic Intracranial Hypertension (IIH) and Internuclear Ophthalmoplegia (INO) should be acetazolamide combined with a structured weight loss program, with prompt consideration of surgical intervention if visual function deteriorates despite maximal medical therapy. 1

Medical Management

First-line Treatment

• Acetazolamide:
  • Starting dose: 250-500 mg twice daily 2
  • Titrate up as tolerated, with a target maximum dose of 4 g daily 2
  • Warn patients about common side effects: diarrhea, dysgeusia, fatigue, nausea, paresthesia, tinnitus, vomiting, depression, and rarely renal stones 2
  • Monitor effectiveness through improvement in papilledema and visual function 1

Alternative/Additional Medical Options

• Topiramate:
  • Consider when acetazolamide is not tolerated 2, 1
  • Starting dose: 25 mg with weekly escalation to 50 mg twice daily 2
  • Dual benefit: carbonic anhydrase activity and appetite suppression 2, 3
  • Important counseling points:
    • Reduces efficacy of hormonal contraceptives
    • Potential side effects: depression, cognitive slowing, teratogenic risks 2
  • Zonisamide may be considered if topiramate side effects are excessive 2

Weight Management

• Structured weight loss program is essential for patients with BMI >30 kg/m² 1
• Target 5-15% reduction in total body weight, which can lead to disease remission 1
• Implement lifestyle modifications:
  • Limit caffeine intake
  • Ensure regular meals and adequate hydration
  • Establish exercise program and sleep hygiene 2

Surgical Management for Progressive Visual Loss

If visual function deteriorates despite maximal medical therapy:

1. CSF Diversion Procedures:

   • Ventriculoperitoneal shunt preferred over lumboperitoneal shunt (fewer revisions) 1
   • Note: 68% continue to have headaches at 6 months and 79% by 2 years after shunting 2
   • 28% may develop iatrogenic low-pressure headaches 2

2. Optic Nerve Sheath Fenestration (ONSF):

   • Consider for asymmetric papilledema causing visual loss in one eye 2
   • Should be performed by an experienced clinician trained in this technique 2

3. Venous Sinus Stenting (investigational):

   • May be considered for documented visual loss despite maximal therapy 1
   • Requires documented pressure gradient >8 mmHg across stenosis 1
   • Requires long-term antithrombotic therapy for >6 months post-procedure 1
   • Not currently recommended for headache management alone 2

Headache Management

Headache in IIH often has migrainous features (68% of cases) 2:

• Acute treatment:

  • NSAIDs or paracetamol (indomethacin may have advantages due to ICP-reducing effects) 2
  • Triptans may be used for migrainous attacks (limit to 2 days/week or max 10 days/month) 2
  • Avoid opioids 2

• Preventive treatment (for persistent headaches):

  • Consider migraine preventatives, especially when ICP is stabilizing 2
  • Caution with medications that may increase weight (beta blockers, tricyclic antidepressants, sodium valproate) 2
  • Consider weight-neutral options like candesartan or venlafaxine 2
  • Botulinum toxin A may be useful for those with coexisting chronic migraine 2

Monitoring and Follow-up

Follow-up intervals should be based on papilledema grade and visual field status:

• Severe papilledema: Every 1-3 months; within 1 week if worsening 2
• Moderate papilledema: Every 3-4 months; every 1-3 months if improving or stable; within 2 weeks if worsening 2
• Mild papilledema: Every 6 months; every 3-6 months if improving; every 3-4 months if stable; within 4 weeks if worsening 2

Important Caveats

• Serial lumbar punctures are not recommended for ongoing management of IIH 2
• CSF diversion is generally not recommended for headache management alone 2
• Medication overuse headache is common in IIH patients and should be addressed 2
• Fulminant IIH with rapidly progressive vision loss may occasionally respond to maximal medical management, but surgical intervention should be readily available 4
• Complete ophthalmoplegia is a rare presentation of IIH that may require urgent CSF diversion 5