What is the treatment for benign intracranial hypertension (BIH)?

Treatment for Benign Intracranial Hypertension (BIH)

The primary treatment for benign intracranial hypertension (now termed idiopathic intracranial hypertension or IIH) is weight loss for obese patients combined with acetazolamide as first-line pharmacological therapy, with surgical interventions reserved for cases with deteriorating visual function despite maximal medical therapy. 1

Treatment Algorithm

First-Line Treatments:

1. Weight Management

   • For patients with BMI >30 kg/m²
   • Goal: 5-15% weight reduction to achieve disease remission
   • Structured weight loss program with dietary modification and exercise 1

2. Pharmacological Treatment

   • Acetazolamide (first-line medication)

     • Starting dose: 250-500 mg twice daily
     • Maximum dose: up to 4 g daily
     • Administration: Every 8 hours to respect its kinetics
     • Duration: Several months with gradual dose reduction 1, 2
     • Monitor for metabolic acidosis
     • Supplement with oral potassium to prevent hypokalemia 2

   • Alternative/Adjunctive Medications:

     • Topiramate: Start at 25 mg daily with weekly escalation to 50 mg twice daily
       • Benefits: Both carbonic anhydrase inhibition and appetite suppression
       • Contraindicated in pregnancy 1
     • Furosemide: Alternative carbonic anhydrase inhibitor 2

Management Based on Disease Severity:

For Mild to Moderate Disease (Stable Vision):

• Weight loss and acetazolamide
• Regular ophthalmologic monitoring:
  • Mild papilledema: Every 6 months
  • Moderate papilledema: Every 3-4 months 1

For Severe Disease or Imminent Risk of Vision Loss:

1. Immediate Interventions:

   • Serial lumbar punctures as a temporizing measure 3
   • Consider IV corticosteroids (e.g., dexamethasone) for rapid intervention
     • Not recommended for long-term use due to side effects 1

2. Surgical Options (when vision deteriorating despite medical therapy):

   • Ventriculoperitoneal (VP) shunt: Preferred due to lower revision rates 1
   • Lumboperitoneal shunt: Alternative CSF diversion method 4
   • Optic nerve sheath fenestration (ONSF): Particularly for asymmetric papilledema 1
   • Venous sinus stenting: Investigational treatment requiring documented pressure gradient >8 mmHg across stenosis 1

Headache Management in IIH

1. Acute Headache Treatment:

   • NSAIDs or paracetamol
   • Indomethacin (advantageous due to ICP-reducing effects)
   • Triptans for migrainous attacks
   • Avoid opioids 1

2. Preventive Treatment:

   • Migraine preventatives (candesartan, venlafaxine) for coexisting chronic migraine
   • Botulinum toxin A for chronic migraine 1
   • Caution regarding medication overuse headache (avoid simple analgesics >15 days/month) 1

Monitoring and Follow-up

• Regular ophthalmologic evaluations to assess:

  • Papilledema
  • Visual acuity
  • Visual fields
  • Optical coherence tomography (OCT) 1

• Follow-up frequency based on disease severity:

  • Severe papilledema: Every 1-3 months
  • Moderate papilledema: Every 3-4 months
  • Mild papilledema: Every 6 months 1

• Expedite review if worsening of visual fields or papilledema 3

Special Considerations

Pregnancy

• Multidisciplinary approach throughout pregnancy, delivery, and postpartum
• Risk-benefit assessment for acetazolamide during pregnancy
• No specific mode of delivery based solely on IIH diagnosis
• Appropriate weight gain for gestational age
• Increased outpatient observation during pregnancy
• For acute exacerbations with imminent risk to vision: Consider serial lumbar punctures until longer-term measures can be implemented 3

IIH Without Papilledema (IIHWOP)

• Manage as typical IIH with weight management and headache treatment
• Surgical management not routinely recommended unless advised by experienced clinicians in a multidisciplinary team setting 3

Pitfalls and Caveats

1. Medication-related:

   • Monitor for metabolic acidosis with acetazolamide
   • Avoid prolonged hypocapnia for treating intracranial hypertension
   • Avoid 4% albumin solutions in severe intracranial hypertension 1
   • Be aware of potential shunt dependence with surgical interventions 4

2. Diagnostic:

   • Ensure proper diagnosis before initiating treatment
   • Rule out secondary causes of intracranial hypertension
   • Consider alternative diagnoses if cranial nerve involvement beyond sixth nerve palsy 3

3. Treatment:

   • Surgical interventions carry significant complication rates
   • Venous sinus stenting requires long-term antithrombotic therapy for >6 months 1
   • CSF shunting is effective but has associated complications and revision rates 4

By following this structured approach to treatment, the risk of vision loss and other morbidities associated with BIH can be significantly reduced while managing symptoms effectively.