Treatment of Idiopathic Intracranial Hypertension (IIH)
Weight loss and acetazolamide are the first-line treatments for IIH, with surgical interventions reserved for cases with progressive visual loss or refractory symptoms. 1
First-line Management Approach
- Weight loss is the foundation of treatment for IIH and should be recommended for all patients 1
- Acetazolamide should be initiated at 250-500 mg twice daily, with gradual titration as tolerated 1, 2
- Maximum dose used in the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT) was 4 g daily, though most patients tolerate 1 g/day 2, 3
- Approximately 48% of patients discontinue acetazolamide at mean doses of 1.5 g due to side effects 2
- Common side effects include diarrhea, dysgeusia, fatigue, nausea, paresthesia, tinnitus, vomiting, depression, and rarely renal stones 2, 1
Alternative Medical Therapies
- Topiramate may be considered as an alternative to acetazolamide, with weekly dose escalation from 25 mg to 50 mg twice daily 2, 4
- Topiramate offers multiple benefits including weight loss, migraine control, and carbonic anhydrase inhibition 5
- When prescribing topiramate, women must be informed about reduced efficacy of hormonal contraceptives and potential side effects including depression, cognitive slowing, and teratogenic risks 2, 1
- Zonisamide may be used as an alternative when topiramate side effects are excessive 2
- Other diuretics such as furosemide, amiloride, and coamilofruse are sometimes used, though evidence for their efficacy is uncertain 2
Headache Management in IIH
- Migrainous phenotype is noted in 68% of IIH patients with headache 2
- Patients should be warned about medication overuse headache risk (use of simple analgesics >15 days/month or opioids/triptans >10 days/month) 2, 1
- Short-term pain management may include NSAIDs or paracetamol; indomethacin may be advantageous due to its ICP-reducing effect 2, 1
- Opioids should not be prescribed for headache management 2
- For migrainous headaches, triptans may be used acutely (limited to 2 days/week or maximum 10 days/month) in combination with NSAIDs/paracetamol and antiemetics 2
- Preventive migraine medications should be considered, avoiding those that increase weight (beta-blockers, tricyclic antidepressants, sodium valproate) 2
- Weight-neutral options like candesartan or venlafaxine may be preferable for migraine prevention 2, 1
- Botulinum toxin A may be useful in those with coexisting chronic migraine 2
Surgical Management
- Surgery should be considered for patients with progressive visual loss despite medical therapy 1, 6
- Ventriculoperitoneal (VP) shunt is the preferred CSF diversion procedure due to lower revision rates 1
- Lumboperitoneal (LP) shunts are an alternative option 1
- Optic nerve sheath fenestration (ONSF) may be considered for asymmetric papilloedema or as first-line treatment in fulminant cases 1
- CSF diversion for headache alone is generally not recommended, as 68% continue to have headaches at 6 months and 79% by 2 years 2, 1
- Venous sinus stenting is emerging as a potentially effective treatment for medically refractory IIH 6, 7
- Neurovascular stenting is not currently recommended as a treatment for headache in IIH 2
Important Considerations and Pitfalls
- Serial lumbar punctures are not recommended for long-term management despite providing temporary relief 1
- CSF is produced at 25 mL/hour, so volume removed during LP is rapidly replaced 1
- Lumbar punctures can cause significant anxiety and may lead to acute and chronic back pain 1
- Medication overuse must be addressed, as it can prevent optimization of preventative treatments 2
- Non-opioids and triptans can be stopped abruptly or weaned within a month, while opioids should be gradually removed 2
- Greater occipital nerve blocks may be considered by some clinicians, but there is a lack of evidence and consensus 2
- Follow-up intervals should be based on papilloedema grade and visual field status, ranging from within 1 week for severe worsening cases to 6 months for mild stable cases 2