What is the treatment and prognosis for Idiopathic Intracranial Hypertension (IIH)?

Treatment and Prognosis for 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

Treatment Approach

Medical Management

• Weight loss of 5-10% of total body weight is the foundation of treatment for all overweight IIH patients, along with a low-salt diet 1, 2
• Acetazolamide is the first-line medical therapy with recommended starting dose of 250-500 mg twice daily, gradually titrated as tolerated 1
• Maximum dose used in clinical trials was 4 g daily, though many patients tolerate 1 g/day; approximately 48% discontinue at mean doses of 1.5 g due to side effects 1, 3
• Common side effects of acetazolamide include diarrhea, dysgeusia, fatigue, nausea, paresthesia, tinnitus, vomiting, depression, and rarely renal stones 1
• Topiramate may be considered as an alternative to acetazolamide, with weekly dose escalation from 25 mg to 50 mg twice daily 1
• When prescribing topiramate, women must be informed about reduced efficacy of hormonal contraceptives and potential side effects including depression, cognitive slowing, and teratogenic risks 1, 4
• Serial lumbar punctures are not recommended for long-term management despite providing temporary relief, as CSF is produced at 25 mL/hour, so volume removed during LP is rapidly replaced 4, 1

Headache Management

• Migrainous headache phenotype is common in IIH patients (68%) 1
• For acute treatment, triptans may be used (limited to 2 days/week or maximum 10 days/month) in combination with NSAIDs/paracetamol and antiemetics 4
• Preventive migraine medications should be considered, avoiding those that increase weight (beta-blockers, tricyclic antidepressants, sodium valproate) 4
• Weight-neutral options like candesartan or venlafaxine may be preferable for migraine prevention 4
• Patients should be warned about medication overuse headache risk (use of simple analgesics >15 days/month or opioids/triptans >10 days/month) 1
• Opioids should not be prescribed for headache management 1

Surgical Management

• Surgery should be considered for patients with progressive visual loss despite medical therapy 1
• Ventriculoperitoneal (VP) shunt is the preferred CSF diversion procedure due to lower revision rates per patient 4, 1
• Lumboperitoneal (LP) shunts are an alternative option 4
• Adjustable valves with antigravity or antisiphon devices should be considered to reduce low-pressure headaches 4, 1
• Optic nerve sheath fenestration (ONSF) may be considered for asymmetric papilledema or as first-line treatment in fulminant cases 4, 5
• ONSF has fewer complications than CSF diversion but should be performed by experienced clinicians 4
• Venous sinus stenting is not currently established as a standard treatment for IIH but may be considered in select cases 4, 5
• Long-term antithrombotic therapy is required for longer than 6 months following neurovascular stenting 4

Prognosis

• Treatment failure rates include worsening vision after stabilization in 34% at 1 year and 45% at 3 years 4, 1
• Headache fails to improve in one-third to one-half of patients despite treatment 4
• CSF diversion for headache alone has limited evidence, with 68% continuing to have headaches at 6 months and 79% by 2 years 4, 1
• Visual outcomes are generally favorable with appropriate treatment, with improvement in Goldmann visual field grade in 60% of patients 6
• Visual function deteriorates in approximately 10% of patients despite treatment 6
• Weight gain during the year before diagnosis is significantly associated with deterioration of visual field grade 6
• Severe visual loss leading to blindness occurs in approximately 4% of patients 6

Common Pitfalls and Considerations

• Failure to address weight management as the foundation of treatment 1
• Inadequate monitoring of visual function, which should include formal visual field testing, not just visual acuity 6
• Medication overuse must be addressed, as it can prevent optimization of preventative treatments 1
• Relying on serial lumbar punctures for management, which provide only temporary relief 4, 1
• Delaying surgical intervention in cases with progressive visual loss despite medical therapy 1
• Prescribing medications that may increase weight in a condition where weight loss is crucial 4, 1