What are the symptoms of idiopathic intracranial hypertension (IIH)?

Symptoms of Idiopathic Intracranial Hypertension (IIH)

The primary symptoms of idiopathic intracranial hypertension include headache that is progressively more severe and frequent, transient visual obscurations, pulsatile tinnitus, visual blurring, and horizontal diplopia, with headache being the most common presenting symptom. 1

Common Symptoms

• Headache: The most frequent symptom, typically progressively more severe and frequent, with a highly variable phenotype that may mimic other primary headache disorders 1

• Visual disturbances:

  • Transient visual obscurations (unilateral or bilateral darkening of vision lasting seconds) 1
  • Visual blurring 1
  • Horizontal diplopia (double vision), often due to sixth nerve palsy 1, 2
  • Progressive visual field loss if untreated 3, 4

• Pulsatile tinnitus: Whooshing sound in the ears that is synchronous with the pulse 1, 5

• Other neurological symptoms:

  • Dizziness 1
  • Neck pain 1
  • Back pain 1
  • Cognitive disturbances 1
  • Radicular pain 1

Clinical Findings

• Papilledema: The hallmark physical finding in IIH, visible on fundoscopic examination 2, 6

• Cranial nerve abnormalities:

  • Sixth nerve palsy may occur, causing horizontal diplopia 2, 6
  • Other cranial nerves are typically not involved; if they are, alternative diagnoses should be considered 2

Frequency and Presentation Patterns

• Symptoms are often more pronounced in the typical IIH patient: female, of childbearing age, with BMI >30 kg/m² 2, 4

• Atypical patients (males, non-obese, children, older adults) may present with similar symptoms but require more thorough investigation 2, 4

Important Considerations

• None of these symptoms are pathognomonic for IIH, meaning they can occur in other conditions 1

• The headache phenotype is highly variable and can mimic other primary headache disorders, making clinical diagnosis challenging 1, 2

• Visual symptoms are particularly important to recognize early, as permanent visual loss is the main morbidity of IIH 3, 4, 5

• Some patients may have IIH without papilledema (IIHWOP), which is a rare subtype that meets all other criteria for IIH but lacks the characteristic fundoscopic findings 2

Warning Signs Requiring Urgent Attention

• Progressive visual field loss 3, 4
• Severe, intractable headaches 6
• New onset of diplopia 2, 6
• Rapid progression of symptoms 7, 6

Early recognition of these symptoms is crucial for timely diagnosis and treatment to prevent permanent visual loss, which is the most serious complication of IIH 3, 4, 5.