Symptoms of Idiopathic Intracranial Hypertension (IIH)
The most common symptoms of IIH include headache that progressively becomes more severe and frequent, visual disturbances, pulsatile tinnitus, and papilledema, with headache affecting nearly 50% of patients as their most debilitating symptom. 1
Primary Symptoms
Headache
- Typically diffuse and progressively worsens over days to weeks
- Often worse in the morning or when lying flat
- Exacerbated by Valsalva maneuvers (coughing, straining)
- Highly variable phenotype that may mimic other primary headache disorders
- Reported as the most impactful symptom by 49.6% of patients 2
Visual Disturbances
- Transient visual obscurations (unilateral or bilateral darkening of vision typically lasting seconds)
- Visual blurring
- Visual field defects
- Diplopia (typically horizontal) from sixth nerve palsy
- Permanent vision loss is a serious potential complication requiring urgent assessment 3
- Reported as the most impactful symptom by 18.1% of patients 2
Pulsatile Tinnitus
- Whooshing or rhythmic sounds in the ears
- Synchronous with pulse
- Reported as the most impactful symptom by 16.8% of patients 2
Papilledema
- Key diagnostic finding on fundoscopic examination
- Present in approximately 60% of cases 3
- May lead to progressive vision loss if untreated
Secondary Symptoms
- Back pain
- Dizziness
- Neck pain
- Cognitive disturbances
- Radicular pain
- Nausea and vomiting
- Altered mental status (in severe cases)
Rare or Severe Presentations
- Complete ophthalmoplegia (rare) 4
- Proptosis 4
- Cushing's triad (hypertension, bradycardia, irregular respiratory pattern) - a late finding 3
- Seizures in approximately 25% of cases 3
- Abnormal posturing (decorticate or decerebrate) in advanced cases 3
- Focal neurological deficits including hemiparesis or cranial nerve palsies 3
Pediatric-Specific Symptoms
- Increasing head circumference
- Bulging fontanelle
- Loss of developmental milestones
- Irritability
- Poor feeding 3
Fulminant IIH
Some patients may experience a more aggressive form called fulminant IIH:
- Rapid worsening of symptoms over days
- Higher risk of permanent vision loss
- Requires urgent intervention, often surgical 5
Clinical Pearls
- None of these symptoms are pathognomonic for IIH 1
- Visual symptoms require urgent assessment as permanent vision loss is a serious complication 3
- Delayed recognition of increased ICP can result in irreversible neurological damage 3
- The condition predominantly affects obese women of reproductive age 1, 3
- Certain medications can contribute to symptoms, including tetracycline-class antibiotics, vitamin A and retinoids, steroids, growth hormone, thyroxine, and lithium 3
- Misdiagnosis is common, with IIH being both underdiagnosed and misdiagnosed 3
Early recognition of these symptoms is critical to prevent serious complications such as permanent vision loss, which can often be reversed if identified and treated early in the disease course 6.