II. Epidemiology

  1. Incidence
    1. General Population: 0.9 per 100,000
    2. Women aged 15-44 years: 3.5 per 100,000
    3. Obese women aged 20-44 years: 19.3 per 100,000
    4. Pseudotumor occurs in children and must be kept in differential in refractory new Headache
      1. (2015) Pediatr Emer Care 31:6-9 [PubMed]
  2. Rare: similar Incidence as
    1. Amyotrophic Lateral Sclerosis
    2. Guillain Barre Syndrome
    3. Muscular Dystrophy

III. Pathophysiology

  1. Intracranial Hypertension
  2. Optic disc edema
    1. Causes transient Optic Nerve ischemia

V. Symptoms

  1. Headache
    1. Location: retro-orbital Headache
    2. Provocative: eye movement worsens Headache
    3. Timing: Chronic Daily Headache, worse on awakening
    4. Characteristics: Throbbing Headache
    5. Associated Symptoms: Nausea and Vomiting
  2. Transient Decreased Visual Acuity (75%)
    1. Monocular or Binocular Acute Vision Loss
    2. Lasts for only a few seconds
    3. Permanent visual changes occur in a few patients
      1. Increased blind spot
        1. Blurred Vision or Tunnel Vision
        2. Dark spot in temporal Visual Field
      2. Profound Vision Loss or blindness (severe cases)
    4. Other visual changes
      1. Photophobia
      2. Diplopia
  3. Pulsatile Tinnitus (60%)
    1. Unilateral or bilateral "whooshing" sound
    2. Palliative:
      1. Lumbar Puncture
      2. Jugular venous compression
  4. Musculoskeletal symptoms
    1. Neck Pain or neck stiffness
    2. Back pain
    3. Arthralgias (Shoulder, wrist, knee)
  5. Neurologic Symptoms and Psychiatric Symptoms
    1. Paresthesias
    2. Radicular pain
    3. Facial palsy
    4. Impaired concentration or memory
    5. Major Depression

VI. Signs

  1. Ophthalmoscopy (Fundoscopy)
    1. Decreased venous pulsations
    2. Papilledema
      1. Not predictive of visual outcome
  2. Visual Field Defects
    1. Best detected by perimetry (Visual Field testing)
    2. Blind spot enlargement
    3. Inferonasal visual loss
    4. Visual Field constriction (tunnel Vision)
  3. Decreased Ocular Motility

VII. Diagnostics: Lumbar Puncture

  1. Opening Pressure consistent with Pseudotumor Cerebri (Idiopathic Intracranial Hypertension)
    1. Obese Children > 280 mm of water (28 cm water)
    2. Non-obese Patient > 250 mm of water (25 cm water)
    3. Non-diagnostic: 200 to 250 mm of water (20 to 25 cm water)
  2. Opening Pressure falsely elevated by:
    1. Sitting position
    2. Prone position (fluoroscopy)
    3. Painful tap
    4. Anxiety
      1. Consider pretreating LP with Benzodiazepine
  3. Send CSF for spinal fluid analysis
    1. CSF Glucose
    2. CSF Protein
    3. CSF Cell Count
    4. CSF Cultures (Bacteria, fungi, Tuberculosis)
    5. CSF Cytology

VIII. Diagnosis: Headache Attributable to Idiopathic Intracranial Hypertension (ICHD-3 Criteria)

  1. New or significantly worsened Headache AND
  2. Idiopathic Intracranial Hypertension diagnosed and CSF Pressure >250 mm (or >280 mm in obese children) AND
  3. At least one of the following
    1. Headache has developed or significantly worsened in temporal relation to IIH or led to its diagnosis
    2. Headache is accompanied by pulsatile Tinnitus or Papilledema
  4. Not better described by another ICHD-3 Diagnosis
  5. Reference: ICHD-3
    1. https://ichd-3.org/7-headache-attributed-to-non-vascular-intracranial-disorder/7-1-headache-attributed-to-increased-cerebrospinal-fluid-pressure/7-1-1-headache-attributed-to-idiopathic-intracranial-hypertension-iih/

IX. Imaging

  1. Head MRI (preferred over CT Head)
    1. Negative MRI does not exclude Idiopathic Intracranial Hypertension (but does evaluate for other causes)
    2. Ventricles may be decreased in size (slit-like) or may be normal
    3. Empty Sella Sign
      1. Test Sensitivity: 48 to 74%
      2. Test Specificity: 84 to 94%
    4. Posterior Globe Flattening
      1. Test Sensitivity: 46 to 65%
      2. Test Specificity: 85 to 98%
    5. Optic Nerve Tortuosity
      1. Test Sensitivity: 26 to 48%
      2. Test Specificity: 82 to 92%
    6. Transverse Sinus Stenosis
      1. Test Sensitivity: 65 to 94%
      2. Test Specificity: 92 to 97%
    7. References
      1. Kwee (2019) Eur J Radiol 116: 106-15 +PMID: 31153551 [PubMed]

XI. Management: Medical

  1. Neurology Consultation
  2. Weight loss
  3. Dietary changes
    1. Low salt diet
    2. Low tyramine diet
  4. Avoid sulfa conjugated medications
  5. Diuretic
    1. Acetazolamide (Diamox)
      1. Dose: 1 to 4 grams daily divided bid-tid
    2. Furosemide (Lasix)
  6. Systemic Corticosteroids
    1. Reserved for urgent management of Vision Loss
  7. Headache Management
    1. Acute Treatment: NSAIDs
    2. Prophylaxis: Tricyclic Antidepressants
  8. Therapeutic large volume Lumbar Puncture
    1. Removal of 20 ml of spinal fluid

XII. Management: Surgical

  1. Optic Nerve Sheath Decompression
    1. Indicated for associated Decreased Visual Acuity
    2. Window or fenestration cut in Optic Nerve sheath
    3. Results in increased Blood Flow to the Optic Nerve
  2. Cerebrospinal fluid Shunt
    1. Lumboperitoneal shunt (preferred over ventricular)
    2. Short term: Very effective
    3. Long term: Multiple revisions often required

XIII. Management: Pregnancy

  1. Careful follow-up
    1. Frequent Neurology evaluation
    2. Frequent Ophthalmology evaluation
    3. Repeated Lumbar Puncture monitoring
  2. Intervention
    1. Acetazolamide (Diamox) after 20 weeks gestation
    2. Systemic Corticosteroids for Vision deterioration
    3. Optic Nerve Sheath Decompression
    4. Ventriculoperitoneal Shunt
  3. Contraindicated Agents
    1. Avoid Tricyclic Antidepressants
    2. Avoid Thiazide Diuretics

XIV. Complications

  1. Blindness

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