II. Epidemiology
III. Pathophysiology
- Intracranial Hypertension
- Optic disc edema
- Causes transient Optic Nerve ischemia
IV. Causes
V. Symptoms
- Headache
- Transient Decreased Visual Acuity (75%)
- Monocular or Binocular Acute Vision Loss
- Lasts for only a few seconds
- Permanent visual changes occur in a few patients
- Increased blind spot
- Blurred Vision or Tunnel Vision
- Dark spot in temporal Visual Field
- Profound Vision Loss or blindness (severe cases)
- Increased blind spot
- Other visual changes
- Photophobia
- Diplopia
- Pulsatile Tinnitus (60%)
- Unilateral or bilateral "whooshing" sound
- Palliative:
- Lumbar Puncture
- Jugular venous compression
- Musculoskeletal symptoms
- Neck Pain or neck stiffness
- Back pain
- Arthralgias (Shoulder, wrist, knee)
- Neurologic Symptoms and Psychiatric Symptoms
- Paresthesias
- Radicular pain
- Facial palsy
- Impaired concentration or memory
- Major Depression
VI. Signs
-
Ophthalmoscopy (Fundoscopy)
- Decreased venous pulsations
- Papilledema
- Not predictive of visual outcome
-
Visual Field Defects
- Best detected by perimetry (Visual Field testing)
- Blind spot enlargement
- Inferonasal visual loss
- Visual Field constriction (tunnel Vision)
- Decreased Ocular Motility
VII. Diagnostics: Lumbar Puncture
- Opening Pressure consistent with Pseudotumor Cerebri (Idiopathic Intracranial Hypertension)
- Obese Children > 280 mm of water (28 cm water)
- Non-obese Patient > 250 mm of water (25 cm water)
- Non-diagnostic: 200 to 250 mm of water (20 to 25 cm water)
- Opening Pressure falsely elevated by:
- Sitting position
- Prone position (fluoroscopy)
- Painful tap
- Anxiety
- Consider pretreating LP with Benzodiazepine
- Send CSF for spinal fluid analysis
- CSF Glucose
- CSF Protein
- CSF Cell Count
- CSF Cultures (Bacteria, fungi, Tuberculosis)
- CSF Cytology
VIII. Diagnosis: Headache Attributable to Idiopathic Intracranial Hypertension (ICHD-3 Criteria)
- New or significantly worsened Headache AND
- Idiopathic Intracranial Hypertension diagnosed and CSF Pressure >250 mm (or >280 mm in obese children) AND
- At least one of the following
- Headache has developed or significantly worsened in temporal relation to IIH or led to its diagnosis
- Headache is accompanied by pulsatile Tinnitus or Papilledema
- Not better described by another ICHD-3 Diagnosis
- Reference: ICHD-3
IX. Imaging
-
Head MRI (preferred over CT Head)
- Negative MRI does not exclude Idiopathic Intracranial Hypertension (but does evaluate for other causes)
- Ventricles may be decreased in size (slit-like) or may be normal
- Empty Sella Sign
- Test Sensitivity: 48 to 74%
- Test Specificity: 84 to 94%
- Posterior Globe Flattening
- Test Sensitivity: 46 to 65%
- Test Specificity: 85 to 98%
- Optic Nerve Tortuosity
- Test Sensitivity: 26 to 48%
- Test Specificity: 82 to 92%
- Transverse Sinus Stenosis
- Test Sensitivity: 65 to 94%
- Test Specificity: 92 to 97%
- References
X. Differential Diagnosis
XI. Management: Medical
- Neurology Consultation
- Weight loss
- Dietary changes
- Low salt diet
- Low tyramine diet
- Avoid sulfa conjugated medications
-
Diuretic
-
Acetazolamide (Diamox)
- Dose: 1 to 4 grams daily divided bid-tid
- Furosemide (Lasix)
-
Acetazolamide (Diamox)
-
Systemic Corticosteroids
- Reserved for urgent management of Vision Loss
-
Headache Management
- Acute Treatment: NSAIDs
- Prophylaxis: Tricyclic Antidepressants
- Therapeutic large volume Lumbar Puncture
- Removal of 20 ml of spinal fluid
XII. Management: Surgical
-
Optic Nerve Sheath Decompression
- Indicated for associated Decreased Visual Acuity
- Window or fenestration cut in Optic Nerve sheath
- Results in increased Blood Flow to the Optic Nerve
- Cerebrospinal fluid Shunt
- Lumboperitoneal shunt (preferred over ventricular)
- Short term: Very effective
- Long term: Multiple revisions often required
XIII. Management: Pregnancy
- Careful follow-up
- Frequent Neurology evaluation
- Frequent Ophthalmology evaluation
- Repeated Lumbar Puncture monitoring
- Intervention
- Acetazolamide (Diamox) after 20 weeks gestation
- Systemic Corticosteroids for Vision deterioration
- Optic Nerve Sheath Decompression
- Ventriculoperitoneal Shunt
- Contraindicated Agents
- Avoid Tricyclic Antidepressants
- Avoid Thiazide Diuretics
XIV. Complications
- Blindness