Idiopathic Intracranial Hypertension

 

We have all dealt with patients presenting with headaches.  They often cause some cephalgia in us as well.  Certainly, in the adult ED chronic headaches are more common and the diagnosis of pseudotumor cerebri more commonly considered.  While it does have a greater likelihood of presenting in the adult population, you still need to consider it in the Pediatric ED.

Pseudotumor Cerebri = Idiopathic Intracranial Hypertension (IIH)

  • May occur at any age in childhood, although more common in adolescents
  • There are criteria used to diagnose adults with IIH (Modified Dandy Criteria)
  • The criteria have be used for adolescents but adjusted for Prepubertal patients.
    • Modified Dandy Criteria [Postpuertal patients]
      • Signs and symptoms of increased ICP
      • Headache, nausea, vomiting, papilledema, transient change in vision
      • No localizing neurologic exam abnormalities
        • With the exception of unilateral or bilateral CNVI palsy
      • Normal neuroimaging (CT or MRI)
      • Increased ICP while in lateral decubitus position of >250 mm H2O
      • Normal CSF composition
      • No other identified cause of intracranial hypertension
    • Proposed Criteria for Prepubertal IIH
      • If symptoms/signs are present, they can only be consistent with generalized intracranial hypertension or papilledema. Must have normal mental status.
      • No evidence of hydrocephalus, mass, structural, or vascular lesion on MRI(with and without contrast) and MR Venography.
      • Cranial nerve palsies allowed if there is no other identifiable cause and they improve with reduction of CSF pressure.
      • Increased ICP adjusted for age while measured in the lateral decubitus position.
        • Neonates >76 mm H2O
        • 1-18 years > 280 mm H2O
      • Normal CSF composition except:
        • Neonates may have up to 19 WBC/mm3
        • 29-56 days of age may have up to 9 WBC/mm3
        • May have elevated protein as well. (up to 150mg/dL)

Risk Factors

  • Preadolescents with IIH
    • Less likely to be obese
    • Male:female = ~50:50
    • More likely to have a underlying etiology (see below)
  • Adolescents with IIH (similar to adults)
    • More likely to be obese
    • More likely to be female

Presentation

  • Headache is the main complaint (naturally), but IIH can be diagnosed without headaches (papilledema found on exam in asymptomatic patient).
  • Nausea, vomiting
  • Change in vision (blurred, double vision [CN palsy], photophobia
  • Papilledema
    • Mild blurring of the disc to gross edema with hemorrhages.
    • In infants with open fontanel, there may be no papilledema but rather buldging fontanel.
  • Visual field cuts (make sure you are checking these).
  • CN Palsies (CN VI is most common, but III, IV, VI, VII, IX, and XII also reported)

 

Potential Mimics of IIH

  • Addison’s Disease
  • Rapid correction of hypothyroidism with thyroxine
  • Corticosteroid withdrawl (after long courses)
  • Hypoparathyroidism
  • COPD
  • Right Heart Failure with Pulmonary hypertension
  • Sleep Apnea
  • Renal Failure
  • Severe iron deficiency
  • Cerebral Venous Sinus Thrombosis
  • Jugular Vein Thrombosis
  • Medications
    • Tetracycline
    • Vitamin A
    • Anabolic Steroids
    • Growth Hormone
    • Nalidixic acid
    • Lithium
    • Desmospressin nasal spray
    • Norplant

Evaluation

  • For those that you are considering IIH in, neuroimaging is recommended prior to LP (to make sure you don’t cause herniation… that’s a good idea).
  • CT has limitations in this realm since it can miss sinus venous thrombosis and other meningeal infiltrative processes.
  • MRI with and without Gadolinium and MR Venogram are preferred by most.
  • LP after normal neuroimaging to measure opening pressure.
    • Needs to be in lateral decubitus position
    • LP under Fluoro is often done in the prone position… so if they go to flouro ask to position in the lateral decubitus position.

Management

  • No current standard of care for children.
  • Weight loss is recommend for the obese.
  • Repeat LPs is discouraged because of poor tolerance and short-lived efficacy.
  • Most respond to medical management
    • Acetazolamide or furosemide
    • Topiramate
    • Analgesics
  • Surgery for those who are refractory to medical management
    • Optic Nerve Fenestration
    • CSF Shunting

 

Ko MW, L GT. Pediatric Idiopathic Intracranial Hypertension (Pseudotumor Cerebri). Horm Res Paediatr. 2010; 74: 381-389.

Friedman DI, Jacobson DM. Diagnostic Criteria for Idiopathic Intracranial Hypertension. Neurology. 2002;59:1492-1495.

Sean M. Fox

I enjoy taking care of patients and I finding it endlessly rewarding to help train others to do the same. I trained at the Combined Emergency Medicine and Pediatrics residency program at University of Maryland, where I had the tremendous fortune of learning from world renown educators and clinicians. Now I have the unbelievable honor of working with an unbelievably gifted group of practitioners at Carolinas Medical Center. I strive every day to inspire my residents as much as they inspire me.

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