Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)

Basics

Description

Diagnostic criteria of idiopathic intracranial hypertension (IIH) include the following:

  • Signs and symptoms of increased intracranial pressure (e.g., headache, vomiting, ocular manifestations, and papilledema)
  • Elevated cerebrocranial fluid pressure but otherwise normal cerebrospinal fluid (CSF)
  • Normal neurologic exam except for papilledema (occasional abducens or other motor cranial neuropathy)
  • Normal neuroimaging study (or incidental findings only)

Epidemiology

  • Boys and girls are affected equally in childhood; in adolescence and adulthood, more women than men are affected.
  • IIH has been reported in patients as young as 4 months of age, with a median age of 9 years.

Incidence

  • Estimated to be 0.71/100,000 cases per year for children <17 years old, with increasing incidence with age and weight
  • Annual incidence is estimated to be 4.18 per 100,000 in obese boys ages 12 to 15 years and 10.7 per 100,000 in obese girls ages 12 to 15 years.

Risk Factors

Genetics

Sporadic, no clear genetic predisposition, unless related to an underlying hormonal, toxic, or inflammatory condition; no data are available in children.

Pathophysiology

Pathogenesis unknown but may involve decreased CSF absorption owing to arachnoid villi dysfunction or elevated intracranial venous pressure. For example, obesity may lead to increased intra-abdominal, intrathoracic, and cardiac filling pressure, leading to elevated intracranial venous pressure.

Etiology

Numerous precipitants of IIH have been reported. In adolescents, it is clearly associated with obesity and weight gain but not clearly linked to obesity in children <11 years of age. Many weaker associations may be due to chance.

Commonly Associated Conditions

  • Exposure to exogenous steroids
  • Corticosteroid withdrawal
  • Lead exposure
  • IIH is often linked to minocycline, tetracycline, sulfonamides, isotretinoin, and thyroid replacements.
  • Also linked to vitamin A deficiency or intoxication, chronic anemia, and hypothyroidism

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