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.

Risk Factors

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