Etiology

Table 597-1 lists the many causes of pseudotumor cerebri. There are many explanations for the development of pseudotumor cerebri, including alterations in CSF absorption and production, cerebral edema, abnormalities in vasomotor control and cerebral blood flow, and venous obstruction. The causes of pseudotumor are numerous and include metabolic disorders (galactosemia, hypoparathyroidism, pseudohypoparathyroidism, hypophosphatasia, prolonged corticosteroid therapy or rapid corticosteroid withdrawal, possibly growth hormone treatment, refeeding of a significantly malnourished child, hypervitaminosis A, severe vitamin A deficiency, Addison disease, obesity, menarche, oral contraceptives, and pregnancy), infections (roseola infantum, sinusitis, chronic otitis media and mastoiditis, Guillain-Barré syndrome), drugs (nalidixic acid, doxycycline, minocycline, tetracycline, nitrofurantoin), isotretinoin used for acne therapy especially when combined with tetracycline, hematologic disorders (polycythemia, hemolytic and iron-deficiency anemias [Fig. 597-1], Wiskott-Aldrich syndrome), obstruction of intracranial drainage by venous thrombosis (lateral sinus or posterior sagittal sinus thrombosis), head injury, and obstruction of the superior vena cava. When a cause is not identified, the condition is classified as idiopathic intracranial hypertension.