Intracranial space-occupying lesion (tumor, abscess).
Cranial nerve palsies (CN VI is most common, although III, VII, IX, and XII have also been reported). Visual field loss is seen in up to 91% of cases. Loss of visual acuity is seen in 6-20% of pediatric cases at presentation. Headache may be warning sign of elevated ICP and impending visual loss. Young patients with IIH who are not experiencing headaches tend to have more neurologic and visual signs at presentation and have a worse prognosis. However, some children may not complain of headache (too young to articulate or not having headaches). Headache is the main complaint among children (62-91% of cases). Patients may also present with other signs of increased ICP: vomiting, altered behavior, decreased level of consciousness, macrocephaly. Presenting symptoms: headache, tinnitus, visual changes (blurred vision, visual loss, photophobia). 
Possibly secondary to transverse sinus stenosis (cause/effect relationship with IIH and stenosis is unclear). Research regarding the role of aquaporin 4 channels regulating cerebral water content is ongoing. Decreased CSF reabsorption via arachnoid granulations. Conditions such as obesity, Turner syndrome, chronic renal failure, Prader-Willi, and delayed puberty may increase the risk of IIH in this setting. Usually resolves with cessation of GH therapy (can resume at a lower dose as risk of IIH appears to be dose-dependent). Proposed mechanism: GH crosses blood-brain barrier to increase local levels of IGF-1 which increases CSF production from choroid plexus. In one large study, occurrence of IIH was 100X greater in group treated with growth hormone vs. Mechanism unknown, but it has been hypothesized that increased levels of vasopressin in these patients may cause increased cerebral volume leading to elevated ICP. Corticosteroid withdrawal in pediatric patients with IBD. Thyroxine is a regulator of sodium transport that may alter CSF dynamics. Most cases occurred after dose was increased due to persistently elevated TSH levels. 
Thyroid disease: Cases of IIH have been reported following therapy for hypothyroidism with levothyroxine.While secondary causes of IIH are not often found in adults, a potential underlying condition is identified in 53-77% of pediatric cases.Excess vitamin A or vitamin A derivatives such as Acutane for acne.Tetracyclines (minocycline, doxycycline).Rapid weight gain has been associated with recurrences in patients with prior diagnosis and treatment of IIH.Less of an association with IIH in pre-pubescent children (perhaps a different mechanism).Strong correlation with IIH in women of childbearing age and post-pubescent adolescents.Can be found in any age group (although IIH is uncommon in infants and very rare in neonates).Characteristically diagnosed in obese women of childbearing age (risk is 2-20 times higher in this group).Occurs in 1 out of every 100,000 people in the general population.
Pseudotumor Cerebri, also known as Idiopathic Intracranial Hypertension (IIH) is a disorder of increased intracranial pressure without evidence of an underlying cause (infection, space-occupying lesion, vascular abnormality, or hydrocephalus)
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