Clinical Recognition Headache of variable severity and duration is the most common presenting symptom It is typically worse in the morning Nausea, vomiting, dizziness, and double or blurred vision also occur If the process is long standing, decreased visual acuity or visual field deficits can result Infants often have nonspecific symptoms of lethargy or irritability Papilledema is seen in virtually all cases, although a syndrome of IIH without papilledema exists Other neurologic symptoms and signs are often absent; however, unilateral or bilateral VI nerve paresis may be seen Initial Assessment Diagnosis should be considered when a child with a prolonged history of headache is found to have evidence of papilledema without other neurologic findings IIH is a diagnosis of exclusion, and other conditions, particularly mass lesions, must be ruled out Because posterior fossa tumors and obstructive or nonobstructive hydrocephalus may mimic IIH early in the course of disease, neuroimaging should be obtained in all children with this constellation of findings MRI is the study of choice, though contrast-enhanced CT may be used if MRI is unavailable or contraindicated Magnetic resonance venography (MRV) is useful in identifying cerebral venous anomalies in atypical (i.e., younger, male, or nonobese) patients In cases of IIH, the ventricles will appear normal or small If no mass lesion is present, an LP should be performed with a manometer to measure opening pressure The patient must be in the lateral decubitus position with legs extended to ensure an accurate reading of the opening pressure Children with idiopathic (e.g., not secondary to Lyme infection or other causes) have elevated opening pressure (greater than 280 mm CSF) but normal CSF cell count, protein, and glucose In children with intermittent symptoms, the opening pressure may be normal when the headache is waning, even though papilledema may persist for several weeks Management For patients with visual changes or cranial nerve involvement, neurosurgical as well as ophthalmologic consultation is recommended For the large majority of patients, removal of sufficient CSF to normalize ICP usually leads to improvement in symptoms Treatment may then be started with acetazolamide (Diamox) to decrease CSF production (60 mg/kg/day divided four times daily) Although recommended by some, corticosteroids have not been proven to be effective in the management of this condition and should only be administered after consultation with a neurologist