Background Idiopathic intracranial hypertension (IIH) is an infrequent disease in childhood. The incidence of IIH in the pediatric population is extremely low ranging from 0.5 per 100,000 to 1.2 per 100,000. Unlike in adults and adolescents, pre-adolescent IIH does not show the same predilection for obesity or female gender. The pathophysiology of IIH is not fully understood, though up to 93% of patients with IIH harbor dural venous sinus stenosis which can be safely and effectively treated with venous sinus stenting (VSS). The underlying cause of venous stenosis is unknown, however, there is growing evidence to suggest that IIH may be related to a microscopic disturbance in the transport and outflow of cerebrospinal fluid (CSF), interstitial fluid (ISF), blood, and lymph. This recently discovered hydrodynamic exchange has been termed the ‘Glymphatic’ system. We present a case of IIH in a 3-year old with a temporal bone lymphangioma and severe transverse sinus stenosis treated successfully with VSS. We hypothesize that the underlying etiology of the patient’s IIH and venous sinus stenosis may be related to a disturbance in glymphatic outflow.

Methods This is a report of a 3-year-old patient with medical refractory idiopathic intracranial hypertension that acutely worsened after surgical resection lymphatic malformation of the right middle ear. The patient underwent venous angiography revealing severe transverse sinus stenosis with a high pressure gradient. The patient was successfully treated with the placement of an adult-sized venous sinus stent, Zilver ® 8mm x 8mm, (Cook Medical) within the right transverse sinus with complete resolution of the pressure gradient and symptoms.

Results Upon one month clinical follow up the patient continued to have complete headache resolution and experienced no complications. The patient was transitioned to Aspirin monotherapy for an additional three months.

Conclusion We present a 3-year old patient with IIH who was found to have a right middle ear lymphatic malformation and severe transverse sinus stenosis successfully treated with venous sinus stenting. The relationship between IIH and venous sinus stenosis as it relates to alterations in the glymphatic system warrants further investigation.

Disclosures K. Russell: None. M. Webb: None. L. Birnbaum: None.