Treatment of IIH in Children

Spontaneous resolution of IIH appears to be more common in children than adults. In some children, IIH resolves following a single lumbar puncture. Because of the potential for permanent visual loss,25,26 however, children with IIH should be followed with the same vigilance as adults.

Three caveats apply to the treatment of visual loss in IIH:

(1)Although visual acuity usually remains normal, once it starts to decrease, it can drop precipitously over several weeks. Failing medical therapy, expeditious optic nerve sheath fenestration or lumboperitoneal shunting should be performed.

(2)Children with IIH secondary to venous sinus thrombosis can experience hyperacute visual loss that simulates optic neuritis or neuroretinitis.

(3)While it is considered axiomatic that visual loss is consequent to axonal injury from swelling of the disc, and it is known that superior venous sinus thrombosis and carotid cavernous fistula can cause a posterior optic neuropathy. It is therefore not inconceivable that the progressive optic atrophy in IIH could simultaneously be caused by vascular compromise of the posterior optic nerve in some cases.

Regarding medical treatment, some have found the combination of furosemide and high-dose acetazolamide to be an effective nonsurgical intervention in children.489 Others believe that oral steroids are more efficacious in children than in adults with IIH and advocate their use.554 When these measures fail, topiramate may be used, especially in obese children.157 Topiramate is an antiepileptogenic medication with secondary carbonic anhydrase activity. It is unclear whether topiramate is superior to acetazolamide in reducing intracranial pressure.

Because of the nonassociation of prepubertal IIH with obesity, gastric stapling and other bariatric procedures have found little application. Current surgical treatment of IIH is limited to optic nerve sheath fenestration and lumboperitoneal shunt. Numerous studies have suggested that optic nerve sheath fenestration is an effective way to restore or preserve vision in IIH,23 and it has become the surgical treatment of choice. Optic nerve sheath fenestration is also efficacious in cases in which lumboperitoneal shunting is unsuccessful. Optic nerve sheath fenestration relieves headaches in about two-thirds of patients.106 Optic nerve sheath fenestration has been shown to be safe and effective in children.332,547

Lumboperitoneal shunts have traditionally been the method of shunting in IIH, however, ventriculoperitoneal shunting has also been used.553 Although various shunting procedures have been devised, lumboperitoneal shunting seems to be the most successful in alleviating symptoms.436

Regardless of the shunt system used, patients with IIH are prone to shunt failure.186 Overdrainage is another important complication of CSF shunts. Thus, successful lumboperitoneal shunting relieves headaches from elevated intracranial pressure, this form of headache may be traded for another due to hindbrain herniation.23 Headache is the most common symptom, with a strong positional component akin to that seen after lumbar puncture.186 The overdrainage also common to all shunt systems can be responsible for iatrogenic Chiari malformation.186 Estimates of Chiari I malformation following lumboperitoneal shunting range from 0 to 70%.89,452 CSF shunting is advocated for children who have intractable headaches as well as visual loss and papilledema unresponsive to optic nerve sheath fenestration.23,89,452 Lumboperitoneal shunting is an effective means of reducing intracranial pressure, but shunt failures are frequent (particularly in obese individuals).23 Shunt infection may be life-threatening, and acquired Chiari type I tonsillar herniation commonly occurs. This procedure is also associated with various other complications, including shunt obstruction, lumbar radiculopathy, infection), and tonsillar herniation.69,88,140

Some have recently advocated venous sinus stenting of collapsed or stenotic venous sinuses.241,242,419 However venous sinus stenting is an irreversible, invasive procedure with the potential for serious complications.101 Notwithstanding its reported efficacy, longitudinal follow-up data are needed before it can be recommended. Furthermore, most investigators now believe that increased venous sinus pressure results from, rather than causes, increased intracranial pressure in IIH.101,173

The finding of a potentially reversible cause of IIH in a child (e.g., dural sinus thrombosis) should not lead to a false sense of security that the child is not at risk for blindness. Our indications for surgical intervention include the following:

(1)Evidence of progressive optic neuropathy (i.e., loss of visual acuity or visual field despite maximal medical therapy, or worsening papilledema in a child who cannot cooperate with examination).

(2)Severe optic neuropathy (i.e., chronic atrophic papilledema) that would seriously jeopardize the patient’s ability to function normally if further visual loss occured.25

If these criteria are met, we believe that optic nerve sheath fenestration should be performed despite the fact that the underlying condition is expected to eventually resolve.

Prognosis of IIH in Children

Stiebel-Kailash et al531 found pubertal age to carry a worse prognosis for visual outcome than other ages. While the long-term prognosis has not been determined with certainty, Kesler et al298 found the recurrence rate to be 40% and noted that recurrences occurred after stopping treatment.