How to treat IIH patients

Lowering intracranial pressure is key for managing sight-threatening condition

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[caption id="attachment_11685" align="alignleft" width="1024"] Choroidal Folds: hypotonous maculopathy (left), papilloedema (right)[/caption]
Courtney E Francis MD
Patients with possible idiopathic intracranial hypertension (IIH) require a complete neurological workup to ensure proper diagnosis and treatment, Courtney E Francis MD told the American Academy of Ophthalmology Annual Meeting in New Orleans, USA. Idiopathic intracranial hypertension is a condition most often seen in overweight young women that can lead to permanent vision loss. However, venous sinus thrombosis, meningioma, meningitis and even very high blood pressure can cause similar signs and symptoms, noted Dr Francis. IIH typically presents with papilloedema and headache often accompanied by nausea, Dr Francis noted. On fundus examination, it can look like hypotony, with disc oedema and choroidal folds, suggesting that a translaminar pressure difference may play a role in both. History also often includes transient vision obscurations and pulsatile tinnitus. Papilloedema, sixth nerve palsy and visual field defects consistent with papilloedema also may be present – and nothing else. “It is a diagnosis of exclusion,” she said. RULING OUT SECONDARY CAUSES Since treatment for IIH differs significantly from treatment of intracranial hypertension secondary to other causes, Dr Francis recommended a diagnostic routine based on modified Dandy criteria. These include signs and symptoms of increased intracranial pressure, no localising findings on neurological exam, normal cerebrospinal fluid except for increased pressure above 20-25cm water, normal neuroimaging except for empty sella turcica, dilated optic nerve sheaths or venous sinus stenosis, patient awake and alert and no other cause of increased ICP identified (Friedman et al. Neurology 2013; 81: 1159-1165). Imaging should include MRI of the brain with and without gadolinium contrast, and magnetic resonance venography of the head to identify potential anatomic abnormalities or tumours, Dr Francis said. She also recommended lumbar puncture with opening pressure measure, and cerebrospinal fluid analysis to rule out meningitis. Treatment of IIH is aimed at lowering intracranial pressure, Dr Francis said. Diet to reduce weight and medication with carbonic anhydrase inhibitors are first-line therapies. In the Idiopathic Intracranial Hypertension Treatment Trial, which included 165 patients of which four were men, patients receiving acetazolamide had improved papilloedema grade and visual field function. The medication was mostly well tolerated up to 4.0gm per day (JAMA 2014; 311(16):1641-1651). Potential surgical treatments for patients intolerant of medication or with more severe vision loss include optic nerve fenestration, CSF diversion surgery and venous sinus stenting, Dr Francis said. Further research into genetic markers as well as the efficacy of surgical interventions are needed to better understand and control IIH, she added. Courtney E Francis: francis3@uw.edu
Tags: idiopathic intracranial hypertension