Ophthalmologic course of bilateral abducens nerve palsies after the treatment of idiopathic intracranial hypertension with venous sinus stenting.

Abstract

Dear Editor, Idiopathic intracranial hypertension (IIH) is associated with numerous ophthalmologic sequelae, including papilledema, visual loss, and unilateral and bilateral abducens nerve palsies (ANP). Successful treatment of IIH can resolve associated ocular motility disturbances, but the time course of ANP resolution is not well defined [1]. We report a case of an IIH patient with bilateral ANPs who was treated with VSS, and subsequently monitored with serial ophthalmologic examinations for recovery of abducens nerve function. A 33-year-old female presented with 3 weeks of severe headache, diplopia, nausea, and vomiting. Lumbar puncture revealed an opening pressure greater than 55 cmH2O. The patient was diagnosed with IIH and started on acetazolamide. Despite medical therapy, the patient continued to clinically deteriorate. Magnetic resonance venography (MRV) showed intracranial venous outflow obstruction secondary to stenosis of the left transverse sinus (TS), with a congenitally hypoplastic right TS. Based on the patient’s neuroimaging and failure of medical therapy, she was evaluated for treatment with venous sinus stenting (VSS). An intraparenchymal intracranial pressure (ICP) monitor was placed, which revealed a mean ICP of 50 cmH2O, with an upper limit of 80 cmH2O. Ophthalmologic examination found bilateral visual loss, severe bilateral papilledema with obscuration of vessels and disk hemorrhage without spontaneous venous pulsations, and bilateral ANPs, left worse than right (Fig. 1). Diagnostic cerebral angiography showed severe stenosis of the lateral aspect of the left transversesigmoid junction (Fig. 2). Venous manometry found mean venous pressures of 55 and 11 mmHg in the left mid-TS and sigmoid sinus, respectively, yielding a pressure gradient of 44 mmHg across the stenosis. The patient was loaded with an institutionally standard dual antiplatelet therapy (aspirin 325 mg and clopidogrel 600 mg), and then underwent VSS with concurrent ICP monitoring. A 10 9 40 mm Protege stent (ev3, Irvine, CA, USA) was deployed across the left transverse-sigmoid junction stenosis, which decreased the venous pressure gradient across previously stenotic segment to 4 mmHg. After VSS, the patient’s mean ICP reduced to 20 mmHg within 48 h, and then to less than 20 mmHg within 72 h. The patient had an uneventful postoperative course and, 4 days after the VSS procedure, the ICP monitor was removed, and she was discharged home on dual antiplatelet therapy consisting of aspirin 325 mg and clopidogrel 75 mg daily for 3 months, followed monotherapy with aspirin 325 mg daily indefinitely. Of note, we routinely obtain a brain computed tomography (CT) after ICP monitor placement (prior to the loading dose of dual antiplatelet therapy) and after ICP monitor removal to confirm a lack of intracranial hemorrhage. If a hemorrhage is identified after ICP monitor placement, dual antiplatelet therapy is not administered and the VSS procedure is aborted. Serial ophthalmologic examinations found gradual recovery of the bilateral ANPs and complete disappearance & Dale Ding dmd7q@hscmail.mcc.virginia.edu