An Unusual Presentation for 6th Nerve Palsy: Isolated Chronic Sphenoid Sinusutis and Bilateral Abducens Palsy

摘要

Isolated inflammatory involvement of the sphenoid sinus is a relatively uncommon entity. Chronic sphenoid infections may present a problem of differential diagnosis. It may be difficult to differentiate between benign and malignant lesions. The sphenoid sinus is the paranasal sinus most commonly implicated when cranial neuropathies are present. In this paper, we report a case of isolated sphenoid sinusitis in a 14-year-old boy who was presented with bilateral VIth nerve palsy. He was initially treated with parenteral antibiotherapy and systemic steroid treatment. As the abducens palsy and the sphenoiditis persisted he underwent an endoscopic sphenoidotomy. Medical treatment consisting of oral antibiotics and systemic steroids had been continued for six weeks period as the eye movements gradually recovered. Given the high prevelence of noninflammatory lesions within the sphenoid sinus, thorough preoperative evaluation is imperative. Presented as poster in 24th ISIAN International Symposium on Infection and Allergy of the Nose, April 20-23, 2005, Sao Paolo- Brazil Introduction The sphenoid sinus has often been referred to as the neglected sinus because of its isolated position and difficult accessibility. Disease restricted to the sphenoid sinus is rare and often manifests with nonspecific or subtle signs and symptoms. The early and accurate diagnosis of isolated sphenoid sinus disease may thus be difficult(1). The early occurrence of complications is explained by the anatomical location of the sinus and its proximity to the intracranial and orbital contents, to which infection may quickly spread. Due to the lack of nasal symptoms the disorder may not be seen in Ear, Nose and Throat department until an advanced stage has been reached(2,3). Chronic sphenoid sinusitis is usually caused by incomplete resolution of acute sinusitis, which may occur following inadequate medical management of the latter condition. The symptoms of chronic sinusitis may be more subtle and vague than for acute sinusitis. Sometimes, mild daily headaches are the only sign of disease. In other cases, asymptomatic disease progression is possible(1). The most encountered presentation of isolated sphenoid sinusitis is with headache and orbital symptoms. The next most frequent symptom is visual compromise, which included blurred vision and loss of visual acuity ranging from mild loss to partial blindness. Diplopia caused by involvement of the abducens nerve is the most common of cranial palsies, occurring in 6% of inflammatory cases and in 50% of neoplastic disease(4).In this paper, we report an unusual case of isolated chronic sphenoiditis (ICS) in a 14-year-old boy who presented with bilateral VIth nerve palsy. Since the only positive diagnostic finding was isolated chronic sinusitis with computed tomographic scan (CT) and magnetic resonance imaging (MRI), a thorough evaluation of the possible causes of bilateral VIth nerve palsy was presented and differential diagnosis was reported with the literature review. Case Report A 14-year-old boy was initially admitted to ophtalmology department with a-month history of diplopia. He was referred to our hospital as a tertiary care centre from a hospital of a neighbouring city. He had been treated with systemic antibiotics before admitting to our hospital. After detecting opacification in both sphenoid sinuses, the ophtalmology department referred the patient to our clinic. Chronic headache in the vertex area and gradual onset of diplopia and bilateral strabismus since one month were the only symptoms. On examination limitation of the lateral deviation of both eyes were the only positive signs. For a detailed investigation, a cranial MRI and CT scan were obtained. The only positive finding was isolated sphenoid sinusitis which was confirmed by coronal CT scan. He was initially treated with parenteral antibiotherapy and systemic steroid treatment. The medical treatment consisted of 100 mg prednisolon tapered 20 mg in eve