| 본문 : The abducens nerve passes ventrally through the subarachnoid space to pierce the dura overlying the clivus. The clival mass can affect the abducens nerve and lead to abducens nerve palsy. Chordomas are rare, slow-growing, locally aggressive neoplasms of bone that arise from embryonic remnants of the notochord. We report the case of a patient with unilateral abducens nerve palsy caused by clival chordoma. A 66-year-old male visited our clinic with a complain of suddenly developed horizontal diplopia for 4 days. The symptoms did not show diurnal variation or any relationship with fatigue. He did not have any neurologic symptoms such as such as headache, nausea, vomiting, and altered level of consciousness. He did not report the presence of any other systemic disease. There was no ocular injection, chemosis, pain, or visual disturbance. The visual acuity was 20/40 in both eyes. There was no proptosis and abnormal lid problem in either eye. The pupils showed normal response to both light and near stimulation. Extraocular examination revealed 6 prism diopters (PD) esotropia at primary gaze without definitive abduction limitation. The esotropia increased to 12 PD at the right gaze. Serologic tests including a thyroid function test and anti-acetylcholine receptor antibody test were conducted to evaluate the cause of diplopia, which revealed normal results. The brain MRI revealed the mass arising from the clivus compressing the pontine area and invading the cavernous sinus. The removal of tumor using endoscopic endonasal transclival approach was performed. The pathologic report confirmed the chordoma. The abducens nerve palsy and diplopia improved after the surgery. |