台耳醫誌

Unilateral abducens nerve palsy (UANP) is a very rare condition in adults, especially as a postoperative complication in otorhinolaryngology surgeries. The most recognized etiologies of UANP include cerebrovascular disease, undetermined factors, and trauma, whereas other causes such as spontaneous intracranial hypotension, local anesthetic effects, intracranial neoplasm, multiple sclerosis, inflammatory disease, and viral infection are occasionally encountered. We present a 51-year-old woman who suffered from sudden onset of isolated left lateral rectus muscle palsy following functional endoscopic sinonasal surgery. The patient denied any underlying systemic disease, previous surgical history, neurological signs, or trauma history. Preoperative physical and fiberscopic examinations revealed hypertrophic turbinates, deviated nasal septum, and mucopus postnasal dripping. Sinonasal computed tomography without contrast reported chronic rhinosinusitis. The procedure was uneventful, and a blood loss of 300 mL was recorded. The postoperative neurological examination was normal except the occurrence of isolated left lateral rectus palsy. Her muscle power was intact in both upper and lower limbs as well. The left lateral rectus muscle paralysis recovered nearly an hour after the operation. However, only a few cases of postoperative UANP have been reported by the earlier scientists in the literature, wherein most etiologies include spontaneous intracranial hypotension, local anesthetic effect, and idiopathic origin. Finally, we propose that clinicians shall rule out the local anesthetic effect initially after functional endoscopic sinus surgery and undergo detailed surveys of spontaneous intracranial hypotension in healthy adults and cerebrovascular diseases in patients with systemic diseases.
 (J Taiwan Otolaryngol Head Neck Surg 2021; 56:191-196)