Background

Primary angiitis of the central nervous system (PACNS) is a newly-emerging disease, and it is known that early diagnosis with treatment is important for the improvement of prognosis.

Case description

Here, we report the case of a previously healthy 13-year-old girl who presented with right eye abduction failure, attributed to isolated right sixth nerve palsy, as the initial symptom of PACNS. Magnetic resonance angiography (MRA) showed stenosis in the distal portion of the right internal carotid artery, and delay alternating with nutation for tailored excitation (DANTE)-prepared contrast-enhanced magnetic resonance imaging confirmed vasculitis at the same site. The patient was subsequently treated with three courses of pulse corticosteroid therapy (methylprednisolone intravenously 30 mg/kg/day for three consecutive days). Diplopia completely resolved within 3 months after three course of steroid pulse therapy, and when taking 10 mg PSL daily. Follow-up MRA confirmed complete resolution of the arterial narrowing, and no relapse was observed after 2 months of steroid cessation.

Discussion

This case report illustrates an unusual presentation of PACNS with isolated sixth nerve palsy. PACNS was thought to cause insults on a single cranial nerve either through local spread of inflammation or hypoxic-ischemic insults on the nerve root due to involvement of feeding microvessels. The decision to perform imaging studies in cases of isolated sixth nerve palsy remains controversial because of the possibility of spontaneous recovery. Our case supports the existing literature that recommends that even an isolated symptom of unilateral abducens nerve palsy requires timely imaging studies.

中文翻译：

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孤立性第六神经麻痹作为中枢神经系统原发性血管炎的初始表现

背景

中枢神经系统原发性血管炎（PACNS）是一种新出现的疾病，众所周知，早期诊断和治疗对于改善预后很重要。

案例说明

在这里，我们报告了一个先前健康的 13 岁女孩的案例，她出现右眼外展失败，归因于孤立的右第六神经麻痹，作为 PACNS 的初始症状。磁共振血管造影 (MRA) 显示右侧颈内动脉远端狭窄，延迟交替与特制激发章动 (DANTE) 对比增强磁共振成像证实同一部位有血管炎。该患者随后接受了三个疗程的脉冲皮质类固醇治疗（甲基强的松龙静脉注射 30 mg/kg/天，连续三天）。经过三个疗程的类固醇脉冲治疗和每天服用 10 mg PSL 后，复视在 3 个月内完全消退。后续 MRA 证实动脉狭窄完全消退，

讨论

该病例报告说明了伴有孤立性第六神经麻痹的 PACNS 的不寻常表现。PACNS 被认为是通过炎症的局部扩散或由于涉及喂养微血管而对神经根造成缺氧缺血性损伤而对单个颅神经造成损伤。由于可能自发恢复，对孤立性第六神经麻痹病例进行影像学检查的决定仍然存在争议。我们的案例支持现有文献，即即使是单侧外展神经麻痹的孤立症状也需要及时的影像学研究。