Kim Woojun, Kang Soo Hwan, An Jae Young
Department of Neurology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea.
Department of Orthopedic Surgery, College of Medicine, St. Vincent's Hospital, The Catholic University of Korea, Seoul, South Korea.
Front Neurol. 2021 Sep 8;12:701571. doi: 10.3389/fneur.2021.701571. eCollection 2021.
Neuralgic amyotrophy (NA) is an acute, monophasic, painful inflammatory dysimmune focal, or multifocal mononeuropathy. The lesion in NA is not always restricted to the brachial plexus but also involves individual nerves or branches. The prognosis of NA is less favorable than previously assumed, but the reasons for poor recovery remain unknown. Nerve constriction may be one of the causes of poor prognosis in NA. Herein, we described a 54-year-old male with a history of type 2 diabetes in whom bilateral neuralgic amyotrophy developed with constriction of the posterior interosseous fascicle within the radial nerve. The patient experienced sudden-onset severe pain in both shoulders followed, 2 days later, by weakness in bilateral shoulders and the left forearm extensors over the subsequent month. The left forearm extensors were more severely affected than both shoulder girdle muscles. He noted a 7-kg weight loss for 1 month before pain onset. After diagnosing diabetic NA based on the clinical symptoms, imaging, and electrophysiological studies, treatment with systemic steroids improved pain and weakness in both shoulder muscles. Weakness in the left forearm extensors persisted after 1 month of steroid treatment. Follow-up ultrasound revealed constriction of the posterior interosseous fascicle within the main trunk of the left radial nerve at the elbow. Surgical exploration at 6 months after onset identified fascicle constriction, for which neurolysis was performed. Weakness in the extensors of the wrist and fingers did not improve during the 16-month follow-up. A single constriction of the fascicle within a peripheral nerve may often be under-recognized if NA presents with variable degrees of weakness in bilateral upper limbs. Furthermore, fascicular constriction without edema of the parent nerve may be easily missed on the initial ultrasound. A lack of early recognition of nerve constriction and delay in surgical intervention can result in unfavorable outcomes. The physician should consider the possibility of the fascicular constriction when evaluating patients suspected of brachial NA with significant weakness in the distal upper limb compared to the proximal weakness or weakness of the distal upper limb that does not improve over time.
神经性肌萎缩（NA）是一种急性、单相、疼痛性炎症性免疫失调性局灶性或多灶性单神经病。NA的病变并不总是局限于臂丛神经，也可累及单根神经或分支。NA的预后比之前认为的要差，但恢复不佳的原因尚不清楚。神经受压可能是NA预后不良的原因之一。在此，我们描述了一名54岁的2型糖尿病男性患者，其双侧神经性肌萎缩伴桡神经骨间后束受压。患者双肩突然出现剧痛，2天后双侧肩部及左前臂伸肌出现无力，持续1个月。左前臂伸肌比双侧肩带肌受累更严重。他在疼痛发作前1个月体重减轻了7公斤。根据临床症状、影像学和电生理检查诊断为糖尿病性NA后，全身应用类固醇治疗改善了双侧肩部肌肉的疼痛和无力。类固醇治疗1个月后，左前臂伸肌仍无力。随访超声显示左桡神经主干在肘部的骨间后束受压。发病6个月后手术探查发现束支受压，进行了神经松解术。在16个月的随访中，腕部和手指伸肌的无力没有改善。如果NA表现为双侧上肢不同程度的无力，外周神经内单一束支的受压可能常常未被充分认识。此外，在最初的超声检查中，母神经无水肿的束支受压可能很容易被遗漏。缺乏对神经受压的早期识别和手术干预的延迟可能导致不良后果。在评估怀疑为臂丛NA且上肢远端无力明显重于近端无力或上肢远端无力随时间无改善的患者时，医生应考虑束支受压的可能性。
