臂丛神经功能障碍

定义

臂丛是由五条脊神经（C5-T1）的腹侧神经组成，这些脊神经具有支配上肢运动、感觉和节前交感神经纤维。这五条脊神经连接起来形成三条主干（上C5-C6；中C7；下C8-T1），这些主干又分为六个部分，成为三条索（外侧、内侧和后侧）。臂丛神经很容易受到不同程度的创伤，而且由于神经丛靠近淋巴结、血管和肺实质，可受到各种疾病影响；糖尿病和血管炎也可引起臂丛神经功能紊乱。有些病例被认为是特发性臂丛神经病。临床特征取决于是整个臂丛神经受累还是其中一部分受累。在泛神经丛病中，手臂无生命地垂在侧边，肢体松弛和屈曲，从肩部斜向下、向上臂中部延伸的线以下感觉完全丧失。 在上躯干病变中，手臂侧悬，肩部内旋，肘部伸直，前臂呈“侍者尖”姿势。肱二头肌和肱桡肌反射缺失，手臂、前臂和拇指外侧感觉丧失。 下躯干病变表现为手内肌无力，手指屈曲反射减弱或消失，两中指内侧及前臂、手内侧感觉丧失。

The brachial plexus is formed by ventral rami of five spinal nerves (C5-T1), which have motor, sensory and preganglionic sympathetic fibres innervating the upper limb. These five rami join to form three trunks (upper-C5-C6; middle-C7; lower-C8-T1) which again divide into six divisions to become three cords (lateral, medial and posterior). The plexus is vulnerable to trauma at various levels and can be affected by a variety of diseases because of its close proximity to lymph nodes, blood vessels and lung parenchyma; diabetes mellitus and vasculitis can also cause brachial plexus dysfunction. Some cases are considered as an idiopathic brachial plexopathy. Clinical features depend on whether the entire plexus or a portion of it is involved. In panplexopathy, the arm hangs lifelessly by the side, the limb is flaccid and areflexic with complete sensory loss below a line extending from the shoulder diagonally downward and medially to the middle of upper arm. In lesions of the upper trunk, the arm hangs at the side, internally rotated at the shoulder, with the elbow extended and the forearm pronated in a “waiter`s tip” posture. The biceps and brachioradialis reflexes are absent and sensory loss is found over the lateral aspect of the arm, forearm and thumb. In lesions of the lower trunk, there is weakness of the intrinsic hand muscles, the finger flexion reflex is diminished or absent, and there is sensory loss over the two medial fingers as well as the medial aspect of forearm and hand.

子条目 共 4 条

• 8B91.0痛性肩部肌萎缩
• 8B91.1劲肋性胸出口综合征
• 8B91.Y其他特指的臂丛神经功能障碍
• 8B91.Z未特指的臂丛神经功能障碍