术后感觉异常(postoperative dysesthesia)
脊柱微创技术的优点不用多说，但因其操作范围相对局限，学习曲线长，尤其初学者，术中操作可能会损伤神经根(nerve root)或背根节(dorsal root ganglion, DRG), 从而引起术后根性症状或术后感觉异常(postoperative dysesthesia, POD)，文献报道，其发生率可高达5∼15%。
POD被定义为DRG神经支配区域的感觉疼痛或烧灼样感觉，可以是自发引起的，也可以是被诱发的，例如触碰到衣服，但没有肢体无力。而神经根损伤与肢体无力有关，伴有或不伴有神经根支配区疼痛或麻木。
临床上，POD常被误诊为神经根的损伤。其临床特点主要是：大多数病人术后当天就会出现，术后第3日会明显加重，大多数表现为异样疼痛或灼烧感，有时疼痛严重VAS评分可高达8-9分，夜间重，白天会改善，有时候触碰到衣服就会明显诱发并加重不适。但大多数病人，根据疼痛程度，经过非甾体抗炎药、曲马多或卡马西平或背根节阻滞（利多卡因和激素混合液）后症状会明显缓解。疼痛持续时间一般为1-2月。
在恢复期，如疼痛逐渐移向DRG支配区的远端，则是一个预后良好的标志。
额外补充：看英文文献经常会遇到单词Dysesthesia, Paresthesia和Hyperalgesia，都表示感觉或疼痛异常，容易引起误解，由于患者教育程度不同，有时给予解释或阐述很难鉴别这三个单词的差别，临床上，就很难准确记录患者的不适（酸痛、刺痛、烧灼感、虫爬感，其实都是感觉异常，但是写文章时候应该用那个单词描述更地道呢？维基百科给出一些解释，摘取部分一道分享给大家。我没有翻译，总感觉有种只可意会不可言传的感觉）。
Hyperalgesia is an increased sensitivity to pain, which may be caused by damage to nociceptors or peripheral nerves and can cause hypersensitivity to stimulus, stimuli which would normally not be cause for a pain reaction.
Dysesthesia (or dysaesthesia) is defined as an unpleasant, abnormal sense of touch. It often presents as pain but may also present as an inappropriate, but not discomforting, sensation. It is caused by lesions of the nervous system, peripheral or central, and it involves sensations, whether spontaneous or evoked, such as burning, wetness, itching, electric shock, and pins and needles. It is sometimes described as feeling like acid under the skin.
Paresthesia is an abnormal dermal sensation (e.g., a tingling, pricking, chilling, burning, or numb sensation on the skin) with no apparent physical cause. The manifestation of a paresthesia may be transient or chronic, and may have any of dozens of possible underlying causes. Paresthesias are usually painless and can occur anywhere on the body, but commonly occur in the extremities. The most familiar kind of paresthesia is the sensation known as "pins and needles" or of a limb "falling asleep". A less well-known and uncommon but important paresthesia is formication, the sensation of bugs crawling underneath the skin.
参考文献：
1. Eur Spine J (2016) 25:2622–2628
2. Eur Spine J (2016) 25:1595–1600
3. Dysesthesia,Paresthesia, and Hyperalgesia from Wikipedia.
作者简介：李永超，同济大学医学院博士在读，师从彭宝淦、谭军教授。以第一作者发表论文8篇 (其中SCI 3篇)，Spine脊柱微信公众号发起者。