Introduction

Spasticity is the result of an exaggeration of the monosynaptic muscle stretch reflex due to lesions affecting the central nervous system, in particular an upper motor neuron lesion. Selective dorsal rhizotomy (SDR) is a surgical technique developed to treat spastic diplegia, one of the common forms of cerebral palsy, resulting from the lack of supraspinal inhibitory controls. The aim of SDR is to identify and cut a critical amount of the sensory rootlets, in particular those contributing the most to spasticity, in order to relieve the patient from lower limb spasticity while preserving motor strength and sphincter control. Various surgical techniques to perform SDR have been proposed over time. Similarly, intraoperative neurophysiology (ION)—first introduced by Fasano and colleagues in 1976—is a safe and effective tool to guide the surgeon in the procedure of SDR, but different ION strategies are used by different authors, and the value of ION itself has been questioned.

Methods

The purpose of this paper is to review the anatomo-physiological background of SDR, the historical development of the surgical technique, and the essential principles of ION.

Results

While some surgeons privilege a single-level approach and others a multi-level approach, nowadays, there are still neither agreement nor guidelines on the percentage of roots to be cut. Rather, a tailored approach based on both the preoperative functional status as well as intraoperative ION findings seems reasonable. ION is considered not essential to decide the percentage of roots to cut, but it assists to distinguish between ventral and dorsal roots, and to preserve sphincterial function, whenever S2 rootlets are included in SDR.

Conclusions

To optimize the balance between reduction of spasticity and preservation of motor strength while minimizing the neurological damage remains the main goal of SDR.

中文翻译：

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选择性背脊神经切开术：圆锥形挫伤的功能解剖和术中神经生理学要点。

介绍

痉挛是由于影响中枢神经系统，特别是上运动神经元病变的病变，导致单突触肌拉伸反射过度的结果。选择性背脊神经切开术（SDR）是开发用于治疗痉挛性截瘫的一种外科手术技术，痉挛性截瘫是由于缺乏上脊髓抑制性控制而导致的脑瘫的常见形式之一。SDR的目的是识别并削减一定数量的感觉根部，特别是对痉挛起最大作用的感觉根部，以便在保持运动强度和括约肌控制的同时，减轻患者下肢的痉挛。随着时间的推移，已经提出了执行SDR的各种外科技术。同样，

方法

本文的目的是回顾SDR的解剖生理背景，外科技术的历史发展以及ION的基本原理。

结果

尽管有些外科医生喜欢采用单层方法，而另一些外科医生则采用多层方法，但如今，对于要切根的比例仍然没有达成共识或没有指导方针。相反，基于术前功能状态以及术中ION发现的量身定制的方法似乎是合理的。ION被认为不是决定要切根的百分比所必需的，但只要SDR中包括S2根，它就有助于区分腹侧根和背侧根，并保留括约肌功能。

结论

在减少痉挛和保持运动强度之间取得最佳平衡，同时最大程度地减少神经损伤，仍然是SDR的主要目标。