Clinically, pain is broadly classified into three types according to the different etiologies and mechanisms that cause pain.
1. injury-derived pain, associated with various injurious stimuli acting on injury receptors.
2, neurogenic pain, associated with nerve injury or spontaneous dysfunction.
3, sympathetic pain, which is mainly sympathetically mediated and related to dysfunction and damage of sympathetic nerves. The chronic pain encountered in clinical practice ;
Although the majority of chronic pain is a mixture of the above three types, it has different clinical manifestations depending on its main etiology.
Among them, the pain closely related to sympathetic nerve mediated, roughly contains the following aspects.
1.Complex localized pain syndrome (CRPS)
Complex local pain syndrome (CRPS) contains two typical sympathetic pain disorders, namely reflex sympathetic dystrophy and burning neuralgia. The lesions are characterized by peripheral neurovascular lesions accompanied by abnormalities in central nervous system signaling. The waterfall-like release of inflammatory mediators and nociceptive factors from the damaged tissues malignantly stimulates peripheral nerves, nerve roots, and the central nervous system, triggering a remodeling of the pain reflecting system in the cerebral crestal medulla and thalamus, ultimately leading to nociceptive hypersensitivity and unusual pain. It is commonly seen in various post-surgical pain syndromes, pain caused by radiotherapy, nerve damage caused by viruses, infections, etc. These painful diseases have similar clinical manifestations despite their different etiologies and mechanisms.
2.Visceral pain
Visceral pain mostly originates from the pain of visceral organs and is transmitted to the center through the vegetative nerves. It is mostly caused by tumors, ischemia or inflammatory lesions. It is characterized by an indefinite location, a wide range of pain, and often associated with involvement pain. The pain caused by the wall layer of thorax, peritoneum, mesentery and diaphragm is transmitted by the somatic nerve, so once the lesion is invaded, a more fixed and clear pain can appear.
3.Peripheral vascular pain diseases
Peripheral vascular pain disorders include pain caused by peripheral vascular contraction dysfunction, embolism, sclerosis and other lesions. Most of these diseases have sympathetic nerve dysfunction and can be diagnosed, prognosed and treated by sympathetic nerve block. For example, Raynaud’s disease, red scarring limb pain, hand and foot cyanosis, reticular cyanosis, arteriovenous embolism, vasculitis, retinopathy, etc.
4.Other
Atypical facial pain, neuropathic pain, etc.
Sympathetic nerve interventions.
1.Commonly used methods.
Stellate ganglion block (SGB), thoracic sympathetic nerve block, lumbar sympathetic nerve block, ventral plexus block, odd ganglion block, intravenous local nerve block. Epidural block, subarachnoid block and local pain point block may also be used as appropriate. Recent studies have shown that neuromodulation techniques have a good modulating effect on sympathetic nerve function. Among them, neurostimulation therapy as the representative, increasingly shows the good therapeutic prospect of neuromodulation techniques for sympathetic nerve-related diseases.
2. Application principles.
Local anesthetic block. Especially if the pain is gradually reduced by repeated blockade, the block should be continued. When the pain symptoms do not improve or only temporarily improve after local anesthetic block, we should consider the use of nerve-destroying drugs, neurodestruction or sympathectomy by physical methods. When sympathetic nerve trunk or ganglion block is performed, the principle of using a single drug, mainly local anesthetic, should be emphasized. As in the case of SGB, which is widely used in clinical practice, a very complicated formulation of anti-inflammatory and analgesic solution is often used for SGB. this is unnecessary and prone to increased complications, and is not consistent with the therapeutic mechanism of SGB.
Neuromodulation techniques. Transcutaneous electrical nerve stimulation, peripheral nerve stimulation, cremasteric electrical stimulation, deep brain stimulation, cortical stimulation, etc. Neurodestructive treatment. Commonly used neurodestructive drugs include anhydrous ethanol, phenol glycerol, etc. Commonly used physical nerve destruction methods include laser, radiofrequency, etc.
3.Note.
Since chronic pain has very complex factors involved in the development of the disease. Sometimes, even with SMP, it is difficult to achieve more satisfactory results with sympathetic intervention alone. Therefore, when choosing complex sympathetic interventions, especially when performing nerve destruction treatment, comprehensive consideration is necessary.