Sympathetic nerve blocks
In some patients with a chronic pain syndrome a nerve block in certain areas of the sympathetic nervous system can lead to a reduction in pain.
A distinction is made between two nervous systems in the body:
- The autonomic nervous system, to which the sympathetic nervous system belongs, regulates, for example, heart rate, perfusion of the organs, blood pressure, respiratory capacity and many other functions of the body. Part of the sympathetic nervous system is the so-called sympathetic trunk. This is a chain of longitudinally connected ganglia, which lie on the vertebral bodies from the cervical spine to the sacrum.
- The voluntary nervous system is responsible for, amongst other things, voluntary muscle movement as well as sensation and pain sensation. Its thicker nerve fibres are accompanied in their course by a network of sympathetic nerve fibres.
Pain, which is registered via the nerve fibres into the spinal cord, also simultaneously activates the sympathetic nervous system. This emits performance-increasing impulses, leads, for example, to increase in blood pressure or change in secretion of sweat. However, in this there is no direct connection with the nerves of pain perception.
Due to nerve damage or other illnesses, "short circuits" may occur between the nerve fibres, for example due to branching out of the sympathetic nerves onto cell bodies of the pain transmitting nerves in the spinal cord. This leads to each activation of the sympathetic nerves being combined with an intensification of pain. As a general rule this connection disappears again. However, if it remains, we talk about "sympathetically maintained pain" (SMP).
Sympathetically maintained pain is diagnosed on the basis of an analgesic sympathetic trunk block. In this the doctor injects local anaesthetics. If as a result a pain-relieving effect (> 50% pain reduction) is evident, SMP is present.
The diagnosis of SMP is crucial for further treatment. In this case the sympathetic trunk is blocked using local anaesthetics or opiates. If this is not sufficient, partial denervation of the sympathetic trunk is a further option. This is achieved by radiofrequency thermocoagulation, for example by using the sfm radiofrequency/thermolesion needle on the appropriate ganglion of the sympathetic trunk.
Benefits of the sfm radiofrequency/thermolesion needle with sympathetic nerve blocks
- Low penetration force thanks to optimum bevel geometry and a smooth transition to the coated needle region
- Minimisation of pain sensation and posttraumatic stress due to the smooth transition to the coated needle
- Best possible navigation to targeted coagulation thanks to the hub design and its realization
- Optimum adjustment of the coagulation field thanks to the large number of design variations
- Treatment can be repeated several times