Neurogenic pain
Contents:
Description:
The neurogenic pain is a type of pain which can be defined how pain owing to damage peripheral or the central nervous system and is not explained by irritation of nociceptors.
The nervous system transmits the coded signal, transforming it to sensation of pain. Defeats of a peripheral nervous system or the central nervous system can lead not only to loss or easing of painful sensitivity, but also to emergence of pain. For example, at diabetic neuropathy or post-herpetic neuralgia there is pain in zones of an innervation of the affected nerves. Though is more rare, but defeat of TsNS - especially spinotalamichesky ways or a thalamus happens the reason of pain. Neurogenic pains very strong are also not removed usual anesthetics.
The neurogenic pain is unusual - it has the nature of burning, a pricking, blow by current, sometimes arises even from a light touch. In a zone of localization of pain sensitivity is usually broken.
Symptoms of the Neurogenic pain:
Symptoms of damage of a nerve testify to a neurogenic pain: sensitivity disturbances, hyperesthesia, weakness and atrophy of muscles, lack of tendon jerks.
The neurogenic pain has many clinical forms. It is possible to refer some defeats of a peripheral nervous system to them, such as post-herpetic neuralgia, diabetic neuropathy, incomplete damage of a peripheral nerve, especially median and elbow (reflex sympathetic dystrophy), a separation of branches of a brachial plexus. The neurogenic pain owing to damage of the central nervous system is usually caused by cerebrovascular accident - it is known under the classical name of "a thalamic syndrome" though researches (Bowsher et al., 1984) show that in most cases the centers of defeat are located in other areas, than a thalamus.
Reasons of the Neurogenic pain:
Mechanisms of a neurogenic pain are various. The same as sensibilized pain receptors, the damaged sensitive fibers, including painful, begin to react to mechanical irritation, and they have a spontaneous activity. Besides, they become sensitive to noradrenaline. Deafferentirovanny nociceptive neurons of a spinal cord also have a spontaneous activity. As it was already told, also disturbances in the highest departments of TsNS are possible (for example, disturbances in a thalamus).
Treatment of the Neurogenic pain:
At a neurogenic pain antiarrhytmic means and anticonvulsants are effective. Lidocaine and мексилетин in low doses suppress spontaneous activity of the damaged nociceptive fibers. Phenytoinum and carbamazepine were the first drugs in which found property to reduce shooting, similar to blow by current pain at an epileptiform neuralgia. Anticonvulsant drugs help at pains of such character.
It is important that at the neurogenic pain which is not giving in to treatment by usual analgetics tricyclic antidepressants for example help, at diabetic neuropathy or post-herpetic neuralgia.
