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Pathological algic system


Emerged in the afferent input (dorsal horns of the spinal cord or caudal trigeminal nucleus) generator itself is not able to cause pathological pain. Local generator regional changes may lead to spinal cord: a relief flexor reflex, changes in motor neuron activity, and others.
Pathological pain as suffering and as a syndrome occurs when the process involved and other departments of pain sensitivity system, in particular brain structures responsible for manifestation of the feelings of pain and its emotional coloring.
Participation in these structures forming pathological pain is not just in their responses to nociceptive signals received, both in physiological pain. Department of pain sensitivity system, in which there was a generator, becomes hyperactive and acquires the ability to change the functional state of the neurons of other levels. From primary and secondary educational change processes plastic is formed and fixed pain sensitivity system integration of new pathologic - abnormal algic system (PAS). That pain sensitivity system department, which is formed under the influence pathologic algic system plays the role of determinants of PAS.
If abnormal algic system is unformed, if it does not include the higher parts of the pain sensitivity of the system - the thalamus and the cerebral cortex - pain does not appear behaviorally. This situation can occur if the nociceptive neurons in the dorsal horn and are not active enough or do not form a generator if the higher parts of pain sensitivity have an effective braking system control. In both cases, the role of the supervisory mechanism that prevents the formation and activity of pathological algic system plays antinociceptive system.
The following table shows the levels of education and pain sensitivity of the system, included in the pathological algic system, which is due to the enhanced nociceptive stimulation from the periphery. These structures constitute the main trunk of PAS, on them are due to the different departments of the central nervous system, involvement in the pathological process which causes additional syndromes. The latter include autonomic disturbances, changes in the cardiovascular system and microcirculation, disregulation functions of internal organs, endocrine and immune systems, psycho-emotional disorders, and others.
Current pain and nature of attacks of pain depends on the characteristics of activation and activity of PAS. An important role in this process is played particularly activation of the generator, which is connected with the activity of PAS. With a significant violation of the brake and increased excitability of neurons is their gipersinhronizatsiya and discharge pulse generator bystronarastajushchih flow. If this flow is as fast and enhanced activation algic pathological system, it has a twinge of paroxysmal character. If the generator develops its activity slowly and slowly activated PAS, the intensity of pain during an attack is slowly growing; when the tonic activity of the generator and PAS constant pain.

Table. Levels of education and altered pain sensitivity system constituting the main trunk system pathological algic

Peripheral units
Sensitize nociceptors, ectopic excitation foci (and regenerating damaged nerves, demyelinated areas nerve neuroma); giperaktivirovannyh group of neurons of the spinal ganglia
spinal level
Units of hyperactive neurons (generators) in afferent nociceptive relay - in the dorsal horns of the spinal cord and in the nucleus of the spinal tract of the trigeminal nerve (caudal nucleus)
supraspinal level
The nuclei of the reticular formation of the barrel, nucleus of the thalamus, and the sensorimotor orbitofrontal cortex, emotiogenic structure

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