Pathological pain of central origin − Rakyat Biologi

This form of pathological pain associated with hyperactivation of nociceptive neurons in the spinal and supraspinal levels. Such neurons form aggregates which are pathologically enhanced excitation generators. In the formation of the generator in the posterior horns of the spinal cord there is a center of origin of spinal pain syndrome in education in the nuclei of the trigeminal nerve - trigeminal neuralgia, in the nuclei of the thalamus - thalamic pain syndrome.

In the early stages of the disease process twinge due to the activation of the generator is triggered by nociceptive stimuli with certain directly related to the receptive field generator; the late stages of an attack provoked by stimuli of various intensities from different fields of the receptor, and can also occur spontaneously. Feature bout of pain (paroxysmal, continuous, short, long, and so forth.) Depends on the characteristics of the generator function and pathological systems. Character same pain (dull, sharp, localized, diffuse, and others.) Is determined by what education systems have become parts of nociceptive pathological algic system.

The generator in the central office can occur nociceptive system, such as in dorsal horns after prolonged nociceptive stimuli from the periphery. In these circumstances, the pain of peripheral origin initially becomes the central component and becomes pain of spinal origin. This situation occurs when causalgia, neuromas and damages afferent nerves, neuralgia, etc.

The generator in the central nociceptive apparatus may also occur when deafferentation, due to increased sensitivity deafferentized nociceptive neurons and the violation of the brake control. Deafferentatsionnye pain syndromes can occur after limb amputation, nerve transection and posterior roots, after a break or transection of the spinal cord. Thus the patient may feel pain sensitivity or lacking in nonexistent body (e.g., non-existent in the limbs of the body parts following transection of the spinal cord). This type of pathological pain is called phantom (from the word «fantom» - a ghost). It is due to the central generator activity, the activity of which is not dependent on nociceptive stimulation from the periphery.

The generator in the central parts of the nociceptive system may occur in infectious lesions of these departments (herpetic and syphilitic lesions), trauma, toxic effects. In the experiment, these generators and associated pain syndromes are reproduced by introducing appropriate department system nociceptive substances causing violation brake (tetanus toxin, penicillin) or activate nociceptive neurons (potassium ions and so forth.).

The central office of the nociceptive system may form secondary generators. Thus, after the generator rear horns of the spinal cord after a certain time in the thalamus secondary generator may occur. Often, the localization of the primary generator in the spinal cord in order to prevent the receipt of his impulses in the brain, producing a partial (break of the ascending tracts), and in severe cases even a complete transection of the spinal cord of conductive paths.