Symptomatic Pains

Symptomatic pains represent the result of irritation in the system of either conductors or centers of pain sensitivity. But while irritation of peripheral sensory nerves and roots causes sharp pains, processes in the substance of the spinal cord, in the stem section of the brain, and in the cerebral hemispheres usually do not cause pain; the latter are observed only when these processes spread to the membranes and posterior roots. Only damage to the visual thalamus, which is the organ of perception and the most important transfer point of sensory pathways, can cause very severe pains and paresthesias. Depending on the localization and nature of the process, pains can be local, radiating, and reflected (reflex). Local pains can primarily be caused by damage to peripheral receptors and conductors of pain sensitivity; these pains, combined with tenderness of the nerve to pressure, are characteristic of neuralgia and neuritis; with damage to the posterior roots, so-called root pains (shooting, girdling) are observed in the area of innervation of the affected root (meningitis, tabes). Pains concentrated in muscles are called myalgias, in joints—arthralgias. In many cases, pains by their localization do not coincide with the site of the pathological process; these are so-called radiating, projection pains, based on the property of a nerve to project the sensation of pain into the area of its peripheral innervation. An example of such pains are the pains observed in amputated limbs: irritation of the nerve in the area of the stump is projected into that area of the cortex where sensations usually originated from the given limb, and thus a false sensation of pain in the amputated part of the limb is created. Reflected (reflex) pains are observed in diseases of one or another internal organ, when the pain is projected from the diseased organ onto the part of the skin corresponding to it in terms of innervation level (the so-called viscerosensory reflex of Mackenzie). In the clinic of internal diseases, the character of these reflected pains sometimes has diagnostic significance; for example, pains radiating to the scapula and right shoulder in gallstones, duodenal ulcer, and even in appendicitis, radiating to the left arm in angina pectoris, to the testicle and area of Poupart's ligament in kidney diseases, etc. (For detailed symptomatology—see the corresponding clinical forms.) In these cases, it is a matter of impulses spreading from sympathetic nerves to the terminal sensory conductors (Head's zones). Disturbance of innervation of internal organs in some cases also leads to the occurrence of pains in the area of the given organ, with temporary disturbance of its function; this is so-called crises of internal organs (gastric, intestinal, laryngeal, bladder, etc.). Headache has special significance. In a number of diseases of the brain, it is one of the dominant symptoms. Being associated with increased temperature, rigidity of the neck, Kernig's symptom, it speaks in favor of inflammation of the brain membranes. In combination with stagnant papilla and a number of other general cerebral and local symptoms—it is characteristic for a tumor of the brain. In the presence of changes in the urine, with the presence of protein and cylinders in it, and in connection with albuminuric retinitis, it speaks for the uremic nature of the disease. In cerebral syphilis, headache is of local or diffuse character, with frequent exacerbations at night, very acute, with the presence of a number of both general cerebral and focal symptoms. Disturbances of cerebral circulation also cause headaches; thus, in sclerosis of cerebral arteries, the pain, starting gradually, has a diffuse character and fluctuates in its course corresponding to the state of circulation. With active hyperemia of the brain, the pain starts more acutely, also has a diffuse character, accompanied by flushes, flickering before the eyes and noise in the ears, dizziness, redness of the face and frequent pulse. With passive hyperemia, the pain is localized mainly in the occiput and forehead, stronger in the morning and accompanied by symptoms of increased intracranial pressure. Headache is also observed in anemia and chlorosis. Arising gradually, it is more felt with fatigue, in the form of dull pressure, and is accompanied by a number of symptoms characteristic of anemia. Various exogenous poisons (alcohol, nicotine, lead, arsenic, carbon monoxide, etc.) can cause headache. Similarly, endogenous factors (uremia, diabetes, gout, chronic constipation, etc.) can cause headache. Headache is a frequent companion of all acute and chronic infections, but some of them (malaria, typhus and relapsing fever) are accompanied by pains of exceptional strength, with a favorite localization in the forehead, acute onset and gradual termination. A completely unique symptom complex—headaches in migraine (see Hemicrania). A special group is also formed by so-called reflex headaches; with anomalies of refraction, the pain is localized in the forehead and the stronger the longer the vision is strained; at night it mostly completely disappears. Forehead localization is also found in pains in diseases of the frontal sinus, nose, and upper incisors; in diseases of the upper molars, the pain is concentrated in the temples, and in diseases of the lower molars—behind the ear. The pain is also localized there in diseases of the external auditory canal and inner ear. In the temple area, behind the ear, and sometimes in the occiput, pains are observed in diseases of the pharynx (angina, adenoids, etc.). In neurasthenia, headache often gives the sensation of a 'pressing helmet' (mainly in the vertex), and in hysteria it is often observed in the form of so-called clavus hystericus (acute pain on a limited area in the region of the crown), sometimes in connection with hyperesthesia of the hairy part of the scalp. In relation to various pains in neuroses, it should generally be noted that they do not have a strictly defined localization and are distinguished by their psychogenic character.

5-transverse section of a fetus; 6-spotted stem (part).