The symptoms of lead poisoning, besides paralysis, are general ill - health, sallow com plexion, metallic taste in the mouth, the for mation of a blue line along the edges of the gums ...-!xt the teeth, and colic and vomiting. The paralysis affects particular muscles, so that the person cannot extend the back of the hand, the wrist consequently drops, and cannot be raised. The affected muscles waste, and a hol low appears on the back of the forearm. Other muscles—those of the shoulder and back of the arm—occasionally suffer.
Treatment consists first of all in removing the person from the source of the poison, which should be carefully investigated. Those who engage in lead works, or in works where lead is largely used, should cultivate strict cleanli ness, and should use the tooth - brush to get rid of any of the dust that may adhere to the teeth and gums. For the colic and vomiting, 10 grains of calomel and 1 to 2 grains of opium are given, followed by a dose of castor oil, and warm fomentations are applied over the abdomen. Iodide of potassium given internally in small quantities (I to 3 grain doses) is believed to remove the lead from the system. For the paralysis, electricity is the only remedy of value.
Paralysis of Sensation is technically called anaesthesia. It also may be due to disease of the brain, or of the spinal cord, or only of the nerves supplying the affected part. It must be remembered that sensation is a mixture of several things. There may be a sensation of mere touch—tactile sense,—or there may be a feeling of pain—pain sense,—or a sensation of heat or cold—temperature sense,—or a sensa tion of pressure or resistance—muscular sense (see p. 444). In complete anaesthesia all these are abolished. Any injury, for instance, de stroying or cutting through at any point the posterior half of the spinal cord, would abolish all sensation below the level of the injury. But injury limited to the posterior half of the spinal cord would abolish all sensation below the level of the injury, but only of that half of the body. But a disease of still more limited extent might exist in the cord, which would abolish all sensation, but only in a portion of the body of that side below the injury, a patch of skin only being so affected. Nay! disease
in the cord might be still more limited, so that not only was a small portion alone of the skin involved, but so that only the sense of touch, or the sense of pain, or the sense of temperature, or the muscular sense was involved, the other sensations being preserved. Thus a patient might have such a limited disease of the cord that only the sense of temperature was destroyed in, let us say, one or two fingers of the right hand. The person might grasp a hot poker, and might be aware, by sense of contact or touch, that he was grasping the poker, but might not perceive that it was hot, and would thus be burnt. The sense of pain might at the same time be pre served, and then the person would become aware of the burn by feeling the pain, but by that time the injury would be done.
Just as it is possible, in cases of paralysis of motion, to determine where the disease is probably situated because of the situation and extent of the paralysis, so, in cases of paralysis of sensation, accurate observation of the char acter of the sensory paralysis and its extent will often enable one to decide in what part of the nervous system the disease is situated. It would be to that part, of course, that treatment would be directed.
Like paralysis of motion in brain disease, there may be paralysis of sensation affecting all of one side of the body. This is called hemi anesthesia.
When sensation is abolished in a part of the body it means that the portion of the nervous system related to that part is destroyed by the disease. But such disease may in its earlier stages only irritate that portion. In this case sensation would be affected, modified in some way, not abolished. The irritation might, for instance, increase the sensitiveness of the part. This is called hypermsthesia. Or, instead of increased sensation, some unusual sensation might be experienced in the part, as the result of the irritation. This is called parmsthesia.