Synonyms.—Polyneuritis; Peripheral Neuritis.
Etiology.—Insufficient and improper food, and exposure, are predisposing causes, and it is said to be more prevalent in females than in males.
Toxic agents are most frequently responsible for neuritis, alcohol heading the list, and while it occurs in persons using strong liquors, it may follow the use of malt drinks.
Of the metallic poisons, lead is the most frequent cause, phosphorus, arsenic, mercury, copper, and zinc following.
Of chemical poisons, bisulphide of carbon, coal gas, ether, naphtha, anilin, ergot, and morphia may be named.
Of the infectious diseases, diphtheria is the most frequent cause, typhoid fever, leprosy, scarlet fever, beri-beri, small-pox, influenza, and tuberculosis being less frequently the cause. Cachectic conditions, such as anemia, cancer, and tuberculosis may be responsible for it, and it sometimes follows rheumatism, gout, the puerperal state, and diabetes.
Pathology.—The pathology of multiple neuritis does not differ materially from that of neuritis occurring in isolated nerves. The lesion may be that of an interstitial neuritis, or of a parenchymatous neuritis, or belli combined. Generally, the peripheral parts suffer more than the central parts.
The motor nerves alone may be involved as in lead-poisoning, or the sensory nerves may alone be affected as in coal-gas poisoning, or both may be involved as in the neuritis due to alcohol and the infectious diseases.
Changes in the spinal cord, such as meningitis, may occur.
Symptoms.—Since there are so many phases of multiple neuritis, it will simplify the description of their many phenomena by describing separately their principal forms.
Acute Febrile Polyneuritis.—The onset is sudden, and frequently resembles the acute infectious fevers. There is a chill followed by febrile reaction, the temperature rapidly rising to 103° or 104°; there is some tenderness in the spleen, and not infrequently some slight jaundice. There is pain in the head, back, and limbs, and sometimes swelling of the articulations, resembling rheumatic fever. Tingling, numbness, and muscular cramps frequently precede loss of power in certain muscles. The extensors of the hands and feet are most commonly involved, giving rise to wrist and foot drop.
Paralysis rapidly extends up the extremities, and sometimes involves the trunk and face. Faradic irritability is lost, and the muscles rapidly waste. Death may occur in from seven to twenty-one days. In milder cases, after a few weeks of suffering, the patient gradually shows improvement, but a complete cure may not take place short of one or two years.
Alcoholic Neuritis.—This is the most common form of the disease, and occurs more frequently in women than in men. Its onset is usually slow, being preceded by impaired digestion, catarrhal gastritis, sleeplessness, irregular or feeble heart's action, and, as the patient expresses it, his feet and hands "go to sleep." There is tenderness along the course of the nerve-trunks, cramp in the muscles, with loss of power and paralysis of the extensor muscles of the upper and lower extremities, giving rise to the characteristic wrist and foot drop. Neuralgic pains, sensory disturbances, delirium and convulsions not infrequently occur, and sometimes result in insanity. Loss of control of the sphincters of the bladder and rectum sometimes occur. Atrophy of the affected muscles usually takes place. Anesthesia of the skin and hyperesthesia of the muscles is a characteristic condition.
Owing to paralysis of the extensor muscles, the "stoppage gait" (lifting the foot high in the air and swinging the foot forward to avoid striking the toes on the ground) is a prominent symptom. There is loss of the superficial and deep reflexes. In some cases the patient passes into a low ataxic or typhoid condition.
Lead Paralysis.—This form is not attended by sensory disturbances and is usually preceded by anemia, lead-colic, obstinate constipation, and a characteristic blue line on the margin of the gums. The paralysis usually develops gradually, though in exceptional cases the onset is sudden.
The muscles supplied by the musculo-spiral nerve are more frequently involved than those of the lower extremities; hence the characteristic wrist-droop in lead paralysis. When the lower limbs are involved, the peroneal muscles are the first to be attacked.
The prognosis is generally favorable, and results in recovery in from four to six months.
Arsenical Paralysis.—This form is more apt to affect the lower extremities, and atrophy of the muscles is more rapid than in lead paralysis: Formication and numbness are the chief sensory symptoms. The "stoppage gait" is generally well marked.
The condition of the reflexes and their behavior to electric stimulation are similar to those of lead-poisoning.
Carbon-bisulfid Neuritis.—In this form of neuritis there is intense pain in the head, dizziness, muscular cramps, and sometimes convulsions.
Coal-gas neuritis involves only the sensory nerves, is usually mild in character, though numbness may persist in the hands and feet for a long time.
Beri-beri, Kakke, or Endemic Neuritis.—This disease occurs. endemically in Japan, China, the Philippines, and Northern Brazil. Its etiology is in doubt, and though many regard it as being due to micro-organisms, its specific character has not yet been determined. Predisposing causes are such as impair the vitality and lower the quality of the blood. Foreigners visiting or residing in endemic localities are apt to be exempt.
Symptoms.—The first evidence of the disease is a sense of weariness or weakness in the lower extremities. Soon a fever develops, the patient grows anemic, and edema develops, which is followed by general anasarca. There is painful atrophy of the muscles, and paralysis of the arms and legs occur. Vomiting sometimes occurs and the urine is usually scanty though not albuminous. If the phrenic nerve be affected, paralysis of the diaphragm may result in death.
Diagnosis.—A well-marked case of neuritis is not usually readily mistaken, but since a multiple neuritis frequently simulates poliomyelitis anterior, locomotor ataxia, and diffuse myelitis, the differential diagnosis may be readily understood by examining the table used by Ranney, and found in his work on Diseases of the Nervous System.
Prognosis.—The prognosis is generally favorable, though much depends upon the cause or rather form of the disease. When due to alcoholism, diphtheria, or beri-beri, the diagnosis should be guarded, since these are grave forms of the disease.
Treatment.—The treatment depends upon the wrongs present, and does not differ materially from that of other diseased conditions. Where possible, the cause should be removed; if due to alcoholism, drink should be restricted, and if from lead, arsenic, bisulfid of carbon, etc., the patient should be removed from the exciting cause, and, as far as possible, endeavor to eliminate the poison. When due to infection, the antiseptics will be of much benefit.
Rest in bed, with support to affected parts, will afford much relief. When fever attends, the special sedatives are to be judiciously used. If the pain is intense, morphia hypodermically should be used, though it should not be continued indefinitely for fear of the morphine habit. When due to sepsis, echinacea, the sulphites, chlorates, and mineral acids will be called for. If due to absorption of lead, sulphur baths, and potassium iodid internally, and galvanism will give good results.
Rhus, bryonia, avena, rhamnus Cal., and melilotus will be useful agents under certain conditions.
The warm baths and massage are not to be overlooked.