4. Jheeal Xerces."—The peripheral nerves are especially prone to disease in diabetes. This fact has been recognized only during the past ten years; prior to that time it was thought that there must be sonic central disease to account for the manifold sensory, motor, and trophic nervous disturbances observed in diabetes. The last expo nent of this view was Althaus, who has set forth at length the dif ferential diagnosis between genuine locomotor ataxia and diabetic psendotabes.
a. ...Vetwitis. — The most important form of peripheral nervous disease is neuritis, which may appear under the guise of multiple neuritis involving wide areas or be limited to single nerves. Its sig nificance, especially in respect to sensory disturbances (neuralgias, parsthesias) in diabetes, was first correctly appreciated by von Ziemssen. Soon after this IL von Hoesslin had the happy inspira tion to refer the other ataxic affections (see below) to neuritis and to draw attention to the similarity of the symptom complex to that seen in multiple neuritis of alcoholic origin. Since that time the doctrine of toxic neuritis or polyneuritis diabetics has won general acceptance, especially since Auche and others have confirmed the clinical diagno sis by the results of post-mortem examination.
Among the neuritic symptoms encountered in the course of dia betes are: (1) Sensory Disturbances. These are the earliest and in milder eases the only neuritic symptoms; they are pmesthesia, bypenesthesia and anesthesia of varied degree and location, pains and cramps in the calves of the legs, and neuralgia. The latter is com monly symmetrical, especially when it is located in the third branch of the trigeminal or in the crural nerves. The diabetic neuralgias are often very obstinate and very painful; they are not, however, incur able. (2) Motor disturbances are not usually very prominent in com parison with the pronounced sensory troubles ; still there are cases in which they gain the upper hand and reach a high degree of severity. There is often simple ataxia, or there may be actual paralysis with atrophy and the reaction of degeneration. The paralyses affect the lower extremities much more commonly than the upper, the crural nerve being the seat of election ; they are bilateral as a rule. Of the cranial nerves the abducens is the most frequently affected, less often the oculomotor, hypoglossus, and spinal accessory nerve. The rectum and bladder are never involved.
b. Vasomotor Disturbances.—The affections in this group, local hyperidrosis, local oedema, local asphyxia, and erythromelalgia, are of rare occurrence.
c. Trophic Disturbances.—Among these are localized atrophy of the skin, glossy skin, thinning and shedding of the nails, falling out of the teeth without precedent disease of the jaws, herpes, pemphi gus, and spontaneous gangrene, so far as the latter is not due to pre existing arteriosclerosis.
d. Tendon Reflexes.—Bouchard was the first to call attention to the fact that the patellar tendon reflexes are often absent in diabetes. I find the following statistics relating to this point : The absence of the tendon reflex was noted by Bouchard in 37 per cent., by Maschka in 30.6, by Auerbach in 35 to 40 per cent., by Eichhorst in 21, by Marie and Guinon in 37.5, by Neviere in 40, by Williamson in 50, and by Grube in 7.6 per cent. Very frequently the abolished reflex was ob served to return at a later period. There is no relation between this symptom and the severity of the general symptoms of diabetes, for while the reflex may be abolished in mild cases and early in the course of the disease, it may, on the other hand, be preserved in cases of extreme gravity, during coma, and in the agony (William son, Grube). It is therefore of no value in a prognostic sense (Rosen stein, G-rube). Inflammatory or degenerative changes in the crural nerve have been regarded as the cause of the loss of the patellar ten don reflex.
Oue or other of the above-described neuritic symptoms is present in almost every case of diabetes; the individual symptoms may ap pear singly or in groups, and it is to little purpose to attempt to dis tinguish various types of multiple diabetic neuritis according to the grouping of the symptoms. One thing only is to be noted: The disturbances of sensation, of motion, and of reflex excitability, when present iu marked degree, are grouped together in a complex which recalls that of tabes. I have already remarked that special services have been rendered by Althaus as regards the symptomatology, and by von Hoesslin as regards the proper significance of this morbid picture.
The neuritic symptoms appear in part very early, and may be among the first troubles complained of by the patient; this is espe cially true of the changes iu the nerves of the eyes and of the neu ralgias. On the other hand, the more severe and wide-spread nett ritic affections belong usually to the later stages of the disease. In general they are more commonly associated with the severe forms of diabetes, in which the nutrition of the patient is markedly interfered with, than with the lighter forms, yet it is impossible to establish any direct relation between them and the intensity of the glycosuria. A repression of the glycosuria by the institution of a suitable diet often has a beneficial effect, but in other cases it has no influence whatever upon the course of the neuritis.