(d) Insidious onset without severe general symptoms, the disease reach ing its highest point by gradual stages—in other words, a true subacute and chronic poliomyelitis—is extremely rare in children. In adults eases of this kind after traumatism or accident have a certain importance and probably rest on a different pathogenesis.
2. Stage of Initial Paralysis.—Immediately after the beginning of the disease ft larger number of muscles are paralyzed than is the case later. Spinal hemiplegia, paralysis of both legs, paralysis of a leg and arm on opposite sides and, rarely, both arms, is observed. Many of the muscles in a single extremity are often affected. Within a few days of the onset the preservation of normal electric irritability enables one to pick out the muscles that are capable of regeneration. Sometimes the varying degree of loss of function and (he pronounced character of the tendon reflexes affords a clue as to which extremity or joint is destined to remain permanently paralyzed. Sometimes pain and bladder disturbances are present. This stage usually lasts many months. At the beginning normal function is rapidly restored in some of the affected muscles, and even in those muscles which at first are persistently paralyzed considerable improvement often occurs after a time.
3. Stage of Permanent Paralysis.—In the end some muscle groups remain permanently paralyzed with loss of function and electric irri tability. This constitutes the irreparable recovery from poliomyelitis with disability. Although even in this stage the affected members may retain a certain degree of function, this remnant,—aside from the effect of therapeutic measures,—depends on the compensatory action of other healthy muscle groups which is brought about by thc growing intelli gence. Atrophy of bones, flail joints, atrophic changes in the skin and deformities, are well marked in this stage.
Haushalter distinguishes 4 stages: (1) prodromal; (2) stage of the onset of paralysis; (3) stage of regeneration with permanent localization of the paralysis; (4) stage of muscular atrophy with deformity of the limbs.
The prognosis may be inferred front the above description. Although the well-marked changes in the spinal cord and the muscular atrophy to which they give rise are susceptible of very little improvement, a great reduction may nevertheless be expected to take place in the extent of the original paralysis. Even when the paralysis is stationary, the prognosis is not altogether unfavorable, since the important point to the patient is not whether certain muscle groups remain permanently atrophic but rather whether Ile will regain the power of performing certain necessary movements; and this power is often regained to a surprising degree by utilizing muscles that have not been affected by the paralysis.
The diagnosis of poliomyelitis may be difficult during the initial stage of the disease. The clinical picture is apt to suggest some general febrile disease, the beginning of an acute infectious disease, a meningitis or an encephalitis, and the sudden discovery of spinal palsies often comes as a great surprise.
The well-marked paralysis of the shoulder girdle is often difficult to distinguish from a birth palsy of the superior trunk of the brachial plexus, particularly in the absence of histmical data. In a birth palsy the infraspinatus muscle is regularly involved, causing inward rotation of the arm, which is absent in poliomyelitis. Electric irritability is often unaffected or but slightly impaired in birth palsies. The diagnosis from inhibition palsies (Vierordt) of the arms may also present difficulties. Syphilitic pseudoparalysis is characterized by the general constitution of the child, the characteristic attitude of the hand, the osteochondritis which is usually present, and pain; paralysie doulaureuse (q.v.), by the
iv-15 well-defined onset of the paralysis with severe pain, the absence of atrophy or localization of the paralysis and, finally, by the rapid and favorable course. Rachitic pseudoparalysis may occasion diagnostic difficulties for a few days, the main points are, the less abrupt onset, the absence of atrophy. the uniform distribution of the muscular weak ness in both legs and, finally, other signs of an existing rachitis. Oppen heim's myatonia, characterized by congenital flaccidity of the muscles of the leg with diminution or absence of electric irritability, abolition of the reflexes but presenting a favorable prognosis, is distinguished from poliomyelitis chiefly by the patient's age. the disproportion between the extensive functional weakness and the slight degree of atrophy and, filially, by the rapid results of electric treatment. Paralysis of the legs from spina bifida is characterized by the presence of local disease in the vertebral column (also in spina bifida occulta) and the existence of sensory and sphincter paralysis. Paralysis following themorrhage into the spinal cord cannot be distinguished from poliomyelitis in its ulti mate results, as the same anatomical changes are finally produced in both cases. It is very probable that many cases of "congenital" polio myelitis must be attributed to an intrapartum hemorrhage into the spinal cord; although cases of very early poliomyelitis have been observed (in a child 15 days old). Rapidly developing spinal palsy during whoop ing-cough may be attributed with equal justice to a hwmorrhage or to an acute inflammation, while a fall has been given as a possible causal factor; this should be accepted with caution as it may be the cause of a hoemorrhage just as well as an early- symptom of poliomyelitis. The distinction between poliomyelitis and Hoffmann-Werding's spinal muscu lar atrophy is exceedingly- difficult. -Without it history and constant observation of the case the differential diagnosis is impossible, since in both conditions the lesion affects the spinal muscle centres. The rapidly progressive course of infantile spinal atrophy soon clears up any doubt in regard to the diagnosis. The diagnosis of Hoffmann's neural muscular atrophy is equally- difficult; but it usually occurs in older children, is at first confined to the peroneal muscles, is bilateral, begins gradually and progresses slowly. Cerebral palsy acqttired in early life and followed by arrested growth of one arm and under-development of the muscles, at the first glance presents some similarity to poliomyelitis, from which, how-ever, it is distinguished by the persistence of electric irritability and of the reflexes, the fact that the paralysis is most marked in the band, and by involvement of the facial muscles and the arm. The possibility of associated cerebrospinal palsies (simultaneous encephalitis and poliomyelitis) must however be kept in mind. Tumors of the spinal cord and spondylitis, even when they lead to atrophic palsies, are usually distinguished by their characteristic symptoms—pain, and involvement of the sphincters, and by the typical course of the disease. Multiple neuritis is rare in childhood and in ease of doubt the weight of proba bility is in favor of poliomyelitis. The points in the differential diag nosis are, sensory disturbances, pain on pressure along the nerves, progress of the disease by successive attacks up to the point of its great est development. If the polyneuritis leaves permanent palsies, the diag nosis is all the more difficult, as the palsies may possibly be due to a secondary spinal disease.