57 Jahrb. f. Kinderheilkunde, N. F. i., 1868. According to Erb (loc. cit., p. 984) and to Ross (loc. cit., p. 111), Salomon was the first to make this observation. Seguin, however, attributes priority to Lobb (Lond. Med. Times and Gaz., 1863), to Hammond (New York Med. Journal, 1865), and to J. Netten Radcliffe between 1863 and 1865. These dates precede that of the publication of Salomon's paper, but the latter seems to have been written without knowledge of earlier observations. (See also Onimus, Soc. de Biol., 1878, who argues that muscle-termination of nerve is partly destroyed.)
58 “Ueber den Einfluss der Stromes dauer auf die Elektrische Bewegung der Muskeln,” Sitzber. d. k. Akad. d. Wissensch. in Wien, 1867, Bd. lxi., quoted by Salomon, loc. cit., p. 388.
Erb has greatly extended these observations, and shown that the galvanic reactions of paralyzed muscles indicate their structural degeneration, and are identical with those observed after section of a peripheric nerve. There are three characteristic peculiarities in the contractions thus obtained: 1st, they are slow, tonic, long drawn out; 2d, they are more painful than in normal muscles submitted to an equal amount of electricity; 3d, in complete degeneration the contraction obtained at anode closure equals or exceeds in intensity that excited by cathode closure [AnSZ = or > KSZ]. The excitability of the muscle to the galvanic current remains increased for several months, then gradually diminishes, and finally falls below normal. The qualitative alterations persist somewhat longer: finally, the muscle fails altogether to contract.
Spinal paralysis differs markedly from progressive muscular atrophy in the absence of constant correlation between the degree of paralysis or atrophy and of electrical changes.
The last positive symptom to be noted in the paralytic stage of infantile paralysis is the diminution and ultimate loss of reflex excitability. This is correlative in time and extent with the loss of faradic contractility. This seems to be an exception to the usual rule, which associates loss of tendon reflex with lesion of the posterior columns or nerve-roots. This is a proof that interruption of the reflex arc at any point suffices to abolish the tendon phenomena.59
59 Buzzard tested the tendon reflex in the zygomaticus major in a patient in whom the sensory branch of the fifth nerve had been stretched, and therefore, to a certain extent insulted. The reflex response was decidedly lower than on the opposite side (Lancet, Nov. 27, 1880).
Negative Symptoms.—The negative symptoms of atrophic paralysis are as important for the diagnosis and pathogeny as are the positive characters, which have now been sufficiently detailed. The absence of decubitus or other nutritive lesions of the skin has been already mentioned. The absence of anæsthesia, or, as a rule, of any marked degree of hyperæsthesia, is most important as indicating immunity of the sensory tracts in the cord. Some diffused hyperæsthesia is sometimes noted during the febrile stage: pain is by no means rare in adults. But in children this is altogether absent, or else slight and transitory. On the other hand, the complete preservation of sensibility constitutes, in children, a serious obstacle to electrical investigation.
After subsidence of the cerebral symptoms, if any, of the initial stage, the functions of the brain are always intact60 and the disposition of the children apt to be remarkably lively. The general health is often remarkable for its vigor. The worst, because the most neglected, cases are naturally most often seen among the poor: the ranks of professional beggars are largely recruited from among the victims of infantile paralysis.
60 Practically, it may often be of importance for the physician to ascertain that an intellectual enfeeblement, or even idiocy, existing at the time of examination had preceded the onset of the paralysis by months or years.