The third autopsy is recorded by Drummond in the Lancet for 1881 (vol. ii.): The subject was a boy of fourteen, who never walked after the age of six. There was found, as the author shows by some good drawings, disintegration in the lateral gray network of fibres halfway between the anterior and posterior horns, extending more or less throughout the cord. In the left lumbar region the tissue had broken down, and a cavity existed filled with serum, which bulged out the wall of the cord, forming an apparent tumor.
Several circumstances are common to all the foregoing five cases. In all, the patients during life had exhibited paresis and atrophy of a large number of muscles (in Barth's case nearly all), with pseudo-hypertrophy of some muscles of the lower extremities. In all, the post-mortem found fatty substitution for muscular fibre in both the atrophied and the hypertrophied muscles. Finally, in all, the lesions found in the cord were principally grouped about the central canal. This was dilated (Pekelharing) or obliterated (Müller, Barth); the hyperæmia was always most intense in its vicinity; and it was in the lateral gray substance adjoining, or in the gray network between it and the lateral white columns, that patches of disintegration were principally noted (Clarke, Ross). Negatively, the absence of any extensive lesion of the anterior cornua is noteworthy in all the cases but one; and here this lesion was evidently secondary to the lateral sclerosis (Barth). On the other hand, the differences between these cases were as numerous as the resemblances. Two resembled each other in the presence of cerebral symptoms and of an internal hydrocephalus to account for them (Pekelharing, Müller); in one alone was there lateral sclerosis (Barth); in one, cavities in the lateral portion of the central gray column (Clarke); in one, traces of an acute polio-myelitis (Müller), Finally, in only three cases (Clarke, Ross, Drummond) was the clinical history perfectly characteristic of the disease.
Comparing these facts with the others, equally significant, where the autopsy in cases of pseudo-muscular hypertrophy has shown the central nervous organs to be perfectly healthy, we should be led to conclude—1st. That if fatty substitution in the muscles is ever to be associated with lesions of the spinal cord, these are to be sought in the central gray substance surrounding the central canal. 2d. That, nevertheless, muscular lesions similar, if not in all respects identical, can develop as the result of an idiopathic process depending on causes at present unknown. 3d. That atrophy of muscular fibre and replacement of it by lipomatous fat are probably determined in several different ways, and must often be regarded as merely secondary processes;79 but that the muscular lesion characteristic of pseudo-hypertrophy, considered as an idiopathic disease, is the hyperplasia of connective tissue which originates in the perimysium interum of the muscles. This lesion was well marked in the Ross-Leech case, much less distinct in the three we have noted as doubtful (Gowers).
79 See Leyden's remarks in his essay "Ueber Polio-myelitis und Neuritis," Zeitschrift für klin. Med., 1880.
PATHOGENY.—These last conclusions, if valid, supersede the necessity for prolonged discussion of the question whether pseudo-hypertrophic paralysis be a peripheric disease or central disease. By the latter term authors almost invariably mean a disease dependent on morbid processes in the spinal cord. Hammond is almost alone in affirming that these exist, and bases his opinion on only three autopsies, of which two are the doubtful cases of Müller and Barth. Mobius,80 recognizing the frequent absence of spinal lesions, nevertheless claims that the hereditary, frequently congenital, nature of the disease proves that it inheres in the nervous system. Gowers, however, points out that the exclusive inheritance through the mother—that is, from the ovum—is a circumstance unknown in nervous diseases. This mode of inheritance is observed in hæmophilia, which also resembles pseudo-hypertrophy in being almost confined to males.
80 Volkmann's Sammlung, No. 171.
The pseudo-muscular hypertrophy of children so strikingly resembles in many particulars the progressive muscular atrophy of adults that the theory of their essential identity could not fail to suggest itself. Friedreich unhesitatingly advocates this theory. Many of the facts which support it become for him additional confirmation of the peripheric nature of the adult disease, where, nevertheless, the anterior ganglion-cells of the cord are habitually found atrophied.81
81 According to the Friedreich theory, the lesion of the anterior cornua is coincident with or consecutive to degeneration of the other extremity of the nervo-muscular motor apparatus.
Lichtheim, Arch. f. Psych., viii., quoted in Brain, 1879, vol. ii., No. 1, quotes a case of progressive muscular atrophy with typical changes in the muscles, but unaccompanied by the slightest change in the nerves or nerve-roots, large ganglion-cells of the anterior cornua, or other part of the spinal cord. The author agrees in regarding the nearly allied pseudo-hypertrophic paralysis as a peripheric affection. See also Hayem.