The diagnosis is not difficult if the possibility of the disease is borne in naind. The changes in the macula are absolutely positive, and all cases reported without the characteristic ocular findings are doubtful and have in part been already acknowledged as diagnostic errors.
The disease is hopeless and no known treatment is of any avail. Fortunately it does not attack all the children in the unhappy families in which it makes its appearance.
Amaurotic idiocy presents certain noticeable points of similarity 1.0 infantile spinal muscular atrophy. Roth diseases occur ill very young children; in both the course is rapidly progressive; in both the termi nation is absolutely fatal; both present sharply defined clinical pictures such as are seen in no other endogenous disease. If amaurotic idiocy is a typical example of the abiotic processes in which the defect of the nervous system prevents the proper renewal of nervous material used up in carrying on the functions of the body, as Edinger assumes, the same thing may he true of infantile muscular atrophy. In the former, the morbid process affects chiefly the cells of the cerebellum, in the latter exclusively those of the spinal cord. From other endog enous diseases both affections are distinguished by rapid exhaustion of the resisting power of the nerve elements.
In this connection mention may be made of the occurrence of family or hereditary diseases of the optic nerve (Lebert, Higier, etc.). In these conditions inflammation and atrophy of the optic nerve occur and may lead to complete blindness. Other changes of the central nervous system are not observed in this disease, which is sometimes associated with deformities of the skull (steeple skull). The disturb ance occurs in older children and in adolescents.
(c) Periodic Paralysis of the Extremities (Myoplegia) This curious disease was first described by Hartwig in 1874 and later studied by Westphal, Oppenheim, Goldflam, Taylor, Mitchell, (Melo and Audihert, Singer, Schlesinger, Buzzard, Fuchs and Infeld. It 1..3. characterized by the paroxysmal occurrence of flaccid paralysis or weakness of the entire muscular system, involving speech and degluti tion; weakne.ss of the abdominal muscles and interference with defeca tion and urination. The reflexes are abolished; the electric irritability
is diminished. Rarely transient spastic phenomena are present. The heart also is sometimes attacked, while, on the other hand, the muscles of the eye, face and diaphragm usually escape. The attack lasts from a few hours to three days, and the intervals of freedotn are measured usually by days or weeks, rarely by months. The attack is often ac companied by sweating. Unusual muscular inactivity or overexertion appear to favor the occurrence of an attack; thus many of the patients have their attacks after certain days in the week on which they deviate from their usual mode of life. Buzzard and Singer have described eases in children. The intensity of the attacks is variable and usually di minishes as time goe.s on. No autopsies have as yet been performed on patients of this kind and the pathology of the condition is still in doubt. Most authorities incline. to the theory of an individual pre disposition to autointoxication, evidenced by occasional finding of acetone and renal elements in the urine, the occurrence of sweating ancl the favorable influence on the tlisease said to be efTeeted by stimu lating diuresis during the intervals of freedom.
(d) M yoIonia Congenita (Thomsen's disease) In 1876 the German physician, Thomsen, described a disease which had attacked several members of his family and which is characterized by muscular rigidity coining on at the beginning of an intentional movement. Since then our knowledge of thi.s affection has been in creased and confirmed by contributions from numerous authors, Seelig mfiller, Striimpell, Westphal, Mobius, Bernhardt, Eulenburg, Schieff erdecker, Schultze and especially Erb. The disease is in most cases congenital. Even in those cases in which symptoms develop late there is probably a congenital predisposition, causing the appearance of mor bid symptoms after severe bodily exertion. The disease is rarely recog nized in early childhood (Friis) and usually manifests itself when the boy begins to receive instruction in gymnastics, at the time of military service or some unusual bodily exertion. Hence it is the fate of these unfortunate sufferers of myotonia to be taken at first for rnaligners.