(b) Amaltrolie Family Idiocy Imaurotic family idiocy occupies a peculiar position among the familial diseases. The hereditary character of the disease. age of the patient, and the symptomatology are so characteristic as to distinguish it from most other cliseases occurring in families and make it in reality a sharply defined nosologic entity. It is quite true that our knowledge of the disease is still comparatively recent, and for that reason it is sible that we do not properly appreciate the existence of atypical forms.
Amaurotic family idiocy usually attacks children in the second half of the first year. It is characterized by increasing flaccidity of the muscles, idiocy, and a peculiar change in the eyes; is associated with convulsions and spasms, and terminates fatally within a few years. Since Sachs described the disease for the first time, in 1S98, about ten cases have been reported, some of which have been studied post mortem. Tay had previously called attention to certain symptoms of the disease, which at Higier's suggestion, received the name of Tay-Sachs disease.
Amaurotic family idiocy is usually observed in several children of the same family, although a number of isolated cases have been described. Of 64 cases collected by Falkenheim, 27 were isolated and the remaining 37 occurred in members of 13 different families. It is a remarkable fact that the disease occurs with preponderating frequency among Jewish children, particularly among the children of the poor Polish and Russian Jews. The preponderance of the Jewish element is clearly shown by the fact that Falkenheim found only four out of 36 families that were Christians. Another remarkable fact is that the disease has been most frequently observed among poor immigrants in North America, while comparatively few observations have been made in the countries from which these people emigrated (so far not a single case has been reported from Vienna).
The characteristic symptoms are as follows: In a normally de veloped child arrest or impairment of the motor function is noticed. The child is unable to raise its head, sitting up becomes impossible, there develop flaccidity and loss of motion in the extremities and as a consequence the child is no longer able to walk or stand. While these symptoms may be attributed to rachitis, a change in the mental facul ties which develops at the same time or soon afterwards attracts at tention. The child forgets how to laugh, it no longer speaks to its parents and acquaintances, and takes no interest in its toys. Intel lectual impairment increases rapidly. Apathy persists and is inter rupted only by such occasional causes as hunger or the evacuation of urine and feces, and the child even finds some difficulty in nursing from the bottle, although the sense of taste usually remains intact even in advanced stages of the disease (the child refuses to take unsweetened milk). Finally the picture of severe complete idiocy develops.
The rapid mental decay is the more noticeable to the parents because indications of failing vision manifest themselves at the same time or soon afterwards. Ophthalmoscopic examination reveals a very peculiar, sharply circumscribed, pale white discoloration of the macula lutea, the fovea centralis persisting as a cherry-red point in the centre of the blind spot. This condition is absolutely peculiar to amaurotic family idiocy. True atrophy of the optic nerve is also noted and is rarely preceded by neuritis. Among other ocular symptoms present are strabismus and nystagmus, A symptom that is quite common is abnormal sensitiveness to noises. As the disease progresses the flac cid muscular paralysis, which is not accompanied by atrophy, is replaced by spasms with exaggeration of the reflexes, Toward the end general convulsions or tonic muscular spasms may develop. Death ensues after increasing general emaciation from marasmus or sonae intercurrent disease (pneumonia). The duration of the disease varies between eighteen months and two years, and the patients do not, as a rule, live to be more than two or three years old. Remissions are rare and have no influence the ultimate outcome.
The pathology of amaurotic family idiocy consists in \vide-spread degeneration of the ganglion cells and fibres of the central nervous system. Inflammatory- changes do not occur. The distribution of the degenerative process is not always the same; in some cases the cere bral cortex, in others the medulla oblongata or spinal cord are chiefly affected. Sachs' original theory of a congenital disturbance in the central nervous system, as well as the theory- of acquired inflammatory changes, has now been abandoned by most authors who have studied the subject. The disease represents a typical abiotic process, in which the primary factor is the change in the ganglion cells, while the degenera tion of the nerve fibres is a secondary condition. In t.he same way, the ocular changes are regarded as a degeneration of the retinal cells; the fovea centrals, which is devoid of cells, remains intact. With good reason, Schaffer explains amaurotic family ilocy by the theory of Edinger that the tissues of the normally or functionally weak nervous system are rapidly used up and insufficiently replaced, a theory which renders this mysterious disease somewhat Inore intelligible.