The changes in the bones have been men tioned in the paragraphs on sporadic cretinism. The skin has a peculiar cachexia. It is swollen and flabby, whitish or yellowish, folded and soggy. The general appearance of old age is striking. The hair and nails are badly devel oped, both breaking easily. Thick, underlying fatty masses are unevenly distributed, usually in the neck, back, upper chest regions, occasionally over the hands. Variable states of tension occur in these fatty masses; at times they are hard, again like empty sacks. The mucous membranes are also pale and gray, often folded but look different from a typical anaemia.
The sexual organ changes have been touched upon in the description of sporadic cretinism. They are characteristically infantile. Menstrua tion is scanty, wanting or develops very late. Fecundation may take place, but the results are either miscarriages, dead children, various mon sters, etc. The secondary sexual characters are all delayed in their development.
The majority (63 per cent, Ewald) of cre tins show a swollen thyroid, but it is not an over-functioning one, nor do they all show athyreosis or hypothyreosis.
Most of the internal organs show reduction in activity. Digestion is usually slow, constipa tion is marked. The metabolism is modified as already indicated. The urinary secretions are apt to be diminished and of high specific gravity.
Mentally cretins show marked variability. A few are practically normal, but most show a characteristic combination of mental traits, in contrast with many other mental defective states. The feeble-mindedness is accompanied by great slowness of all reactions, marked re tardation of motion, apathy and indolence. This indolence is a marked feature. Many cretins will lie in the sun all day long, and in the hos pital or other institutions will lie around and do nothing for weeks or months. In the milder grades there is often great shyness which makes them unapproachable and serves to make them appear more feeble-minded than they really are. It is with the greatest difficulty that they can be trained to the simplest of performances. With many, in spite of the marked general stolidity of their average mood, they may show great excitement and emotional outbreaks.
They are very negligent, love to sit still, but many show much variability in this respect. As noted the great majority suffer • from impair ment of the chief sensory tracts. Hearing seems to suffer most. The defect in hearing is asso ciated with speech defects. Taste and smell are
also involved. They take little interest in their food or drink and therefore show little interest in hunger, which is marked. The sense of sight is frequently diminished. It is highly probable that the receptors and conduction paths are less involved than the perception areas in this dimi nution in sensory intake. The hearing seems to be affected primarily as to its receptor and con duction paths. Pain, touch and thermal sensi bilities are all dulled. Motility is extremely re tarded. The reflexes are active (50 per cent). The field of vision is reduced in many, although the fundus is usually normal (Hitschmann).
Aberrant and abortive types are to be ex pected. In the former one may find patients with striking development of one or more fea tures, in the latter a very great shading off to almost normal states, i.e., endemic goitre with mild mental signs.
Endemic Deafmutiam.— This combination is extremely frequent where endemic cretinism is present (29 per cent, Scholz). It may con stitute one of the aberrant types just mentioned with striking development of single features, or it may be associated with all the grades of a complete cretin picture. According to the studies of Kocher, the loss of hearing is due to a bony defect which has destroyed the possibil ity of normal cochlear development. Bad hear ing is reported at 32 per cent among cretins in Scholz's investigations.
The changes found in the brain which may account for the feeble-mindedness have been variable. Meningeal inflammation and mild grades of hydrocephalus have been found by Scholz and Zingerle. The brain is often sym metrical, small or single lobes are diminished in size. Often the brain's development is ar rested at an infantile stage, the pallium or the ganglia being involved alone or together. The cerebellum is often imperfectly developed, which fact stands in correlation with the marked incoordination and possibly in relation with de fective labyrinthine development.
The car difficulties have been protean. Pe ripheral, conducting and central mechanisms have been found at fault; at all events they all seem secondary to the developmental anomalies induced by the action of the poisonous substance on the thyroid. The speech defects usually go hand in hand with those of hearing, but this is not universal. The cortical developmental de fect is sufficiently explanatory for most of the cases.