Psychosomatic Medicine 1:496-507 (1939)
© 1939 American Psychosomatic Society

Alterations in the Hypothalamus in Mental Deficiency

¹ Department of Anatomy, University of Cincinnati, College of Medicine, Cincinnati, Ohio

A histologic study was made of the diencephalon in 16 cases of mental deficiency, cases which did not show evidence of disease or injury to the cerebral cortex, and most of which at least could be classified as "primary amentia".

Pathologic involvement of the third ventricle region was evident in all but 2 cases. Ependymitis and meningitis, and distortion of the walls of the third ventricle were the most common findings.

The nucleus tubero-mammillaris was the only cell group in the hypothalamus which did not show a marked reduction in the number of cells. There was an average cell reduction of 27 per cent for the para-ventricular nucleus. In 15 cases the supraoptic nucleus showed an average cell loss of 35 percent. The nucleus tuberis lateralis showed an average cell loss of 52 per cent. The average amount of cell reduction for the substantia grisea was 33 per cent.

The normal appearance of the cells in the hypothalamic nuclei suggests that the cell reduction occurred at an earlier period in the history of the patients.

Through its influence upon the hypophysis and the parasympathetic nervous system the anterior hypothalamus is probably concerned chiefly with growth, nutrition and the conservation of energy. The posterior hypothalamus through the suprarenals, thyroids, and sympathetic nervous system is probably concerned with the mobilization and discharge of energy. Hence it is believed that the alteration in the hypothalamus may play a role in the widespread physiological inadequacy and the abnormalities of growth and development, which are so common in mental deficiency.