E

Abstract

Anorexia nervosa and bulimia have been considered as psychiatric diseases, but in light of the known roles of the hypothalamus in controlling feeding behavior, some consider them hypothalamic diseases. Both occur predominantly in young women. Anorexia nervosa is characterized by extreme emaciation as a result of voluntary starvation, related to a distorted body image with fear of gaining weight. Occasional cases have been described in association with hypothalamic tumors, akin to the diencephalic syndrome of infants with hypothalamic mass lesions. Mild diabetes insipidus may occur. There are no characteristic neurological signs, although “hung-up” tendon reflexes have been described. Bulimia (literally “ox-eating”) is characterized by binge eating followed by induced vomiting and excessive use of laxatives. Anti­depressant medications may help in both anorexia nervosa and bulimia. Hyperphagia akin to that seen in bulimia may occur as one feature of the Kleine–Levin syndrome. Disorders of eating may also occur in frontotemporal lobar degeneration syndromes of behavioral/disinhibited type. The neuroanatomical substrates of eating disorders are debated: hypothalamic and brainstem lesions may be associated with changes in appetite and eating behavior, but more complex syndromes are associated with right frontal (e.g., Gourmand syndrome) and temporal lobe damage.