Disorders & Disease
Due to the functional nature of the hypothalamus any disturbances to its function will result homeostatic problems. Examples include thirst disorders, a change to appetite and temperature disturbances.
Traumas and lesions to certain areas of the hypothalamus cause the above mentioned problems.
- Lesion in the anterior portion of hypothalamus results in an increase in temperature (hyperthermia)
- A lesion to the caudal part of the hypothalamus can cause a decrease in temperature (hypothermia)
A study by Anand and Brobeck found that bilateral lesions to the hypothalamus in rats and catscan result in hyperphagia, a decrease in food intake or a complete loss of appetite. An increase in food intake and obesity is caused by very specific lesions to the venteromedial nuclei. Bilateral lesions to the lateral hypothalamus led to a loss of appetite but unilateral lesions did not cause the same symptoms. However, bilateral lesions to other parts of the hypothalamus do not result in any change to the feeding pattern of these animals except in the areas adjacent to the lateral hypothalamus. This may result in a decrease in food intake for a few days following the creation of the lesions.
Therefore, it has been surmised from this that the lateral hypothalamus may act as the feeing centre and the venteromedial nucleus has an inhibitory effect on this centre.
Cited from Bal K. Anand and John R. Brobeck. 1951. HYPOTHALAMIC CONTROL OF FOOD INTAKE
IN RATS AND CATS Yale J Biol Med. 24(2): 123–140.
Congenital abnormalities to the hypothalamus cause changes to the hypothalamic-pituitary axis. Isolated anterior pituitary hormone deficiencies such as those with isolated growth hormone or gonadotropins can cause hyposmia or anosmia and are considered to have Kallman’s syndrome.
The effect of disturbances to the hypothalamic-pituitary axis can result in:
Another interesting finding in studies of the hypothalamus is the behavioural role the hypothalamus plays. A small study in 1978 found that a number of symptoms experienced by those suffering anorexia nervosa, self mutilation, sexual disorders, obsessive compulsive disorder and aggression pointed to hypothalamic disorders. The neurotransmitters involved in these patho-physiology disorders are also affected by the release of serotonin and norepinephrine which is found in high quantites in the hypothalamus.
Cited from J. A. Yaryura-Tobias and F. Neziroglu. 1978. Compulsions, Aggression, and Self-Mutilation: A Hypothalamic Disorder?