Chronic Insomnia Can Be Sign of Cushing’s, Case Report Finds

Chronic insomnia can be a sign of Cushing’s syndrome, and doctors need be aware of this possibility, according to a case report of a woman diagnosed with Cushing’s shortly after seeking help for her insomnia.

This case also emphasized the usefulness of the dexamethasone suppression test in identifying the specific cause of Cushing’s.

The case report, “Cushing’s syndrome manifesting as chronic insomnia caused by adrenal cortical adenoma with incidental pituitary microadenoma: a case report,” was published in the Journal of Biomedicine and Translational Research.

Cushing’s syndrome is caused by excess levels of cortisol, a hormone that helps control the body’s response to stress. Cushing’s disease is a specific type of Cushing’s syndrome, where excess cortisol levels are the direct result of a tumor in the brain’s pituitary gland.

Typical symptoms include physical changes, like weight gain and a rounded face. However, excess cortisol levels can also cause mental and emotional symptoms, such as insomnia, irritability, and low libido.

“These neuropsychiatric symptoms should not be ignored and need to be explored holistically from every aspect in order to establish the right diagnosis,” the scientists wrote.

The research team, based in Indonesia, described a 30-year-old woman who came to their clinic with complaints of insomnia and headache over the previous six months. She also had difficulties concentrating, muscle weakness, and weight gain.

Upon physical examination, clinicians noted she had some characteristic features of Cushing’s, including a round face and reddish-purple striae (stretch marks) on her stomach.

Laboratory tests showed her blood cortisol levels were elevated, which is consistent with the presence Cushing’s syndrome. Imaging tests also revealed she had two small tumors: one in the pituitary gland, and one in the left adrenal gland, which sits atop that kidney.

Theoretically, either of these tumors could cause Cushing’s syndrome. If the patient had Cushing’s disease, then the pituitary tumor would release abnormally high levels of adrenocorticotropic hormone (ACTH), which in turn, would prompt the adrenal glands to produce excessive amounts of cortisol. However, it was also possible that the tumor on her left adrenal gland was causing too much cortisol to be released.

To differentiate between the two, clinicians performed the high dose dexamethasone suppression test, or HDDST. Dexamethosone is a steroid that lowers ACTH levels in the body. Therefore, if the tumor in the pituitary gland is the root cause of Cushing’s, a reduction in ACTH levels triggered by the test should substantially decrease cortisol levels.

Test results showed the patient’s cortisol levels remained high after taking dexamethasone. Based on these observations, clinicians concluded that the woman’s Cushing’s syndrome was caused by the tumor in her left adrenal gland, and not by the one in her pituitary gland.

This shows how the HDDST “can help distinguishing the main etiology [cause] of Cushing’s syndrome in this case where the patient had more than one possible source of cortisol overproduction.”

Surgeons removed the left adrenal gland, and the woman was treated with hydrocortisone to prevent adrenal insufficiency (excessively low adrenal activity) following the removal. By nine months after surgery, her symptoms had substantially eased.

The scientists emphasized that Cushing’s may present with symptoms similar to those of other neurological and psychological conditions, including chronic insomnia, “and should be explored thoroughly accompanied by adequate physical examination to establish the proper diagnosis.”