Empty Sella Syndrome and Pituitary Function

The sella turcica is a depression in the base of the skull that holds the pituitary gland. In partially empty sella syndrome, this space is filled with spinal fluid, with a small pituitary gland at the bottom. In completely empty sella, this space is completely filled with spinal fluid, with no visible pituitary gland.

Primary empty sella syndrome occurs when a defect of the pituitary gland allows spinal fluid to fill the sella turcica. People with primary empty sella syndrome may have high levels of prolactin, a hormone that regulates metabolism, the immune system, and reproductive system. In some cases, the pituitary gland may be smaller than normal, and in rare cases with increased pressure, spinal fluid may drain from the nose.

Secondary empty sella syndrome results from a genetic mutation, surgery, head trauma, increased intracranial pressure, or radiation treatments. People with secondary empty sella syndrome generally have symptoms common with the loss of pituitary function, including a change in menstrual periods, fatigue, infertility, and lower tolerance for infections.

People with empty sella syndrome typically have a normal medical history and physical exam. The most common symptom is headache, but there is no evidence to support that empty sella syndrome itself causes headaches. Experts believe that the connection is coincidental; empty sella syndrome is often discovered during the same imaging doctors use to investigate a patient's headaches.

Symptoms of empty sella syndrome vary depending on the underlying cause. Most people are asymptomatic. In rare cases, pressure increases in the skull, causing spinal fluid to drip from the nose and possibly leading to vision changes. Pituitary gland function is normally not affected, however people with secondary empty sella syndrome due to trauma or a pituitary tumor are more likely to have these symptoms.

In about 20 percent of cases, empty sella syndrome affects pituitary function. When this occurs, one or all of the pituitary hormones can be involved. One of the most common hormone deficiencies in cases like this involves growth hormone, but it is unclear how this affects adults. Deficiencies of other pituitary-related hormones, like thyroid-stimulating hormone and antidiuretic hormone, are rare.

Primary empty sella syndrome is four times more common in women than men, though men are more likely to experience hormonal dysfunctions.

Most cases occur in middle-aged women with obesity and high blood pressure, but they are usually asymptomatic. Researchers estimate that less than one percent of people with empty sella syndrome develop symptoms. Although women are more likely to have this condition, men seem to be more likely to be symptomatic.

Empty sella syndrome is diagnosed based on patient history, clinical evaluation, and imaging, but it is usually only diagnosed if the patient has symptoms of pituitary insufficiency or if the condition appears on an MRI or CT scan. If the patient is symptomatic, blood tests can determine which hormone levels are affected.

Doctors determine treatment on a case-by-case basis. Asymptomatic empty sella syndrome does not require treatment. In symptomatic cases, treatment is directed toward specific symptoms; for example, people with secondary empty sella syndrome may need hormone replacement therapy. Surgery is rarely necessary unless spinal fluid is leaking from the nose.

Empty sella syndrome is not life threatening. Most people do not even know they have it, and it does not affect life expectancy. If empty sella syndrome develops due to an underlying condition, such as cancer, injury, or head trauma, the underlying condition determines the long-term outlook for that person.