An Overview of Empty Sella Syndrome

The pituitary gland, which many endocrinologists refer to as the body's "master gland," is a round, pea-sized structure that lies at the base of the brain behind the nasal cavity. It is protected within a bony cavity called the sella turcica. 

There is a rare condition in which the sella turcica becomes partially or completely filled with cerebrospinal fluid, causing the pituitary gland to become flattened against the bony wall of the sella turcica. Because most of the sella is now filled with fluid instead of tissue, on medical imaging studies it appears to be empty. This condition is called the "empty sella syndrome."

Symptoms

Strictly speaking, empty sella syndrome is not a syndrome at all, since a syndrome is a set of medical signs or symptoms that tend to occur together. Empty sella syndrome, in contrast, is merely a description of what is seen on an imaging study, and there is no typical set of clinical signs or symptoms associated with this imaging finding.

The most common symptom reported by people with primary empty sella syndrome is headache. It is not really clear whether empty sella causes headaches, or whether people with chronic headaches are simply more likely to have brain scans (and therefore, are more likely to be diagnosed with empty sella syndrome that is not actually producing symptoms).

Rarely, people with primary empty sella syndrome may have high levels of prolactin, a hormone which is secreted by the pituitary gland. In women, high prolactin levels can cause infertility, loss of menstrual periods, and low libido. In men, elevated prolactin levels can cause impotence and loss of libido, as well as breast enlargement and/or discharge from the nipples.

Symptoms are much more common in people with secondary empty sella syndrome. The underlying condition that is causing the empty sella may itself produce symptoms. In addition, the loss of some or all pituitary function is often seen with secondary empty sella.

Pituitary malfunction with empty sella. The pituitary gland is a "master gland," in that it secretes hormones that regulate several other important hormone-producing glands throughout the body, including the thyroid gland, the adrenal glands, the ovaries, and the testicles. With secondary empty sella syndrome, the pituitary gland may not be able to secrete its regulatory hormones in the appropriate amounts. 

Depending on which specific pituitary hormones are disrupted, a person with empty sella may experience a host of symptoms. These may be related to hypothyroidism due to TSH deficiency (fatigue, constipation, dry skin, weight gain, cold sensitivity), low cortisol levels due to ACTH deficiency (low blood pressure, gastrointestinal symptoms, propensity toward infections, fatigue), antidiuretic hormone deficiency (extreme thirst with excessive urination), growth hormone deficiency (weakness and fatigue), and LH and FSH gonadotropin deficiency (causing irregular periods and hot flashes in women, or erectile dysfunction in men). 

Causes

When empty sella syndrome is discovered on an imaging study, doctors will first classify it as being either primary or secondary.

Primary empty sella means that no specific underlying cause is identifiable. It is believed that in most cases, primary empty sella syndrome occurs when a congenital defect in the tissue lining the brain creates the potential for cerebrospinal fluid to enter the sella turcica, flattening the pituitary gland and displacing it to one side. In these cases the pituitary gland itself, while difficult to see on an imaging study, is almost always functioning normally. Consequently most people with primary empty sella syndrome have no associated symptoms. Primary empty sella is most often diagnosed in middle-aged women who are overweight or obese and have hypertension. Why empty sella syndrome appears to be more common in these people is unknown.

Secondary empty sella syndrome is caused by some identifiable underlying condition that changes the anatomy of the pituitary gland and/or the sella turcica. There are several causes of secondary empty sella syndrome including head trauma, infection, surgery, radiation therapy, stroke, a postpartum disorder called Sheehan's syndrome, pituitary tumor, and pseudotumor cerebri (intracranial hypertension of unknown cause). People with secondary empty sella syndrome often develop symptoms, either due to the underlying cause itself or due to subsequent disruption of pituitary gland function.

Diagnosis

In most people with primary empty sella syndrome, the diagnosis is made incidentally when a brain imaging study (MRI or CT scan) is done for another reason. If there are no symptoms, doctors will usually do screening blood tests measuring thyroid hormones and cortisol levels. If these are normal, generally no further evaluation is necessary.

For people with secondary empty sella syndrome, symptoms lead to a medical workup looking for hormonal abnormalities. Various blood tests generally find one or more hormone deficiencies, and subsequent imaging studies lead to the diagnosis of empty sella.

Treatment

The large majority of people with primary empty sella have no symptoms and no hormonal abnormalities and do not need to be treated. In those uncommon cases in which primary empty sella syndrome is causing symptoms due to elevated prolactin levels, treatment with bromocriptine usually decreases prolactin production to the point that symptoms are eliminated.

In people with secondary empty sella syndrome, treatment usually consists of replacing the deficient hormones with pills. However, depending on the underlying cause, surgical treatment may be needed.

A Word From Verywell

Empty sella syndrome is usually diagnosed as an incidental finding on a brain imaging study that has been done for another reason. Most people who are given this diagnosis have no symptoms and need no treatment.

However, when empty sella syndrome has a specific underlying cause, it may be accompanied by various hormonal abnormalities that can have serious consequences. Once the correct diagnosis is made, these hormone deficiencies are treatable.