What is Empty Sella Syndrome(ESS)?
The pituitary gland sits in the sella turcica, sometimes called the pituitary fossa, a bony cup at the base of the brain, which protects it. On MRI scans of a normal brain, the pituitary gland would normally almost fill the sella turcica.
ESS is a condition where the pituitary gland appears flattened or shrunken within the sella turcica on an MRI scan. Alternatively, the sella turcica can enlarge with the pituitary gland size remaining relatively normal, giving the appearance of an ‘empty sella’. The pituitary gland usually continues to function normally, but in a minority of cases can become under active (hypopituitarism).
Causes of Empty Sella Syndrome?
ESS can be due to primary or secondary causes. Primary Empty Sella Syndrome occurs in people who have a weakness in the membrane (diaphragma sellae) that normally covers the pituitary gland. Cerebrospinal fluid is the fluid that flows around the brain. As a result of the weakened membrane, this fluid can leak into the sella turcica and apply pressure on the gland. This can lead to either a flattening of the pituitary gland or expansion of the sella turcica, giving the appearance of an empty sella.
In secondary ESS, the sella turcica becomes empty because the pituitary gland has been removed through surgery or damaged through radiation treatment or pituitary apoplexy. In some cases, there has been a pituitary tumour that has shrunk without treatment.
How common is Empty Sella Syndrome?
It is difficult to estimate how common ESS is.
Evidence from brain imaging techniques suggests that some degree of primary empty sella is common in the normal population and it is more frequently seen in women than men. Pituitary hormone deficiency (hypopituitarism), however, is only present in a small minority of such individuals.
Secondary ESS only affects people who have already had treatment for a pituitary disorder. It affects both genders equally. ESS is not inherited.
Symptoms of Empty Sella Syndrome
Most people with ESS do not have symptoms and it is often only detected when brain scans are undertaken for other reasons.
A minority of people may experience headaches or disturbed vision. Deficiency in the production of one or more pituitary hormones (hypopituitarism) is present in less than 10% of people with primary ESS. You can find out more information about this on the hypopituitarism page.
Diagnosis of Empty Sella Syndrome
ESS is diagnosed on CT or MRI scans of the pituitary area or brain. It is often identified coincidentally whilst carrying out investigations for other reasons. As a result you may hear the term incidental finding used by the Endocrine team. You may be investigated as an outpatient. Blood tests are also carried out to make sure the pituitary gland is functioning properly and to check for hormonal deficiencies.
Treatment for Empty Sella Syndrome
If you have ESS and have no symptoms or hormonal dysfunction, then you do not require any specific treatment. If you are deficient in one or more hormones, replacement of those hormones may be required and will be discussed with you by the Endocrine team. Normal pituitary hormone replacement treatment is not usually associated with any side-effects. You would be reviewed by your Endocrine team to ensure your hormone replacements are at adequate levels for you.
If you have normal pituitary function then you may have occasional long-term follow-up.
