The sella turcica is a bony structure at the base of the brain, resembling a saddle. This protective cavity houses the pituitary gland. Sometimes, imaging scans reveal this space appears “empty,” a condition known as empty sella. This finding, which can be partial or complete, refers to its appearance on imaging, not a literal absence of the gland.
Understanding the Sella Turcica and Empty Sella
The sella turcica, meaning “Turkish saddle” in Latin, is a depression within the sphenoid bone of the skull. It provides a secure enclosure for the pituitary gland, a pea-sized endocrine gland often called the “master gland.” This gland produces and releases hormones that regulate bodily functions, including growth, metabolism, and reproduction.
In an empty sella, the subarachnoid space, which normally surrounds the brain and spinal cord, extends into the sella turcica. This space, filled with cerebrospinal fluid (CSF), can exert pressure on the pituitary gland. The pituitary gland may become compressed, flattened, or displaced against the sella walls, appearing “empty” or reduced in size on imaging studies.
A partial empty sella indicates some pituitary gland remains visible within the sella, though the space is predominantly filled with CSF. A complete empty sella suggests the gland is so flattened or compressed it’s not readily discernible on imaging. Despite the term, the sella is not truly empty but filled with CSF.
Causes and Commonality of Partial Empty Sella
Partial empty sella is frequently identified incidentally during brain imaging. This anatomical variation is often benign and does not typically cause health concerns. It is categorized into two main types: primary and secondary empty sella.
Primary empty sella is the more common type, with no identifiable underlying cause. One theory suggests it may arise from a congenital defect in the diaphragma sellae, a membrane that partially covers the pituitary gland, allowing CSF to enter and flatten the gland. This type is more prevalent in middle-aged women, particularly those who are obese or have high blood pressure, and can also be associated with increased intracranial pressure.
Secondary empty sella occurs when an underlying medical condition or event damages the pituitary gland or sella turcica. This damage can result from factors like previous pituitary surgery, radiation therapy, trauma, or the regression of a pituitary tumor. In these cases, the empty sella is a consequence of a known process that caused the pituitary gland to shrink or flatten.
Primary empty sella’s prevalence in the general population ranges from 8% to 35%, highlighting its commonality as an anatomical finding. It is often discovered incidentally during routine imaging, reinforcing its nature as a variation rather than a disease for many. The presence of a partial empty sella on imaging does not automatically imply disease or dysfunction.
When Partial Empty Sella Requires Attention
While often incidental, partial empty sella can sometimes be associated with symptoms or conditions warranting medical evaluation. Headaches are frequently reported, though it is not always clear if they are directly caused by the empty sella or are coincidental. Some individuals may experience vision changes, such as blurred vision or visual field defects, if the expanded subarachnoid space or other factors affect the optic nerves.
Hormonal imbalances can occur if the pituitary gland’s function is affected. This might manifest as hypopituitarism, where the pituitary produces insufficient hormone levels, leading to symptoms like fatigue, low energy, or irregular menstruation. Hyperprolactinemia, an elevated prolactin level, can also be observed, potentially causing nipple discharge or menstrual irregularities. These hormonal issues are typically linked to the underlying cause or pressure on the pituitary stalk, rather than the empty sella itself.
Diagnosis typically involves imaging studies, most commonly magnetic resonance imaging (MRI) or computed tomography (CT) scans. These scans visualize the sella turcica and pituitary gland, revealing CSF within the cavity and the degree of pituitary compression. If symptoms suggest hormonal issues, an endocrine evaluation may be performed, involving blood tests to measure pituitary hormone levels.
Identifying the specific cause is important because management depends on whether the empty sella is primary and asymptomatic or secondary to another condition. For instance, if secondary to a regressed pituitary tumor, ongoing monitoring for recurrence might be necessary. A thorough medical assessment helps differentiate between a benign anatomical variant and a condition requiring intervention.
Living with Partial Empty Sella
For many individuals, a diagnosis of partial empty sella without associated symptoms does not require specific treatment. If the pituitary gland functions normally and there are no hormonal imbalances or neurological symptoms, active intervention is usually not needed. The condition is considered a benign anatomical variation.
Regular monitoring may be recommended, particularly if symptoms develop or if the partial empty sella is secondary to another medical condition. This could involve periodic imaging scans or endocrine evaluations to assess pituitary function. Such an approach helps ensure any potential changes are identified and addressed promptly.
Individuals with partial empty sella can often live without significant health impact. The prognosis is favorable for those without symptoms or underlying pituitary dysfunction. Understanding this anatomical finding helps alleviate concerns and provides a clear path for appropriate medical follow-up, if necessary.