Empty Sella Syndrome (ESS) describes a finding on brain imaging where the anatomical structure housing the pituitary gland appears to be filled with fluid rather than the gland itself. This condition is typically identified incidentally when scans are performed for other medical concerns, meaning many individuals who have it do not experience related health issues. Despite the concerning name, the pituitary is usually still present but is compressed or flattened. ESS is classified as a radiological observation that only becomes a syndrome when it causes noticeable symptoms or hormonal dysfunction.
Defining the Empty Sella
The term “sella turcica” is Latin for “Turkish saddle,” referring to the saddle-shaped depression in the sphenoid bone located at the base of the skull. This small, bony compartment serves as the protective home for the pituitary gland, an endocrine organ that regulates numerous body functions. A membrane called the diaphragma sellae normally covers the top of the sella turcica, forming a barrier that keeps the pituitary gland securely in place.
Empty Sella Syndrome develops when this membrane has a defect or opening, allowing the subarachnoid space to expand. This expansion permits cerebrospinal fluid (CSF)—the fluid that cushions the brain and spinal cord—to flow into the sella turcica. The pressure from the CSF pushes down on the pituitary gland, causing it to flatten against the walls of the bony cavity. On an MRI or CT scan, the cavity looks predominantly filled with CSF, giving the appearance of an “empty” sella, though the flattened gland often continues to function normally.
Primary and Secondary Causes
Empty Sella Syndrome is categorized into two main types based on its origin: primary and secondary. Primary ESS is the most common form, developing spontaneously without an identifiable underlying cause (idiopathic). This type is thought to result from a congenital or acquired defect in the diaphragma sellae, allowing CSF to enter and exert chronic pressure on the pituitary gland. Primary ESS is frequently associated with specific patient characteristics, including obesity and high blood pressure (hypertension).
Secondary ESS results from a known medical event that causes the pituitary gland to shrink or regress within the sella turcica. This type is a consequence of damage to the gland or the surrounding structure. Common causes include previous brain surgery, particularly procedures targeting the pituitary gland (hypophysectomy), or therapeutic interventions such as radiation therapy. The gland may also shrink following a traumatic brain injury or from an event like pituitary apoplexy (bleeding or infarction of the gland).
Recognizing the Signs and Symptoms
Many individuals with Empty Sella Syndrome never develop any symptoms, and for them, the finding is purely radiological. When symptoms do manifest, they generally fall into two distinct groups: neurological issues related to fluid pressure and endocrine issues related to hormonal imbalance. Headaches are the most frequently reported neurological symptom, likely due to the increased pressure exerted by the cerebrospinal fluid within the skull.
More severe, though rare, neurological issues can include visual disturbances if the increased fluid pressure affects the optic nerves or the optic chiasm. In sporadic instances, the pressure can cause a leak of cerebrospinal fluid from the nose, known as CSF rhinorrhea, which requires immediate attention.
Endocrine symptoms arise when compression interferes with the pituitary gland’s hormone-producing functions, leading to hypopituitarism (underproduction of hormones). Since the pituitary regulates numerous glands, this can result in a wide range of issues:
- Fatigue, intolerance to stress, and trouble fighting infections due to low adrenal hormones.
- Menstrual irregularities or infertility in women.
- Reduced libido or erectile dysfunction in men, often stemming from low levels of sex hormones.
Diagnostic Imaging and Testing
The diagnosis of Empty Sella Syndrome is primarily established through specialized medical imaging. Magnetic Resonance Imaging (MRI) is considered the most effective tool, providing detailed cross-sectional images of the brain and pituitary gland. MRI clearly visualizes the cerebrospinal fluid filling the sella turcica and the degree of pituitary compression, allowing clinicians to distinguish between an “empty” appearance and other structural issues.
Although less detailed for soft tissues, Computed Tomography (CT) scans can also be used to confirm the finding when an MRI is not feasible. Beyond imaging, a comprehensive hormonal workup (endocrine evaluation) is performed to assess the functional impact of the condition. Blood tests measure the levels of various pituitary hormones and those of the glands they control (such as the thyroid and adrenal glands) to check for hypopituitarism. This screening is performed even in asymptomatic individuals, ensuring that subtle functional deficiencies are identified early.
Management and Treatment Approaches
Treatment for Empty Sella Syndrome is highly specific to the individual and depends entirely on the presence and severity of symptoms. If the condition is discovered incidentally, and the individual has no related complaints and normal hormone function, no specific intervention is required. In these asymptomatic cases, the recommended approach is “watchful waiting,” involving periodic monitoring with follow-up blood tests to ensure hormonal levels remain within a healthy range.
For individuals who experience symptoms, treatment focuses on addressing the consequences of the condition rather than the anatomical finding itself. Hormone replacement therapy is the standard method for managing hypopituitarism, supplementing deficient pituitary hormones, such as thyroid-stimulating hormone or cortisol. Patients experiencing chronic headaches may be managed with pain relievers or medications aimed at reducing increased intracranial pressure, often in consultation with a neurologist. Surgical intervention is reserved for rare and severe complications, such as a persistent cerebrospinal fluid leak from the nose or severe visual impairment caused by pressure on the optic structures.