Empty Sella Syndrome (ESS) is a condition related to an anatomical structure at the base of the skull, often discovered incidentally during brain imaging for an unrelated reason. The condition is frequently benign and does not cause noticeable symptoms. The term describes a specific finding on a scan where the pituitary gland appears flattened or shrunken, making the bony cavity that houses it look empty.
Understanding the Sella Turcica and Empty Sella Syndrome
The sella turcica, Latin for “Turkish saddle,” is a saddle-shaped bony compartment located at the base of the skull, specifically in the sphenoid bone. This protective cavity serves as the housing for the pituitary gland, a small but powerful endocrine gland. In a person without this condition, the pituitary gland nearly fills the entire sella turcica.
Empty sella syndrome is a radiological finding where the sella turcica appears to be partially or completely filled with cerebrospinal fluid (CSF) rather than the gland. The CSF is the clear fluid that surrounds and cushions the brain and spinal cord. In this condition, the pressure of the CSF causes the pituitary gland to be compressed, flattening it against the walls of the sella turcica.
The sella is not truly empty, but the flattened pituitary gland becomes difficult to visualize on imaging, giving the appearance of an empty space. This appearance is typically identified through diagnostic imaging, such as a Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scan of the brain. Many cases of empty sella are discovered by chance when a patient undergoes a scan for headaches or another neurological complaint. The condition is often classified as an anatomical variation rather than a disease, as the pituitary gland frequently continues to function normally.
The extent of the condition is described by how much of the sella is filled with CSF. A partial empty sella means less than half of the cavity is filled. In contrast, a total empty sella indicates that more than half of the space is occupied by CSF, with the pituitary gland often reduced to a thin layer. Even in cases of total empty sella, the pituitary gland may still be functioning correctly.
Distinguishing Causes: Primary versus Secondary ESS
Empty Sella Syndrome is categorized into two distinct types based on its origin: Primary and Secondary. The distinction helps medical professionals understand the likely presence of symptoms and the best course of management. The primary form is more common and is not caused by an underlying disease or identifiable event.
Primary ESS is thought to be related to a small congenital defect in the diaphragma sellae, the membrane that normally covers the sella turcica and separates it from the brain cavity. This opening allows the arachnoid membrane, which holds the CSF, to bulge into the sella turcica. The subsequent pressure from the CSF leads to the compression and flattening of the pituitary gland. This form is most often found in middle-aged women who may also be obese or have high blood pressure. Since the pituitary gland is often still structurally intact, primary ESS rarely leads to significant symptoms or hormonal deficiencies.
Secondary ESS results from an identifiable event that has caused damage to the pituitary gland or the sella structure. This type occurs when the pituitary gland shrinks or is removed due to a previous medical intervention or condition. Causes of secondary ESS can include surgery, radiation therapy targeting the area, or trauma to the head. The secondary form can also develop after a pituitary tumor shrinks spontaneously or is removed, leaving the bony cavity vacant. Because the gland has been physically damaged or altered, individuals with secondary ESS are more likely to experience functional problems and related symptoms.
Clinical Manifestations and Associated Symptoms
Many individuals with Empty Sella Syndrome, especially the primary type, remain completely asymptomatic throughout their lives. The condition may only be discovered when a brain scan is performed for a completely different reason. When symptoms do occur, they generally fall into two categories: neurological/structural complaints and endocrine dysfunction.
Chronic headaches are the most common complaint reported by symptomatic patients with ESS. The condition has also been associated with signs of increased pressure within the skull, known as idiopathic intracranial hypertension (or pseudotumor cerebri). This pressure can lead to papilledema, which is swelling of the optic disc, and may result in visual disturbances or a loss of visual clarity. In rare instances, severe cases involving high intracranial pressure can cause cerebrospinal fluid to leak from the nose, a condition called CSF rhinorrhea.
The second category of symptoms relates to the pituitary gland’s function as the body’s hormonal control center. When the gland is significantly compressed or damaged, it can lead to hypopituitarism, a deficiency in one or more pituitary hormones. Endocrine symptoms depend on which hormones are affected, potentially including fatigue, irregular menstrual periods, or erectile dysfunction. Hormone deficiencies are present in a minority of primary ESS cases, but they are a more frequent concern in secondary ESS due to the physical damage to the gland.
Management and Treatment Approaches
The management of Empty Sella Syndrome is highly individualized and depends almost entirely on the presence and severity of symptoms. Because the majority of people with a finding of empty sella have no symptoms and normal pituitary function, no intervention is typically necessary. In these asymptomatic cases, the standard approach is observation with regular check-ups to monitor the condition over time.
For individuals who are symptomatic, treatment focuses on addressing the specific complaints and any underlying hormonal imbalances. If endocrine testing reveals hypopituitarism, the primary treatment is hormone replacement therapy (HRT). This involves replacing the deficient hormones, such as thyroid hormones, cortisol, or sex hormones, to restore normal physiological levels.
Neurological symptoms, such as chronic headaches or elevated intracranial pressure, are treated medically. Medications like acetazolamide may be used to help manage symptoms related to high pressure in the skull. Surgical intervention is considered only in very rare circumstances, typically reserved for severe complications like persistent CSF leakage from the nose or rapidly deteriorating vision caused by pressure on the optic nerve. In these instances, a shunt may be surgically placed to relieve the pressure on the brain.