Empty sella syndrome is a rare condition that describes an abnormality of the sella turcica, a depression in the bone at the base of the skull where the pituitary gland is contained. The condition refers to when this saddle-shaped structure is malformed and filled with cerebrospinal fluid, which compresses and flattens the pituitary gland, making the sella turcica appear empty.
Types and causes of empty sella syndrome
Empty sella syndrome occurs as either a primary or and secondary condition. Primary empty sella syndrome is usually caused by a large opening that forms in the diaphragm sellae, a membrane that covers and protects the pituitary gland inside the socket. This opening allows fluid in, causing a pressure increase in the sella turcica that flattens the pituitary gland out within the walls of the cavity. Primary empty sella syndrome is sometimes observed in cases of obesity or hypertension and as a result of idiopathic intracranial hypertension.
In secondary empty sella syndrome, the pituitary gland regresses within its cavity as a result of injury, surgery or radiotherapy. Damage to the pituitary may lead to symptoms such as infertility, cessation of menstrual periods (amenorrhea), fatigue and intolerance to infections and stress.
Empty sella syndrome may be suspected in cases of hormone deficiency, early onset of puberty, dysfunction of the pituitary gland and pituitary tumors. Procedures that may be used to confirm the diagnosis include a computed tomography (CT) scan and magnetic resonance imaging (MRI) scan. A CT scan uses a combination of X-rays and computer technology to provide detailed images of the body that may not be achieved using a normal X-ray, while an MRI scan uses strong magnetic fields to generate 2-D images of internal structures. MRI scans can differentiate empty sella syndrome from other conditions that lead to an enlarged sella.
In the case of primary empty sella syndrome, the condition is not treated if the pituitary gland is functioning as usual. If prolactin is raised, however, and disrupting ovarian or testicular function, a medication such as bromocriptine may be used to lower levels of this hormone. Cases of secondary empty sella syndrome are treated by replacing hormones that are lacking.