What is empty sella syndrome?

Empty Sella Syndrome: Definition, Diagnosis, and Management

Empty sella syndrome is a condition characterized by the flattening of the pituitary gland against the floor of the sella turcica (the bony structure that houses the pituitary gland), with the space being filled with cerebrospinal fluid (CSF). This can be detected on imaging studies, particularly MRI, which is the gold standard for diagnosis 1.

Types and Causes

Empty sella can be classified into two types:

• Primary Empty Sella (PES): Occurs without any history of previous pituitary pathologies 2. It is considered idiopathic and may be associated with idiopathic intracranial hypertension.

• Secondary Empty Sella: Occurs after treatment of pituitary tumors (surgery, medication, or radiotherapy), spontaneous necrosis of adenomas, pituitary infections, autoimmune diseases, or brain trauma 2.

Diagnosis

Imaging

• MRI with high-resolution pituitary protocols: Gold standard for diagnosis 3, 1

  • Shows flattened pituitary gland against the sellar floor
  • CSF-filled sella turcica
  • Can confirm absence or ectopia of the posterior pituitary gland
  • Can characterize empty sella even without IV contrast 3

• CT: Less sensitive than MRI but may show sellar enlargement 1

  • May detect solid lesions but can miss cystic tumors
  • Not recommended as first-line imaging 3

Prevalence and Clinical Significance

• Incidence is approximately 12% in neuroimaging studies, but can reach up to 35% in clinical practice 4
• Most cases are incidental radiological findings without clinical manifestations 4, 5

Clinical Presentation

Empty sella can present in several ways:

1. Asymptomatic: Most commonly, it's just an incidental finding on brain imaging 5

2. Empty Sella Syndrome: When accompanied by:

   • Endocrine disorders (19-40% of patients have at least one hormone deficit) 4
   • Neurological symptoms
   • Ophthalmologic symptoms

3. Specific symptoms may include:

   • Hormonal deficiencies (hypothyroidism, hypoadrenalism, hypogonadism) 6
   • Headaches
   • Visual disturbances
   • Rarely, sinus bradycardia (as reported in one case) 7

Evaluation

For patients with empty sella finding:

• Hormonal evaluation: Essential at the time of diagnosis 4

  • Up to 40% of patients may have at least one hormone deficiency 1
  • Test for pituitary hormones (TSH, ACTH, GH, LH/FSH)

• Ophthalmologic examination: To assess for papilledema, especially if idiopathic intracranial hypertension is suspected 1

• Blood pressure measurement and assessment for symptoms of hormone deficiencies 1

Management

Management depends on whether the patient is symptomatic:

• Asymptomatic Empty Sella:

  • Good prognosis with little impact on quality of life 5
  • Follow-up evaluation at 24-36 months due to low risk of progression 4

• Symptomatic Empty Sella (Empty Sella Syndrome):

  • Hormone replacement therapy based on specific deficiencies:

    • Levothyroxine for hypothyroidism
    • Cortisone acetate for hypoadrenalism
    • Growth hormone replacement if deficient
    • Sex hormone replacement for hypogonadism 1

  • Important: In patients with both adrenal insufficiency and hypothyroidism, steroids should be started before thyroid hormone replacement to avoid adrenal crisis 1

Follow-up

• Regular endocrine evaluation is necessary to monitor for development of new hormonal deficiencies 1
• Multidisciplinary approach involving endocrinology, neurology, and ophthalmology is recommended for proper management 2

Prognosis

• Most patients with partial empty sella have a good prognosis and remain asymptomatic 1
• The majority of patients never become symptomatic, and if symptoms do arise, they usually have little impact on quality of life 5

Common Pitfalls and Caveats

1. Missing hormonal deficiencies: Up to 30% of patients with empty sella may have hypopituitarism requiring treatment 1

2. Incorrect treatment sequence: In patients with both adrenal insufficiency and hypothyroidism, starting thyroid replacement before steroids can precipitate an adrenal crisis 1

3. Overlooking secondary causes: In atypical presentations, secondary causes of increased intracranial pressure should be thoroughly investigated 1

4. Inadequate follow-up: Even asymptomatic patients should be reevaluated after 24-36 months due to potential for developing symptoms 4