What is Empty Sella Syndrome (ESS)?

Empty Sella Syndrome (ESS)

Empty Sella Syndrome is a radiographic finding characterized by the presence of cerebrospinal fluid in the sella turcica with compression of the pituitary gland, which can be asymptomatic or present with endocrine, ophthalmological, and neurological symptoms. 1, 2

Definition and Classification

• Empty Sella (ES): A radiological finding where the sella turcica is partially or completely filled with cerebrospinal fluid, causing compression of the pituitary gland
• Empty Sella Syndrome (ESS): The combination of this radiographic finding with clinical symptoms

ESS is classified into two types:

1. Primary Empty Sella (PES):

   • Idiopathic with no history of previous pituitary pathologies
   • Often associated with congenital deficiency of the sellar diaphragm
   • May be associated with idiopathic intracranial hypertension 3

2. Secondary Empty Sella:

   • Results from previous pituitary conditions or treatments:
     • Post-surgical intervention
     • Following radiotherapy
     • After medical treatment of pituitary tumors
     • Spontaneous necrosis of pituitary adenomas
     • Pituitary infectious or autoimmune diseases
     • Brain trauma 3

Prevalence and Epidemiology

• Incidence of approximately 12% on neuroimaging studies
• Can reach up to 35% in clinical practice 2
• Most commonly found incidentally during imaging for unrelated conditions 4
• Up to 30% of patients with empty sella may demonstrate some degree of hypopituitarism upon testing 1

Pathophysiology

The primary mechanisms include:

• Herniation of subarachnoid space into the sella turcica through a deficient sellar diaphragm
• Increased intracranial pressure causing downward herniation
• Spontaneous necrosis of a previous pituitary adenoma (explains many cases of enlarged empty sella) 5
• Pulsation of cerebrospinal fluid through a developmental or acquired dehiscence of the diaphragm sella 6

Clinical Presentation

Many cases are asymptomatic and discovered incidentally. When symptomatic (ESS), presentations may include:

• Endocrine abnormalities:

  • Hypopituitarism (19-40% of patients have at least one hormone deficit) 2
  • Hypogonadotropic hypogonadism 6
  • Hypothyroidism
  • Hypoadrenalism
  • Growth hormone deficiency

• Neurological symptoms:

  • Headaches
  • Visual disturbances (from compression of optic structures)
  • Rarely, spontaneous CSF rhinorrhea 7

• Ophthalmological findings:

  • Visual field defects
  • Papilledema (when associated with increased intracranial pressure)

Diagnostic Evaluation

Imaging

• MRI of the sella: Gold standard for diagnosis 2

  • Shows flattened pituitary gland against the sellar floor
  • CSF-filled sella turcica
  • High-resolution pituitary protocols are recommended 6
  • T1-weighted images can identify normal neurosecretory granules

• CT of the sella: Less sensitive than MRI

  • May show sellar enlargement
  • Can detect solid lesions but may miss cystic tumors 6

Laboratory Assessment

• Comprehensive hormonal evaluation is necessary:
  • Anterior pituitary function tests (TSH, ACTH, GH, FSH, LH, prolactin)
  • Target organ hormones (T4, cortisol, IGF-1, estradiol/testosterone)

Additional Evaluations

• Ophthalmologic examination (mandatory to assess for papilledema) 1
• Lumbar puncture (when increased intracranial pressure is suspected)
  • Diagnostic criterion: >250 mm CSF in adults or >280 mm CSF in children 1

Management

Management depends on the presence of symptoms and underlying cause:

Asymptomatic Empty Sella

• Regular monitoring
• Reevaluation at 24-36 months due to low risk of progression 2

Symptomatic Empty Sella Syndrome

• Hormone replacement therapy for specific deficiencies:

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

• Surgical intervention (rarely needed):

  • Reserved for cases with progressive visual deterioration or CSF rhinorrhea
  • Endoscopic transsphenoidal approach with sellar elevation using various materials 7

Prognosis

• Most patients with empty sella have a good prognosis
• The majority never become symptomatic
• If symptoms do arise, they usually have little impact on quality of life 4
• Regular endocrine evaluation is necessary to avoid overlooking patients with hypopituitarism requiring treatment 1

Common Pitfalls and Caveats

• Misdiagnosis: Empty sella can be mistaken for other sellar lesions
• Overlooking hormonal deficiencies: Up to 40% of patients may have at least one hormone deficiency that requires treatment 1, 2
• Failure to distinguish between primary and secondary empty sella: Different management approaches are needed
• Inadequate follow-up: Even asymptomatic cases require periodic reassessment
• Missing underlying pathology: Empty sella may be secondary to a pituitary adenoma that underwent spontaneous necrosis 5