Makindo Medical Notes

Related Subjects: |Male Infertility |Prolactin |Prolactinoma |Sheehan's syndrome |Acromegaly and Giantism

Empty Sella Syndrome involves the flattening or shrinking of the pituitary gland within the sella turcica, often discovered incidentally during imaging studies. While most cases are asymptomatic with normal pituitary function, thorough evaluation is essential to rule out underlying conditions.

About Empty Sella Syndrome

Empty Sella Syndrome is a condition characterized by the herniation of cerebrospinal fluid (CSF) into the sella turcica, which results in the pituitary gland appearing flattened or partially absent on imaging studies. This condition can be primary or secondary and is often discovered incidentally during neuroimaging for unrelated reasons. While the majority of individuals with Empty Sella Syndrome maintain normal pituitary function, a small percentage may exhibit hormonal deficiencies or other clinical symptoms.

• An enlarged sella filled with CSF gives the appearance of an "empty" sella turcica.
• Most patients are female (80%), with a high prevalence in obese individuals (70%) and those with hypertension (30%).
• Pituitary function remains normal in approximately 90% of cases.

Anatomy

• The sella turcica is a saddle-shaped depression located in the sphenoid bone at the base of the skull.
• It houses the pituitary gland, a critical endocrine organ responsible for regulating various hormonal functions.
• The sellar diaphragm is a small membrane that covers the sella turcica; an incomplete diaphragm can facilitate the herniation of CSF.

Causes

• Primary Causes:
  • Defective or enlarged sellar diaphragm opening.
  • Herniation of the subarachnoid space into the sella turcica.
  • Raised intracranial pressure (ICP).
  • Developmental defects affecting the structure of the sella turcica.
• Secondary Causes:
  • Post-infarction, hemorrhage, or apoplexy affecting the pituitary gland.
  • Neurosurgical interventions or radiotherapy targeting the sellar region.
  • Postpartum pituitary necrosis, known as Sheehan's syndrome.
  • Idiopathic intracranial hypertension (pseudotumor cerebri).

Clinical Presentation

• Primary Disease:
  • Typically seen in middle-aged women.
  • Often asymptomatic and clinically insignificant.
  • May present with chronic headaches in some cases.
  • Can cause secondary hyperprolactinemia due to pituitary stalk effect, leading to galactorrhea or menstrual irregularities.
• Secondary Disease:
  • Hypopituitarism resulting from the underlying cause (e.g., hemorrhage, infarction).
  • Cerebral diabetes insipidus presenting with polyuria and polydipsia.
  • Symptoms depend on the extent of pituitary dysfunction.

Investigations

• Laboratory Tests:
  • Complete Blood Count (CBC), Urea & Electrolytes (U&E), Liver Function Tests (LFT), C-Reactive Protein (CRP), and Glucose levels to assess overall health and exclude other conditions.
  • Pituitary Function Tests including cortisol, Thyroid Function Tests (TFT), prolactin (PRL), estrogen, testosterone, and Growth Hormone (GH) levels to evaluate hormonal status.
  • Prolactin levels may be elevated due to the stalk effect, where inhibition of prolactin secretion is disrupted.
• Imaging Studies:
  • Magnetic Resonance Imaging (MRI) of the Pituitary: Preferred imaging modality for detailed visualization of the sella turcica, pituitary gland, and surrounding structures.
  • Computed Tomography (CT) Scan: Used if MRI is contraindicated or unavailable, though it is less sensitive for soft tissue evaluation.
• Visual Field Testing (Perimetry): Performed if there is concern about visual defects due to mass effect or optic nerve compression.

Management

• Hormonal Replacement: Necessary if there is evidence of hypopituitarism. This may include:
  • Glucocorticoids for adrenal insufficiency.
  • Thyroid hormones for hypothyroidism.
  • Sex hormones (estrogen or testosterone) for gonadal insufficiency.
  • Desmopressin for diabetes insipidus.
• No Treatment Needed:
  • In cases where pituitary function is normal and the patient is asymptomatic, no specific treatment is required.
  • Regular monitoring is recommended to detect any changes in pituitary function over time.
• Monitoring:
  • Lifetime monitoring of pituitary function is advised to identify and manage any emerging hormonal deficiencies.
  • Periodic imaging may be necessary in cases with secondary Empty Sella to monitor structural changes.
• Address Underlying Causes:
  • In secondary Empty Sella, managing the primary condition (e.g., controlling intracranial pressure, treating pituitary necrosis) is essential.
  • Early intervention in cases of Sheehan's syndrome or idiopathic intracranial hypertension can prevent further complications.

Prognosis

• Primary Empty Sella:
  • Generally favorable, with most individuals maintaining normal pituitary function and experiencing no significant clinical symptoms.
  • Some may develop mild hormonal imbalances over time, necessitating regular monitoring.
• Secondary Empty Sella:
  • Prognosis depends on the underlying cause and the extent of pituitary damage.
  • With appropriate hormonal replacement and management of the primary condition, individuals can lead normal lives.
  • Chronic hypopituitarism may require lifelong hormone therapy and regular follow-up.

Conclusion

Empty Sella Syndrome is a structural abnormality of the sella turcica that can be primary or secondary in nature. While most cases are asymptomatic with normal pituitary function, it is crucial to perform a comprehensive evaluation to rule out underlying conditions that may affect endocrine health. Early detection and appropriate management, especially in secondary cases, are essential to prevent complications related to pituitary hormone deficiencies. Regular monitoring ensures timely intervention and maintenance of optimal hormonal balance.

References

• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Empty Sella Syndrome. Available at: https://www.niddk.nih.gov
• Mayo Clinic. Empty Sella Syndrome. Available at: https://www.mayoclinic.org
• Garcia, S. A., & Kennedy, E. B. (2000). Primary Empty Sella Syndrome: A Series of 40 Cases. Neurosurgery.
• Hildebrandt, T., & Ossewaarde, J. M. (2013). Empty Sella Syndrome: An Overview. Journal of Neurology, Neurosurgery & Psychiatry.
• Rocha, A., et al. (2016). Empty Sella Syndrome: Clinical Features and Management. Endocrine Connections.
• American Association of Neurological Surgeons (AANS). Empty Sella. Available at: https://www.aans.org