empty sella syndrome (ESS)

Introduction

empty sella is usually an incidental finding seen in some patients on CT brain scan
it implies that the pituitary is either shrunken or displaced from the sella turcica by subarachnoid fluid due to raised intracranial pressure with herniation of the arachnoid space into pituitary fossa through a deficient diaphragm, found in 20% of the population
partial empty sella refers to a sella turcica filled less than 50% with CSF, and complete empty sella refers to a sella filled to more than 50% with CSF

primary idiopathic empty sella
- congenital incompetent diaphragm sellae is thought to be a potential pathophysiologic cause of primary empty sella
secondary empty sella
- idiopathic intracranial hypertension hence incidence higher in females, obesity
  - most have ESS - usually partial ¹⁾
  - other radiologic features that are suggestive of this cause²⁾:
    - optic nerve sheath distension
    - posterior globe flattening
    - optic nerve tortuosity in vertical or horizontal planes
    - papilledema/optic nerve head protrusion
    - optic nerve head enhancement
    - Meckel cave enlargement
    - arachnoid pits (aberrant arachnoid granulations) / small meningoceles, typically within the temporal bone and sphenoid wing
    - enlarged oculomotor cistern
    - prominent perivascular spaces
    - transverse sinus stenosis
    - acquired cerebellar tonsillar ectopia
    - slit-like ventricles
    - increased subcutaneous fat thickness in the scalp and neck (a slim patient is unlikely to develop idiopathic intracranial hypertension)
- pituitary infarction - Sheehan's syndrome
- trauma / surgery / radiation / etc

cystic pituitary macroadenoma
- may produce hyperprolactinaemia and galactorrhoea
arachnoid cyst
Rathke's cleft cyst
craniopharyngioma
epidermoid cyst

asymptomatic
may have headaches associated with benign raised intracranial hypertension if this is the cause
hypopituitarism
- hyperprolactinaemia is present in 10% to 17% of cases resulting from a microprolactinoma or functional hyperprolactinemia ³⁾
- growth hormone deficiency is identified in 4% to 60% of patients, but the clinical significance in adults is unclear ⁴⁾
  - consider screening with early morning fasting cortisol levels
- gonadotropin deficiency is seen in 2% to 32% of patients
- adrenocorticotropin, thyroid-stimulating hormone, and antidiuretic hormone deficiencies are seen in about 1% of individuals with empty sella
  - consider morning levels of TSH, T4

¹⁾

²⁾

³⁾ , ⁴⁾