What is pituitary apoplexy?

Pituitary Apoplexy: A Life-Threatening Endocrine Emergency

Pituitary apoplexy is a rare but potentially life-threatening endocrine emergency characterized by acute hemorrhage or infarction of the pituitary gland, typically occurring within a pre-existing pituitary adenoma, presenting with sudden-onset severe headache, visual disturbances, nausea, vomiting, and potentially altered consciousness. 1

Clinical Presentation

Pituitary apoplexy typically presents with:

• Sudden-onset severe headache (frontal or retro-orbital)
• Visual disturbances (including bitemporal hemianopsia)
• Nausea and vomiting
• Photophobia
• Altered mental status or decreased level of consciousness
• Signs of meningeal irritation
• Ophthalmoplegia or diplopia 2

The condition occurs more frequently in men aged 50-60 years but can develop at any age, including during pregnancy or postpartum periods. It is rare in children and adolescents but can be more severe when it occurs in pediatric populations 3, 1.

Pathophysiology and Risk Factors

Pituitary apoplexy results from:

• Hemorrhage and/or infarction within the pituitary gland
• Most commonly occurs in pre-existing pituitary adenomas (particularly macroadenomas)
• Can occasionally occur in previously normal pituitary glands

Risk factors include:

• Surgery
• Pregnancy
• Medications (including GnRH agonists)
• Systemic conditions
• Rapid tumor growth exceeding blood supply 1, 4

Diagnosis

Imaging

• MRI is the gold standard for diagnosing pituitary apoplexy 5
• CT scan may be used if MRI is unavailable

Laboratory Assessment

• Complete pituitary hormone assessment:
  • Morning cortisol and ACTH
  • TSH and free T4
  • Gonadotropins
  • Prolactin
• Serum sodium and electrolytes (may show abnormalities in severe cases) 5

Management

Management should follow a structured approach based on clinical presentation:

Immediate Management

1. Hemodynamic stabilization
2. Immediate initiation of intravenous methylprednisolone 1 mg/kg after obtaining blood samples for pituitary axis assessment 5
3. Correction of electrolyte abnormalities
4. Replacement of hormonal deficiencies (cortisol replacement should precede thyroid replacement) 5, 6

Definitive Treatment

For severe or progressive symptoms:

• Urgent transsphenoidal surgery is recommended for patients with:
  • Severe or progressive visual impairment
  • Altered consciousness
  • Neurological deterioration
• Surgery should preferably be performed within seven days of symptom onset
• Endoscopic approach is preferred when available 5

For stable patients:

• Conservative management with:
  • Intravenous glucocorticoids
  • Monitoring of fluid and electrolyte levels
  • Regular assessment of pituitary function 1

Approximately 70% of patients require surgery, while about one-third can be managed conservatively 1.

Post-Acute Management

• Oral prednisolone (0.5-1 mg/kg once daily) for patients with headache without visual disturbance who are hemodynamically stable
• Conversion to oral prednisolone with gradual weaning over 4 weeks to 5 mg maintenance dose 5
• Regular monitoring of pituitary function and visual fields

Long-Term Follow-Up

• Long-term follow-up by a multidisciplinary team with expertise in pituitary pathology
• Monitoring for water and electrolyte disturbances (high risk of diabetes insipidus [26%] and SIADH [14%]) 5
• Patient education on "sick day rules" for steroid adjustment
• Medical alert identification for patients with adrenal insufficiency 5

Prognosis

• Hormone deficiencies resulting from structural damage to the pituitary are typically permanent and require lifelong replacement therapy 5
• Approximately 70% of patients with moderate to intense headaches show improvement after transsphenoidal surgery 5
• Early diagnosis and treatment are crucial to prevent severe neurological and endocrine sequelae 4

Special Considerations

• In children and adolescents, pituitary apoplexy can be more severe than in adults, and selected patients might benefit from early surgery 3
• Clinicians should maintain a high index of suspicion for pituitary apoplexy in patients presenting with acute neurological or endocrine symptoms, especially following administration of medications like GnRH agonists 4
• Pituitary apoplexy can mimic meningitis or subarachnoid hemorrhage, making it a challenging diagnosis 7