The headaches have gradually decreased over the next few hours. A magnetic resonance imaging (MRI) scan of the brain is obtained (Fig. 11.2).

An MRI is obtained a few weeks later (Fig. 11.3).

• Pituitary apoplexy
  
• This condition typically presents with sudden onset, evolving within hours to 1 or 2 days. It includes severe headaches associated with nausea, vomiting, and/or decreased level of consciousness. It may be accompanied by impairment of visual acuity, restriction of visual fields, ophthalmoplegia, and endocrinologic deficits.1–3
  
• Although some authors describe pituitary apoplexy as having a more subtle onset or even occurring as clinically silent,⁴ for the majority pituitary apoplexy is characterized by acute symptoms with patients seeking emergent medical attention.^1–3

• The history should include questions regarding symptoms and signs resulting from sudden and fulminant expansion of the pituitary tumor (which may be due to hemorrhage, infarction, or hemorrhagic infarction).
  
• Hypocortisolism resulting from destruction or compression of the pituitary gland
  
• Impairment of visual acuity or fields and ophthalmoplegia resulting from compression of neural structures when the sudden enlargement is superior or lateral
  
• Meningismus due to leakage of blood and necrotic tissue in the subarachnoid space
  
• Look for precipitating factors (refer to Question 9).
  
• Symptoms and signs related to the presence of a secreting or nonsecreting (hypopituitarism) pituitary tumor
  
• Differential diagnosis involves most commonly subarachnoid hemorrhage, followed by meningitis.^1,5

• Hypopituitarism is present in the majority of patients who present with apoplexy^1,2 and requires rapid initiation of steroid replacement to avoid an adrenal crisis.
  
• Urgent surgical decompression is not necessary if the patient is neurologically intact with no visual impairment.
  
• MRI should be obtained to confirm the suspected diagnosis and visualize the underlying pathology.
  
• Send endocrine laboratory panel including prolactin, luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone, T₃, T₄, AM cortisol, and insulin-like growth factor-1. Also obtain endocrinology consultation to assist in management.
  
• Obtain ophthalmologic consultation to document visual-field deficit.
  
• Magnetic resonance angiography may also be obtained if subarachnoid hemorrhage is suspected to rule out the possibility of aneurysm.

• The MRI (Fig. 11.2) reveals a pituitary tumor with a suprasellar extension containing mixed intensities suggestive of an acute intratumoral hemorrhage.
  
• Neurologic and neuro-ophthalmologic examinations are normal, and a large part of the tumor appears necrotic. Hence, conservative management is justified: obtain follow-up MRI in a few weeks provided the patient remains stable.

• Opinions may vary among different authors.
  
• Urgent decompression is required for sudden onset of blindness, for progressive deterioration of vision, or for neurologic deterioration due to hydrocephalus.
  
• Surgery is indicated for decreased level of consciousness and for hypothalamic dysfunction. It is also required for impairment of visual acuity, constriction of visual fields, or progressive deterioration of oculomotricity. For visual impairment, surgery is recommended within the first week.³
  
• Ventricular drainage may be necessary in the presence of hydrocephalus.

• The MRI (Fig. 11.3) reveals a complete disappear ance of the tumor. Sporadic cases of pituitary apoplexy cured by isolated medical treatment have been reported.⁶

• This is controversial. For the majority of cases, it results from hemorrhage, infarction, or hemorrhagic infarction of a pituitary tumor secondary to its rapid growth.¹ This may be due to a discrepancy between the rate of neoplastic progression and the availability of circulatory input. However, although pituitary apoplexy typically occurs in pituitary macroadenomas, small tumors also hemorrhage.⁷ One theory suggests intrinsic vasculopathy of the pituitary adenoma with secondary susceptibility to infarction and hemorrhage.⁸
  
• Most patients had an undiagnosed pituitary adenoma at the time of apoplexy presentation.⁹ Although pituitary apoplexy occurs most of the time in pituitary adenomas, it may also occur in^1,2
  
  
  
  • Healthy pituitary gland
    
  • Pituitary abscess
    
  • Metastatic tumor
    
  • Lymphocytic hypophysitis
    
  • Craniopharyngioma

• Precipitating factors are identified in ~50% of cases.⁴ There is no preponderance of tumor type.¹⁰ Precipitating factors that have been involved include¹⁰
  
  
  
  • Treatment with bromocriptine
    
  • Treatment with anticoagulants
    
  • Stimulation tests of hormonal therapy with gonadotrophin-releasing hormone agonists
    
  • Thrombocytopenia
    
  • Reduced blood flow in the gland: head trauma, recent surgery
    
  • Pregnancy

• Pituitary apoplexy is a potentially life-threatening condition, but the overall outcome with appropriate management is good.^5,9
  
  
  
  • Visual acuity: Outcome is related to duration, severity of the initial defect, appearance of the optic disk, and timing of decompression.^1,11 However, even complete blindness may have remarkable improvement if surgical decompression is undertaken early.¹²
    
  • Ophthalmoparesis is reported to have good outcome whether treated conservatively or with surgical decompression.⁸
    
  • Endocrine function: The majority of patients require endocrine replacement therapy.^1,3,8,9
  
  
• Thickening of the sphenoid sinus mucosa during acute pituitary apoplexy may represent an indirect measure of increased intrasellar pressure. This finding has been associated with higher grades of apoplexy, larger tumors with compression of parasellar structures, and worse endocrinologic and neurologic outcomes.¹³
  
• Recurrent apoplexy has been documented in patients managed conservatively after their first apoplectic event but rarely after surgical treatment of the initial episode.³