What is the most likely diagnosis for a patient with headache, altered mental status, bilateral lateral vision loss, and hypotension?

Pituitary Apoplexy

The most likely diagnosis is pituitary apoplexy (option d), which classically presents with sudden severe headache, altered mental status, bitemporal hemianopsia (bilateral lateral vision loss), ophthalmoplegia (downward and lateral eye deviation), and hypotension due to acute adrenal insufficiency from pan-hypopituitarism. 1, 2, 3

Clinical Presentation Matches Classic Pituitary Apoplexy

The constellation of symptoms described is pathognomonic for pituitary apoplexy:

• Sudden severe headache is present in 97% of cases and is the most common presenting symptom 2
• Altered mental status occurs as part of the classic syndrome resulting from hemorrhagic infarction of a pituitary adenoma 1, 3
• Bitemporal hemianopsia (bilateral lateral vision loss) occurs in 71% of cases due to compression of the optic chiasm by the rapidly expanding hemorrhagic pituitary mass 2
• Ophthalmoplegia with downward and lateral eye deviation indicates cranial nerve involvement, particularly CN III palsy, which is characteristic of pituitary apoplexy 1, 3
• Hypotension is a critical finding indicating acute adrenal insufficiency from pan-hypopituitarism, which occurs with high incidence in pituitary apoplexy 1, 4

Why Other Options Are Incorrect

Pituitary adenoma (option a) without apoplexy would not present acutely with altered mental status and hypotension. Adenomas typically cause gradual visual field defects over months to years, not sudden onset with hemodynamic instability 2

Sheehan syndrome (option b) occurs postpartum in women with severe hemorrhage and hypotension during delivery, causing pituitary infarction. This patient's presentation lacks obstetric context, and Sheehan syndrome does not typically present with acute severe headache, ophthalmoplegia, or sudden visual loss 4

Craniopharyngioma (option c) is a slow-growing tumor that causes gradual visual field defects and endocrine dysfunction over time, not acute catastrophic presentation with altered mental status and hypotension 2

Pathophysiology and Risk Factors

Pituitary apoplexy results from hemorrhagic infarction of a pituitary adenoma (most commonly null-cell adenomas in 61% of cases), though it can rarely occur in normal glands 2, 3. The pathophysiology involves tumor overgrowth of its blood supply, leading to sudden hemorrhage or infarction 4

Hypertension is an important predisposing factor, present in 26% of cases at presentation 2. Other risk factors include thrombocytopenia, anticoagulation, systemic factors, and iatrogenic causes 4, 5

Immediate Management Algorithm

1. Hemodynamic stabilization with IV fluids and vasopressors if needed 4
2. Immediate high-dose corticosteroid replacement (hydrocortisone 100 mg IV every 6-8 hours) due to high incidence of acute adrenal insufficiency—this is essential and potentially life-saving 1, 4
3. Correct electrolyte abnormalities, particularly hyponatremia 4
4. Urgent MRI imaging (not CT)—MRI correctly identifies pituitary hemorrhage in 88% of cases versus only 21% for CT 2
5. Emergent neurosurgical consultation for transsphenoidal decompression if visual deficits are present 2, 4

Surgical Timing Is Critical

Transsphenoidal surgery performed within 8 days results in complete restoration of visual acuity in 100% of patients, compared to only 46% when surgery is delayed beyond 8 days 2. Surgery improves visual acuity in 86% overall and is indicated for any visual field defects or visual acuity abnormalities 2

Common Pitfalls to Avoid

• Do not delay corticosteroid replacement while awaiting imaging or surgical intervention—acute adrenal crisis is life-threatening 1, 4
• Do not rely on CT scanning alone—it misses pituitary hemorrhage in 79% of cases; MRI is the imaging method of choice 2
• Do not assume normal initial imaging excludes the diagnosis—repeat imaging may be necessary if clinical suspicion remains high 5
• Do not overlook thrombocytopenia or coagulopathy as precipitating factors, particularly in patients with hematologic malignancies or on anticoagulation 5

Long-term Endocrine Sequelae

Following pituitary apoplexy, long-term hormone replacement is frequently required: 58% need steroid replacement, 45% need thyroid hormone, 43% of males need testosterone, and 6% require desmopressin for diabetes insipidus 2. Annual pituitary imaging is indicated as tumor recurrence occurs in approximately 6% of cases 2