Overview
Recognise acute haemorrhage or infarction within a pituitary lesion, give life-saving cortisol support, document neuro-ophthalmic severity and coordinate urgent MRI and specialist decompression decisions.
Apoplexy often presents as a thunderclap or rapidly peaking retro-orbital headache. Blood and necrotic tissue expand within the confined sella, compressing optic pathways and cavernous sinus nerves. Chemical irritation can mimic meningitis, while hypothalamic involvement or raised pressure may alter consciousness. A normal neurological examination early does not make the syndrome safe to observe without imaging.
Acute cortisol deficiency is the main endocrine threat. ACTH loss impairs vascular tone and stress response, producing hypotension, hyponatraemia and hypoglycaemia. TSH, gonadotrophin and growth hormone axes may also fail, but glucocorticoid is prioritised. Diabetes insipidus is less common initially and may become apparent after cortisol replacement unmasks free-water loss.
Not all confirmed cases require immediate surgery. A medically stable patient with preserved or improving vision may be monitored by a specialist team, while severe or progressive visual loss and consciousness deterioration favour early decompression. The decision depends on repeated objective examinations, MRI and local neurosurgical expertise rather than a one-time headache score.
Key points
- Pituitary apoplexy is a clinical emergency caused by haemorrhage or infarction in the pituitary, usually within an adenoma; imaging haemorrhage without an acute syndrome is not synonymous with apoplexy.
- Think of it in sudden severe headache with visual acuity or field loss, diplopia, ptosis, vomiting, meningism, photophobia or reduced consciousness, even when no pituitary tumour was previously known.
- Exclude subarachnoid haemorrhage and meningitis in parallel, but do not let an unrevealing routine head CT close the diagnosis because pituitary MRI is more sensitive.
- Draw cortisol and the broader pituitary panel before glucocorticoid only when this creates no treatment delay; haemodynamic instability or major neuro-ophthalmic compromise requires empirical hydrocortisone.
- Society for Endocrinology emergency guidance supports hydrocortisone 100 to 200 mg intravenously as an adult bolus followed by infusion or divided parenteral treatment under the acute protocol.
- Record acuity, colour, pupils, ocular movements and fields serially; deterioration, severe persistent visual deficit or reduced consciousness strengthens the case for urgent transsphenoidal decompression.
Aetiology
Haemorrhage into a pituitary lesion
Bleeding within an often previously unrecognised pituitary adenoma abruptly expands sellar contents and compresses surrounding structures.
Pituitary infarction
Loss of blood supply can cause necrosis and swelling within enlarged pituitary tissue, producing the same acute neuro-endocrine syndrome.
Physiological or treatment-related stress
Major illness, surgery, haemodynamic change or anticoagulation may accompany an event, although a clear precipitant is not always found.
Pathophysiology
- 1Sellar tissue acutely expands
Haemorrhage or infarction increases pressure within the confined sella and causes a sudden severe retro-orbital or thunderclap headache.
- 2Visual pathways are compressed
Upward and lateral expansion affects the optic chiasm and cavernous sinus nerves, causing field loss, acuity change, diplopia or ophthalmoplegia.
- 3ACTH secretion fails
Acute corticotroph damage reduces cortisol stress response, impairing vascular tone and contributing to hypotension, hyponatraemia and hypoglycaemia.
- 4Neurological pressure effects progress
Meningeal irritation, hypothalamic involvement or raised intracranial pressure can produce vomiting, neck stiffness, confusion and reduced consciousness.
Clinical features and red flags
Sudden severe retro-orbital or frontal pain is usually the earliest feature and may be accompanied by nausea, vomiting, photophobia or neck stiffness.
Reduced acuity, colour desaturation, bitemporal or other field loss and a relative afferent pupillary defect indicate anterior visual pathway involvement.
Third-nerve dysfunction with ptosis and a poorly reactive pupil, or fourth- and sixth-nerve palsies, can arise from cavernous sinus expansion.
Hypotension, prostration, vomiting, hyponatraemia and hypoglycaemia may reflect sudden ACTH deficiency rather than pain or intracranial pathology alone.
Drowsiness, confusion or collapse can result from haemodynamic failure, electrolyte disturbance, hypothalamic compression or raised intracranial pressure.
Major surgery, anticoagulation, pregnancy, dynamic pituitary tests, hypertension or dopamine-agonist initiation may precede apoplexy, although many cases have no identified trigger.
Investigations
- 01
Urgent pituitary MRIFirst step - Why
- Confirm sellar haemorrhage or infarction and show compression of optic, cavernous and hypothalamic structures.
- Interpretation and limitations
- MRI is the preferred study; sequences and signal evolve with blood age, so expert neuroradiology review is needed when clinical suspicion remains high.
- 02
Emergency head CT - Why
- Evaluate subarachnoid haemorrhage and other acute intracranial causes when MRI is not immediately available.
- Interpretation and limitations
- CT may show a hyperdense expanded sella but has lower sensitivity for apoplexy; a negative routine scan does not remove the need for pituitary MRI.
- 03
Baseline endocrine bloods - Why
- Capture cortisol, free T4, TSH, prolactin, IGF-1, gonadotrophins and sex hormones before treatment where safe.
- Interpretation and limitations
- Results map later replacement, but a normal or pending cortisol must not defer empirical hydrocortisone in an unstable or visually compromised patient.
- 04
Formal neuro-ophthalmic assessment - Why
- Quantify acuity, fields, colour, pupils and ocular movements for serial treatment decisions.
- Interpretation and limitations
- Trend is crucial: objective deterioration supports decompression, while stable or improving deficits can inform carefully monitored conservative care.
- 05
Differential diagnosis
Subarachnoid haemorrhage
Thunderclap headache, meningism and reduced consciousness overlap; urgent neuroimaging distinguishes aneurysmal bleeding from a sellar event.
Meningitis
Fever, headache, photophobia and neck stiffness suggest infection, while visual-field loss, ophthalmoplegia and sellar MRI findings favour apoplexy.
Migraine
A prior stereotyped pattern with full recovery is reassuring, but new severe headache with ocular motor or endocrine signs requires emergency imaging.
Cavernous sinus disease
Painful ophthalmoplegia can arise from thrombosis, infection or tumour; visual, systemic and imaging features localise the lesion.
Management
01FIRSTFirst hour of suspected apoplexyFirst stepAcute severe headache is accompanied by visual, ocular-motor, meningeal or consciousness change.+
- 1Perform ABCDE assessment, bedside glucose, neurological and focused visual examination while establishing intravenous access and monitoring.
- 2Draw cortisol and other pituitary samples if immediately available, then give empirical parenteral hydrocortisone for instability or significant neuro-ophthalmic features.
- 3Correct circulatory and glucose disturbance, assess sodium and pursue emergency subarachnoid haemorrhage or meningitis treatment in parallel when indicated.
- 4Contact the regional endocrine-neurosurgical team early and obtain urgent pituitary MRI, using dedicated CT if MRI cannot be performed.
02WATCHSpecialist conservative managementThe patient is stable with preserved or improving vision and no deteriorating consciousness.+
Complications
Adrenal crisis
Acute ACTH deficiency can cause refractory hypotension, hypoglycaemia, hyponatraemia and death unless glucocorticoid treatment is given promptly.
Permanent visual loss
Sustained optic nerve or chiasmal compression can irreversibly damage acuity and fields if deterioration is not recognised and managed promptly.
Persistent hypopituitarism
Haemorrhage or necrosis can leave enduring cortisol, thyroid, gonadal and growth-hormone deficiencies, requiring structured replacement and long-term surveillance.
Vasopressin deficiency
Posterior pathway dysfunction may produce polyuria and hypernatraemia, sometimes becoming apparent only after cortisol replacement restores renal free-water clearance.
Monitoring and follow-up
- Record Glasgow Coma Scale, headache, acuity, fields, colour, pupils and ocular motility at a frequency matched to severity and any new complaint.
- Follow pulse, blood pressure, capillary glucose, sodium, renal function, input and urine output closely through steroid initiation and surgery.
- Repeat formal ophthalmic examination when management may change, avoiding undocumented statements such as vision seems better.
- After discharge, reassess all pituitary axes and replacement at four to six weeks because acute values and steroid exposure can mislead.
- Use interval MRI to monitor residual adenoma and recurrence, with earlier imaging for renewed headache, diplopia or field deterioration.
- Review steroid-emergency competence, quality of life, return to driving or employment and fertility concerns during longer-term pituitary follow-up.
Special situations
The syndrome defines apoplexy
Haemorrhagic change on an incidental MRI without acute headache or neuro-ophthalmic findings is not managed automatically as clinical pituitary apoplexy.
CT can answer the wrong emergency
An early CT may appropriately exclude a large subarachnoid bleed yet still miss the sellar infarction responsible for headache and visual loss.
Steroids can reveal polyuria
Cortisol deficiency reduces free-water clearance; replacing it may unmask underlying arginine vasopressin deficiency and a rising sodium.
Serial vision drives decisions
The direction of objective field and acuity change after stabilisation often matters more than the initial radiological haemorrhage volume alone.
Conservative does not mean passive
Non-operative care requires a setting capable of frequent examination, immediate endocrine treatment and rapid surgical conversion if deterioration occurs.
Common pitfalls
- 01
Do not wait for a low cortisol result before giving hydrocortisone to an unstable or severely visually affected patient.
- 02
Do not accept a normal routine head CT as exclusion of pituitary apoplexy when the clinical syndrome remains convincing.
- 03
Do not perform lumbar puncture for apparent meningism before intracranial mass and haemorrhage safety have been evaluated.
- 04
Do not base surgery solely on MRI appearance without repeated visual and consciousness assessment after medical stabilisation.
- 05
Do not overlook subarachnoid haemorrhage, meningitis and cavernous sinus pathology merely because a sellar lesion is visible.
- 06
Do not discharge after headache improves without cortisol cover, early pituitary and visual review, emergency teaching and tumour surveillance.