Pituitary apoplexy

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

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.
Stabilise fluid, sodium and glucose carefully because ACTH deficiency, vomiting and posterior-pituitary disturbance can all complicate the neurological presentation.
Every patient needs ongoing endocrine and neurosurgical follow-up, with repeat pituitary and visual assessment at four to six weeks and longer surveillance for tumour and hormonal outcomes.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

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.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Sellar tissue acutely expands
Haemorrhage or infarction increases pressure within the confined sella and causes a sudden severe retro-orbital or thunderclap headache.
2
Visual pathways are compressed
Upward and lateral expansion affects the optic chiasm and cavernous sinus nerves, causing field loss, acuity change, diplopia or ophthalmoplegia.
3
ACTH secretion fails
Acute corticotroph damage reduces cortisol stress response, impairing vascular tone and contributing to hypotension, hyponatraemia and hypoglycaemia.
4
Neurological pressure effects progress
Meningeal irritation, hypothalamic involvement or raised intracranial pressure can produce vomiting, neck stiffness, confusion and reduced consciousness.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

Acute headache

Sudden severe retro-orbital or frontal pain is usually the earliest feature and may be accompanied by nausea, vomiting, photophobia or neck stiffness.

Optic compromise

Reduced acuity, colour desaturation, bitemporal or other field loss and a relative afferent pupillary defect indicate anterior visual pathway involvement.

Ocular motor palsy

Third-nerve dysfunction with ptosis and a poorly reactive pupil, or fourth- and sixth-nerve palsies, can arise from cavernous sinus expansion.

Cortisol failure

Hypotension, prostration, vomiting, hyponatraemia and hypoglycaemia may reflect sudden ACTH deficiency rather than pain or intracranial pathology alone.

Altered consciousness

Drowsiness, confusion or collapse can result from haemodynamic failure, electrolyte disturbance, hypothalamic compression or raised intracranial pressure.

Precipitating context

Major surgery, anticoagulation, pregnancy, dynamic pituitary tests, hypertension or dopamine-agonist initiation may precede apoplexy, although many cases have no identified trigger.

Red flags requiring action

Haemodynamic instability, altered consciousness, reduced visual acuity or severe field defects are explicit indications for immediate empirical glucocorticoid in suspected apoplexy.
A fixed dilated pupil, rapidly declining vision or new dense ophthalmoplegia requires urgent neuro-ophthalmic and neurosurgical reassessment rather than waiting for the next ward round.
Meningism, fever or petechiae still requires antimicrobial and lumbar-puncture decision-making for meningitis; a pituitary lesion does not exclude infection.
Thunderclap headache needs the appropriate subarachnoid haemorrhage pathway in parallel because missing an aneurysmal bleed is catastrophic.
Polyuria, rising sodium or impaired thirst after steroid treatment signals emerging water-balance failure and requires closely supervised fluid and desmopressin decisions.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

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
Electrolytes glucose osmolality and fluid balance
Why
Detect adrenal, SIADH-like and diabetes-insipidus complications during the acute period.
Interpretation and limitations
Hyponatraemia has several mechanisms; urine volume and paired serum or urine osmolality become especially important after hydrocortisone changes water clearance.
06
Infection and haemorrhage assessment
Why
Evaluate alternative or precipitating diagnoses and procedural safety.
Interpretation and limitations
Full blood count, inflammatory markers, clotting, cultures and vascular imaging are selected clinically; anticoagulation reversal balances intracranial bleeding against thrombotic indication.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

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.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

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.

1Admit where frequent neurological, visual, fluid and electrolyte observation can be delivered with immediate specialist access.
2Continue glucocorticoid and supportive therapy, recording formal baseline and repeated visual findings rather than relying on subjective improvement.
3Review MRI, tumour type, comorbidity and patient preference jointly between endocrinology, neurosurgery and ophthalmology.
4Convert to surgery promptly if visual acuity, field, cranial nerves or consciousness worsens, and plan early outpatient reassessment if stability persists.

03DECOMPRESSUrgent surgical considerationSevere or persistent visual deficit, progressive neuro-ophthalmic signs or deteriorating consciousness follows stabilisation.

1Optimise haemodynamics and cortisol without delaying transfer to a pituitary neurosurgical centre with high-dependency support.
2Document objective visual severity immediately before intervention and discuss the realistic recovery and endocrine consequences with the patient or representative.
3Perform transsphenoidal decompression at timing determined by the specialist team and clinical trajectory, preserving tissue for expert pathology.
4Monitor postoperatively for cortisol deficiency, central hypothyroidism, sodium disturbance, CSF leak and diabetes insipidus.

04FOLLOWRecovery and surveillanceThe acute episode has stabilised after conservative or operative treatment.

1Reassess full pituitary and visual function at four to six weeks, adjusting replacement from valid tests and symptoms.
2Repeat MRI on the pituitary service schedule to assess residual tumour, haemorrhage resolution and future treatment need.
3Continue six- to twelve-month specialist follow-up initially, then individualise for recurrence, residual adenoma and lasting hormone deficits.
4Educate about adrenal crisis, sudden headache and visual recurrence, and address driving, work, fertility and psychological recovery.

Key medicines and prescribing safety3 treatments · regimens, roles and cautions

Treat acute ACTH-cortisol failure and support haemodynamic stability during pituitary apoplexy.

Emergency intravenous hydrocortisone

Give 100 to 200 mg intravenously as an initial adult bolus under Society guidance, followed by the local infusion or divided parenteral regimen.

Obtain endocrine samples first only when this is immediate and safe; monitor glucose, sodium and fluid, and never postpone treatment for imaging or laboratory confirmation.

Restore circulating volume in cortisol-related hypotension and vomiting while acute physiology is assessed.

Isotonic sodium chloride

Give monitored intravenous 0.9% sodium chloride according to haemodynamics, sodium, urine output and cardiac or renal reserve.

Avoid uncritical rapid volume in heart or renal failure and do not correct chronic severe hyponatraemia faster than the current local safety limits.

Maintain cortisol coverage while the damaged ACTH axis and residual pituitary function are reassessed.

Oral hydrocortisone after stabilisation

Step down from parenteral treatment to an endocrinologist-defined stress regimen, then physiological divided replacement when illness and absorption allow.

Do not stop on discharge without valid recovery testing; provide the emergency card, sick-day instructions and injection access before leaving hospital.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

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.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

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.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

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.

11Common pitfallsFrequent interpretation and management errors.

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.