Pituitary apoplexy: sudden headache, vision change and urgent treatment

The pituitary is a small gland at the base of the brain that controls many of the body's hormones. Pituitary apoplexy happens when part of it bleeds (haemorrhage) or when an area of tissue dies because of a lack of blood supply (infarction). The Pituitary Foundation explains that this usually happens in association with a pituitary tumour, which is nearly always benign.

The sudden swelling raises pressure in the small bony space around the gland. That pressure can squeeze the optic nerves and the nerves that move the eyes, and it can stop the gland producing hormones such as ACTH, which controls cortisol. In women who have a severe blood loss during or immediately after childbirth, a similar problem is called Sheehan's syndrome.

The condition is uncommon. The Pituitary Foundation says the true frequency is difficult to estimate, but an estimated prevalence is about 6 in every 100,000 people, and that in people without a known pituitary tumour it is very rare.

The Pituitary Foundation says the most frequent cause is bleeding into a pre-existing benign pituitary tumour or death of an area of tissue in the pituitary as a result of the tumour. In many cases the tumour is undiagnosed and the apoplexy is the first sign.

• High blood pressure.

• Major surgery, particularly heart surgery.

• Having had dynamic pituitary function tests recently.

• Blood-thinning medicines (anticoagulants).

• A history of radiotherapy to the pituitary gland.

• Pregnancy.

• Head injury.

• Rarely, a sudden, severe and prolonged drop in blood pressure in a previously normal gland.

Symptoms usually appear within hours and are caused by the build-up of pressure around the gland. The Pituitary Foundation lists a severe, sudden-onset headache, nausea and vomiting, paralysis affecting movements of the eyes, visual impairment including double vision or loss of part of the visual field, and decreased consciousness.

A thunderclap headache with vision change or drooping of an eyelid, drowsiness or confusion is a reason to call 999 or go to A&E. The NHS says to call 999 for signs of stroke, and sudden vision loss with severe headache should be assessed in the same urgent way. Do not wait to see whether symptoms settle.

Hormone deficiency can add to the emergency. The NHS describes adrenal crisis in Addison's disease as the most serious complication, where symptoms get worse very quickly with severe dehydration, low blood pressure, seizures or loss of consciousness, and it is treated with an injection of steroid medicine. Low cortisol after apoplexy is treated with similar urgency.

When pituitary apoplexy is suspected, the Pituitary Foundation says urgent hospital admission is required. Initial assessment includes a detailed history, a physical examination including cranial nerves and visual fields, and blood tests of pituitary hormones.

An urgent MRI scan is carried out on all patients with suspected apoplexy and provides a diagnosis in over 90% of patients. CT scans are used only if the MRI does not give a clear result or is not possible, since a CT provides a conclusive diagnosis in only 21 to 28% of patients.

If adrenal insufficiency is suspected, patients immediately receive intravenous and intramuscular cortisol replacement in anticipation of the test results.

The first priority is to stabilise the patient and give cortisol replacement if needed, which both treats adrenal insufficiency and helps to reduce swelling of the gland. After that there are two main approaches, chosen by a multidisciplinary team including endocrinology, neurosurgery and ophthalmology.

The Pituitary Foundation says many patients who suffer a pituitary apoplexy go on to make a full recovery, but all require long-term management, the details of which depend on the underlying tumour and the success of treatment. As standard, it says patients should have a full endocrine review at 4 to 8 weeks, an MRI scan at 3 to 6 months and an annual clinical review, preferably in a joint endocrine and neurosurgical clinic.

Some people develop AVP deficiency (previously called diabetes insipidus) for a short time after the operation, which is usually temporary. Others need lifelong hormone replacement. Anyone on steroid replacement should know the sick day rules and carry a steroid emergency card, as the NHS advises for people with adrenal conditions.

Recovery of vision varies from person to person, and eye movement problems and visual field loss are monitored by ophthalmology.

Recovery involves more than the hospital stay. Fatigue, mood change and worry about a recurrence are common, and the Pituitary Foundation provides information, helplines, support groups and telephone buddies. The same organisation notes that many people with pituitary conditions have no driving restrictions, but that the DVLA should be notified of conditions lasting over 3 months that could affect driving, and visual field loss in particular may affect eligibility.

Keep a list of your hormone medicines and doses and make sure that your GP, pharmacist and any hospital that treats you know about your pituitary condition.

Pituitary apoplexy is an emergency and is treated through NHS emergency departments and regional neurosurgical and endocrine units. The emergency pathway does not involve choosing a provider.

After discharge, follow-up usually continues with an NHS endocrinologist, and some people seek a second opinion from a private pituitary specialist about long-term hormone replacement or surgery on the underlying tumour. Pituitary surgery is concentrated in specialist centres, so it is reasonable to ask how many pituitary operations a surgeon performs each year.