What is pituitary apoplexy?
Pituitary apoplexy is caused either by the death of an area of tissue (an infarction) or a haemorrhage in the pituitary gland, usually in association with the presence of a pituitary tumour. It requires urgent medical diagnosis and treatment.Pituitary apoplexy can also be known as Pituitary infarction. In women during or immediately after childbirth, it is termed Sheehan’s syndrome.Pituitary apoplexy is caused either by the death of an area of tissue (an infarction) or a haemorrhage in the pituitary gland, usually in association with the presence of a pituitary tumour. It requires urgent medical diagnosis and treatment. Pituitary apoplexy can also be known as Pituitary infarction. In women during or immediately after childbirth, it is termed Sheehan’s syndrome. The true frequency of pituitary apoplexy is difficult to estimate.
It has recently been estimated that the prevalence of pituitary apoplexy is approximately six people in every 100,000.
In people with pituitary tumours who require surgery, apoplexy has been reported in between 0.6% and 10% of patients.
In people without known pituitary tumours, apoplexy is very rare.
Causes
Pituitary apoplexy is most frequently caused by bleeding into a pre-existing benign tumour of the pituitary gland, or by death of an area of tissue in the pituitary gland as a result of the tumour.
In many cases, the tumour is undiagnosed and the patient is only made aware of its presence when the symptoms of pituitary apoplexy develop.
There are some factors that may make it more likely for patients with a pituitary tumour to develop pituitary apoplexy.
These include:
- high blood pressure (hypertension)
- major surgery (particularly heart surgery)
- recently having had dynamic pituitary function tests taken
- use of some medications such as blood thinning medication (anticoagulants)
- a history of radiation therapy to the pituitary gland
- pregnancy
- head injury
Rarely, pituitary apoplexy may occur in people with a previously normal pituitary gland after a sudden, severe and prolonged drop in blood pressure.
Pituitary apoplexy is not inherited.
Symptoms
Usually, pituitary apoplexy occurs very suddenly. It can be life-threatening and requires urgent medical diagnosis and treatment. Symptoms are caused by a build-up of pressure in the space surrounding the pituitary gland. They can include the following:
- severe, sudden-onset headache
- nausea and vomiting
- paralysis, affecting movements of the eyes
- visual impairment, including double vision or visual field impairment
- decreased consciousness
Over time, other symptoms may develop due to the inability of the pituitary gland to produce the correct hormones.
Diagnosis
Pituitary apoplexy is an emergency and, when suspected, urgent hospital admission is required for further investigation.
Initial assessment includes a detailed history, particularly focusing on symptoms that may indicate the pituitary gland has not been functioning properly. This will be followed by a thorough physical examination, including the cranial nerves and visual fields.
An urgent MRI scan will be carried out on all patients with suspected pituitary apoplexy. This provides a diagnosis in over 90% of patients. Computerised tomography (CT) scans will only be used if the MRI scan does not give a clear result or is not possible, as CT scans provide a conclusive diagnosis in only 21–28% of patients.
Patients will also have blood tests to assess whether their pituitary gland is producing all the hormones that it should and in the right quantities. Nearly 80% of patients will be deficient in one or more pituitary hormones (hypopituitarism) when they have these blood tests.
Doctors will particularly want to assess whether the pituitary gland is producing a hormone called adrenocorticotropic hormone. This hormone controls the release of cortisol from the adrenal glands, which is vital to ensure that the body’s metabolism works correctly. If this is not the case, a condition called secondary adrenal insufficiency develops. This condition is seen in two-thirds of patients with pituitary apoplexy and must be treated immediately.
If suspected, patients will immediately be given intravenous and intramuscular cortisol replacement in anticipation of the results of any tests to confirm the condition.
Treatment
It is first important to ensure that the patient is stabilised and is receiving cortisol replacement therapy if needed. This will not only treat secondary adrenal insufficiency but also help to reduce the swelling of the pituitary gland to reduce immediate symptoms.
There are two main treatment options for pituitary apoplexy: surgical or non-surgical (conservative) management. The decision about which of these treatment options to pursue will be made on an individual basis by a multidisciplinary team including experts in endocrinology, neurosurgery and ophthalmology.
Surgical Management
If the patient is showing severe visual impairment or decreased consciousness, the team may consider surgical management. This involves an operation to stop the bleeding and reduce the pressure on the pituitary gland. The operation is carried out via the nose. Whenever possible, it will be carried out by an experienced pituitary surgeon. Following surgery, the team will closely monitor the patient to make sure their pituitary gland is still functioning correctly and producing the right hormones.
Non -surgical management (conservative).
If the patient shows mild visual impairment and has fewer symptoms, conservative management may be considered. This involves making sure the patient receives treatment for any hormone deficiencies and is monitored closely. Patients will have daily clinical and neurological examinations to assess their condition and check that it is stable.
Once discharged from hospital following pituitary apoplexy, outpatient follow-up with an endocrinologist is required. Repeat blood tests are needed to assess whether the hormones that are normally produced by the pituitary gland are affected, and whether any long-term hormone supplementation will be needed. These tests can be carried out as an outpatient.
Side-effects
Patients treated with surgery require careful monitoring to ensure that their pituitary gland is functioning properly. If this is not the case, replacement hormones will be given. In general, hormone replacement is well tolerated and does not usually have any significant side-effects. Some patients may also develop AVP Deficiency (diabetes insipidus)for a short time after the operation. However, this is usually only temporary.
Long-term implications
Many patients who suffer a pituitary apoplexy go on to make a full recovery. All patients will require long-term management, the exact details of which depend upon the nature of the underlying pituitary tumour and the success of treatment.
As standard, all patients should have a full endocrine review at 4–8 weeks and an MRI scan at 3–6 months following the pituitary apoplexy event. They should also receive an annual clinical review, preferably in a joint endocrine/neurosurgical clinic.
