Pituitary ApoplexyWhat is Pituitary Apoplexy? The pituitary gland is the main hormone secreting gland of the body. It sits just above the sphenoid sinus, at the base of the brain (Diagram, courtesy of Bartleby.com, Creative Commons License). The blood supply is from very fine blood vessels which branch from the internal carotid artery - the hypophyseal vessels. If the pituitary gland enlarges, such as due to a pituitary tumor (usually a pituitary adenoma), the gland may out-grow its blood supply, or the vessels become more fragile until a haemorrhage occurs. This causes death of the pituitary gland (or part of the gland) called haemorrhagic pituitary infarction. This causes the syndrome of pituitary apoplexy. Apoplexy is the old-fashioned name for a stroke - and these patients literally can be "struck" down. At the point of infarction, the patient will almost always experience sudden severe headache - The Thunderclap Headache. However, there must be people who experience pituitary infarction without the catastrophic, severe head pain. In post-mortem studies, about 1% of all persons will be shown to have lost up to one quarter of their pituitary gland at some point in their lives - this remains a bit of a mystery. However, in those who do present with a sudden severe headache, haemorrhage into the pituitary is almost always founf either on MRI scanning or at surgery to remove the tumour mass or residual debris.
Diagram Courtesy of Bartleby.com, Creative Commons License.
Pituitary Apoplexy Management and OutcomeClinical suspicion should arise in someone who collapses with headache and is drowsy, confused or even is in coma, yet has a normal CT Brain. Most patients (>75%) will not have a known pituitary adenoma, and this will be their first symptoms of pituitary disease. Hypertension may be a risk factor for apoplexy. Examination of he eyes may show that there is no response to light (complete blindness can occur (remember that the pituitary gland sits just underneath the optic chiasm). Headache is nearly universal (97% in the largest series I know). Visual loss or impairment, usually due to visual field loss, occurs in about 70%, and the other prominent symptom is nausea (>80%).If doll's eye movements are assessed, there may be no movement of the eyes at all - ophthalmoplegia, as the main cranial nerves to the eye muscles (oculomotor nerve, trochlear nerve, abducens nerve) all travel in or through the cavernous sinus either side of the pituitary gland. In fact a sudden onset cavernous sinus syndrome can be due to pituitary infarction A CT Brain scan can be normal. Signs of pituitary disease can be very subtle on CT and unless looked for specifically are easily overlooked. Even with highly trained eyes, it can be impossible to determine the state of the pituitary without an MRI Brain scan. Pituitary function tests - a baseline would be cortisol or Synacthen test, TSH, Prolactin, FSH, LH and Testosterone, - should be done, and I'd always ask for a consultation from an endocrinologist. Often pituitary apoplexy is not considered initially, and the first concern would be that the patient has meningitis or even subarachnoid haemorrhage - there is no doubt that they look ill. You should think "could it be pituitary?" when you have a classic thunderclap headache, yet a normal CT. Supportive care is important - comatose patients should be nourished, and pressure sores prevented. However, corticosteroids should be administered pending the results of endocrine tests. If there is coma or visual impairment, pituitary surgery should be considered, as improvement in vision may follow surgery. If a patient survives the initial coma (risk of death is low in modern practice) improvement in vision usually occurs, and is thought to be better in those where surgery has been performed earlier.
Other Headache Types Associated with Pituitary TumoursPituitary tumours can be associated with other headaches than the thunderclap headache of apoplexy - here are some I know have been reported in the medical literature:
ReferencesRandeva et al Classical pituitary apoplexy: clinical features, management and outcome.Clinical Endocrinology 1999;51:181-88 (Free Abstract only)Jassal DS et al. Pituitary Apoplexy Masquerading as MeningoencephalitisHeadache 2004;44: 75-78 (Free Abstract only) Silvestrini M et al. Ophthalmoplegic Migraine-Like Syndrome Due to Pituitary ApoplexyHeadache 1994; 34: 484-486 (Free Abstract only) Levy A. Pituitary Disease: Presentation, diagnosis and management. Journal of Neurology Neurosurgery and Psychiatry 2004;75(Suppl3):iii47-iii52 (Full free text)
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