Treatment of prolactinomas (pituitary adenomas that secrete prolactin) with dopamine agonist drugs, as well as withdrawal of such treatment, has been reported to precipitate apoplexy.Hemorrhage from a Rathkes cleft cyst, a remnant of Rathkes pouch that normally regresses after embryological development, may cause symptoms that are indistinguishable from pituitary apoplexy. Pituitary apoplexy is regarded by some as distinct from Sheehans syndrome, where the pituitary undergoes infarction as a result of prolonged very low blood pressure, particularly when caused by bleeding after childbirth. This condition usually occurs in the absence of a tumor. Others regard Sheehans syndrome as a form of pituitary apoplexy. Mechanism
The pituitary gland is located in a recess in the skull base known as the sella turcica ("Turkish saddle", after its shape). It is attached to the hypothalamus, a part of the brain, by a stalk that also contains the blood vessels that supply the gland. It is unclear why pituitary tumors are five times more likely to bleed than other tumors in the brain. There are various proposed mechanisms by which a tumor can increase the risk of either infarction (insufficient blood supply leading to tissue dysfunction) or hemorrhage. The pituitary gland normally derives its blood supply from vessels that pass through the hypothalamus, but tumors develop a blood supply from the nearby inferior hypophyseal artery that generates a higher blood pressure, possibly accounting for the risk of bleeding.
Pituitary apoplexy is bleeding into or impaired blood supply of the pituitary gland. This usually occurs in the presence of a tumor of the pituitary, although in 80% of cases this has not been diagnosed previously. The most common initial symptom is a sudden headache, often associated with a rapidly worsening visual field defect or double vision caused by compression of nerves surrounding the gland. This is often followed by acute symptoms caused by lack of secretion of essential hormones, predominantly adrenal insufficiency.The diagnosis is achieved with magnetic resonance imaging and blood tests. Treatment is by the timely correction of hormone deficiencies. In many cases, surgical decompression is required. Many people who have had a pituitary apoplexy develop pituitary hormone deficiencies and require long-term hormone supplementation. The first case of the disease was recorded in 1898. Signs and symptoms
Acute symptoms
The initial symptoms of pituitary apoplexy are related to the increased pressure in and around the pituitary gland. The most common symptom, in over 95% of cases, is a sudden-onset headache located behind the eyes or around the temples. It is often associated with nausea and vomiting. Occasionally, the presence of blood leads to irritation of the lining of the brain, which may cause neck rigidity and intolerance to bright light, as well as a decreased level of consciousness. This occurs in 24% of cases.