Many pituitary tumors (25%) are found to have areas of hemorrhagic infarction on MRI scans, but apoplexy is not said to exist unless it is accompanied by symptoms.In some instances, lumbar puncture may be required if there is a suspicion that the symptoms might be caused by other problems (meningitis or subarachnoid hemorrhage). This is the examination of the cerebrospinal fluid that envelops the brain and the spinal cord; the sample is obtained with a needle that is passed under local anesthetic into the spine. In pituitary apoplexy the results are typically normal, although abnormalities may be detected if blood from the pituitary has entered the subarachnoid space. If there is remaining doubt about the possibility of subarachnoid hemorrhage (SAH), a magnetic resonance angiogram (MRI with a contrast agent) may be required to identify aneurysms of the brain blood vessels, the most common cause of SAH.Professional guidelines recommend that if pituitary apoplexy is suspected or confirmed, the minimal blood tests performed should include a complete blood count, urea (a measure of renal function, usually performed together with creatinine), electrolytes (sodium and potassium), liver function tests, routine coagulation testing, and a hormonal panel including IGF-1, growth hormone, prolactin,  luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone, thyroid hormone, and either testosterone in men or estradiol in women.Visual field testing is recommended as soon as possible after diagnosis, as it quantifies the severity of any optic nerve involvement, and may be required to decide on surgical treatment.
Finally, 10–25% develop diabetes insipidus, the inability to retain fluid in the kidneys due to a lack of the pituitary antidiuretic hormone. This may be treated with the drug desmopressin, which can be applied as a nose spray or taken by mouth. Epidemiology
Pituitary apoplexy is rare. Even in people with a known pituitary tumor, only 0.6–10% experience apoplexy; the risk is higher in larger tumors. Based on extrapolations from existing data, one would expect 18 cases of pituitary apoplexy per one million people every year; the actual figure is probably lower.The average age at onset is 50; cases have reported in people between 15 and 90 years old. Men are affected more commonly than women, with a male-to-female ratio of 1.6. The majority of the underlying tumors are "null cell" or nonsecretory tumors, which do not produce excessive amounts of hormones; this might explain why the tumor has often gone undetected prior to an episode of apoplexy. History
The first case description of pituitary apoplexy has been attributed to the American neurologist Pearce Bailey in 1898. This was followed in 1905 by a further report from the German physician Bleibtreu. Surgery for pituitary apoplexy was described in 1925. Before the introduction of steroid replacement, the mortality from pituitary apoplexy approximated 50%.The name of the condition was coined in 1950 in a case series by physicians from Boston City Hospital and Harvard Medical School. The term "apoplexy" was applied as it referred to both necrosis and bleeding into pituitary tumors. References


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