loss or double vision only may be managed conservatively, with close observation of the level of consciousness, visual fields, and results of routine blood tests. if there is any deterioration, or expected spontaneous improvement does not occur, surgical intervention may still be indicated. if the apoplexy occurred in a prolactin-secreting tumor, this may respond to dopamine agonist treatment. after recovery, people who have had pituitary apoplexy require follow-up by an endocrinologist to monitor for long-term consequences. mri scans are performed 3–6 months after the initial episode and subsequently on an annual basis. if after surgery some tumor tissue remains, this may respond to medication, further surgery, or radiation therapy with a "gamma knife". prognosis in larger case series, the mortality was 1.6% overall. in the group of patients who were unwell enough to require surgery, the mortality was 1.9%, with no deaths in those who could be treated conservatively. after an episode of pituitary apoplexy, 80% of people develop hypopituitarism and require some form of hormone replacement therapy. the most common problem is growth hormone deficiency, which is often left untreated but may cause decreased muscle mass and strength, obesity and fatigue. 60–80% require hydrocortisone replacement (either permanently or when unwell), 50–60% need thyroid hormone replacement, and 60–80% of men require testosterone supplements. 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.