CLINICAL RECOGNITION

Insult to the pituitary can be in the form of hemorrhage, infarction or both. When abrupt and sometimes catastrophic hemorrhagic infarction occurs in the pituitary it is defined as apoplexy. The constellation of headache, vomiting, visual impairment (Apoplexy Triad) and altered consciousness with hemodynamic instability, although not specific for pituitary apoplexy, are reasons to consider the diagnosis (Table 1). Often the presentation in this dramatic fashion is the first time the patient is aware that he/she harbors a pituitary tumor. Asymptomatic hemorrhage and infarct into a pituitary tumor can occur in 10-25% of patients, however true apoplexy (the constellation of symptoms noted above) occurs in 2-10% of pituitary tumor patients.

Table 1. Signs and Symptoms of Pituitary Apoplexy

The most common presenting complaint, headache, can present variably from retro-orbital to unilateral to bilateral temporal headaches. These are the symptoms during the acute phase of apoplexy. As the hemorrhagic infarct resolves often times the patient is left with hypopituitarism (refer to section on Hypopituitarism).

Certain conditions will predispose a patient to the catastrophe of pituitary apoplexy. (Table 2). While all large pituitary tumors are at risk for hemorrhagic infarction, certain functional pituitary tumors such as those in Cushing’s disease or acromegaly may be particularly prone. Nearly 25% of all patients with apoplexy have inadequately treated hypertension.

PATHOPHYSIOLOGY

The main symptoms and consequences of apoplexy are due to the increased pressure present within the bony walls of the sella turcica in which the pituitary resides. A sudden increase in the sella contents due to blood and edema results in increased pressure. This increased pressure and meningeal irritation are responsible for the neurologic symptoms described in Table 2,including the increased pressure in the cavernous sinus and the cranial nerve palsies as well as bitemporal-hemianopsia. Extravasation of blood into the subarachnoid space causes meningeal irritation.

DIAGNOSIS AND DIFFERENTIAL

Physicians must promptly recognize that patients presenting with the triad of headache, vomiting and visual disturbances may have any one of several diagnoses that require urgent attention to prevent death or irreversible neurologic impairment.

TREATMENT

The key to successful management of patients with pituitary apoplexy is a team approach including critical care neurologists, neurosurgeons, neuro-ophthalmologist and endocrinologists. Together each of these specialists provide needed expertise in the management and ongoing care of these patients. Acute secondary adrenal insufficiency is seen in approximately two-thirds of patients and is the major source of mortality associated with this condition. Prompt glucocorticoid replacement is therefor mandatory and should not ne delayed for confirmatory testing. The initial management is stabilization of the hemodynamic status with IV 0.9% NaCl boluses to maintain normal tissue perfusion, and usually high dose parenteral glucocorticoids (100 mg hydrocortisone q 8h intravenous). Unless significant cerebral edema is present, hydrocortisone rather than dexamethasone is favored.

Although there is a general consensus that patients with pituitary apoplexy and significant neuro-ophthalmic signs or reduced level of consciousness should have surgical decompression, there is significant controversy in the best timing for the surgical procedure due to lack of good quality outcomes data. (see figure 1 for a suggested management approach).

Figure 1Treatment of Pituitary Apoplexy.

FOLLOWUP

While 80% of patients have residual hypopituitarism following apoplexy (with or without surgical decompression) some patients do not display immediate evidence of hypopituitarism. In addition, recurrent apoplexy and tumor regrowth has been reported to occur. MRI of the pituitary should be obtained at 3-6 month intervals until the anatomy is stable and then yearly for 5 years. A month after discharge from the hospital and recovery from the acute event, if necessary, patients are subject to repeat endocrine testing to determine if the endocrine defects persist. Repeat testing will confirm whether the patient needs to remain on life-long hormone replacement therapy.

GUIDELINE

Rajasekaran, S., Vanderpump, M., Baldeweg, S., Drake, W., Reddy, N., Lanyon, M., Markey A., Plant, G., Powell, M., Sinha, S., Wass, J. UK guidelines for the management of pituitary apoplexy. ClinEndocrinol (Oxf) 2011 Jan 74(1);9-20. PMID 21044119

http://www.ncbi.nlm.nih.gov/pubmed/21044119

REFERENCES

1. Chung, T-T and J.P. Monson. Hypopituitarism.

http://www.endotext.org/neuroendo/neuroendo12/neuroendoframe12.htm

2.

Mariotti, S. 2011.Normal physiology of the hypothalamic pituitary thyroid axis.http://www.thyroidmanager.org/Chapter4/4-frame.htm

3.

Vanderpump M¹, Higgens C, Wass JA.UKguidelinesfor the management of pituitary apoplexy a rare but potentially fatal medical emergency. Emerg Med J. 2011 Jul;28(7):550-1. doi: 10.1136/emj.2010.106898. Epub 2010 Dec 23.PMID:21183525