Background
The word apoplexy is defined as a sudden neurologic impairment, usually due to a vascular process. Pituitary apoplexy is characterized by a sudden onset of headache, visual symptoms, altered mental status, and hormonal dysfunction due to acute hemorrhage or infarction of a pituitary gland. An existing pituitary adenoma is usually present. The visual symptoms may include both visual acuity impairment and visual field impairment from involvement of the optic nerve or chiasm and ocular motility dysfunction from involvement of the cranial nerves traversing the cavernous sinus.[1]
Pathophysiology
This condition stems from an acute expansion of a pituitary adenoma or, less commonly, in a nonadenomatous gland, from infarction or hemorrhage. The anterior pituitary gland is perfused by its portal venous system, which passes down the hypophyseal stalk. This unusual vascular supply likely contributes to frequency of pituitary apoplexy.
Some postulate that a gradual enlarging pituitary tumor becomes impacted at the diaphragmatic notch, compressing and distorting the hypophyseal stalk and its vascular supply. This deprives the anterior pituitary gland and the tumor itself of its vascular supply, apoplectically causing ischemia and subsequent necrosis.
Another theory stipulates that rapid expansion of the tumor outstrips its vascular supply, resulting in ischemia and necrosis. This explanation is doubtful, since most tumors that undergo apoplexy are slow growing.
Epidemiology
Frequency
International
This condition results in an estimated 1.5-27.7% of cases of pituitary adenoma, although the figure is probably closer to 10%.
Mohr and Hardy reviewed hospital records of 664 patients who had surgery for pituitary adenomas.[2] They noted typical symptomatic pituitary apoplexy to occur in only 0.6% of patients with significant hemorrhagic and necrotic changes in 9.5% of surgical specimens.
Frequency of intratumoral hemorrhage increases to 26% if using only MRI criteria without clinical evidence of apoplexy.
Sex
The male-to-female predominance is 2:1.
Age
The age range is 37-57 years.
Nawar RN, AbdelMannan D, Selman WR, Arafah BM. Pituitary tumor apoplexy: a review. J Intensive Care Med. Mar-Apr 2008;23(2):75-90. [Medline].
Mohr G, Hardy J. Hemorrhage, necrosis, and apoplexy in pituitary adenomas. Surg Neurol. Sep 1982;18(3):181-9. [Medline].
Mou C, Han T, Zhao H, Wang S, Qu Y. Clinical features and immunohistochemical changes of pituitary apoplexy. J Clin Neurosci. Jan 2009;16(1):64-8. [Medline].
Bahmani Kashkouli M, Khalatbari MR, Yahyavi ST, Borghei-Razavi H, Soltan-Sanjari M. Pituitary apoplexy presenting as acute painful isolated unilateral third cranial nerve palsy. Arch Iran Med. Jul 2008;11(4):466-8. [Medline].
Hori A. Suprasellar peri-infundibular ectopic adenohypophysis in fetal and adult brains. J Neurosurg. Jul 1985;63(1):113-5. [Medline].
Okuda O, Umezawa H, Miyaoka M. Pituitary apoplexy caused by endocrine stimulation tests: a case report. Surg Neurol. Jul 1994;42(1):19-22. [Medline].
Silberstein L, Johnston C, Bhagat A, Tibi L, Harrison J. Pituitary apoplexy during induction chemotherapy for acute myeloid leukaemia. Br J Haematol. Oct 2008;143(2):151. [Medline].
Thurtell MJ, Besser M, Halmagyi GM. Pituitary apoplexy causing isolated blindness after cardiac bypass surgery. Arch Ophthalmol. Apr 2008;126(4):576-8. [Medline].
Kumar V, Kataria R, Mehta VS. Dengue hemorrhagic fever: A rare cause of pituitary tumor hemorrhage and reversible vision loss. Indian J Ophthalmol. Jul-Aug /2011;59:311-2. [Medline].
Vaphiades M. The "pituitary ring sign": An MRI sign of pituitary apoplexy. Neuro-ophthalmology. 2007;31:111-6.
Weisberg LA. Pituitary apoplexy. Association of degenerative change in pituitary ademona with radiotherapy and detection by cerebral computed tomography. Am J Med. Jul 1977;63(1):109-15. [Medline].
Ahmed SK, Semple PL. Cerebral ischemia in pituitary apoplexy. Acta Neurochir. 2008;150:1193-6.
Chokyu I, Tsuyuguchi N, Goto T, Chokyu K, Chokyu M, Ohata K. Pituitary apoplexy causing internal carotid artery occlusion--case report. Neurol Med Chir (Tokyo). 2011;51:48-51. [Medline].
Madhusudhan S, Madhusudhan TR, Haslett RS, Sinha A. Pituitary apoplexy following shoulder arthroplasty: a case report. Med Case Reports. Jul/2011;5:284 [Epub ahead of print]. [Medline].
Mohindra S, Kovai P, Chhabra R. Fatal Bilateral ACA Territory Infarcts after Pituitary Apoplexy: A Case Report and Literature Review. Skull Base. Jul/2010;20:285-8. [Medline].
Binning MJ, Liu JK, Gannon BS, Osborn AG, Couldwell WT. Hemorrhagic and nonhemorrhagic Rathke cleft cysts mimicking pituitary apoplexy. J Neurosurg. 2008;108:3-8.
Kaplun J, Fratila C, Ferenczi A, Yang WC, Lantos G, Fleckman AM. Sequential pituitary MR imaging in Sheehan syndrome: report of 2 cases. AJNR Am J Neuroradiol. May 2008;29(5):941-3. [Medline].
Bills DC, Meyer FB, Laws ER Jr, et al. A retrospective analysis of pituitary apoplexy. Neurosurgery. Oct 1993;33(4):602-8; discussion 608-9. [Medline].
Thomason K, Macleod K, Eyres KS. Hyponatraemia after orthopaedic surgery - a case of pituitary apoplexy. Ann R Coll Surg Engl. Apr 2009;91(3):3-5. [Medline].
Muthukumar N, Rossette D, Soundaram M, Senthilbabu S, Badrinarayanan T. Blindness following pituitary apoplexy: timing of surgery and neuro-ophthalmic outcome. J Clin Neurosci. Aug 2008;15(8):873-9. [Medline].
Absalom M, Rogers KH, Moulton RJ, Mazer CD. Pituitary apoplexy after coronary artery surgery. Anesth Analg. Mar 1993;76(3):648-9. [Medline].
Burde RM, Savino PJ, Trobe JD. Chiasmal visual loss. In: Clinical Decisions in Neuro-ophthalmology. 1992:74-88.
Conomy JP, Ferguson JH, Brodkey JS, Mitsumoto H. Spontaneous infarction in pituitary tumors: neurologic and therapeutic aspects. Neurology. Jun 1975;25(6):580-7. [Medline].
Dejager S, Gerber S, Foubert L, Turpin G. Sheehan's syndrome: differential diagnosis in the acute phase. J Intern Med. Sep 1998;244(3):261-6. [Medline].
Elster AD, Sanders TG, Vines FS, Chen MY. Size and shape of the pituitary gland during pregnancy and post partum: measurement with MR imaging. Radiology. Nov 1991;181(2):531-5. [Medline].
Embil JM, Kramer M, Kinnear S, Light RB. A blinding headache. Lancet. Jul 19 1997;350(9072):182. [Medline].
Harrington DO, Drake NV. Chiasm. In: The Visual Fields, Text and Atlas of Clinical Perimetry. 1990:290-6.
Holness RO, Ogundimu FA, Langille RA. Pituitary apoplexy following closed head trauma. Case report. J Neurosurg. Oct 1983;59(4):677-9. [Medline].
Hylton NM. Suspension of breast-feeding following gadopentetate dimeglumine administration. Radiology. Aug 2000;216(2):325-6. [Medline].
Kan AK, Calligerous D. A case report of Sheehan syndrome presenting with diabetes insipidus. Aust N Z J Obstet Gynaecol. May 1998;38(2):224-6. [Medline].
Krisht AF, Tindall GT. Pituitary apoplexy. In: Clinical Decisions in Neuro-ophthalmology. 1999;295-301.
Lavallée G, Morcos R, Palardy J, Aubé M, Gilbert D. MR of nonhemorrhagic postpartum pituitary apoplexy. AJNR Am J Neuroradiol. Oct 1995;16(9):1939-41. [Medline].
Masago A, Ueda Y, Kanai H, Nagai H, Umemura S. Pituitary apoplexy after pituitary function test: a report of two cases and review of the literature. Surg Neurol. Feb 1995;43(2):158-64; discussion 165. [Medline].
Miki Y, Asato R, Okumura R, et al. Anterior pituitary gland in pregnancy: hyperintensity at MR. Radiology. Apr 1993;187(1):229-31. [Medline].
Moszkowski EF. Postpartum pituitary insufficiency: report of five unusual cases with long-term follow-up. South Med J. Aug 1973;66(8):878-82. [Medline].
O'Connor G, Dinn J, Farrell M, Phillips J, Stack J, Eustace P. Pituitary apoplexy in an ectopic pituitary tumour. Eur J Ophthalmol. Jan-Mar 1991;1(1):33-8. [Medline].
Patel MC, Guneratne N, Haq N, West TE, Weetman AP, Clayton RN. Peripartum hypopituitarism and lymphocytic hypophysitis. QJM. Aug 1995;88(8):571-80. [Medline].
Prager D, Braunstein GD. Pituitary disorders during pregnancy. Endocrinol Metab Clin North Am. Mar 1995;24(1):1-14. [Medline].
Reid RL, Quigley ME, Yen SS. Pituitary apoplexy. A review. Arch Neurol. Jul 1985;42(7):712-9. [Medline].
Rose-Innes AP. Sheehan syndrome. In: Gilman S, ed. Neurology Medlink. 2001.
Rotman-Pikielny P, Patronas N, Papanicolaou DA. Pituitary apoplexy induced by corticotrophin-releasing hormone in a patient with Cushing's disease. Clin Endocrinol (Oxf). May 2003;58(5):545-9. [Medline].
Rovit RL, Fein JM. Pituitary apoplexy: a review and reappraisal. J Neurosurg. Sep 1972;37(3):280-8. [Medline].
Tovi F, Hirsch M, Sacks M, Leiberman A. Ectopic pituitary adenoma of the sphenoid sinus: report of a case and review of the literature. Head Neck. May-Jun 1990;12(3):264-8. [Medline].
Wakai S, Fukushima T, Teramoto A, Sano K. Pituitary apoplexy: its incidence and clinical significance. J Neurosurg. Aug 1981;55(2):187-93. [Medline].
Wray SH. Neuro-ophthalmologic manifestations of pituitary and parasellar lesions. Clin Neurosurg. 1977;24:86-117. [Medline].
Yousem DM, Arrington JA, Zinreich SJ, Kumar AJ, Bryan RN. Pituitary adenomas: possible role of bromocriptine in intratumoral hemorrhage. Radiology. Jan 1989;170(1 Pt 1):239-43. [Medline].

