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Pituitary Apoplexy Jirasak P. R2 MD Historical Aspects • 1898 Bailey –first description • 1938 Sheehan – pituitary infarction and panhypopituitarism after obstetrical hemorrhage • 1950 Brougham – described 5 cases, recognized and named clinical syndrome Pituitary Apoplexy is defined clinically – An acute clinical syndrome with the sudden onset of: • • • • • Headache Vomiting Visual disturbances Ophthalmoplegia Alterations in the state of consciousness – Occurs primarily in patients with pre-existing pituitary adenomas, though also in nontumorous pituitaries – Caused by extensive pituitary hemorrhage and infarction Subacute pituitary apoplexy – Asymptomatic pituitary hemorrhage (and infarction) with/without a pituitary tumor Prevalence • True prevalence uncertain – difficulty in recognizing and diagnosing syndrome • Surgical series: 10-15% adenomas show hemorrhage-most silent • Clinical syndrome estimated at 0.6-10% of adenomas, based on symptoms and sudden decrease or loss of pituitary function • Non-adenomatous pituitaries: no data Prevalence (2) • Mean age: 47+15 years (range: 6-88) • Males : females - 1.5 : 1 • About 2/3 of patients unaware of tumor at time of apoplectic event • Relationship to tumor type: no predilection for cell type of adenoma; rare in craniopharyngioma and hamartoma Pathophysiology - theories • Ischemic necrosis – Most tumors are not that big • Ischemia and infarction 2o compression of stalk and superior hypophyseal artery. Most vessels from inferior hypophyseal artery • Intrinsic vasculopathy of tumors. Pit. tumors >5x more likely to bleed than other intracranial tumors • Is primary event hemorrhagic or ischemic? Hemorrhage seen in 100%, ischemic necrosis in 60% Pathophysiology • The anterior pituitary gland is perfused by its portal venous system • contributes to frequency of pituitary apoplexy causing ischemia and subsequent necrosis Signs and Symptoms Variable, depending on which features of apoplexy predominate • Tumor expansion - Upward Visual fields and acuity Hypothalamic dysfunction: temp, BP, cardio-resp dysfunc., altered consciousness, other neurol sx. - Lateral Ophthalmoplegia, V nerve dysfunction, internal carotid artery compression - Downward Asymptomatic or epistaxis Signs and Symptoms • Subarachnoid bleeding - Meningeal irritation and photophobia - Aseptic meningitis • Endocrine disturbances Presenting Signs and Symptoms (9 series over 30 year period; n = 272) Headache Visual field or acuity reduction Ocular palsies Nausea and vomiting Meningismus Decreased level of consciousness Photophobia Fever Percent 85 63 49 42 17 16 10 7 - Evolution: few hours to 2 days - Symptom severity proportional to tumor size - Headaches generally precede ocular manifestations Roleh et al,1993; Bills et al, 1993; Bonicki et al,1993; Randeva et al,1999 headache • sudden and postulated to result from stretching and irritation of the dura mater • irritation of the trigeminal nerve from the expanding mass • retro-orbital in location and may be unilateral at onset, then becomes generalized Ocular involvement • Visual acuity defects (52%) and visual field defects (64%) • upward expansion of the tumor, which compresses the optic chiasm, optic tracts, or optic nerve • The classic visual field defect is a bitemporal superior quadrantic defect Ocular involvement • Ocular paresis (78%) • results from compression of the cavernous sinus • the oculomotor nerve (cranial nerve III) is involved most commonly • a unilateral dilated pupil, ptosis, and a globe that is deviated inferiorly and laterally • The sixth cranial nerve is least commonly involved Pituitary apoplexy can occur in ectopic sites • Hori examined normal adult brains at autopsy and found ectopic pituitary cells in the leptomeninges of the peri-infundibular region in 75%. • Ectopic pituitary adenomas commonly present late because they displace rather than invade vital nervous structures. • They may be discovered only after the patient has pituitary apoplexy. • Only one case of an ectopic pituitary adenoma that underwent apoplexy has been reported. Endocrine Disturbances • Sudden onset – features of adrenal insufficiency predominate • Other abnormalities reflect underlying tumor: hormone hypersecretion (GH, Prl, ACTH, TSH) and hypopituitarism GH deficiency Gonadal deficiency Male 88% Female Adrenal insufficiency Hypothyroidism Hyperprolactinemia 52% 71% 46% 12% Diabetes insipidus 2-3% 86% - and - resolution of hypersecretory syndromes Data from Veldhuis & Hammond, 1980 and Randeva et al, 1999 Precipitating Events In half of cases (from series), no precipitating event recorded Publications in past 15 years (300) • Irradiation – no evidence • Sudden changes in BP or ICP, often associated with procedures - Angiography, LP, PEG, repetitive coughing, surgical procedures - primarily cardiac (15) • Head trauma (4) • Anticoagulation and clotting disorders (5) • Releasing hormones – for dx (31) and rx (6) • Bromocriptine (8) Sheehan syndrome • pituitary apoplexy of a nontumorous gland • presumably due to postpartum arterial spasm of arterioles supplying the anterior pituitary and its stalk. • In 1937, Sheehan reported 11 cases of women who died in the puerperium • all of whom had necrosis of the anterior pituitary gland (adenohypophysis). • Nine of the 11 cases had severe hemorrhage at delivery. The other 2 cases had no hemorrhage but were gravely ill prior to delivery Sheehan syndrome • Normally, the pituitary gland hypertrophies in pregnancy from diffuse nodular hyperplasia of prolactin secreting cells • Usually, at least 1-2 liters of blood loss and hypovolemic shock • 1-2% of women suffering significant postpartum hemorrhage • inability to lactate after delivery due to prolactin deficiency occurs and amenorrhea due to gonadotrophin deficiency classically develops Sheehan syndrome • after delivery, shaved pubic hair or axillary pubic hair fails to regrow, and waxy skin depigmentation develops • Signs of hypothyroidism and hypoadrenalism may develop • posterior pituitary (neurohypophysis) involvement with diabetes insipidus may occur • clinical presentation of acute pituitary apoplexy has only been reported case CT Findings in Pituitary Apoplexy • Non-contrast CT is hyperdense in acute stage and may be more specific than MRI which is often isodense • Ring sign, if present is diagnostic • Useful to exclude subarachnoid hemorrhage acutely • However, no pathognomonic findings Time of diagnosis 5 days 3 weeks later 6 months later MacCagnan P et al, JCEM 80:2190, 1995 MRI Findings in Pituitary Apoplexy Stage Days Intensity: T1 Intensity: T2 Acute 0-7 Isointense Very hypointense (similar to blood) Subacute 7-21 Moderately hyperintense (variable) Moderately hyperintense (variable) Chronic 21 - years Very hyperintense Very hyperintense 11-18-03 T1 plain 11-18-03 T1 post gad. 4-10-04 T1 plain 4-10-04 T1 plain Therapy • Medical – Acute – Glucocorticoids in doses to cover acute stress at time dx made or suspected: hydrocortisone, 300mg/d – Use of larger doses in presence of severe neurologic deficits, i.e., decreased states of consciousness; rationale anecdotal – Fluid and electrolyte replacement as needed • Medical – Chronic – Replacement therapy for hypopituitarism, as appropriate upon testing Therapy • Surgical – Considerable controversy in literature – In early reports, recommended for all patients – Subsequent reports suggested many patients can be managed medically – Two major endpoints to consider: Recovery of visual acuity, visual fields, and oculomotor fx. Preservation / recovery of pituitary function Visual Outcome and Timing of Surgery 100 Complete recovery Partial recovery No improvement Percent 80 60 40 20 0 <8 days >8 days Visual Acuity <8 days >8 days Visual Fields <8 days >8 days Ocular Paresis Randeva et al, 1999 Hormone Replacement and Timing of Surgery Percent requiring replacement 100 Glucocorticoids Thyroxine Testosterone Vasopressin/DDAVP 80 60 40 20 0 2.2 Arafah et al, 90 n=8 6.0 Randeva et al, 99 n=35 Mean Days to Surgery 7.7 Bills et al, 93 n=37 Summary • Classical pituitary apoplexy is an acute clinical syndrome that has life-threatening consequences, requiring immediate medical and frequently surgical therapy. • Although hemorrhage into a pituitary macroadenoma is the typical setting, it may be the first manifestation of the tumor. • In more than half of the cases clinical manifestations are milder or nonexistent. Summary (2) • Immediate institution of glucocorticoid therapy is essential when the diagnosis is suspected because of the high frequency of adrenal insufficiency. • Controversy exists concerning the need for surgical therapy in all cases. However, in patients with oculoparesis and visual field impairment, early surgical intervention results in better functional recovery. Summary (3) • Early surgical intervention also appears to improve the retention and/or recovery of pituitary function. • Re-bleeding commonly occurs irrespective of previous therapy and careful follow-up is important.