Pituitary apoplexy Int 李明吉

Introduction The word "apoplexy" comes from the Greek "apoplexia" meaning a seizure, in the sense of being struck down. In Greek "plexe" is "a stroke." The ancients believed that someone suffering a stroke had been struck down by the gods apoplexy :a sudden neurologic impairment, usually due to a vascular process

Introduction Pituitary apoplexy : --sudden onset of headache --visual symptoms (VF&VC:optic nerve or chiasm Ocular motility:cranial nerves in cavernus sinus ) --altered mental status --hormonal dysfunction There is usually an existing pituitary adenoma present.

Pathophysiology -- stems from an acute expansion of a pituitary adenoma or, less commonly, in a nonadenomatous gland, from infarction or hemorrhage. -- Some postulate : gradual enlarging pituitary tumor compressing and distorting the hypophyseal stalk and its vascular supply causing ischemia and subsequent necrosis -- Another theory :rapid expansion of the tumor outstrips its vascular supply resulting in ischemia and necrosis (doubtful? tumors that undergo apoplexy are slow growing)

Frequency: This condition results in an estimated 1. 5-27 Frequency: This condition results in an estimated 1.5-27.7% of cases of pituitary adenoma Sex: Male-to-female predominance is 2:1. Age: The age range is 37-57 years.

Clinical manifestations headache in 95% of cases. The headache is sudden .Frequently, it is retro-orbital in location and may be unilateral at onset, then becomes generalized. Vomiting occurs in 69% of patients and often accompanies the headache.

Clinical manifestations The classic visual field defect is a bitemporal superior quadrantic defect. Ocular paresis (78%) results from compression of the cavernous sinus, which make cranial nerves III, IV, VI vulnerable to compression. diplopia may be present. Of the cranial nerves, the oculomotor nerve is involved most commonlyunilateral dilated pupil, ptosis, Less commonly, cranial nerve IV is involved

Clinical manifestations Horner syndrome may develop from damage to the sympathetic fibers. Involvement of the hypothalamus may alter thermal regulation. Destruction of adenohypophyseal tissue may lead to endocrinologic deficiencies.

Predisposing factors Predisposing factors :endocrine stimulation tests, bromocriptine treatment, head trauma, pregnancy, and pituitary irradiation. Some believe :more prevalent in patients who produce excess pituitary hormones (eg, acromegaly, Cushing syndrome)  because the tumor is fueled by the hormones. Others :most pituitary tumors that undergo apoplexy are endocrinologically silent.

Sheehan syndrome Sheehan syndrome refers to 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 -- 11/11 necrosis of the anterior pituitary gland -- 9/11severe hemorrhage at delivery. -- 2/11 no hemorrhage but were gravely ill prior to delivery. The pituitary gland hypertrophies in pregnancy. This hypertrophy combined with locally released factors mediate vascular spasm more susceptible to infarction from compromised blood flow.

Sheehan syndrome inability to lactate (prolactin deficiency ) amenorrhea (gonadotrophin deficiency), skin depigmentation. hypothyroidism hypoadrenalism diabetes insipidus (posterior pituitary involvement)

Imaging Studies CT scan and MRI. MRI is the most sensitive imaging study for evaluating the pituitary gland, possibly visualizing hemorrhage not seen on CT scan. In the first 3-5 days, hemorrhage within the sella is isointense or hypointense on T1-weighted images. On T2-weighted sequences, the blood appears hypointense.

Imaging findings CT: CT(-): -acute: sellar/suprasellar mass with patchy or confluent hyperdensity,may assocciated with SAH -chronic:’’empty sella’’(filled with CSF) CT(+):minimal or no enhancement (rim-pattern suggestive of PA)

Imaging findings MR: T1:early acute, enlarged gland, iso/hypointense with brain late acute/subacute:hyperintense chronic:hypointense T2:acute: enlarged, hypointense (hemorrhagic) or hyperintense (nonhemorrhagic) pituitary subacute:hyperintense Chronic:hyperintense T1+:rim enhancement

case 69 y/o male Headache, vomitting L’t ptosis, L’t EOM limitation(medial) Feverantibiotics , subsided after steroid usage Ptosis persistenttransfer to NS for operation Pathology report:pituitary adenoma

case CT(-):a sellar lesion with slight high density CT(+):without obvious intra-lesion enhancement.

case T2 T1 T1 GD+ mixed signal intensity on T1W, T2W images. Hematoma content is suspected. Mild contrast enhancement.

- sudden onset of severe headache - nonprojectile vomiting, 46-year-old man , - sudden onset of severe headache - nonprojectile vomiting, - followed by high fever and cranial nerve palsies a large heterogeneous mass, highly consistent with a hemorrhagic macroadenoma Infect Med 17(12):806,810,811, 2000 Pituitary Apoplexy: An Overlooked Cause of Fever and CNS Abnormalities

Precontrast T1 :a heterogeneous mass in the sella,

T2 and FLAIR :heterogeneity of signal, consistent with hemorrhage and or proteinaceous debris.

Post contrast T1: no detectable enhancement. The normal calibler left cavernous carotid (first image) narrowed right cavernous carotid (following 3 images w/arrows).

Treatment Administer high-dose corticosteroids (most patients have hypopituitarism). Hydorcortisone100 mg IV initially, then q6-8h until surgery evaluate electrolytes, glucose, and pituitary hormones Administer appropriate endocrinologic replacement therapy alone or combined with transsphenoidal surgical decompression of the tumor

Thank you for your attention!

參考資料 Emedicine-pituitary apoplexy,January 27, 2005 Diagnostic imaging-Brain Wake Radiology website Infect Med 17 Pituitary Apoplexy: An Overlooked Cause of Fever and CNS Abnormalities