What is a chiasmal lesion?
Chiasmal syndrome is the set of signs and symptoms that are associated with lesions of the optic chiasm, manifesting as various impairments of the affected’s visual field according to the location of the lesion along the optic nerve.
What is pituitary apoplexy?
Pituitary apoplexy is a condition in which the pituitary tumor spontaneously hemorrhages (bleeds). The term “pituitary apoplexy” can also describe a less common condition when a pituitary tumor outgrows its blood supply (a stroke).
Are pituitary tumors genetic?
Family history. Most people who develop pituitary tumors don’t have a family history of the disease. But rarely, pituitary tumors can run in families. Sometimes when pituitary tumors run in families, they are found along with other types of tumors as part of an inherited genetic syndrome (see the next section).
What symptoms would Chiasmal compression cause?
The symptoms of compressive lesions of the optic chiasm vary among patients and can be very diverse. Symptoms include not only decreased visual acuity and visual field defects, but also endocrine symptoms, headache, and photophobia1,2.
Why would a pituitary tumor affect vision?
Sometimes a pituitary tumor affects the optic nerve on just one side. In other cases, it affects a structure known as the “optic chiasm,” where the optic nerves from each eye merge together. When a pituitary tumor pushes the optic chiasm, it causes visual loss in both eyes.
Can pituitary tumors cause death?
Vision problems occur when the tumor “pinches” the nerves that run between the eyes and the brain. Sudden loss of vision, loss of consciousness, and even death can result from sudden bleeding into the tumor.
Can pituitary apoplexy cause death?
Pituitary apoplexy is a medical emergency and can be fatal if untreated. With treatment, however, the prognosis is good.
What happens when optic chiasm is damaged?
Damage to the retina or one of the optic nerves before it reaches the chiasm results in a loss of vision that is limited to the eye of origin. In contrast, damage in the region of the optic chiasm—or more centrally—results in specific types of deficits that involve the visual fields of both eyes (Figure 12.8).
What diseases can affect the optic chiasm?
Diseases of the Optic Chiasm
- Inflammatory disorders such as multiple sclerosis.
- Infections such as tuberculosis.
- Benign (noncancerous) tumors and cysts.
- Cancerous tumors.
- Vascular (blood vessel) disorders.
Can pituitary tumors be treated without surgery?
Radiation therapy uses high-energy x-rays to kill abnormal pituitary tumor cells. Radiation is extremely effective in stopping tumor growth and, with time, will lead to tumor shrinkage. Radiation therapy may be an option if the tumor cannot be treated effectively through medication or surgery.
Can you go blind from pituitary tumor?
A pituitary tumor can cause havoc on your body by causing it to secrete too much or too little of the hormones it regulates. A pituitary adenoma may also pinch or compress the optic nerves associated with sight, causing some vision loss or total blindness.
How is pituitary apoplexy treated?
The primary treatment for most patients with pituitary apoplexy is urgent endoscopic endonasal surgery and intravenous administration of the stress doses of glucocorticoids (such as hydrocortisone).
Is a pituitary tumor an emergency?
Pituitary apoplexy is a medical emergency. It is caused by either a bleed into and/or death of an area of tissue in the pituitary gland. It is usually associated with the presence of a pituitary tumour.
Is pituitary tumor curable?
Most pituitary tumors are curable. If a pituitary tumor is diagnosed early, the outlook for recovery is usually excellent. However, if tumors grow large enough, or grow rapidly, they are more likely to cause problems and will be more difficult to treat.
What is the pathophysiology of chiasmal syndrome?
Chiasmal syndrome is the set of signs and symptoms that are associated with lesions of the optic chiasm, manifesting as various impairments of the sufferer’s visual field according to the location of the lesion along the optic nerve.
What is the meaning of Chiasmia in biology?
chiasm. in genetics, the points at which members of a chromosome pair are in contact during the prophase of meiosis and because of which recombination, or crossing over, occurs on separation. See also chiasma formation.
What is chiasm in meiosis?
[ki-az´mah] (pl. chias´mata) (L.; Gr.) chiasm. in genetics, the points at which members of a chromosome pair are in contact during the prophase of meiosis and because of which recombination, or crossing over, occurs on separation.
What is the difference between anterior and posterior chiasmal syndrome?
Anterior chiasmal syndrome affects the junction of the optic nerve and chiasm. Middle chiasmal syndrome relates to the decussating fibers in the body of the optic chiasm while posterior chiasmal syndrome involves the caudal fibers.