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What is an incongruous defect?

What is an incongruous defect?

A congruous visual field defect is identical between the two eyes, whereas an incongruous defect differs in appearance between the eyes. For lesions behind the LGN, visual field defects are generally more congruous if the lesion is located more posteriorly along the visual pathway.

What causes bilateral hemianopia?

Bitemporal hemianopsia most commonly occurs as a result of tumors located at the mid-optic chiasm. Since the adjacent structure is the pituitary gland, some common tumors causing compression are pituitary adenomas and craniopharyngiomas. Also, another relatively common neoplastic cause is meningiomas.

What can cause homonymous hemianopia?

Any type of intracranial lesion in the appropriate location can cause a homonymous hemianopia; however, vascular causes (cerebral infarction and intracranial hemorrhage) are the most frequent in adults, ranging from 42 to 89 percent, followed by brain tumors, trauma, surgical interventions, and other central nervous …

What part of the brain is damaged to cause left visual field loss?

In homonymous hemianopsia, an injury to the left part of the brain results in the loss of the right half of the visual world of each eye. An injury to the right part of the brain produces loss of the left side of the visual world of each eye.

What happens if the optic chiasm is compressed?

When there is compression at optic chiasm the visual impulse from both nasal retina are affected, leading to inability to view the temporal, or peripheral, vision. This phenomenon is known as bitemporal hemianopsia.

Can hemianopia be temporary?

Hemianopia, sometimes called hemianopsia, is partial blindness or a loss of sight in half of your visual field. It’s caused by brain damage, rather than a problem with your eyes. Depending on the cause, hemianopia may be permanent or temporary.

Is homonymous hemianopia reversible?

Some children may have homonymous hemianopia before surgery because of the brain malformation, stroke, or disease which caused the seizures in the first place. After these surgeries, however, homonymous hemianopia is an irreversible and permanent result.

Can you drive with homonymous hemianopia?

With homonymous hemianopia, one should be allowed to drive because people with only one functioning eye are allowed to drive and that is the same vision problem. As explained above, homonymous visual field loss such as hemianopia affects the same half of both eyes.

What does complete homonymous hemianopsia mean in visual field?

Complete homonymous hemianopsia means the entire half of the visual field is impaired. Hemianopsias, however, are often incomplete. Blindsight refers to an ability to detect shape, color, or motion in the area of an otherwise complete hemianopsia.

What is visual field loss on the same side of both eyes?

Homonymous hemianopsia. Homonymous hemianopsia (or homonymous hemianopia) is hemianopic visual field loss on the same side of both eyes. Homonymous hemianopsia occurs because the right half of the brain has visual pathways for the left hemifield of both eyes, and the left half of the brain has visual pathways for the right hemifield of both eyes.

Can a person with hemianopia regain their sight?

The body of evidence would therefore suggest hemianopia is not always an absolute and permanent visual loss. This raises the question as to whether the natural course of a hemianopia can be advantageously manipulated by therapeutic intervention.

What is the difference between neglect and hemianopsia?

Whereas hemianopsia can be assuaged by allowing patients to move their eyes around a visual scene (ensuring that the entire scene makes it into their intact visual field), neglect cannot. Neglect can also apply to auditory or tactile stimuli and can even leave a patient unaware of one side of his or her own body.