polyopia การใช้

• These episodes of polyopia can last from seconds to hours.
• Most cases of polyopia are accompanied by another neurological condition.
• Thus, polyopia results from altered coding of contour information by neurons near the lesioned area.
• In cases of epilepsy, polyopia is often experienced alongside palinopsia as these two conditions share an epileptic mechanism.
• This mechanism may explain why polyopia extending into a patient s scotoma occurs following damage to primary visual cortex.
• In other cases of polyopia, it is necessary to determine all other present visual disturbances before attempting treatment.
• Further research should be conducted to determine if the treatment of associated neurological disturbances can reduce the effects of polyopia.
• Polyopia is often accompanied by visual field defects ( such as the presence of a scotoma ) or transient visual hallucinations.
• Infarctions, tumors, multiple sclerosis, trauma, encephalitis, migraines, and seizures have been reported to cause cerebral polyopia.
• Neurological imaging can be performed to determine if there are present occipital or temporal lobe infarctions that may be causing the polyopia.
• Monocular diplopia may be due to repetitive images caused by cerebral polyopia or by ghosting image due to refractive errors or retinal diseases.
• The onset of polyopia is not immediate upon perception of visual stimuli; rather, it occurs within milliseconds to seconds of fixation upon a stimulus.
• Instead, Cornblath offers a possible pathophysiological mechanism in which polyopia results from the recoding of visual receptive fields in primary visual cortex ( Area V1 ).
• Polyopia has been described by patients as images  suddenly multiplying .  These multiple images can drift, fade, and disappear, depending on the severity of the condition.
• The mechanism of infarction differs by patient, but polyopia is experienced most commonly in patients that suffer from epilepsy in the occipital cortex, or in patients who suffer from cerebral strokes.
• "' Entomopia "'( from the eye " ), is a form of polyopia in which a grid-like pattern of multiple copies of the same visual image is seen.
• However, Bender s theory does not account for recent studies in which fixation did not change and no eye movements were produced while polyopia was experienced, therefore polyopic images were not a result of involuntary eye movements.
• Cerebral polyopia has been reported in extrastriate visual cortex lesions, which is important for detecting motion, orientation, and direction . suggesting deafferentation hyperexcitability could be a possible mechanism, similar to visual release hallucinations ( Charles Bonnet syndrome ).