There have not been significant studies done on the primary prevention of palinopsia, as palinopsia is a symptom indicating disease rather than a disease itself. Illusory palinopsia after-images are affected by environmental light and motion, which indicates changes in neuronal excitability for both pathways. It is therefore proposed that 5-HT2 receptor excitotoxicity may be involved in the mechanism of illusory palinopsia. Drugs that cause palinopsia (trazodone, nefazodone, risperidone, and mirtazapine) are similar in sharing antagonism at the 5-HT2 receptor which binds the neurotransmitter serotonin, and the hallucinogen LSD is an agonist for 5-HT2A and 5-HT2C. It is thought to occur from changes in the excitability of neurons in the visual pathways. Illusory palinopsia results from a dysfunction in visual perception.
It is thought to occur from localized cortical hyperexcitability or heightened activity in the posterior visual pathway through the mechanisms of cortical deafferentation, focal cortical irritation, and epileptic discharges. Hallucinatory palinopsia results from a dysfunction in visual memory. Given that palinopsia has a wide range of etiologies, both genetics and environmental factors may play roles in risk for palinopsia. Medications that have been reported to cause illusory palinopsia include trazodone, nefazodone, mirtazapine, topiramate, clomiphene, oral contraceptives, and risperidone. Illusory palinopsia can be caused by changes in neurotransmitter receptors associated with migraines, hallucinogen persisting perception disorder (HPPD), trauma to the head, or drugs or other medications. Illusory palinopsia is associated with alterations in visual perception of a real external stimulus affected by immediate environmental factors. The seizures that cause palinopsia are associated with metabolic imbalances, such as hyperglycemia, carnitine deficiency, ion channel disturbances, and Creutzfeldt-Jakob disease. Examples of lesions that may cause hallucinatory palinopsia are neoplasms, infarctions, hemorrhages, arteriovenous malformations, aneurysm, abscesses, and tuberculomas.
It can be caused by posterior cortical lesions or seizures. Hallucinatory palinopsia is associated with a dysfunction of visual memory. Although migraines occur more frequently in females than males and more frequently in younger to middle aged populations than elderly populations, there have not been significant studies done comparing palinopsia between the categories. Palinopsia may occur in up to 10% of migraineurs and seem to occur more frequently in migraine with aura than without aura. There is limited data on the epidemiology of palinopsia. The images from illusory palinopsia are short-lasting, low-resolution and indistinct. Individuals with illusory palinopsia see images that are affected by immediate environmental factors, such as light and motion. Individuals with hallucinatory palinopsia see images that are long-lasting, high-resolution, and occur anywhere within the visual field. Palinopsia can be categorized into two general categories: hallucinatory palinopsia and illusory palinopsia. Images from palinopsia are positive images, or the same colors as the original visual stimulus, whereas physiological after-images are negative images, or complementary colors of the original visual stimulus. Whereas physiological after-images appear immediately after removal of the original visual stimulus, palinopsia after-images may appear immediately or after a time interval. Images from palinopsia are longer-lasting and more intense than physiological after-images. Palinopsia is distinct from a physiological after-image, which is a benign, normal response in which an image briefly persists after a person has stopped looking at the original visual stimulus. Palinopsia derives its name from the Greek word palin which means "again" and opsia which means "seeing.”
Palinopsia refers to a pathological group of visual symptoms in which there is an abnormal persistence or recurrence of an image in time.
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