Viruses
Patients with both Epstein-Barr virus and infectious mononucleosis have cited an increase in the sizes of perceived objects, coinciding with other symptoms of Alice in Wonderland Syndrome. Additionally, it has been observed that Epstein-Barr patients who cite hallucinations display abnormal MRI scans. The MRI may show swelling of the cerebral cortex, transient T2 prolongation, and transient lesions. Unlike in MRIs, no abnormalities have been reported in CT scans. It is thus recommended that an Epstein-Barr patient who cites visual hallucinations have an MRI scan. Macropsia may appear either before the onset, or after the resolution, of all clinical symptoms associated with the illness. The duration of the disturbances have been shown to range between two weeks and seven months. Almost all patients with macropsia due to infectious mononucleosis make full recoveries. Patients with Coxsackievirus B1 have reported numerous symptoms of Alice in Wonderland Syndrome, the most common of which being macropsia and micropsia. Pathophysiology
Macropsia may be a result of optical magnification differences between the eyes, retinal receptor distribution, or the cortical processing of the sampled image. The current hypothesis for the occurrence of dysmetropsia is due to the stretching or compression of the retina leading to the displacement of receptors. Macropsia arises from a compressed receptor distribution leading to a larger perceived image size and conversely, micropsia results from stretching of the retina leading to a more sparse receptor distribution that gives a smaller perceived image size.
The intensity of the macropsia episodes decreased with the decreasing amount of zolpidem administered; it is implied in the article that the level of intensity was based on the patients accounts of her macropsia episodes, and that no external diagnosis was used. Hoyler points out notable similarities among the different reported cases of zolpidem-induced disorganization. The similarities were that all the cases were reported by women, the disorganization and agitation followed the first administration of zolpidem, and once zolpidem was discontinued, there were no lasting residual effects. It is believed that zolpidem-related macropsia is more prevalent in women because plasma zolpidem concentration is 40% higher in women, a concentration that further increases in anorexic women.Citalopram-induced macropsia is similar to zolpidem-induced macropsia since both types have been observed in relatively few cases, and neither of the drugs side effects can be supported by experimental evidence. Citalopram is an antidepressant that inhibits serotonin reuptake. The first case of macropsia thought to be induced by citalopram involves a woman who experienced macropsia after her first administration of 10 mg citalopram. Just as with zolpidem, after the immediate discontinuation of citalopram, there were no further episodes of macropsia. Illicit drugs
There are suggestions that visual distortions, such as macropsia, can be associated with cocaine use. Episodes of temporary drug-induced macropsia subside as the chemicals leave the body. Migraine
Past research has linked macropsia to migraine.